Haem iron versus ferrous iron salts to treat iron deficiency anaemia in Gambian children: protocol for randomised controlled trial {1}

BACKGROUND

The World Health Organization recommends universal iron supplementation for children aged 6-23 months in countries where anaemia is seen in over 40% of the population. Conventional ferrous salts have low efficacy due to low oral absorption in children with inflammation. Haem iron is more bioavailable, and its absorption may not be decreased by inflammation. This study aims to compare daily supplementation with haem iron versus ferrous sulphate on haemoglobin concentration and serum ferritin concentration after 12 weeks of supplementation.

METHODS

This will be a two-arm, randomised controlled trial. Gambian children aged 6-12 months with anaemia will be recruited within a predefined geographical area and recruited by trained field workers. Eligible participants will be individually randomised using a 1:1 ratio within permuted blocks to daily supplementation for 12 weeks with either 10.0 mg of elemental iron as haem or ferrous sulphate. Safety outcomes such as diarrhoea and infection-related adverse events will be assessed daily by the clinical team (see Bah et al. Additional file 4_Adverse event eCRF). Linear regression will be used to analyse continuous outcomes, with log transformation to normalise residuals as needed. Binary outcomes will be analysed by binomial regression or logistic regression, Primary analysis will be by modified intention-to-treat (i.e., those randomised and who ingested at least one supplement dose of iron), with multiple imputations to replace missing data. Effect estimates will be adjusted for baseline covariates (C-reactive protein, alpha-1-acid glycoprotein, haemoglobin, ferritin, soluble transferrin receptor).

DISCUSSION

This study will determine if therapeutic supplementation with haem iron is more efficacious than with conventional ferrous sulphate in enhancing haemoglobin and ferritin concentrations in anaemic children aged 6-12 months.

TRIAL REGISTRATION

Pan African Clinical Trial Registry PACTR202210523178727.

Early iron supplementation in exclusively breastfed Gambian infants: a randomized controlled trial

Objective

To investigate the effect of daily iron supplementation for 14 weeks on the serum iron concentration and other markers of iron status in exclusively breastfed infants in Gambia.

Methods

A placebo-controlled, randomized, double-blind trial was performed in rural Gambia between 3 August 2021 and 9 March 2022. Overall, 101 healthy, exclusively breastfed infants aged 6 to 10 weeks were recruited at vaccination clinics and through community health workers. Infants were randomized to receive iron supplementation (7.5 mg/day as ferrous sulfate in sorbitol solution) or placebo for 98 days. Venous blood samples were collected at baseline and on day 99 to assess the serum iron concentration and other markers of iron and haematological status.

Findings

At day 99, the serum iron concentration was significantly higher in the iron supplementation group than the placebo group (crude difference in means: 2.5 µmol/L; 95% confidence interval: 0.6 to 4.3) and there were significant improvements in other iron and haematological markers. There were 10 serious adverse events (five in each group), 106 non-serious adverse events (54 with iron supplementation; 52 with placebo) and no deaths. There was no marked difference between the groups in maternally reported episodes of diarrhoea, fever, cough, skin infection, eye infection or nasal discharge.

Conclusion

In exclusively breastfed Gambian infants, iron supplementation from 6 weeks of age was associated with a significant improvement in markers of iron status at around 6 months of age. There was no indication of adverse effects on growth or infections.

Institutional determinants of insurance penetration in Africa

This paper investigates the institutional determinants of insurance demand in Africa. We used a panel of 42 countries over the period 1996-2017. A system GMM approach was used for the estimations. Consistent with previous results, we find that institutional quality has positive and significant effects on insurance penetration in Africa. Specifically, regulatory quality, rule of law, control of corruption, political stability and absence of violence, and government effectiveness are the five institutional quality indicators that have positive and significant effects on the demand for total insurance and life insurance. However, only regulatory quality, control of corruption and government effectiveness are positively associated with non-life insurance demand. This indicates that governments should improve the business environment and strengthen the political environment to boost insurance development in Africa.

Supplementary Information

The online version contains supplementary material available at 10.1057/s41288-022-00278-2.

Sprinkler flow rate affects physiological, behavioural and production responses of Holstein cows during heat stress

Holstein Friesian cows are known for their high milk yield. They are popular in the commercial dairy  sector of Pakistan. Heat stress is a major challenge for these animals owing to the longer summer season with high ambient temperatures (35 - 40 °C) and relative humidity (30 - 50%) in the area (Butt et al., 2020). Mitigating the effects of heat stress requires substantial investments in energy and water. Spraying dairy  cows with water in the holding pen or at the feed bunk is common practice as it lowers  body  temperature and respiration rate (Kendall et al., 2007; Chen et al., 2013; 2016), and improves feed  intake  and milk yield (Keister et al., 2002). Owing to the recent decrease in global groundwater, studies have  focused on strategies to reduce the use of water to cool dairy cows (Chen et al., 2016). Sprinkler flow  rates  of 1.3 and 4.9 L/min had similar effects on physiological responses of cows to heat load but  produced a 73%  difference in water use (Chen et al., 2016). Similarly, Tresoldi et al. (2019) concluded that  a sprinkler flow rate of 4.9 L/min had poor efficiency compared with 3.3 L/min, as the additional water did not result in increased biologically relevant cooling. These studies were conducted in Mediterranean climates with an average temperature humidity index in the range of 76 to 78. A recent study with Nili Ravi buffaloes revealed a sprinkler flow rate 1.25 L/min was more efficient than one of 2.0 L/min during subtropical summers (Bah et al., 2021). Because water is projected to be scarce in Pakistan by 2030 (Mustafa et al., 2013), holistic strategies for water conservation in the dairy sector are important nationally. The objective of this study was to evaluate the effects of various sprinkler flow rates on the performance of lactating Holstein Friesian cows in a typical corporate dairy farm setting during the subtropical summer. Performance of these cows was assumed to be similar, irrespective of the sprinkler flow rates.

Iron supplementation of breastfed Gambian infants from 6 weeks to 6 months of age: protocol for a randomised controlled trial

Background: A recent analysis showed that plasma iron concentrations decline rapidly from birth in Gambian infants, irrespective of sex or birthweight, to concentrations well below normal expected values for iron-replete children older than two months of age (typically >10 μmol/L). The development and function of neural and immune cells may thus be compromised before the minimum age at which children should receive iron supplementation as per World Health Organisation recommendations. Methods: This study is a two-arm, double-blind, placebo-controlled, randomised superiority trial. Infants will be randomised to receive iron drops (7.5mg/day of iron as ferrous sulphate) or placebo daily for 98 days, to test the impact on serum iron concentrations in healthy, breastfed infants (n = 100) aged 6-10 weeks at enrolment. Participants will be visited daily and supplemented by the field team. Daily health and weekly breastfeeding questionnaires will be administered. Anthropometry, and venous blood and faecal samples will be collected at enrolment and after 98 days of supplementation with serum iron as the primary endpoint. Low birthweight (less than 2.5kg at birth) and infants born prematurely (< 37 weeks) will not be excluded. Formula-fed and infants with any illness will be excluded. An additional study exploring maternal stakeholder perspectives of the intervention will be conducted by means of maternal interviews and four focus group discussions with local stakeholders. Discussion: Most breast-fed Gambian infants have very low circulating iron levels by five months of age. This study will introduce iron supplements much earlier in infancy than has previously been attempted in a low-income setting with the primary aim of increasing serum iron concentration. Trial registration: Clincaltrials.gov ( NCT04751994); 12 th February 2021.

Random antral follicle count performed on any day of the menstrual cycle has the same predictive value as AMH for good ovarian response in IVF cycles

OBJECTIVE

To determine whether the predictive value of AFC for ovarian response to stimulation for IVF depends on the day of the menstrual cycle when ultrasound is performed.

METHODS

410 women undergoing their first IVF cycle were included. All the women had AFC performed twice. The first measurement, random AFC (r-AFC), was performed during the fertility workup whatever the day of their menstrual cycle. Three groups were constituted according to the period of ultrasound performance: at early follicular phase i.e., day 1 to day 6 (eFP-AFC); at mid follicular phase i.e., day 7 to 12 (mFP-AFC) and at luteal phase i.e., day 13 or after (LP-AFC). A second AFC measurement was performed before the start of the ovarian stimulation (SD1-AFC). AMH dosing was done in the early follicular phase.

RESULTS

Random AFC (r-AFC) was correlated to AMH (r = 0.69; p<0.001), SD1-AFC (r = 0.75; p<0.001) and number of oocytes retrieved (r = 0.49; p<0.001). When regarding AFC depending on the cycle day group, the correlation with AMH was 0.65, 0.66 and 0.85 for the eFP-AFC, the mFP-AFC and the LP-AFC respectively (all p were <0.001). The ROC analysis showed the same predictive value for good ovarian response (more than 6 oocytes retrieved) for the eFP-AFC, mFP-AFC and LP-AFC (AUC 0.73, 0.75 and 0.84 respectively; p = 0.28). The AUC of r-AFC (0.76) were similar to those of AMH (0.74) and SD1-AFC (0.74) (p = 0.21 and 0.92 respectively).

CONCLUSION

AFC is strongly correlated with AMH and highly predictive of good ovarian response during the whole menstrual cycle.

P–599 random antral follicle count, performed at any day of the menstrual cycle, demonstrates the same predictive value for ovarian response in in vitro fertilization cycles

Study question

Does antral follicle count (AFC) retains its predictive value for ovarian response to stimulation for in vitro fertilization (IVF) throughout the whole menstrual cycle?

Summary answer

AFC is strongly correlated to anti-mullerian hormone (AMH) and highly predictive of good ovarian response whatever the day of cycle the ultrasound is performed.

What is known already

Usually performed in the early follicular phase (at day 2–3 of the menstrual cycle), AFC and AMH are the most accurate markers of ovarian reserve. They are routinely used to predict ovarian response to ovarian stimulation for IVF and eventually to individualize the gonadotropin starting dose.

Study design, size, duration

Retrospective cohort study performed between January, 2017 and December, 2019.

Participants/materials, setting, methods

410 consecutive women aged 20 to 42 years were included. Random AFC (r-AFC) was performed during the fertility workup whatever the day of their menstrual cycle was: early follicular phase i.e. day 1 to day 6 (eFP-AFC), mid follicular phase i.e. day 7 to 12 (mFP-AFC) and luteal phase i.e. day 13 or after (LP-AFC). A second AFC was performed before the start of the stimulation (SD1-AFC). AMH was measured in the early follicular phase.

Main results and the role of chance

Random AFC (r-AFC) was correlated to AMH (r = 0.692; p &lt; 0.001), SD1-AFC (r = 0.756; p &lt; 0.001) and number of oocytes retrieved (r = 0.491; p &lt; 0.001). When regarding AFC depending on the cycle day group, the correlation with AMH was significantly higher for the LP-AFC, (LP-AFC) (r = 0.853) than for the eFP-AFC (r = 0.657; p &lt; 0.001) and for the mFP-AFC (r = 0.668). The correlation with SD1-AFC was similar regardless of the time of performance of r-AFC (r = 0.739, 0.783, 0.733, respectively for eFP, mFP and LP-AFC). Moreover, the ROC analysis showed the same predictive value for good ovarian response (more than 6 oocytes retrieved) for the eFP-AFC, mFP-AFC and LP-AFC (AUC 0.73, 0.75 and 0.84 respectively) as well as for AMH and SD1-AFC (AUC 0.74 and 0.74, respectively).

Limitations, reasons for caution

This is a retrospective analysis, however data were prospectively collected and the method for ultrasound acquisition of AFC was standardized.

Wider implications of the findings: The absence of significant variation of AFC across the menstrual cycle allows to its random performance. Ultrasound performed besides early follicular phase discloses informations on ovaries, the uterus and the endometrium. It is more comfortable and convenient for women and physicians by limiting targeted appointment during menstruation and reiterated examination.

Trial registration number

Not applicable

Gametocyte carriage after seasonal malaria chemoprevention in Plasmodium falciparum infected asymptomatic children

BACKGROUND

Treatment of clinical Plasmodium falciparum malaria with sulfadoxine-pyrimethamine (SP) and amodiaquine (AQ) is associated with increased post-treatment gametocyte carriage. The effect of seasonal malaria chemoprevention (SMC) with SP and AQ on gametocyte carriage was assessed in asymptomatic P. falciparum infected children.

METHODS

The study was carried out in eastern Gambia. Asymptomatic P. falciparum malaria infected children aged 24-59 months old who were eligible to receive SMC (SMC group) and children 5-8 years that were not eligible to receive SMC (comparison group) were recruited. Gametocytaemia was determined by molecular methods before and after SMC administration. Gametocyte carriage between the groups was compared using the chi-squared test and within-person using conditional logistic regression.

RESULTS

During the 2017 and 2018 malaria transmission seasons, 65 and 75 children were recruited in the SMC and comparison groups, respectively. Before SMC administration, gametocyte prevalence was 10.7% (7/65) in the SMC group and 13.3% (10/75) in the comparison group (p = 0.64). At day 13 (IQR 12, 13) after SMC administration, this was 9.4% (5/53) in children who received at least the first dose of SMC treatment and 12.7% (9/71) for those in the comparison group (p = 0.57). Similarly, there was no difference in prevalence of gametocytes between children that adhered to all 3-day doses of SMC treatment 15.6% (5/32) and those in the comparison group (p = 0.68). In the SMC group, within-group gametocyte carriage was similar before and after SMC administration in children that received at least the first dose of SMC treatment (OR 0.6, 95% CI 0.14-2.51; p = 0.48) and in those that adhered to all 3-day doses of SMC treatment (OR 1.0, 95% CI 0.20-4.95; p = 1.0).

CONCLUSION

In this study with relative low gametocyte prevalence prior to SMC treatment, no evidence was observed that SMC treatment increased gametocyte carriage in asymptomatic P. falciparum malaria infected children.

Sero-epidemiological evaluation of malaria transmission in The Gambia before and after mass drug administration

BACKGROUND

As The Gambia aims to achieve malaria elimination by 2030, serological assays are a useful surveillance tool to monitor trends in malaria incidence and evaluate community-based interventions.

METHODS

Within a mass drug administration (MDA) study in The Gambia, where reduced malaria infection and clinical disease were observed after the intervention, a serological sub-study was conducted in four study villages. Spatio-temporal variation in transmission was measured with a panel of recombinant Pf antigens on a multiplexed bead-based assay. Village-level antibody levels were quantified as under-15 sero-prevalence, sero-conversion rates, and age-adjusted antibody acquisition rates. Antibody levels prior to MDA were assessed for association with persistent malaria infection after community chemoprophylaxis.

RESULTS

Seasonal changes in antibodies to Etramp5.Ag1 were observed in children under 15 years in two transmission settings-the West Coast and Upper River Regions (4.32% and 31.30% Pf prevalence, respectively). At the end of the malaria season, short-lived antibody responses to Etramp5.Ag1, GEXP18, HSP40.Ag1, EBA175 RIII-V, and Rh2.2030 were lower amongst 1-15 year olds in the West Coast compared to the Upper River, reflecting known differences in transmission. Prior to MDA, individuals in the top 50th percentile of antibody levels had two-fold higher odds of clinical malaria during the transmission season, consistent with previous findings from the Malaria Transmission Dynamics Study, where individuals infected before the implementation of MDA had two-fold higher odds of re-infection post-MDA.

CONCLUSIONS

Serological markers can serve dual functions as indicators of malaria exposure and incidence. By monitoring age-specific sero-prevalence, the magnitude of age-stratified antibody levels, or identifying groups of individuals with above-average antibody responses, these antigens have the potential to complement conventional malaria surveillance tools. Further studies, particularly cluster randomised trials, can help establish standardised serological protocols to reliably measure transmission across endemic settings.

Antibody responses to a suite of novel serological markers for malaria surveillance demonstrate strong correlation with clinical and parasitological infection across seasons and transmission settings in The Gambia

BACKGROUND

As malaria transmission declines, sensitive diagnostics are needed to evaluate interventions and monitor transmission. Serological assays measuring malaria antibody responses offer a cost-effective detection method to supplement existing surveillance tools.

METHODS

A prospective cohort study was conducted from 2013 to 2015 in 12 villages across five administrative regions in The Gambia. Serological analysis included samples from the West Coast Region at the start and end of the season (July and December 2013) and from the Upper River Region in July and December 2013 and April and December 2014. Antigen-specific antibody responses to eight Plasmodium falciparum (P. falciparum) antigens-Etramp5.Ag1, GEXP18, HSP40.Ag1, Rh2.2030, EBA175 RIII-V, PfMSP1₁₉, PfAMA1, and PfGLURP.R2-were quantified using a multiplexed bead-based assay. The association between antibody responses and clinical and parasitological endpoints was estimated at the individual, household, and population level.

RESULTS

Strong associations were observed between clinical malaria and concurrent sero-positivity to Etramp5.Ag1 (aOR 4.60 95% CI 2.98-7.12), PfMSP1₁₉ (aOR 4.09 95% CI 2.60-6.44), PfAMA1 (aOR 2.32 95% CI 1.40-3.85), and PfGLURP.R2 (aOR 3.12, 95% CI 2.92-4.95), while asymptomatic infection was associated with sero-positivity to all antigens. Village-level sero-prevalence amongst children 2-10 years against Etramp5.Ag1, HSP40.Ag1, and PfMSP1₁₉ showed the highest correlations with clinical and P. falciparum infection incidence rates. For all antigens, there were increased odds of asymptomatic P. falciparum infection in subjects residing in a compound with greater than 50% sero-prevalence, with a 2- to 3-fold increase in odds of infection associated with Etramp5.Ag1, GEXP18, Rh2.2030, PfMSP1₁₉, and PfAMA1. For individuals residing in sero-positive compounds, the odds of clinical malaria were reduced, suggesting a protective effect.

CONCLUSIONS

At low transmission, long-lived antibody responses could indicate foci of malaria transmission that have been ongoing for several seasons or years. In settings where sub-patent infections are prevalent and fluctuate below the detection limit of polymerase chain reaction (PCR), the presence of short-lived antibodies may indicate recent infectivity, particularly in the dry season when clinical cases are rare. Serological responses may reflect a persistent reservoir of infection, warranting community-targeted interventions if individuals are not clinically apparent but have the potential to transmit. Therefore, serological surveillance at the individual and household level may be used to target interventions where there are foci of asymptomatically infected individuals, such as by measuring the magnitude of age-stratified antibody levels or identifying areas with clustering of above-average antibody responses across a diverse range of serological markers.

Rapid reduction of malaria transmission following the introduction of indoor residual spraying in previously unsprayed districts: an observational analysis of Mopti Region, Mali, in 2017

Background

The National Malaria Control Programme (NMCP) of Mali has had recent success decreasing malaria transmission using 3rd generation indoor residual spraying (IRS) products in areas with pyrethroid resistance, primarily in Ségou and Koulikoro Regions. In 2015, national survey data showed that Mopti Region had the highest under 5-year-old (u5) malaria prevalence at 54%—nearly twice the national average—despite having high access to long-lasting insecticidal nets (LLINs) and seasonal malaria chemoprevention (SMC). Accordingly, in 2016 the NMCP and other stakeholders shifted IRS activities from Ségou to Mopti. Here, the results of a series of observational analyses utilizing routine malaria indicators to evaluate the impact of this switch are presented.

Methods

A set of retrospective, eco-observational time-series analyses were performed using monthly incidence rates of rapid diagnostic test (RDT)-confirmed malaria cases reported in the District Health Information System 2 (DHIS2) from January 2016 until February 2018. Comparisons of case incidence rates were made between health facility catchments from the same region that differed in IRS status (IRS vs. no-IRS) to describe the general impact of the 2016 and 2017 IRS campaigns, and a difference-in-differences approach comparing changes in incidence from year-to-year was used to describe the effect of suspending IRS operations in Ségou and introducing IRS operations in Mopti in 2017.

Results

Compared to communities with no IRS, cumulative case incidence rates in IRS communities were reduced 16% in Ségou Region during the 6 months following the 2016 campaign and 31% in Mopti Region during the 6 months following the 2017 campaign, likely averting a total of more than 22,000 cases of malaria that otherwise would have been expected during peak transmission months. Across all comparator health facilities (HFs) where there was no IRS in either year, peak malaria case incidence rates fell by an average of 22% (CI₉₅ 18–30%) from 2016 to 2017. At HFs in communities of Mopti where IRS was introduced in 2017, peak incidence fell by an average of 42% (CI₉₅ 31–63%) between these years, a significantly greater decrease (p = 0.040) almost double what was seen in the comparator HFCAs. The opposite effect was observed in Ségou Region, where peak incidence at those HFs where IRS was withdrawn after the 2016 campaign increased by an average of 106% (CI₉₅ 63–150%) from year to year, also a significant difference-in-differences compared to the comparator no-IRS HFs (p < 0.0001).

Conclusion

Annual IRS campaigns continue to make dramatic contributions to the seasonal reduction of malaria transmission in communities across central Mali, where IRS campaigns were timed in advance of peak seasonal transmission and utilized a micro-encapsulated product with an active ingredient that was of a different class than the one found on the LLINs used throughout the region and to which local malaria vectors were shown to be susceptible. Strategies to help mitigate the resurgence of malaria cases that can be expected should be prioritized whenever the suspension of IRS activities in a particular region is considered.

Optimisation and standardisation of a multiplex immunoassay of diverse Plasmodium falciparum antigens to assess changes in malaria transmission using sero-epidemiology

Background: Antibody responses have been used to characterise transmission and exposure history in malaria-endemic settings for over a decade. Such studies have typically been conducted on well-standardised enzyme-linked immunosorbent assays (ELISAs). However, recently developed quantitative suspension array technologies (qSAT) are now capable of high-throughput and multiplexed screening of up to hundreds of analytes at a time. This study presents a customised protocol for the Luminex MAGPIX © qSAT using a diverse set of malaria antigens. The aim is to develop a standardised assay for routine serological surveillance that is implementable across laboratories and epidemiological settings. Methods: A panel of eight Plasmodium falciparum recombinant antigens, associated with long- and short-lived antibody responses, was designed for the Luminex MAGPIX © platform. The assay was optimised for key steps in the protocol: antigen-bead coupling concentration, buffer composition, serum sample dilution, and bead storage conditions. Quality control procedures and data normalisation methods were developed to address high-throughput assay processing.  Antigen-specific limits of quantification (LOQs) were also estimated using both in-house and WHO reference serum as positive controls. Results: Antigen-specific bead coupling was optimised across five serum dilutions and two positive controls, resulting in concentrations operational within stable analytical ranges. Coupled beads were stable after storage at room temperature (22⁰C) for up to eight weeks. High sensitivity and specificity for distinguishing positive and negative controls at serum sample dilutions of 1:500 (AUC 0.94 95%CI 0.91-0.96) and 1:1000 (AUC 0.96 95%CI 0.94-0.98) were observed. LOQs were also successfully estimated for all analytes but varied by antigen and positive control. Conclusions: This study demonstrates that developing a standardised malaria-specific qSAT protocol for a diverse set of antigens is achievable, though further optimisations may be required. Quality control and data standardisation methods may also be useful for future analysis of large sero-epidemiological surveys.

Optimisation and standardisation of a multiplex immunoassay of diverse Plasmodium falciparum antigens to assess changes in malaria transmission using sero-epidemiology

Background: Antibody responses have been used to characterise transmission and exposure history in malaria-endemic settings for over a decade. Such studies have typically been conducted on well-standardised enzyme-linked immunosorbent assays (ELISAs). However, recently developed quantitative suspension array technologies (qSAT) are now capable of high-throughput and multiplexed screening of up to hundreds of analytes at a time. This study presents a customised protocol for the Luminex MAGPIX ^© qSAT using a diverse set of malaria antigens. The aim is to develop a standardised assay for routine serological surveillance that is implementable across laboratories and epidemiological settings.

Methods: A panel of eight Plasmodium falciparum recombinant antigens, associated with long- and short-lived antibody responses, was designed for the Luminex MAGPIX ^© platform. The assay was optimised for key steps in the protocol: antigen-bead coupling concentration, buffer composition, serum sample dilution, and bead storage conditions. Quality control procedures and data normalisation methods were developed to address high-throughput assay processing.  Antigen-specific limits of quantification (LOQs) were also estimated using both in-house and WHO reference serum as positive controls.

Results: Antigen-specific bead coupling was optimised across five serum dilutions and two positive controls, resulting in concentrations operational within stable analytical ranges. Coupled beads were stable after storage at room temperature (22⁰C) for up to eight weeks. High sensitivity and specificity for distinguishing positive and negative controls at serum sample dilutions of 1:500 (AUC 0.94 95%CI 0.91-0.96) and 1:1000 (AUC 0.96 95%CI 0.94-0.98) were observed. LOQs were also successfully estimated for all analytes but varied by antigen and positive control.

Conclusions: This study demonstrates that developing a standardised malaria-specific qSAT protocol for a diverse set of antigens is achievable, though further optimisations may be required. Quality control and data standardisation methods may also be useful for future analysis of large sero-epidemiological surveys.

[Dysthyroidism in children and adolescents at the Mali hospital]

INTRODUCTION

Dysthyroidism (hyperthyroidism or hypothyroidism) in children and adolescents is much rarer than in adults. The purpose of our study was to study the epidemiological, clinical, paraclinical, etiological and etiological aspects and to specify the therapeutic and evolutionary modalities of this condition.

METHOD

This was a five-year descriptive, retrospective and prospective study of children and adolescents under 18 years of age with dysthyroidism.

RESULTS

We collected 90 children and adolescents with dysthyroidism (hyperthyroidism 77.8% (n=70) and hypothyroidism 22.2% (n=20). For hyperthyroidism (n=70): the average age was 13.07 years and the sex ratio was 0.16. The family history of dysthyroidism was found in 24.3% (n=17). Clinical manifestations were dominated by tachycardia 88.57% (n=62), weight loss 87.14% (n=61), vibrating pulse 87.14% (n=61) and palpitation 81.42% (n=57). Bilateral exophthalmos was present in 70% of patients (n=49) with palpebral retraction in 51.42% (n=56). Goitre was present in 54 patients (77.1%). It was diffuse in 62.9% (n=44) and nodular in 12.9% (n=9). Basedow's disease represented the first etiology with 84.3% (n=59), followed by toxic multinodular goitre12, 9% (n=9). Sixty-eight patients (97.1%) received medical treatment with synthetic antithyroid drugs. Clinical remission was achieved in 64.3% (n=45) and 54.3% of patients were in biological euthyroidism at 6 months follow-up. For hypothyroidism (n=20): the average age was 10.70 years and the sex ratio was 0.53. Six family cases of hypothyroidism and three cases of family goitre were found. The clinical picture was dominated by signs of hypo metabolism at hypersomnia type 95% (n=19) and anorexia 75% (n=15). The skin was dry in 60% (n=12). A staturo-weight delay in 65% (n=13), behavioural disorders in 55% (n=11), weight gain in 40% (n=8) and puberty delay in 10% (n=2). Goitre was nodular in 25% (n=5) with cervical adenopathy present in 15% (n=3). Hashimoto's thyroiditis accounted for 45% (n=9) of etiologies followed by iodine deficiency disorders in 15% (n=3) and iatrogenic causes (2 cases of thyroidectomy). All patients were started on hormone replacement therapy for life. Five patients with large multinodular goiter received total thyroidectomy in addition to medical treatment. Euthyroidism was observed in 55% (n=11) of patients at 6 months follow-up.

CONCLUSION

Dysthyroidism in children and adolescents exists in our health facilities. Its management is deficient because of the technical and financial platform. Our public health decision-makers must help implement a screening strategy to facilitate faster diagnosis and treatment.

[Epidemiological And Clinical Aspects Of Obesity In The Medicine And Endocrinology Service Of Mali Hospital]

INTRODUCTION

Lifestyle changes have played an important role in increasing the prevalence of obesity. The objectives were to describe the epidemiological, clinical and progressive aspects of obesity in patients of the Mali hospital.

PATIENTS AND METHOD

this is a descriptive study with retrospective collection of data from the medical records of patients hospitalized in the Medicine and Endocrinology department. Our patients benefited from weight gain, height, waist measurement and hip measurement with calculation of the body mass index.

RESULTS

the study concerned 90 obese patients out of 1515 hospitalized (5.94% of frequency). The mean age was 42 ± 5 with extremes 10 and 74. The sex ratio was 0.38. Obesity was mixed: 75.4% of men, 60% of woman; Android in 36% of men, 18% of women and the only child aged 10 had morbid obesity. The reason for hospitalization was complications of obesity in 13.30%. The psychological reactions collected were: anxiety 54.40%, indifference 40% and shame 5.60%. There were 68.90% complications including 37.80% cardio metabolic (hypertension associated in 51.10%). The lipid assessment carried out showed hyper LDLdemia: 70%; HDL hypoemia: 67.80%, hyper triglyceridaemia: 66.70%. Our patients received dietary and dietary advice. No drug or surgical treatment has been initiated despite the indication. We recorded 3.30% of deaths.

CONCLUSION

The epidemiological and clinical description, diagnosis and evaluation of the repercussions of obesity are easy in our daily practice. However, care remains insufficient due to the inadequacy of the technical platform, the lack of financial means and the prejudices of our patients (ignorance of obesity as a disease).

[Management of Hyperprolactinemia at the Hôpital du Mali]

INTRODUCTION

Hyperprolactinemia, which is a supra-physiological secretion of prolactin, is the most common anterior pituitary disorder encountered in clinical practice. Its incidence and prevalence are poorly defined in Africa and the rest of the world. The objectives were to study the clinical, paraclinical, etiological and therapeutic aspects of hyperprolactinemia at the Mali hospital.

METHODOLOGY

This was a 5-year cross-sectional study. Data collection was retrospective (July 2011 to October 2015) and prospective (December 2015 to July 2016).

RESULTS

We collected 37 cases of hyperprolactinemia. The sex ratio was 0.85. The average age was 37.32 years with extremes ranging from 15 to 74 years. The clinical picture was dominated in women by amenorrhea (80%), galactorrhea (70%), headache (55%), hypofertility (50%), visual disorders (25%) and in men by decreased libido (64.7%), gynecomastia (47.1%), headache (47.1%), visual disorders (41.2%) and erection disorders (29.4%). Basal prolactinemia was greater than 100ng/ml in 45.9% of patients. Cerebral CT had objectified: 11 cases of macroadenomas and 5 cases of pituitary microadenomas. The main causes of hyperprolactinemia were: prolactin pituitary adenoma (43.24%); hypothyroidism (5.40%) and estrogen-progestin use in 5.40%. For treatment, 64.9% of patients were placed on cabergoline; 27% on bromocriptine and 8.10% on simple clinical and biological monitoring.

CONCLUSION

Hyperprolactinemia is a condition that exists in our health care facilities. Clinicians should consider this in the face of galactorrhea amenorrhea or decreased libido. It is also necessary to improve the technical platform for better care.

In Vivo Delivery of a DNA-Encoded Monoclonal Antibody Protects Non-human Primates against Zika Virus

Zika virus (ZIKV) infection is endemic to several world regions, and many others are at high risk for seasonal outbreaks. Synthetic DNA-encoded monoclonal antibody (DMAb) is an approach that enables in vivo delivery of highly potent mAbs to control infections. We engineered DMAb-ZK190, encoding the mAb ZK190 neutralizing antibody, which targets the ZIKV E protein DIII domain. In vivo-delivered DMAb-ZK190 achieved expression levels persisting >10 weeks in mice and >3 weeks in non-human primate (NHPs), which is protective against ZIKV infectious challenge. This study is the first demonstration of infectious disease control in NHPs following in vivo delivery of a nucleic acid-encoded antibody, supporting the importance of this new platform.

[Problem Of Diabetic Foot Amputations]

INTRODUCTION

The diabetic foot wound is a real public health problem, 10% of the reasons for hospitalization. The risk of amputation is 10 to 30 times higher in diabetics than the general population.

OBJECTIVE

To study the problem of amputations of the diabetic foot.

METHOD

This was a descriptive and cross-sectional study that took place in the Department of Medicine and Endocrinology of the Mali Hospital from July 1st, 2016 to June 30th, 2017.

RESULTS

Twenty-five (25) diabetic patients were enrolled in our study. The sex ratio was 0.66. At admission, 100% of our patients had arterial disease, 96% neuropathy, and mixed foot in 80%. Poor glycemic control in 64% of patients; osteitis in 52% of cases; 92% of the patients had a 100% amputation risk according to the University of Texas classification. Nearly half or 46% of patients had amputations in the leg. We recorded 1 death case that is 4%.

CONCLUSION

The problem of amputation of diabetic feet is a function of the poor equilibrium and progressive neurological and vascular complications of diabetes.

[Status Of Markers Of Oxidative Stress At The Internal Medicine And Endocrinology Department Of The Mali Hospital]

Oxidative stress represents an imbalance between the endogenous antioxidant defenses and the production of pro-oxidant molecules. The present study describes oxidative stress markers (oxidant and antioxidant) metabolic disturbances in diabetic and non-diabetic patients at the Internal Medicine and Endocrinology ward of hospital of Mali.

MATERIALS AND METHODS

We conducted a descriptive case / control study involving 30 diabetic and 30 non-diabetic patients. Studied markers were Glutathione erythrocyte peroxidase (GPX), intra erythrocyte Superoxide dismutase (SOD), plasmatic uric acid, direct and total bilirubins, albumin and markers for diagnosis and monitoring of diabetes.

RESULTS

Non-diabetic patients (9%) had higher glutathione peroxidase levels compared diabetics (3%) (p = 0.005). An increase in superoxide dismutase was observed in 73.3% of diabetics versus 40% of nondiabetics (p = 0). The albumin, uric acid and bilirubin levels were identical in both populations. Glycated hemoglobin was significantly correlated with microangiopathies (p = 0.0058) and macro angiopathies( p=0,0007) in diabetics.

CONCLUSION

The study showed an increase in antioxidant defenses in diabetics by the elevation of superoxide dismutase and a relative normalization of glutathione peroxidase.

An observational analysis of the impact of indoor residual spraying with non-pyrethroid insecticides on the incidence of malaria in Ségou Region, Mali: 2012-2015

Background

Ségou Region in Central Mali is an area of high malaria burden with seasonal transmission, high access to and use of long-lasting insecticidal nets (LLINs), and resistance to pyrethroids and DDT well documented in Anopheles gambiae s.l. (the principal vector of malaria in Mali). Ségou has recently received indoor residual spraying (IRS) supported by Mali’s collaboration with the US President’s Malaria Initiative/Africa Indoor Residual Spraying programme. From 2012 to 2015, two different non-pyrethroid insecticides: bendiocarb in 2012 and 2013 and pirimiphos-methyl in 2014 and 2015, were used for IRS in two districts. This report summarizes the results of observational analyses carried out to assess the impact of these IRS campaigns on malaria incidence rates reported through local and district health systems before and after spraying.

Methods

A series of retrospective time series analyses were performed on 1,382,202 rapid diagnostic test-confirmed cases of malaria reported by district routine health systems in Ségou Region from January 2012 to January 2016. Malaria testing, treatment, surveillance and reporting activities remained consistent across districts and years during the study period, as did LLIN access and use estimates as well as An. gambiae s.l. insecticide resistance patterns. Districts were stratified by IRS implementation status and all-age monthly incidence rates were calculated and compared across strata from 2012 to 2014. In 2015 a regional but variable scale-up of seasonal malaria chemoprevention complicated the region-wide analysis; however IRS operations were suspended in Bla District that year so a difference in differences approach was used to compare 2014 to 2015 changes in malaria incidence at the health facility level in children under 5-years-old from Bla relative to changes observed in Barouéli, where IRS operations were consistent.

Results

During 2012–2014, rapid reductions in malaria incidence were observed during the 6 months following each IRS campaign, though most of the reduction in cases (70% of the total) was concentrated in the first 2 months after each campaign was completed. Compared to non-IRS districts, in which normal seasonal patterns of malaria incidence were observed, an estimated 286,745 total fewer cases of all-age malaria were observed in IRS districts. The total cost of IRS in Ségou was around 9.68 million USD, or roughly 33.75 USD per case averted. Further analysis suggests that the timing of the 2012–2014 IRS campaigns (spraying in July and August) was well positioned to maximize public health impact. Suspension of IRS in Bla District after the 2014 campaign resulted in a 70% increase in under-5-years-old malaria incidence rates from 2014 to 2015, significantly greater (p = 0.0003) than the change reported from Barouéli District, where incidence rates remained the same.

Conclusions

From 2012 to 2015, the annual IRS campaigns in Ségou are associated with several hundred thousand fewer cases of malaria. This work supports the growing evidence that shows that IRS with non-pyrethroid insecticides is a wise public health investment in areas with documented pyrethroid resistance, high rates of LLIN coverage, and where house structures and population densities are appropriate. Additionally, this work highlights the utility of quality-assured and validated routine surveillance and well defined observational analyses to rapidly assess the impact of malaria control interventions in operational settings, helping to empower evidence-based decision making and to further grow the evidence base needed to better understand when and where to utilize new vector control tools as they become available.

Electronic supplementary material

The online version of this article (10.1186/s12936-017-2168-2) contains supplementary material, which is available to authorized users.

[Turner syndrome in the hôpital du Mali, a case]

Turner syndrome is a chromosomal aberration linked to the complete or partial absence of an X chromosome. Its prevalence is 1/2500 female newborns. We report a case in the department of internal medicine and endocrinology of the hospital of MALI. This was a 14-year old girl who consulted for stunting and puberty. She presented clinically a dysmorphic syndrome, TANNER stage1 secondary sexual characteristics, weight and height at -3 DS and a bone age estimated to 9½ years old on the X-ray of the hand. The hormonal assessment showed an elevation of FSH and LH and the genetic study showed an iso chromosome Xq. This result was part of a Turner syndrome with Xq iso chromosome.

[Hirsutism secondary to a luteal cyst of the right ovary at the department of internal medicine and endocrinology of the Mali Hospital]

The authors are reporting here for the first time a documented case of androgen-secreting luteal cyst responsible for primary sterility in Mali. A 26-year married woman with a history of familial hyper androgenia of diabetes and high blood pressure who consulted for hyper androgen syndrome and primary infertility. Hirsutism with the presence of hairs on her chin, upper lips, thorax, forearms, arms, and her legs under waxing which made a Ferriman and Galloway scoreof10. A pelvic ultrasound coupled with a laparoscopy allowed us to retain the diagnosis of luteal cyst.

CONCLUSION

Hyper androgenicity in women is rare and the luteal cystis one of its multiple etiologies.

On the role of endothelial TRPC3 channels in endothelial dysfunction and cardiovascular disease

In endothelium, calcium (Ca(2+)) influx through plasma membrane Ca(2+)-permeable channels plays a fundamental role in several physiological functions and in the pathogenesis of cardiovascular disease. Current knowledge on the influence of Ca(2+) influx in signaling events associated to endothelial dysfunction has grown significantly over recent years, particularly after identification of members of the Transient Receptor Potential Canonical (TRPC) family of channel forming proteins as prominent mediators of Ca(2+) entry in endothelial cells. Among TRPC members TRPC3 has been at the center of many of these physiopathological processes. Progress in elucidating the mechanism/s underlying regulation of endothelial TRPC3 and characterization of signaling events downstream TRPC3 activation are of most importance to fully appreciate the role of this peculiar cation channel in cardiovascular disease and its potential use as a therapeutic target. In this updated review we focus on TRPC3 channels, revising and discussing current knowledge on channel expression and regulation in endothelium and the roles of TRPC3 in cardiovascular disease in relation to endothelial dysfunction.

Vasoactive and antioxidant activities of plants used in Mexican traditional medicine for the treatment of cardiovascular diseases

This study demonstrated that the aqueous extracts of plants employed in Mexican traditional medicine for the treatment of cardiovascular diseases are able to modify the tone of arterial smooth muscle. Agastache mexicana (Kunth) Lint & Epling (Labiatae), Chenopodium murale L. (Chenopodiaceae), Chirantodendron pentadactylon Larreat (Sterculiaceae), Dracocephalum moldavica L. (Labiatae), Psittacanthus calyculatus G. Don (Loranthaceae), Prunus serotina ssp. capuli (Cav. ex Spreng) McVaugh (Rosaceae), and Sechium edule Sw. (Cucurbitaceae) contain secondary metabolites that promote vascular relaxation and display antioxidant activities. As expected, their antioxidant effects showed a significant correlation with the polyphenolics content. However, a lower correlation was found between the antioxidant activity and the maximum vasodilatory effect, suggesting that the vasodilatation elicited by the plant extracts could be only partly attributed to their antioxidant properties. The extract of P. calyculatus, which displayed a maximum vasorelaxant effect that was higher than that of acetylcholine, induced endothelium-dependent vasodilatation. Futhermore, the vasorelaxant response to the P. calyculatus extract was reduced after adding an inhibitor of soluble guanylate cyclase activity, providing evidence that the NO/cGMP pathway is involved. On the other hand, the extracts of Bocconia frutescens L. (Papaveraceae), Magnolia grandiflora L. (Magnoliaceae), and Solanum rostratum Dunal (Solanaceae) induced concentration-dependent contraction of rat aortic rings, suggesting that these plants have potential health benefits for the treatment of ailments such as venous insufficiency. The pharmacological activities of the extracts studied provide scientific support for their ethnomedical use.

'Desperate house genes': the dramatic example of hypoxia

BACKGROUND

Microenvironmental conditions in normal or tumour tissues and cell lines may interfere on further biological analysis. To evaluate transcript variations carefully, it is common to use stable housekeeping genes (HKG) to normalise quantitative microarrays or real-time polymerase chain reaction results. However, recent studies argue that HKG fluctuate according to tissues and treatments. So, as an example of HKG variation under an array of conditions that are common in the cancer field, we evaluate whether hypoxia could have an impact on HKG expression.

METHODS

Expression of 10 commonly used HKG was measured on four cell lines treated with four oxygen concentrations (from 1 to 20%).

RESULTS

Large variations of HKG transcripts were observed in hypoxic conditions and differ along with the cell line and the oxygen concentration. To elect the most stable HKG, we compared the three statistical means based either on PCR cycle threshold coefficient of variation calculation or two specifically dedicated software. Nevertheless, the best HKG dramatically differs according to the statistical method used. Moreover, using, as a reference, absolute quantification of a target gene (here the proteinase activating receptor gene 1 (PAR1) gene), we show that the conclusions raised about PAR1 variation in hypoxia can totally diverge according to the selected HKG used for normalisation.

CONCLUSION

The choice of a valid HKG will determine the relevance of the results that will be further interpreted, and so it should be seriously considered. The results of our study confirm unambiguously that HKG variations must be precisely and systematically determined before any experiment for each situation, to obtain reliable normalised results in the experimental setting that has been designed. Indeed, such assay design, functional for all in vitro systems, should be carefully evaluated before any extension to other experimental models including in vivo ones.

[Undesirable effects of medicine in the Internal Medicine Service of the University Hospital Center du Point G]

The aim of this study was to determine the frequency of adverse reactions to drugs, the WHO grade, describe the clinical features and identify the drug responsible. This was a descriptive cross-sectional study which took place from February 2005 to January 2006 in the Internal Medicine Department at the hospital point G. Were included in this study, all patients hospitalized during the study period, which presented adverse drug reactions (ADRs) that the relation of cause and effect was certain or likely. Thus, 47 ADRs were identified in 39 patients of 426 admitted during the same period a frequency of 9.2%. The average age of our patients was 48.5 ± 16.5 years. The sex-ratio was 1.6 for women. Eighty-two percent of our patients had an ADR and 18% more than one. The WHO grade 1 was the most met or 36.2%, followed by grades 4 and 2 respectively 27.7% and 25.5%. Antidiabetics were responsible for adverse reactions in 46.8% and 21.3% in TB. Adverse events were neurological in 53.2% and type of manifestations of hypoglycemia 46.8% (22/47 cases), polyneuritis 6.4% (3 / 47 cases) and 29.8% in digestive cases dominated by vomiting 12.8% (6 / 47 cases), the epigastria pain 6.4% (3 / 47 cases). The outcome was favorable in 87.2% of cases, however, 3 cases of death among those over 60 years all grade 4 WHO. ADRs deserve special attention to this high death rate (6.4% 3/47 cases) where the interest to search systematically for all patients under medical treatment with a good clinical examination and questioning some thoroughly.

Concentrations of isoflavones and their metabolites in the blood of pregnant and non-pregnant heifers fed soy bean

The present study compared the changes in isoflavones (daidzein and genistein) and their metabolite (equol and para-ethyl-phenol) concentrations in the blood plasma of cyclic and pregnant heifers after feeding with soy bean. Twelve healthy heifers were divided into three groups: cyclic heifers (days 8-12 of the estrous cycle; control group; n=4), an early pregnancy group (2 months pregnant; n=4) and a late pregnancy group (8 months pregnant; n=4). All heifers were fed a single dose of 2.5 kg of soy bean and then blood samples were taken from the jugular vein for 8 h at predetermined intervals. The concentrations of soy bean-derived isoflavones and their active metabolites were measured in the blood plasma on an HPLC system. In the blood plasma of the early- and late-pregnant heifers, we found lower concentrations and time-dependent decreases in daidzein and genistein in comparison to cyclic heifers (P<0.05). Moreover, we noticed significant increases of equol and para-ethyl-phenol in the blood plasma of the early-pregnant heifers (P<0.05). In contrast, in the blood plasma of the late-pregnant heifers, we did not find an increase in the isoflavone metabolite concentrations compared with the early-pregnant heifers (P>0.05). In conclusion, physiological status (cyclicity or pregnancy) of the females influenced the concentrations of isoflavone metabolites in the blood plasma of the heifers. The stage of pregnancy affects isoflavone absorption, biotransformation and metabolism differently and results in higher concentrations of active metabolites of isoflavones during early pregnancy in comparison to their lower concentrations during late pregnancy. Therefore, we surmise that cows are more sensitive to active isoflavone metabolite actions during early pregnancy than cyclic heifers and heifers in late pregnancy.

A randomised controlled trial of azithromycin following surgery for trachomatous trichiasis in the Gambia

BACKGROUND/AIM

Trachomatous trichiasis frequently returns following surgery. Several factors may promote recurrence: preoperative disease severity, surgeon ability, surgical procedure, healing responses, and infection. This study investigates whether enhanced control of infection, both of Chlamydia trachomatis and other bacteria, with azithromycin can improve surgical outcome in a trachoma control programme.

METHODS

Individuals with trachomatous trichiasis were examined and operated. After surgery patients were randomised to the azithromycin or control group. The azithromycin group and children in their household were given a dose of azithromycin. Antibiotic treatment was repeated at 6 months. All patients were reassessed at 6 months and 12 months. Samples were collected for C trachomatis polymerase chain reaction and general microbiology at each examination.

RESULTS

451 patients were enrolled. 426 (94%) were reassessed at 1 year, of whom 176 (41.3%) had one or more lashes touching the eye and 84 (19.7%) had five or more lashes. There was no difference in trichiasis recurrence between the azithromycin and control group. Recurrent trichiasis was significantly associated with more severe preoperative trichiasis, bacterial infection, and severe conjunctival inflammation at 12 months. Significant variability in outcome was found between surgeons. Visual acuity and symptoms significantly improved following surgery.

CONCLUSION

In this setting, with a low prevalence of active trachoma, azithromycin did not improve the outcome of trichiasis surgery conducted by a trachoma control programme. Audit of trichiasis surgery should be routine.

Trial of the Trachoma Rapid Assessment methodology in The Gambia

PURPOSE

To test the validity and repeatability of a newly designed Trachoma Rapid Assessment (TRA) methodology.

METHOD

Results from an initial TRA in 20 villages (TRA1) are compared with those of a second validation TRA (TRA2) after 6 weeks in 13 villages, randomly selected out of the original 20, conducted by different field staff. Findings of TRA1 and TRA2 are compared with those of a door-to-door survey of the entire population of all 13 villages.

RESULTS

There is a considerable amount of variation between the results of TRA1 and TRA2 and between the results of both TRA's and the door-to-door survey. Even indicators that should have remained the same, like distance to Primary Health Centre or distance to trichiasis surgery facility, scored differently.

CONCLUSIONS

The TRA methodology is easy to use and the results are quickly available. The scoring system indicates which intervention(s) of the SAFE strategy are needed and facilitates priority setting. The definition of some indicators, like availability and use of latrines, may need modification. In some cases, the scoring system seems to exaggerate differences between the actual findings. The consistency between two TRA's in the same village is low and the accuracy in measuring the actual situation is doubtful.

Smooth muscle relaxing activity of gentiopicroside isolated from Gentiana spathacea

Bioassay directed fractionation of the (1:1) chloroform-methanol extract of Gentiana spathacea H.B.K (Gentianaceae) led to the isolation of gentiopicroside (gentiopricrin) (1), the major spasmolytic component of the plant. Gentiopicroside inhibited, in a concentration-dependent manner, the spontaneous contractions of isolated guinea pig ileum. Contractions induced by histamine, acetylcholine, BaCl2 and KCl on the ileum were also significantly blocked by this monoterpene glucoside, which suggests that this compound might be interfering with calcium influx into the smooth muscle cells.

Cowdria ruminantium antibodies in acaricide-treated and untreated cattle exposed to Amblyomma variegatum ticks in The Gambia

An indirect enzyme-linked immunosorbent assay (ELISA), based on the major antigenic protein I fragment B (MAPI-B) of Cowdria ruminantium, was used to assess seroprevalence in cattle in The Gambia. Two groups of 20 N'Dama and 20 Gobra zebu cattle were monitored for 12 months with flumethrin treatment and for another 10 months without acaricidal treatment. Two groups of 20 N'Dama and 20 Gobra cattle served as untreated controls. During the period of acaricidal treatment, the cumulative proportions of positive serum samples were 25.6 +/- 5.6% (+/- confidence interval) and 34.7 +/- 6.8% in treated N'Dama and Gobra cattle respectively; the proportion of positive sera in untreated cattle was 52.2 +/- 6.9% in N'Damas and 61.4 +/- 7.3% in Gobras. Within breed, difference in antibody prevalence between treated and untreated cattle was significant (P < 0.001) but between breed differences were not significant. In the 10 months following suspension of acaricide application, there was an increase of proportion of positive serum samples in previously treated N'Dama and Gobra cattle. In both previously treated and untreated animals the peak of positive seroreactions occurred during and subsequent to the period of activity of Amblyomma variegatum adults. Cumulative seroprevalences in previously treated N'Dama and Gobra cattle were 32.6 +/- 6.9% and 44.7 +/- 8.5%, respectively; in untreated animals seroprevalence was 38.6 +/- 7.2% in N'Dama and 65.3 +/- 8.4% in Gobra cattle. Throughout the study period, within the N'Dama breed, the seropositive rate in previously treated cattle did not differ from that in untreated animals. Conversely, within the Gobra breed, the number of positive seroreactions was higher (P < 0.002) in untreated animals than in previously treated cattle. These results provide a support for designing A. variegatum and heartwater control strategies, if necessary, in The Gambia in relation to cattle breeds.

Spasmolytic activity of some plants used by the Otomi Indians of Quéretaro (México) for the treatment of gastrointestinal disorders

The present study was performed to investigate the effect of chloroform-methanol (1:1) extracts derived from Baccharis heterophylla H. B. K (Asteraceae), Desmodium grahami Gray (Leguminosae), Dyssodia pinnata var. pinnata Rob. (Asteraceae), Gentiana spathacea H. B. K. (Gentianaceae), Loeselia mexicana Brand. (Polemoniaceae), Selaginella pallescens Spring. (Selaginellaceae) and Zornia diphylla Pers. (Fabaceae) on the spontaneous contractions of isolated rat ileum. The concentration-response curves and IC50 values were obtained and the respective relaxant potencies were compared with that of the CHCl3-MeOH (1:1) extract of Datura lanosa. The data showed that all the extracts produce a concentration-dependent inhibition of spontaneous ileum contractions. In addition, the antimicrobial activity of the extracts against pathogenic enterobacteria was tested. The pharmacological actions shown by the extracts of the selected species tend to support ethnomedical use of the plants for the treatment of gastrointestinal disorders.

Efficiency and cost of strategic use of acaricide for tick control in N'Dama cattle in The Gambia

The efficiency of strategic and strategic/selective applications of flumethrin spray formulation for controlling ticks were assessed, respectively, in two groups of fourteen N'Dama cattle (Group S and Group S/S) by comparison of the number of feeding ticks with thirteen untreated N'Dama cattle (Group U) over a period of 11 months (June 1996 to April 1997). During the expected peak of tick abundance, acaricide was applied fortnightly on the whole body in animals in Group S and only on the most infested body areas in cattle in Group S/S. Weight changes and skin lesions, directly associated with tick attachment, were recorded in cattle in the three groups. The costs of the two tick control schemes were estimated. Maximum level of ticks, all species together, feeding on cattle was observed in the rainy season. Both in Group S/S and Group S, cattle carried a lower (P < 0.001) number of feeding ticks than animals in Group U over the whole study period. Percentage of tick control, over the entire period of tick investigation, was satisfactory in both acaricide-treated groups, reaching 61.2 and 75.2% in Groups S/S and S, respectively. However, the proportion of control varied according to tick species or genus. Significantly lower prevalence of skin lesions was observed on the ano-genital and udder region in cattle in Group S/S (P < 0.05) and Group S (P < 0.01) in comparison with cattle in Group U. Mean amount of acaricide solution used and relative estimated cost of treatment in cattle in Group S/S were, respectively, 25- and 14-fold lower than those in cattle in Group S. At the end of the study, animals in Groups S/S and S were, respectively, 7.2 and 15.9 kg heavier than animals in Group U. The difference was statistically significant (P < 0.02) only between Groups S and U. However, the efficiency, low cost and derived benefits of the strategic/selective acaricide application scheme indicated that it might be the most cost effective.

Effect of controlling natural field-tick infestation on the growth of N'Dama and Gobra zebu cattle in the Gambia

The effect of tick infestations on liveweight gain (LWG) was assessed by comparison of weight changes in flumethrin-treated N'Dama and Gobra zebu cattle (16-20 months old) with respective control groups submitted to natural tick challenge over 1 year. Flumethrin was applied monthly, fortnightly or weekly. Preventive treatments against anaplasmosis, babesiosis and trypanosomosis were given. Mortality rate was recorded and post-mortem examinations carried out. In both treated and control animals, significantly fewer Hyalomma spp. and Amblyomma variegatum were found on N'Dama than on Gobra zebu cattle. Both breeds are equally susceptible to Rhipicephalus senegalensis infestation. Total annual tick burdens did not cause significant differences in LWG between acaricide-treated and control cattle in either breeds. LWG was also not affected during or after the annual peak of tick infestation (composed mainly by A. variegatum and R. senegalensis). Equally-high mortality (35%), due to unidentified causes, was recorded in acaricide-treated and control Gobra cattle; mortality in N'Dama cattle was 7.5%. In both breeds, about the 90% of mortality occurred at the end of the dry season. Breed differences in tick burden confirm previous results. If tick-borne infections do not influence LWG or mortality, then it is concluded that intensive tick control is not justifiable in Gambian livestock.

Susceptibility to different tick genera in Gambian N'Dama and Gobra zebu cattle exposed to naturally occurring tick infestations

Tick collection on one side of the body and whole tail was performed weekly over one year on 11 Gambian N'Dama (Bos taurus) and 11 Gobra zebu (Bos indicus) cattle to assess breed susceptibility to naturally occurring ticks. Enzyme-linked immunosorbant assay was also performed to assess the serological prevalence of Anaplasma marginale antigen and Babesia bigemina antibody. Packed red cell volume was measured and liveweight gain was recorded. Significantly higher numbers of Amblyomma variegatum (P < 0.002) and Hyalomma spp. (P < 0.001) were found on Gobra zebu than on N'Dama cattle. The serological prevalence of A. marginale antigen was significantly (P < 0.001) lower in N'Dama breed, whilst no difference in the serological prevalence of B. bigemina antibody was found between N'Dama and Gobra cattle. Packed red cell volume was negatively affected by A. marginale infection in both breeds, but to a lesser extent in N'Dama cattle. Liveweight gain was significantly (P < 0.003) higher in N'Dama in comparison with Gobra cattle during the period of abundance of A. variegatum and Hyalomma spp. adults. The significantly lower burdens of A. variegatum and Hyalomma spp. ticks in Gambian N'Dama in comparison with Gobra zebu cattle confirms previous findings. It also shows a more deleterious effect of ticks and tick-borne diseases on animal production and health in Gobra zebu than in N'Dama cattle. The presence of a tick resistant trait in N'Dama cattle is suggested.

Experimental Trypanosoma congolense infection on naturally occurring ticks in N'dama and Gobra zebu cattle

The effects of experimental Trypanosoma congolense infection in Gambian N'dama and Gobra zebu cattle on number of naturally-occurring adult ticks attaching were studied. An indirect fluorescent antibody test was performed to detect serological prevalence of Cowdria ruminantium antibody. The intravenously imposed trypanosome infection did not result in significant (P > 0.05) differences in Amblyomma variegatum and Hyalomma spp. infestations between control and infected N'dama cattle. Control N'damas carried significantly (P < 0.001) lower numbers of A. variegatum and Hyalomma spp. than the control zebus. Serological frequency of C. ruminantium antibody was similar in both control or infected N'dama and in control or infected zebu cattle. No deaths occurred among N'dama cattle, while all six trypanosome infected zebus progressively died within nine weeks post-infection but trypanosomosis was excluded as the primary cause of death. Examined Giemsa-stained blood smears were negative for the presence of tick-borne micro-organisms. Four positive cases of cowdriosis were identified during post-mortem examination. It was concluded that N'damas, even when submitted to trypanosome infection, react consistently better than Gobra zebus to tick attachment. These results emphasize the benefits of rearing disease resistant cattle breeds, such as N'dama, in areas where risks of trypanosomosis and cowdriosis coexist.

Hepatotoxic pyrrolizidine alkaloids in the Mexican medicinal plant Packera candidissima (Asteraceae: Senecioneae)

A study of the hepatotoxic pyrrolizidine alkaloids (PAs) contained in Packera candidissima (Greene) Weber & Löve (Senecio candidissimus Greene), a Mexican medicinal plant used for the treatment of kidney ailments and noted for its antiseptic properties, is reported. Analysis by TLC and GC-MS have shown the presence in high levels of both PAs and their N-oxides in the root (0.76% dry weight) and the aerial parts (0.36% dry weight) of the plant material. GC-MS analysis showed the presence of senecionine, integerrimine, retrorsine, and usaramine in the aerial parts. The root was found to contain senkirkine as the major component. These results indicate that users of this herb are at high risk of poisoning, especially members of certain cultural groups in Northern Mexico and the Hispanic population in the southwestern United States. In addition, two sesquiterpenes, neoadenostylone and epineoadenostylone were identified from the neutral extracts of this plant material. The 6 alpha-angeloyloxy-9-oxo-delta 10(1)-furanoeremophilane is reported for the first time as a natural product.

A comparison of field tick infestation on N'Dama, Zebu and N'Dama x Zebu crossbred cattle

Tick burdens, estimated from cumulative tick counts, were determined on N'Dama, Zebu and F1 N'Dama x Zebu crossbred cattle. N'Dama showed significantly fewer ticks than the Zebu and F1 cattle (P < 0.001). A previous trypanosomosis infection did not affect tick burdens on the three genotypes. Amblyomma variegatum had a prevalence of 84.8% and Hyalomma spp. 15.2%, with the ratio similar on all cattle breeds. Trypanosomosis infection increased the serological prevalence of Anaplasma marginale in Zebu and F1 cattle but not in N'Dama cattle. These observations supported the view that N'Dama cattle are less susceptible to tick attachment than Zebu cattle.

Comparison of the efficacy of propranolol and amiodarone in suppressing ventricular arrhythmias following myocardial infarction

The purpose of this prospective randomized trial was to compare the efficacy of propranolol and amiodarone in suppressing ventricular arrhythmias during the first 6 months following myocardial infarction (MI). 97 patients were treated with either amiodarone (n = 48) or propranolol (n = 49) starting on the 9th day following MI. Holter monitoring was carried out on four occasions: on D7, D21, D90 and D180. There was no statistical difference in the incidence of 'major' arrhythmias (an average of at least 10 ventricular premature complexes (VPCs) h-1, multiform or paired VPCs or runs) between the two groups on D7. A significant difference in favour of amiodarone became apparent at D180 (P = 0.04). Patients were also classified according to whether treatment failed or was successful. 'Success' was recorded when arrhythmias remained minor or became minor (less than 10 uniform VPCs h-1) and 'failure' when arrhythmias remained major or became major, or when patients were withdrawn because of side-effects, or lost to follow-up. The difference remained in favour of amiodarone (P = 0.03 at D21; P = 0.05 at D90; P = 0.06 at D180). Evaluation of the percentage reduction in the number of VPCs at D21, D90 or D180 compared with D7 showed superiority of amiodarone at D90 (P less than 0.01) and D180 (P less than 0.04). In this study, the overall effect of amiodarone on ventricular arrhythmias following MI was shown to be superior to that of propranolol.