Unexplored vegetal green synthesis of silver nanoparticles: A preliminary study with Corchorus olitorus Linn and Ipomea batatas (L.) Lam

Antibacterial properties of silver ion are known from ancient times. The plant extract mediated synthesis of nanoparticles is gaining popularity due to green chemistry for the generation of nanosized materials. Corchorus olitorus Linn and Ipomea batatas (L.) Lam are world crops having leaves of high nutritional value. In the present work, Ag and AgCl nanoparticles were synthesized by incubating leaf aqueous extracts with silver nitrate salt, making them to react in the dark. Plasmon resonance bands, studied by ultraviolet spectroscopy, have been obtained. X-ray diffraction (XRD) revealed the average size of pure crystallites composed of Ag and AgCl. Optimization studies for the synthesis process highlight positive impact of pH, reaction time and reactants quantities.Key words: Silver, nanoparticles, Corchorus olitorus, Ipomea batatas, X-ray diffraction

Natural Substances for the Synthesis of Silver Nanoparticles against Escherichia coli

The development of drug-resistant strains is rising and the search for new and novel ways of fighting new or reemerging microbes goes on. A hope of treating such multidrug-resistant infections came from plants mediated nanoparticles since nature is a generous source which provides a variety of chemical compounds that can be used for new drug discovery. Silver nanoparticles are reported to possess antiviral, antibacterial, antifungal, antiparasitic, larvicidal activity and anticancer properties. We reported green synthesis of silver nanoparticles mediated food plants Megaphrynium macrostachyum, Corchorus olitorus, Ricinodendron heudelotii, Gnetum bucholzianum, and Ipomoea batatas and their antibacterial efficacy against the Enterobacteriaceae Escherichia coli. The nature and size of the obtained nanoparticles are discussed as well as their Minimum Inhibitory Concentration (MIC) and the Minimum Bactericide Concentration (MBC) values considering their application in medical industry

Incidence and factors associated with seroconversion to hepatitis C virus seropositivity amongst patients on maintenance hemodialysis, Douala-Cameroon

Hepatitis C virus (HCV) infection one of the most common blood-borne infections is endemic in Cameroon and a serious problem in hemodialysis (HD). We aimed to determine the annual incidence and factors associated with seroconversion to hepatitis C positivity amongst patients on maintenance HD after an exposition of two years in a center with a high prevalence of hepatitis C (20.6%) and where no isolation policy is practiced. This was a retrospective cohort study carried out in January 2015 in the HD unit of Douala General Hospital in Cameroon including 71 patients on maintenance HD who tested negative for HCV in January 2013. Socio-demographic characteristics and clinical data were recorded, while for each patient 10 mL of blood was collected and patients retested for HCV using a fourth-generation ELISA test (BIOREXR BXEO781A). Fisher's exact test was used for dichotomous variables and using Mann Whitney's test for quantitative variables. Statistical significance was set at P <0.05. Mean age was 47 ± 13 years with 60.6% male. Blood transfusion was the main means for anemia management (85.9%) with a median number of blood units received of 5 (1–44). Facility HCV prevalence was 19.3% in January 2015. Five out of the 71 patients developed anti-HCV antibodies giving us a seroconversion rate of 7.1% and an incidence of 3.6/100 patient years. There was no significant association between age (P = 0.4), number of blood units received (P = 0.8) origin of blood units (P = 0.8), scarifications (P = 0.09) and seroconversion. After two years of exposure seroconversion to HCV positivity was 7.1% in our center with no associated factors. In a setting with high prevalence of HCV, isolation of positive patient may help to reduce the rate of transmission

Association of urinary sodium excretion with blood pressure and risk factors associated with hypertension among Cameroonian pygmies and bantus: A cross-sectional study

Background: High salt intake increases blood pressure (BP) and hypertension risk. This study aimed to examine association of urinary sodium excretion with BP and hypertension correlates among Cameroonian pygmies under hunter-gatherer subsistence mode and Bantus, living in urban area under unhealthy behavioral habits. Methods: In this cross-sectional cluster sampling study, we randomly enrolled rural pygmies living in Lolodorf and urban Bantus living in Douala. The World Health Organization steps questionnaire was used to collect socio-demographic and lifestyle data. Height, weight, BP and single overnight spot urine samples were obtained in all participants. BP was measured in triplicate. Urinary sodium and potassium excretion was determined by flame photometry. Data were recorded and analyzed using SPSS 16.0. Results: We included 150 Pygmies and 150 Bantus aged 38±12 years and 33±11 years, respectively (p< 0.0001). Compare to Bantus, pygmy's height and weight were respectively: 1.54±0.09 m vs 1.72±0.12 m; and 54.4±9.2 kg vs 77.2±14.8 kg, all p< 0.0001. Age-standardized prevalence of hypertension was 3.3% among Pygmies and 28% among Bantus (p< 0.0001). Age-adjusted systolic and diastolic BP were lower in Pygmies than in Bantus (107±12 vs 119±17 mmHg and 71±11 vs 78±13 mmHg respectively, all P< 0.0001). BP increased with age but to a lesser extent in Pygmies (all p< 0.01). Urinary sodium excretion was lower in Pygmies than in Bantus (46.9±32.4 vs 121.5±61.0 mmol/l, p< 0.0001). Systolic and diastolic BP were positively associated with urinary sodium excretion in Bantus (all p< 0.05). In the two groups, urinary potassium excretion was similar, and was not related to blood pressure. In the total study group and in Bantus taken separately, urinary sodium excretion was higher in hypertensive than in normotensive subjects. Multivariable logistic regression showed that urinary sodium excretion, Bantu status and age emerged as independent determinants of hypertension in the whole study group (OR (95%CI): 1.012 (1.005-1.018); 11.408 (3.599-36.165); 1.095 (1.057-1.135) respectively, p< 0.0001). Conclusion: Hunter-gatherer pygmies exhibit low level of urinary sodium excretion related to low rate of hypertension and slower BP increase with age. Salt intake was a major driver of hypertension in our study population. Our findings highlight the need of efforts to implement nationwide prevention programs promoting risk factor screening and healthier lifestyles including reduction of dietary salt intake in Cameroonian.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

BACTERIAL AND FUNGAL UROPATHOGENS IN DIABETIC PATIENTS AND THEIR SUSCEPTIBILITY PATTERNS: CASE STUDY OF TWO HOSPITALS IN DOUALA

Background: Diabetic patients are more prone to develop urinary tract infections (UTI), than non-diabetic patients. These infections are responsible for considerable morbidity, particularly if they are unrecognised or untreated. The successful management of UTI in diabetic patients depends on the proper identification of the pathogens responsible and the selection of efficient antibiotics/antifungals against them. Methods: A cross-sectional study was carried out in the Endocrinology/Diabetic units of the General Hospital and the Laquintinie Hospital in Douala (Cameroon). Midstream urine samples were collected from the patients and analysed macroscopically and microscopically. Samples containing up to five leukocytes/mm3 were inoculated onto culture media for bacterial isolation and microbial load. Bacteriuria counts ≥10/mL was considered significant. Biochemical identification and susceptibility testing to antibiotics were carried out in positive cultures, using the VitekTM 2automated system. The susceptibility testing to antifungals was done by the disc diffusion method. Urine dipstick analysis was done using CombiScreenTM 11SYS PLUS. Results: Three hundred and fifteen patients comprising of 192 (60.95%) females, were enrolled. The overall UTI frequency was 20%, with rates of symptomatic bacteriuria and asymptomatic bacteriuria being 6.37% and 13.63% respectively. A total of 75 uropathogens were isolated, 3fungi (4%) and 72 bacteria (96%) strains. The most isolated bacteria were Escherichia coli (45.33%). Gram-positive cocci included Staphylococcus aureus, and coagulase negative Staphylococci were also found. The only fungus isolated was Candida albicans. The susceptibility rate for Gram-negative bacilli was 100% for Imipenem, 93.30% for Amikacin, and Piperacillin+Tazobactam. The lowest rates were observed for Amoxicillin and Cotrimoxazole. Gram-positive cocci were 100% susceptible to Moxifloxacin, Nitrofurantoin, Quinupristin/ Dalfopristin, Linezolid, Tetracycline, Tigecycline, and Rifampicin. The susceptibility rate for Vancomycin and Oxacillin were 66.70% and 55.50% respectively. All the isolated strains of C. albicans were susceptible to Econazole, Ketoconazole, Fluconazole and Flucytosine; and all were resistant to Nystatine. Conclusion: Many uropathogens were isolated from diabetic patients, and low susceptibilities to "first-line" drugs were observed. Dipstick urinalysis has a great contribution in urine culture examination

Spectroscopic synthetic optimizations monitoring of silver nanoparticles formation from Megaphrynium macrostachyum leaf extract

Nanobiotechnology is one of the most promising areas in modern nanoscience and technology. Metallic nanoparticles have found uses in many applications in different fields, such as catalysis, photonics, electronics, medicine and agriculture. Synthesized nanoparticles through chemical and physical methods are expensive and have low biocompatibility. In the present study, silver nanoparticles have been synthesized from Megaphrynium macrostachyum (Benth. & Hook. f.) Milne-Redh., Marantaceae, leaf extract. Megaphrynium macrostachyum is a plant with large leaves found in the rainforest of West and Central Africa. Synthetic optimizations following factors such as incubation time, temperature, pH, extract and silver ion concentration during silver formation are discussed. UV–visible spectra gave surface plasmon resonance for synthesized silver nanoparticles based Megaphrynium macrostachyum peaks at 400–450 nm. X-ray diffraction revealed the average size of pure crystallites composed from Ag and AgCl. Keywords: Silver, Nanoparticles, Megaphrynium macrostachyum, UV–visible spectroscop

Prélèvement de plaquettes pour la chirurgie cardiaque: Première expérience d'aphérèse à l'Hôpital général de Douala

Cardiac surgery with extracorporeal circulation (ECC) is usually associated with the loss of a significant amount of blood. Adequate prophylaxis against blood loss and good perioperative hemostasis are known as processes limiting postoperative bleeding. Until now, the need for platelets in patients operated with extracorporeal circulation in our Department has been compensated for by total blood transfusion or platelet concentrates collected from several donors. We here report our first experience with platelet concentrate collection by apheresis at the General Hospital in Douala.SCOPUS: ar.jinfo:eu-repo/semantics/publishe