Role of abdominal ultrasound imaging in evaluation of children with suspected upper gastrointestinal disease

Objectives: To evaluate the sonographic abdominal findings in children with suspected upper gastrointestinal disease, establish indications for sonography and describe the gastrointestinal disease patterns that can be evaluated by ultrasound.Design: Descriptive prospective study.Setting: Kenyatta National Hospital and Department of Diagnostic Imaging and Radiation Medicine, University of Nairobi.Subjects: Fifty-six children who presented with vomiting and suspected upper gastrointestinal disease. Age range was from six days to 12 years with mean age of one year five months. Seventy seven percent were two years and below.Results: Of the 56 children, six were normal on sonography; 18 (32.1%) had intussusception, 16 (28.6%) gastroesophageal reflux, seven (12.5%) pyloric stenosis, four appendicitis, three jejunal/ileal atresia and two enteric duplication cysts. All the children with pyloric stenosis were male. The male: female ratio for intussusception and GER was 1.5:1 and 1.6:1 respectively. The most common clinical presentation in children found to have intussusception was palpable abdominal mass, and few of them presented with bloodstained stool. More than two thirds of the children with gastro-oesophageal reflux presented with complications of recurrent pneumonia and failure to thrive. The sonographic findings correlated with fluoroscopy for GER except in two children where sonography was found to be more sensitive. The sonographic findings correlated with surgical outcome for pyloric stenosis, intussusception, jejunal/ ileal atresia and enteric duplication cysts.Conclusion: Trans-abdominal sonography has a definite role in investigating the child suspected to have upper gastrointestinal disease and should be considered as the initial imaging modality, instead of fluoroscopy, thereby avoiding or limiting the use of ionising radiation. Findings in this study confirm that ultrasound is an accurate, reliable and rapid screening method to evaluate the causes of upper gastrointestinaldisease in children

Diarrhea due to Cryptosporidium parvum in immunocompromised and immunocompetent patients in Khartoum State

Objective: The objective of this study is to search for Cryptosporidium parvum in Sudanese immunocompromised and immunocompetent patients presenting with diarrhea.Methods: Two hundred and thirteen stool specimens were collected from different groups of patients presenting with diarrhea and healthy control (immunocompromised: 78; immunocompetent: 90; Control: 45).The immunocompromised group included 25 HIV positive patients, 27 tuberculosis patients, 11 patients with renal failure and 15 patients receiving immunosuppressive chemotherapy. Antigen ELISA was performed to detect the presence of the parasite in stool. Positive specimens were examined by the modified ZN stain to look for the oocyst of C.parvum.Result: Seventy one of the immunocompromised patients (91.0%), twenty nine of immunocompetent patients (32.2 %) and ten of the control group (22.2%) were found to be positive for C.parvum. A significant difference was noticed between the immunocompromised patients and the other groups (

Screening the Efficacy of Some Traditional Herbal Drugs for Treatment of Hymenolepis diminuta Infection in Rats

Background: Hymenolepis nana (human infecting tapeworm) and H. diminuta (rodent infecting tapeworm) are currently incriminated to be the cause of non-specific bowel disturbances. They are in most instances resistant to the available anticestodal compounds due to misuse of drugs and probably adaptation of the parasites to the commercially available drugsObjective: Our objective is to study the toxicity and curative efficacy of different medicinal plants that are candidate for the treatment of tapeworm infections in man.Methods: Four medicinal plants were tested for their ability to treat Hymenolepis diminuta tapeworm infection in rats. These plants are Amaranthus viridis, Cucurbita maxima, Hagenia abyssinica and Balanites aegyptiaca. Selection of these plants was based on ethnobotanicalinformation. The evaluation of the efficiency of these medicinal plants was based on the “controlled test design”, modified from Moskey and Harwood10: Following pre-infection screening, and life cycle establishment rats were grouped to six experimental groups for each plant. Stool specimens were collected from all groups, the mean of eggs counts per gram of faeces were counted. The reduction percentage of eggs per gram (EPG) was calculated and time to clear eggs was compared with that of Niclosamide. Niclosamide drug was used in this study as a control treatment14.Results: There were no signs of toxic effect on the rats due to administration of any of the tested medicinal plants. Amaranthus viridis leavs exhibited a very weak efficacy. It did not reduce eggs ineither water or food significantly as compared to the untreated control group (p> 0.05). The deparasitization activity of this plant (35%) was not significant. Similarly, Balanites aegyptiaca seeds were not effective in treatment of the infection in rats. Egg counts and deparasitization infood and water, were not significantly (p> 0.05) different from those of the untreated control group. On the other hand, Cucurbita maxima and Hagenia abyssinica seeds were very effective in the treatment of Hymenolepis diminuta infection in rats. Egg reduction (100%) was highly significant (p< 0.01) in food and water as compared to that of the untreated control group of rats (zero%). C. maxima seeds in food deparasitized 80% of the worms, while Hagenia abyssinica deparasitized 100%.Conclusion: Our conclusion was that Hagenia abyssinica was the most active plant of this group in the treatment of Hymenolepis diminuta infection in rats

Effect of iodine incorporation on characteristic properties of cadmium telluride deposited in aqueous solution

The electrodeposition of polycrystalline I-doped CdTe was successfully performed from aqueous solutions containing cadmium nitrate (Cd(NO3)2 and tellurium oxide (TeO2). The effects of different I-doping concentrations in the electrolytic bath on the deposited CdTe layers deposited were evaluated structurally, optically, morphologically and electronically using X-ray diffraction (XRD), ultraviolet-visible spectrophotometry, scanning electron microscopy, photoelectrochemical cell measurement and direct-current (DC) conductivity test respectively. The XRD show reduction in the (111) cubic CdTe peak intensity and the calculated crystallite size of the CdTe:I layers above 5 ppm I-doping. At I-doping of 1000 ppm of the CdTe-bath and above, the deposition of only crystalline Te due to the formation of Cd-I complexes debarring the deposition of Cd and co-deposition of CdTe in aqueous solution was observed. Morphologically, reductions in grain size were observed above 5 ppm I-doping with high pinhole density and the formation of cracks within the CdTe:I layers. For the as-deposited CdTe:I layers, conduction type remained n-type across all the explored I-doping concentration of 200 ppm. For the CdCl2 and Ga2(SO4)2+CdCl2 treated CdTe:I layers, the transition from n- to p-type conductivity was observed for the CdTe:I baths doped with 20 ppm and above due to the reduced cadmium deposition on the substrate. The highest conductivity was observed at 5 ppm I-doping of the CdTe-bath. Observations made on the CdTe:I in aqueous solution differs from the non-aqueous solvent documented in the literature. These results are reported systematically in this communication

Experience and Challenges from Clinical Trials with Malaria Vaccines in Africa.

Malaria vaccines are considered amongst the most important modalities for potential elimination of malaria disease and transmission. Research and development in this field has been an area of intense effort by many groups over the last few decades. Despite this, there is currently no licensed malaria vaccine. Researchers, clinical trialists and vaccine developers have been working on many approached to make malaria vaccine available.African research institutions have developed and demonstrated a great capacity to undertake clinical trials in accordance to the International Conference on Harmonization-Good Clinical Practice (ICH-GCP) standards in the last decade; particularly in the field of malaria vaccines and anti-malarial drugs. This capacity is a result of networking among African scientists in collaboration with other partners; this has traversed both clinical trials and malaria control programmes as part of the Global Malaria Action Plan (GMAP). GMAP outlined and support global strategies toward the elimination and eradication of malaria in many areas, translating in reduction in public health burden, especially for African children. In the sub-Saharan region the capacity to undertake more clinical trials remains small in comparison to the actual need.However, sustainability of the already developed capacity is essential and crucial for the evaluation of different interventions and diagnostic tools/strategies for other diseases like TB, HIV, neglected tropical diseases and non-communicable diseases. There is urgent need for innovative mechanisms for the sustainability and expansion of the capacity in clinical trials in sub-Saharan Africa as the catalyst for health improvement and maintained

Progress in development of graded bandgap thin film solar cells with electroplated materials

Photovoltaic devices are developed mainly based on p-n or p-i-n type device structures, and these devices can utilise only a fraction of the solar spectrum. In order to further improve device parameters and move towards low-cost and high-efficiency next generation solar cells, device architectures capable of harvesting all photons available should be designed and developed. One such architecture is the fully graded bandgap device structure as proposed recently based on both n-type and p-type window layers. These designs have been experimentally tested using well researched GaAs/AlGaAs system producing impressive device parameters of open circuit voltage (Voc) ~1175 mV and fill factor (FF) ~0.85. The devices have also been experimentally tested for the evidence of impurity photovoltaic (PV) effect and impact ionisation taking place within the same device. Since these structures have been experimentally proved with a well-established semiconductor, the effort has been focussed on developing these devices using low-cost and scalable electroplated semiconductors, in order to minimise manufacturing cost. This paper reviews and summarises the work carried out during the past decade on this subject. Graded bandgap devices produced using only two or three electroplated semiconductor layers have been explored and their conversion efficiencies have gradually increased from 10.0%, through 12.8% to 15.3% for different structures. While the work is progressing along this line, the paper summarises the achievements to date

Room temperature chiral magnetic skyrmion in ultrathin magnetic nanostructures

Magnetic skyrmions are chiral spin structures with a whirling configuration. Their topological properties, nanometer size and the fact that they can be moved by small current densities have opened a new paradigm for the manipulation of magnetisation at the nanoscale. To date, chiral skyrmion structures have been experimentally demonstrated only in bulk materials and in epitaxial ultrathin films and under external magnetic field or at low temperature. Here, we report on the observation of stable skyrmions in sputtered ultrathin Pt/Co/MgO nanostructures, at room temperature and zero applied magnetic field. We use high lateral resolution X-ray magnetic circular dichroism microscopy to image their chiral N\'eel internal structure which we explain as due to the large strength of the Dzyaloshinskii-Moriya interaction as revealed by spin wave spectroscopy measurements. Our results are substantiated by micromagnetic simulations and numerical models, which allow the identification of the physical mechanisms governing the size and stability of the skyrmions.Comment: Submitted version. Extended version to appear in Nature Nanotechnolog

Effect of gallium doping on the characteristic properties of polycrystalline cadmium telluride thin film

Ga-doped CdTe polycrystalline thin films were successfully electrodeposited on glass/fluorine doped tin oxide (FTO) substrates from aqueous electrolytes containing cadmium nitrate (Cd(NO3)2⸱4H2O) and tellurium oxide (TeO2). The effects of different Ga-doping concentrations on the CdTe:Ga coupled with different post-growth treatments were studied by analysing the structural, optical, morphological and electronic properties of the deposited layers using X-ray diffraction (XRD), ultraviolet-visible spectrophotometry, scanning electron microscopy, photoelectrochemical cell measurement and direct-current conductivity test respectively. XRD results show diminishing (111)C CdTe peak above 20 ppm Ga-doping and appearance of (301)M GaTe diffraction above 50 ppm Ga-doping indicating the formation of two phases; CdTe and GaTe . Although, reductions in the absorption edge slopes were observed above 20 ppm Ga-doping for the as-deposited CdTe:Ga layer, no obvious influence on the energy gap of CdTe films with Ga-doping were detected. Morphologically, reductions in grain size were observed at 50 ppm Ga-doping and above with high pinhole density within the layer. For the as-deposited CdTe:Ga layers, conduction type change from n- to p- were observed at 50 ppm, while the n-type conductivity were retained after post-growth treatment. Highest conductivity was observed at 20 ppm Ga-doping of CdTe. These results are systematically reported in this pape

Biophysical and electrochemical studies of protein-nucleic acid interactions

This review is devoted to biophysical and electrochemical methods used for studying protein-nucleic acid (NA) interactions. The importance of NA structure and protein-NA recognition for essential cellular processes, such as replication or transcription, is discussed to provide background for description of a range of biophysical chemistry methods that are applied to study a wide scope of protein-DNA and protein-RNA complexes. These techniques employ different detection principles with specific advantages and limitations and are often combined as mutually complementary approaches to provide a complete description of the interactions. Electrochemical methods have proven to be of great utility in such studies because they provide sensitive measurements and can be combined with other approaches that facilitate the protein-NA interactions. Recent applications of electrochemical methods in studies of protein-NA interactions are discussed in detail