47 research outputs found

    The Yield from Routine Chest X-Rays in Stage 3 Breast Cancer Patients

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    Context: Cancer of the breast is a common malignancy in Nigerian women and various imaging examinations, including the chest radiograph are routinely requested in all patients with this disease.Objective: The objective of this study was to determine the positive yield from routine chest radiographs in Nigerian patients with locally advanced stage 3 breast cancers but who had no clinical symptoms or signs of pulmonary or pleural metastatic disease. Methods: This descriptive retrospective study evaluated clinical records and chest radiographs of 61 female Nigerian patients with local stage 3 histologically diagnosed breast cancers, who presented at the radiotherapy unit of the University College hospital, Ibadan, over a 12-month period. Allabnormalities on the chest radiographs were documented.Results: The ages of the study group ranged from 25 to 67 years with a mean of 47years. Fortyseven (77%) of the patients had normal chest radiographs. Of the 14 abnormal radiographs, bilateral lung parenchymal metastases were seen in 4 cases one of whom also had bilateralpleural effusion. Other abnormal findings included hilar adenopathy, right lower lobe collapse, lymphagitis carcinomatosis and cardiomegaly.Conclusion: The authors conclude that a 23% detection rate from these screening chest radiographs is high and should be recommended as over 70% of Nigerian Patients with breast cancers present with advanced tumors

    A Mathematical Investigation of the Turkevich Organizer Theory in the Citrate Method for the Synthesis of Gold Nanoparticles

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    Gold nanoparticles are commonly manufactured by the citrate reduction method, a synthesis method pioneered by Turkevich et al. (1951). Based on their experimental evidence, Turkevich et al. (1951) advanced the organizer theory, a nucleation-growth synthesis mechanism. Subsequently, Kumar et al. (2007) developed a mathematical model for the description of the synthesis, basing it on such a theory. However, this model has not been thoroughly tested. Recently, contrary to the evidence provided by Turkevich et al. (1951), other mechanistic descriptions of the synthesis, which emphasize the role of the pH of the solution, have been advanced in the literature. In this paper, we investigated the model of Kumar et al. (2007) for different conditions of pH, temperature and initial reactant concentrations. To solve the model, we used the numerical code Parsival, which is used for solving population balance equations. We tested the model for different synthesis conditions studied experimentally by various researchers, for which results are available in the literature. The model poorly predicted the experimental data because the Turkevich organizer theory does not account for the acid-base properties of chloroauric acid and sodium citrate. A new model, with a more accurate mechanistic description of the synthesis and of the chemistry involved, is therefore required

    A model for the formation of gold nanoparticles in the citrate synthesis method

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    This paper presents a new model for predicting the evolution of the particle size of gold nanoparticles (GNPs) in the citrate synthesis method. In this method, the precursor is an acid solution of tetrachloroauric acid, while the reducing agent is a base solution of sodium citrate. The acid-base properties of the solutions influence how the size of the particles evolves during the synthesis. In the literature, various mechanistic theories have been proposed to explain this evolution. Turkevich et al. (1951), who pioneered this synthesis method, suggested the “organizer theory”. This mechanistic description of the synthesis was modelled by Kumar et al. (2007), but recently Agunloye et al. (2017) showed that in several cases this model performed poorly, since it does not account for the acid-base properties of the reactants. In this work, we present a kinetic model based on the synthesis seed-mediated mechanistic description proposed by Wuithschick et al. (2015). In this description, the precursor concurrently reduces into gold atoms and hydroxylates into a passive form. The gold atoms then aggregate into seed particles, which finally react with the passive form of the precursor in a growth step. We validated the model using experimental data from the literature obtained for conditions in which the seed-mediated mechanism is valid. The predicted GNP final sizes closely agree with those obtained experimentally

    Hidrogenionic potential (pH) of the attractant, trap density and control threshold for Ceratitis capitata (Diptera: tephritidae) on Hamlin oranges in São Paulo central region, Brazil

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    This study evaluated the effect of initial pH values of 4.5, 6.5 and 8.5 of the attractant (protein bait) Milhocina® and borax (sodium borate) in the feld, on the capture of fruit flies in McPhail traps, using 1, 2, 4 and 8 traps per hectare, in order to estimate control thresholds in a Hamlin orange grove in the central region of the state of São Paulo. The most abundant fruit fly species was Ceratitis capitata, comprising almost 99% of the fruit flies captured, of which 80% were females. The largest captures of C. capitata were found in traps baited with Milhocina® and borax at pH 8.5. Captures per trap for the four densities were similar, indicating that the population can be estimated with one trap per hectare in areas with high populations. It was found positive relationships between captures of C. capitata and the number of Hamlin oranges damaged, 2 and 3 weeks after capture. It was obtained equations that correlate captures and damage levels which can be used to estimate control thresholds. The average loss caused in Hamlin orange fruits by C. capitata was 2.5 tons per hectare or 7.5% of production.Esta pesquisa teve como objetivos: avaliar o efeito do pH inicial, 4.5; 6.5 e 8.5, do atrativo proteico Milhocina® e bórax (tetraborato de sódio) na captura de moscas-das-frutas em armadilhas McPhail; estudar densidades de armadilhas, 1; 2; 4 e 8 por hectare, para estimar níveis de controle em laranja cv. Hamlin, na região central de São Paulo. A espécie predominante, com 99% das moscas-das-frutas capturadas, foi Ceratitis capitata, sendo 80% de fêmeas. As maiores capturas de C. capitata ocorreram nas armadilhas com Milhocina® e bórax em pH 8.5. As capturas, nas 4 densidades, foram semelhantes, indicando que a população pode ser estimada com uma armadilha por hectare em áreas de altas populações. Houve relações positivas entre capturas de C. capitata e o número de frutos danificados, 2 e 3 semanas após a captura. Assim, foram obtidas equações que relacionam a captura e o dano, possibilitando estimar níveis de controle desse inseto. As perdas médias causadas por C. capitata em laranja cv. Hamlin chegaram a 2,5 toneladas de frutos por hectare ou 7,5% da produção.info:eu-repo/semantics/publishedVersio

    Detection of Urinary Tract Pathology in Some Schistosoma haematobium

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    Screening for Schistosoma haematobium infection and its possible morbidity was carried out in 257 adult participants in Eggua community, Ogun State, Nigeria. Parasitological assessment for the presence of ova of S. haematobium in urine and abdominopelvic ultrasonographic examination for bladder and secondary kidney pathology were carried out. S. haematobium prevalence of 25.68% (66/257) was recorded among the participants. There was a significantly higher prevalence of 69.2% of urinary schistosomiasis in the females than the prevalence of 31.8% in males (P=0.902). The intensity of infections was mostly light (55) (21.8%) compared to heavy (10) (3.9%) with the mean intensity of 16.7 eggs/10 mL urine. Structural bladder pathology prevalence among participants was 33.9%. The bladder and kidney pathologies observed by ultrasound in subjects with S. haematobium infections included abnormal bladder wall thickness (59%), abnormal bladder shape (15.2%), bladder wall irregularities (15.2%), bladder masses (1.5%), bladder calcification (1.5%), and hydronephrosis (3%). Infection with S. haematobium was associated with bladder pathology. Higher frequencies of bladder abnormalities were observed more in the participants with light intensity of S. haematobium infection than in those with heavy infection. More bladder pathology was also seen in women than in men, although this was not statistically significant. In conclusion, there is evidence that the development of bladder pathology may be associated with S. haematobium infection

    Abdominal ultrasonography in HIV/AIDS patients in southwestern Nigeria

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    <p>Abstract</p> <p>Background</p> <p>Though the major target of the HIV-virus is the immune system, the frequency of abdominal disorders in HIV/AIDS patients has been reported to be second only to pulmonary disease. These abdominal manifestations may be on the increase as the use of antiretroviral therapy has increased life expectancy and improved quality of life. Ultrasonography is an easy to perform, non invasive, inexpensive and safe imaging technique that is invaluable in Africa where AIDS is most prevalent and where sophisticated diagnostic tools are not readily available. Purpose: To describe the findings and evaluate the clinical utility of abdominal ultrasonography in HIV/AIDS patients in Ibadan, Nigeria</p> <p>Methods</p> <p>A Prospective evaluation of the abdominal ultrasonography of 391 HIV-positive patients as well as 391 age and sex-matched HIV-negative patients were carried out at the University College Hospital, Ibadan.</p> <p>Results</p> <p>Of the 391 cases studied, 260 (66.5%) were females; the mean age was 38.02 years, (range 15–66 years). The disease was most prevalent in the 4th decade with an incidence of 40.4%. Compared with the HIV-negative individuals, the HIV+ group of patients had a significantly higher proportion of splenomegaly (13.5% vs. 7.7%; p < 0.01), lymphadenopathy (2.0% vs. 1.3%; p < 0.70), and renal abnormalities (8.4% vs. 3.8%; p < 0.02). There were no differences in hepatic and pancreatic abnormalities between the HIV+ and HIV- groups. There were significantly fewer gallstones in the HIV+ group (1.4% vs. 5.1%; p < 0.01).</p> <p>Conclusion</p> <p>AIDS is a multi-systemic disease and its demographic and clinical pattern remains the same globally. Ultrasonography is optimally suited for its clinical management especially in Africa. Its accuracy and sensitivity may be much improved with clinico-pathologic correlation which may not be readily available in developing countries; further studies may provide this much needed diagnostic algorithms.</p

    The role of routine post-natal abdominal ultrasound for newborns in a resource-poor setting: a longitudinal study

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    <p>Abstract</p> <p>Background-</p> <p>Neonatal abdominal ultrasound is usually performed in Nigeria to investigate neonatal symptoms rather than as a follow up to evaluate fetal abnormalities which were detected on prenatal ultrasound. The role of routine obstetric ultrasonography in the monitoring of pregnancy and identification of fetal malformations has partly contributed to lowering of fetal mortality rates. In Nigeria which has a high maternal and fetal mortality rate, many pregnant women do not have ante-natal care and not infrequently, women also deliver their babies at home and only bring the newborns to the clinics for immunization. Even when performed, most routine obstetric scans are not targeted towards the detection of fetal abnormalities.</p> <p>The aim of the present study is to evaluate the benefit of routinely performing abdominal scans on newborns with a view to detecting possible abnormalities which may have been missed ante-natally.</p> <p>Methods-</p> <p>This was a longitudinal study of 202 consecutive, apparently normal newborns. Routine clinical examination and abdominal ultrasound scans were performed on the babies by their mother's bedside, before discharge. Neonates with abnormal initial scans had follow-up scans.</p> <p>Results-</p> <p>There were 108 males and 94 females. There were 12 (5.9%) abnormal scans seen in five male and seven female neonates. Eleven of the twelve abnormalities were in the kidneys, six on the left and five on the right. Three of the four major renal anomalies- absent kidney, ectopic/pelvic kidney and two cases of severe hydronephrosis were however on the left side. There was one suprarenal abnormality on the right suspected to be a possible infected adrenal haemorrage. Nine of the abnormal cases reported for follow- up and of these, two cases had persistent severe abnormalities.</p> <p>Conclusions-</p> <p>This study demonstrated a 5.9% incidence of genito urinary anomalies on routine neonatal abdominal ultrasound in this small population. Routine obstetric USS is very useful but inadequate availability of skilled personnel and cost implications create great challenges in poor resource settings like Nigeria. However, awareness should be created so that parents who can afford such investigations can make informed decisions.</p

    Novel functional insights into ischemic stroke biology provided by the first genome-wide association study of stroke in indigenous Africans

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    \ua9 The Author(s) 2024. Background: African ancestry populations have the highest burden of stroke worldwide, yet the genetic basis of stroke in these populations is obscure. The Stroke Investigative Research and Educational Network (SIREN) is a multicenter study involving 16 sites in West Africa. We conducted the first-ever genome-wide association study (GWAS) of stroke in indigenous Africans. Methods: Cases were consecutively recruited consenting adults (aged &gt; 18 years) with neuroimaging-confirmed ischemic stroke. Stroke-free controls were ascertained using a locally validated Questionnaire for Verifying Stroke-Free Status. DNA genotyping with the H3Africa array was performed, and following initial quality control, GWAS datasets were imputed into the NIH Trans-Omics for Precision Medicine (TOPMed) release2 from BioData Catalyst. Furthermore, we performed fine-mapping, trans-ethnic meta-analysis, and in silico functional characterization to identify likely causal variants with a functional interpretation. Results: We observed genome-wide significant (P-value &lt; 5.0E−8) SNPs associations near AADACL2 and miRNA (MIR5186) genes in chromosome 3 after adjusting for hypertension, diabetes, dyslipidemia, and cardiac status in the base model as covariates. SNPs near the miRNA (MIR4458) gene in chromosome 5 were also associated with stroke (P-value &lt; 1.0E−6). The putative genes near AADACL2, MIR5186, and MIR4458 genes were protective and novel. SNPs associations with stroke in chromosome 2 were more than 77 kb from the closest gene LINC01854 and SNPs in chromosome 7 were more than 116 kb to the closest gene LINC01446 (P-value &lt; 1.0E−6). In addition, we observed SNPs in genes STXBP5-AS1 (chromosome 6), GALTN9 (chromosome 12), FANCA (chromosome 16), and DLGAP1 (chromosome 18) (P-value &lt; 1.0E−6). Both genomic regions near genes AADACL2 and MIR4458 remained significant following fine mapping. Conclusions: Our findings identify potential roles of regulatory miRNA, intergenic non-coding DNA, and intronic non-coding RNA in the biology of ischemic stroke. These findings reveal new molecular targets that promise to help close the current gaps in accurate African ancestry-based genetic stroke’s risk prediction and development of new targeted interventions to prevent or treat stroke

    Stroke genetics informs drug discovery and risk prediction across ancestries

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    Previous genome-wide association studies (GWASs) of stroke — the second leading cause of death worldwide — were conducted predominantly in populations of European ancestry1,2. Here, in cross-ancestry GWAS meta-analyses of 110,182 patients who have had a stroke (five ancestries, 33% non-European) and 1,503,898 control individuals, we identify association signals for stroke and its subtypes at 89 (61 new) independent loci: 60 in primary inverse-variance-weighted analyses and 29 in secondary meta-regression and multitrait analyses. On the basis of internal cross-ancestry validation and an independent follow-up in 89,084 additional cases of stroke (30% non-European) and 1,013,843 control individuals, 87% of the primary stroke risk loci and 60% of the secondary stroke risk loci were replicated (P < 0.05). Effect sizes were highly correlated across ancestries. Cross-ancestry fine-mapping, in silico mutagenesis analysis3, and transcriptome-wide and proteome-wide association analyses revealed putative causal genes (such as SH3PXD2A and FURIN) and variants (such as at GRK5 and NOS3). Using a three-pronged approach4, we provide genetic evidence for putative drug effects, highlighting F11, KLKB1, PROC, GP1BA, LAMC2 and VCAM1 as possible targets, with drugs already under investigation for stroke for F11 and PROC. A polygenic score integrating cross-ancestry and ancestry-specific stroke GWASs with vascular-risk factor GWASs (integrative polygenic scores) strongly predicted ischaemic stroke in populations of European, East Asian and African ancestry5. Stroke genetic risk scores were predictive of ischaemic stroke independent of clinical risk factors in 52,600 clinical-trial participants with cardiometabolic disease. Our results provide insights to inform biology, reveal potential drug targets and derive genetic risk prediction tools across ancestries
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