Antimicrobial activity of the ethanol extract and fractions of the seeds of Garcinia kola Heckel (Guttiferae)

The crude ethanol extract, aqueous and chloroform fractions of the seeds of Garcinia kola Heckel (Guttiferae) was investigated for antimicrobial activity. Agar well diffusion and minimum inhibitoryconcentration determinations were the methods employed for the study. Clinical bacterial and fungal isolates were used as indicator organisms while standard antimicrobial agents were included in thestudy. The crude ethanol extract showed significant inhibitory activity against clinical isolates of both Gram positive and Gram negative organisms. It was active against Staphylococcus aureus, Bacillussubtilis, Streptococcus viridans, Escherichia coli, Pseudomonas aeroginosa and Klebsiella pneumonia. It also showed significant inhibitory activity against fungi like Penicillium notatum, Aspergillus niger and Candida albicans. Both the aqueous and chloroform fractions showed activity against the clinical isolates of S. aureus, E. coli and P. aeruginosa. The MIC values obtained ranged between 2.5 and 7.5mg/ml for bacteria and fungi isolates. The results showed that the crude ethanol extract has broad spectrum of activity, while the fractions exhibited narrow spectrum of activity, since they were activeagainst S. aureus, E. coli, and P. aeruginosa only. These observations could be the basis for the usefulness of the seeds of G. kola in the treatment remedies for microbial infections

Validation of the physiological background correction method for the suppression of the spill-in effect near highly radioactive regions in positron emission tomography

BACKGROUND: Positron emission tomography (PET) imaging has a wide applicability in oncology, cardiology and neurology. However, a major drawback when imaging very active regions such as the bladder is the spill-in effect, leading to inaccurate quantification and obscured visualisation of nearby lesions. Therefore, this study aims at investigating and correcting for the spill-in effect from high-activity regions to the surroundings as a function of activity in the hot region, lesion size and location, system resolution and application of post-filtering using a recently proposed background correction technique. This study involves analytical simulations for the digital XCAT2 phantom and validation acquiring NEMA phantom and patient data with the GE Signa PET/MR scanner. Reconstructions were done using the ordered subset expectation maximisation (OSEM) algorithm. Dedicated point-spread function (OSEM+PSF) and a recently proposed background correction (OSEM+PSF+BC) were incorporated into the reconstruction for spill-in correction. The standardised uptake values (SUV) were compared for all reconstruction algorithms. RESULTS: The simulation study revealed that lesions within 15-20 mm from the hot region were predominantly affected by the spill-in effect, leading to an increased bias and impaired lesion visualisation within the region. For OSEM, lesion SUVmax converged to the true value at low bladder activity, but as activity increased, there was an overestimation as much as 19% for proximal lesions (distance around 15-20 mm from the bladder edge) and 2-4% for distant lesions (distance larger than 20 mm from the bladder edge). As bladder SUV increases, the % SUV change for proximal lesions is about 31% and 6% for SUVmax and SUVmean, respectively, showing that the spill-in effect is more evident for the SUVmax than the SUVmean. Also, the application of post-filtering resulted in up to 65% increment in the spill-in effect around the bladder edges. For proximal lesions, PSF has no major improvement over OSEM because of the spill-in effect, coupled with the blurring effect by post-filtering. Within two voxels around the bladder, the spill-in effect in OSEM is 42% (32%), while for OSEM+PSF, it is 31% (19%), with (and without) post-filtering, respectively. But with OSEM+PSF+BC, the spill-in contribution from the bladder was relatively low (below 5%, either with or without post-filtering). These results were further validated using the NEMA phantom and patient data for which OSEM+PSF+BC showed about 70-80% spill-in reduction around the bladder edges and increased contrast-to-noise ratio up to 36% compared to OSEM and OSEM+PSF reconstructions without post-filtering. CONCLUSION: The spill-in effect is dependent on the activity in the hot region, lesion size and location, as well as post-filtering; and this is more evident in SUVmax than SUVmean. However, the recently proposed background correction method facilitates stability in quantification and enhances the contrast in lesions with low uptake

Improved identification of abdominal aortic aneurysm using the Kernelized Expectation Maximization algorithm

Abdominal aortic aneurysm (AAA) monitoring and risk of rupture is currently assumed to be correlated with the aneurysm diameter. Aneurysm growth, however, has been demonstrated to be unpredictable. Using PET to measure uptake of [18F]-NaF in calcified lesions of the abdominal aorta has been shown to be useful for identifying AAA and to predict its growth. The PET low spatial resolution, however, can affect the accuracy of the diagnosis. Advanced edge-preserving reconstruction algorithms can overcome this issue. The kernel method has been demonstrated to provide noise suppression while retaining emission and edge information. Nevertheless, these findings were obtained using simulations, phantoms and a limited amount of patient data. In this study, the authors aim to investigate the usefulness of the anatomically guided kernelized expectation maximization (KEM) and the hybrid KEM (HKEM) methods and to judge the statistical significance of the related improvements. Sixty-one datasets of patients with AAA and 11 from control patients were reconstructed with ordered subsets expectation maximization (OSEM), HKEM and KEM and the analysis was carried out using the target-to-blood-pool ratio, and a series of statistical tests. The results show that all algorithms have similar diagnostic power, but HKEM and KEM can significantly recover uptake of lesions and improve the accuracy of the diagnosis by up to 22% compared to OSEM. The same improvements are likely to be obtained in clinical applications based on the quantification of small lesions, like for example cancer

Comparison of Correction Techniques for the Spill in Effect in Emission Tomography

In positron emission tomography (PET) imaging, accurate clinical assessment is often affected by the partial volume effect (PVE) leading to overestimation (spill-in) or underestimation (spill-out) of activity in various small regions. The spill-in correction, in particular, can be very challenging when the target region is close to a hot background region. Therefore, this study evaluates and compares the performance of various recently developed spill-in correction techniques, namely: background correction (BC), local projection (LP), and hybrid kernelized (HKEM) methods. We used a simulated digital phantom and 18F-NaF PET data of three patients with abdominal aortic aneurysms (AAA) acquired with Siemens Biograph mMRTM and mCTTM scanners respectively. Region of Interest (ROI) analysis was performed and the extracted SUVmean, SUVmax and target-to-background ratio (TBR) scores were compared. Results showed substantial spill-in effects from hot regions to targeted regions, which are more prominent in small structures. The phantom experiment demonstrated the feasibility of spill-in correction with all methods. For the patient data, large differences in SUVmean, SUVmax and TBRmax scores were observed between the ROIs drawn over the entire aneurysm and ROIs excluding some regions close to the bone. Overall, BC yielded the best performance in spill-in correction in both phantom and patient studies

Assessment of different quantification metrics of [¹⁸F]-NaF PET/CT images of patients with abdominal aortic aneurysm

Background: We aim to assess the spill-in effect and the benefit in quantitative accuracy for [18F]-NaF PET/CT imaging of abdominal aortic aneurysms (AAA) using the background correction (BC) technique. Methods: Seventy-two datasets of patients diagnosed with AAA were reconstructed with ordered subset expectation maximization algorithm incorporating point spread function (PSF). Spill-in effect was investigated for the entire aneurysm (AAA), and part of the aneurysm excluding the region close to the bone (AAAexc). Quantifications of PSF and PSF+BC images using different thresholds (% of max. SUV in target regions-of-interest) to derive target-to-background (TBR) values (TBRmax, TBR90, TBR70 and TBR50) were compared at 3 and 10 iterations. Results: TBR differences were observed between AAA and AAAexc due to spill-in effect from the bone into the aneurysm. TBRmax showed the highest sensitivity to the spill-in effect while TBR50 showed the least. The spill-in effect was reduced at 10 iterations compared to 3 iterations, but at the expense of reduced contrast-to-noise ratio (CNR). TBR50 yielded the best trade-off between increased CNR and reduced spill-in effect. PSF+BC method reduced TBR sensitivity to spill-in effect, especially at 3 iterations, compared to PSF (P-value ≤ 0.05). Conclusion: TBR50 is robust metric for reduced spill-in and increased CNR

Iterative reconstruction incorporating background correction improves quantification of [18F]-NaF PET/CT images of patients with abdominal aortic aneurysm

Background A confounding issue in [18F]-NaF PET/CT imaging of abdominal aortic aneurysms (AAA) is the spill in contamination from the bone into the aneurysm. This study investigates and corrects for this spill in contamination using the background correction (BC) technique without the need to manually exclude the part of the AAA region close to the bone. Methods Seventy-two (72) datasets of patients with AAA were reconstructed with the standard ordered subset expectation maximization (OSEM) algorithm incorporating point spread function (PSF) modelling. The spill in effect in the aneurysm was investigated using two target regions of interest (ROIs): one covering the entire aneurysm (AAA), and the other covering the aneurysm but excluding the part close to the bone (AAAexc). ROI analysis was performed by comparing the maximum SUV in the target ROI (SUVmax(T)), the corrected cSUVmax (SUVmax(T) − SUVmean(B)) and the target-to-blood ratio (TBR = SUVmax(T)/SUVmean(B)) with respect to the mean SUV in the right atrium region. Results There is a statistically significant higher [18F]-NaF uptake in the aneurysm than normal aorta and this is not correlated with the aneurysm size. There is also a significant difference in aneurysm uptake for OSEM and OSEM + PSF (but not OSEM + PSF + BC) when quantifying with AAA and AAAexc due to the spill in from the bone. This spill in effect depends on proximity of the aneurysms to the bone as close aneurysms suffer more from spill in than farther ones. Conclusion The background correction (OSEM + PSF + BC) technique provided more robust AAA quantitative assessments regardless of the AAA ROI delineation method, and thus it can be considered as an effective spill in correction method for [18F]-NaF AAA studies

Health Status and Measurement of Some Haematological Parameters of New Secondary School Students in Benin City, Nigeria

Background: A good school health programme is necessary to optimize the educational opportunities and make appropriate adjustments for optimal development of the school child. This study was done to determine some haematological parameters as a correlate of health status of new entrants in two mission owned secondary schools in Benin City.Methodology: This is a cross-sectional study carried out among 150 students of two mission-owned secondary school in Benin City in which the packed cell volume, Rhesus factor, the Hemoglobin, genotype and blood group were analyzed.Results: Of the 150 students studied, 75.3% were males while 24.7% were females. The mean ages of the students were 10.5%EF%BF%BD 1.0yrs. Eighty-nine per cent of the students had a packed cell volume of between 33% and 42%. Ninety seven percent (96.7%) were rhesus D positive, 77.3% were of genotype AA, while 56.7% of them were of blood group O.Conclusion: Majority of the students were of good health status and had haematological profile similar to report of studies conducted elsewhere in Nigeria

Improved correction techniques to compensate for partial volume and spill-in effects in PET

A major barrier to accurate tumour quantification and detectability in positron emission tomography (PET) is partial volume effect (PVE). PVE could either be spill-in effect or spill-out effect, leading to overestimation and underestimation (or loss) of tumour activity respectively. Many correction techniques are being employed to restore the real tumour activity in a process known as resolution recovery. However, past studies have shown that most of these correction techniques only correct for one of these two effects, leaving the other uncorrected for. Therefore, this study is aimed at developing and evaluating new correction techniques which are capable of compensating for both effects. Digital XCAT2 phantom with an [ 18 F]-Fluorodeoxyglucose (FDG) distribution was used to simulate the pelvic bed, consisting of a hot bladder, and surrounded by 6 lesions (L1-L6) with diameters ranging from 6 - 20 mm, placed at different distances from the bladder. Analytical simulation and reconstruction was done with Software for Tomographic Image Reconstruction (STIR) using simulated Siemens mMR scanner template. The reconstructed images were corrected for partial volume effect by using 2 existing techniques: Point spread function (PSF) reconstruction and background correction (BC) method; as well as 2 newly-developed techniques: hybrid kernelized method (HK) and improved local projection (iLP) method. To estimate the quantification and noise properties of these correction techniques, we carried out region of Interest (ROI) analysis using recovery coefficient (RC) and contrast-to-noise ratio (CNR). The result shows that OSEM and PSF could not correct for the spill-in effect from the bladder as lesions close to the bladder have an overestimated SUV max of up 40%. The spill of activity from the bladder to the surroundings causes the background uptake to increase, thereby lowering the CNR of both OSEM and PSF. iLP and HK have steady RC for all lesions with an increased CNR. PSF is a robust correction method for lesions bigger than 8 mm and those farther away from the bladder. Hence, combining the new correction methods with PSF might give a more robust result. However, there is need to further validate these techniques with acquired phantom and patient datasets

A comparative analysis of medicinal and aromatic plants used in the traditional medicine of Iğdir (Turkey), Nakhchivan (Azerbaijan), and Tabriz (Iran)

A total of 341 naturally distributed taxa belonging to 65 families are used in the traditional medicine in Iğdır (Turkey), Nakhchivan (Azerbaijan), and Tabriz (Iran). Local people in three different regions generally use herbal remedies for digestive, respiratory, urogenital systems, as well as dermal, neurological and psyschological diseases. On the basis of localities three highly prevelant usesin Iğdır are colds (32 taxa), stomach disorders (28 taxa), and cough (24 taxa); in Nakhchivan rheumatism (24 taxa), gastrointestinal disorders (24 taxa), and anthelmintic (20 taxa), and in Tabriz diuretic (24 taxa), fever (22 taxa), and cough (20 taxa). Our findings reveal that in these three areas belonging to three neighbouring countries 4 taxa are widely distributed and used almost forthe same applications; Glycyrrhiza glabra (for digestive and respiratory systems), Malus sylvestris ssp. orientalis (for respiratory system), Rosa canina (for digestive and urinogenital systems), and Urtica dioica (for digestive system). The studied areas show several resemblances from cultural and other aspects. © 2018, Pakistan Botanical Society. All Rights Reserved