Effective use of cerium anomalies as a redox proxy in carbonate-dominated marine settings

Rare earth elements and yttrium (REY) have a distinct distribution pattern in seawater, and this pattern may be faithfully preserved in carbonate sediments and rocks. Anomalous concentrations of redox-sensitive cerium (Ce) compared with neighbouring REY originate in oxic water column conditions, and as such, Ce anomalies can provide a potentially useful redox proxy in carbonate-dominated marine settings. The methods used to extract REY from carbonates vary widely, and may suffer from widespread leaching of REY from accessory non-carbonate minerals and organic matter, limiting the application of Ce anomalies for palaeo-redox reconstruction. We have systematically compared different methods on 195 carbonate samples with varying purity (% carbonate) from both modern and ancient environments. We used sequential leaching experiments in nitric acid to identify the most ‘seawater-like’ portion of the carbonate sample where contributions from non-carbonate minerals and organic matter are minimised. We also compared the results of sample dissolution in different types and strengths of acid. Our results confirm that REY concentrations can be inadvertently contaminated by partial leaching of clays and Fe (oxyhydr)oxides during a single-step digestion, and we suggest a pre-leach of 20% of the sample, followed by a partial leach of 40% of the sample to selectively dissolve carbonate. We suggest that REY studies are optimised in carbonates with > 85% CaCO₃, and show that dolomites behave differently during the leaching process and must be treated separately. We present REY patterns for modern carbonate-rich sediments from a range of environments, and show that seawater REY are faithfully preserved in some non-skeletal carbonate, but modified leaching procedures are necessary for impure, unlithified or organic rich carbonate sediments. We combine REY with Fe-speciation data to identify how Fe oxides and clays contribute to the REY signal and explore how the two proxies can be used together to provide a complex and high-resolution redox reconstruction in carbonate-dominated marine environments

The challenge in the diagnosis and management of an advanced abdominal pregnancy in a resource-low setting: a case report

Abstract Background Abdominal pregnancy is a rare form of ectopic pregnancy that is frequently left undiagnosed by inexperienced obstetricians and radiologists. It is associated with higher risk of maternal hemorrhage at any gestation and more at advanced gestation. Case presentation We present the case of a 22-year-old sub-Saharan African woman, gravida 3 para 0, who was diagnosed with advanced abdominal pregnancy of 25 weeks’ gestation by a transvaginal ultrasound after the failure of two medical terminations of pregnancy in the first and second trimesters and a series of repeated obstetric ultrasounds showing intrauterine pregnancy. Laparotomy was done and her recovery was uneventful. Conclusions The management of advanced abdominal pregnancy is more challenging as compared to earlier gestation so patients with failed medical termination of pregnancy should be critically analyzed for ectopic pregnancy as early as possible

Bowel Resection and Ileotransverse Anastomosis as Preferred Therapy for 15 Typhoid Ileal Perforations and Severe Peritoneal Contamination in a Very Elderly Patient

Typhoid ileal perforation (TIP) is the most lethal complication of typhoid fever. Although TIP is a surgical emergency by consensus, there is still much controversy regarding the most appropriate surgical approach to be used. Bowel exteriorization and secondary closure are usually recommended for patients presenting late with multiple TIPs and heavy peritoneal soiling. We, however, discuss a unique case of an 86-year-old patient with 15 typhoid ileal perforations successfully treated with one-step surgery comprising bowel resection and ileotransverse anastomosis in a resource-constrained setting of Cameroon

Occurrence and challenges in the management of severe chronic plaque type psoriasis in a limited resourced setting: a case report

Plaque-type psoriasis is a major dermatosis with significant effects on quality of life. Case complexity is often high in low-resourced settings such as in Africa where the incidence has been on the rise. Despite major advancements and newer therapeutic modalities over the last decade, an insight into the real-life, day to day challenges in low resourced settings reveal an interplay between the difficulty in obtaining these drugs and use of alternative traditional indigenous agents. We report the case of a 50 year old immunocompetent male who presented with chronic and extensive well demarcated plaques covered with silver-white scales occupying about 61% of his body surface area. Patient was however lost to follow up for about 8 months during which time, the lesions responded to some unknown homemade indigenous medications which was preferred to a systemic medication. Paramount importance on proper counselling and the need to retain patients in care is warranted by physicians and allied health personnel. Also, incentives aimed at subsidizing the newer systemic agents for patients in low resourced cohorts will go a long way to combat this multi-faceted disorder which is often unrecognized and under diagnosed

Risk factors for acute respiratory infections in children under five years attending the Bamenda Regional Hospital in Cameroon

Abstract Background Acute respiratory infections (ARI) are a leading cause of morbidity and mortality in under-five children worldwide. About 6.6 million children less than 5 years of age die every year in the world; 95% of them in low-income countries and one third of the total deaths is due to ARI. This study aimed at determining the proportion of acute respiratory infections and the associated risk factors in children under 5 years visiting the Bamenda Regional Hospital in Cameroon. Methods A cross-sectional analytic study involving 512 children under 5 years was carried out from December 2014 to February 2015. Participants were enrolled by a consecutive convenient sampling method. A structured questionnaire was used to collect clinical, socio-demographic and environmental data. Diagnosis of ARI was based on the revised WHO guidelines for diagnosing and management of childhood pneumonia. The data was analyzed using the statistical software EpiInfo™ version 7. Results The proportion of ARIs was 54.7% (280/512), while that of pneumonia was 22.3% (112/512). Risk factors associated with ARI were: HIV infection ORadj 2.76[1.05–7.25], poor maternal education (None or primary only) ORadj 2.80 [1.85–4.35], exposure to wood smoke ORadj 1.85 [1.22–2.78], passive smoking ORadj 3.58 [1.45–8.84] and contact with someone who has cough ORadj 3.37 [2.21–5.14]. Age, gender, immunization status, breastfeeding, nutritional status, fathers’ education, parents’ age, school attendance and overcrowding were not significantly associated with ARI. Conclusion The proportion of ARI is high and is associated with HIV infection, poor maternal education, exposure to wood smoke, passive cigarette smoking, and contact with persons having a cough. Control programs should focus on diagnosis, treatment and prevention of ARIs

A diagnostic algorithm for pulmonary hypertension due to left heart disease in resource-limited settings: can busy clinicians adopt a simple, practical approach?

Pulmonary hypertension (PH) has progressively moved from an orphan disease to a significant global health problem with a major disease burden in limited-resource countries, where over 97% of patients live. The aetiologies of PH differ between high- and low-income nations, but PH due to left heart disease is credited to be the most frequent contemporary form. Although a straightforward diagnosis of PH requires the use of right heart catheterisation (RHC), access to equipment for RHC is a deterrent. Furthermore, the risk associated with RHC limits its uptake to a selection of specialised centres. Moreover, the rigour and clinical reasoning for diagnosis in clinical medicine is rapidly changing and revealing that PH can complicate a diverse range of medical conditions needing other explorations. In this article, we provide for the busy clinician, a simplified diagnostic algorithm for PH that is relevant for making a correct early diagnosis and limiting the impact of PH