The Effect of Bariatric Surgery on Adipose Tissue Energy Metabolism in Type 2 Diabetes

Obesity-related metabolic disturbances typically occur when the available energy exceeds the storage capacity of white adipose tissue (WAT), which can lead to ectopic lipid deposition, insulin resistance and type 2 diabetes. The re-discovery of the existence of energy consuming brown adipose tissue (BAT) in adult humans has ignited interest in finding novel approaches for BAT activation to be used for the treatment of obesity and diabetes. Currently, bariatric surgery procedures provide marked and sustained weight loss, and remission of diabetes in some severely obese patients. Energy metabolism in adipose tissue in the presence of obesity and diabetes, and the changes that occur after weight loss induced by surgery are largely understudied. The present work hypothesized that the WAT and BAT energy metab-olism are different between obese and non-obese subjects, and also between obese with and without diabetes subgroups. Bariatric surgery improves adipose energy metabolism in severely obese patients independent of diabetes status. Here, severely obese patients, with a mean BMI of 40 kg/m², roughly half with diabetes, and age-matched lean metabolically healthy controls, were studied with PET-CT and MRI to measure adipose tissue energy (glucose and fatty acid) metabolism, and blood flow distribution. The regional distribution of WAT; and the browning of supraclavicular BAT were also studied. White adipocyte size and numbers in biopsies were measured. Obese patients were studied before and at 6 months after surgery, and normal weight healthy controls studied once. When the obese patients were treated as a combined group, their blood flow distribution, glucose and fatty acid metabolism rates in WAT were significantly impaired compared to nonobese healthy control subjects. Blood flow, fatty acid or glucose uptake rates when expressed per expanded depot mass were higher in the obese group compared to controls. Fatty acid uptake per adipocyte was higher only for diabetic patients of the obese group compared to the controls. Excessive accumulation of WAT was a limiting factor with regards BAT fatty acid metabolism, or then the browning of adipose tissue in the supraclavicular depot. After surgery, adipose glucose uptake rates increased independent of diabetes status. Fatty acid and blood flow rates decreased significantly when expressed per depot size, and per adipocyte. However, the postsurgery depot glucose uptake rates were similar to values in the presurgery state. BAT lipid metabolism increased significantly with weight loss, and values were associated with decreased adiposity along with improved whole body insulin sensitivity. The current study highlights the negative impact of severe obesity and diabetes on adipose tissue energy metabolism, which appears to be partly due to expanded fat mass mediated by adipocyte hypertrophy or hyperplasia. Weight reduction with bariatric surgery improves adipose energy metabolism, and conse-quently the overall metabolic health in obese individuals regardless of the presence of diabetes

Application of Principal Components Analysis on Venture Capital Investment Decision Process in Ghana

In response to the numerous complaints by the business community of inadequate and high cost of capital to runtheir businesses, the Government of Ghana, in 2004 established the Venture Capital Trust Fund with a vision toprovide low cost financing to businesses to enable them grow, create jobs and improve wealth creation towardspoverty alleviation. The Trust Fund operates through institutional partnerships by means of joint venturearrangements that establish Venture Capital Financing Companies managed by Fund Managers, who areresponsible for deal sourcing, selection, monitoring and exit of Fund investments. Small and Medium-ScaleEnterprises seeking for funding submit a Business Proposal, among other documents, to the Venture CapitalFinancing Companies. The Business Proposal goes through an initial review, and if found to be viable a secondround review is initiated. When all claims are verified and authenticated, due diligence follows. Considering theamount of time that due diligence and negotiation of terms may take, it is imperative that the FinancingCompanies minimize their efforts during screening so that only those ventures with the most potential proceed tothe next stage. Yet, at the same time, the screening process should also be careful not to eliminate potentiallyviable Proposals prematurely. To achieve this, the use of statistical models will aid in the screening process. Inthis study, Principal Components Analysis have been applied to the several variables considered at the initialreview stage. The implication of this study is that properly developed statistical models may be successfulscreening decision aides.Keywords: Venture Capital, Small and Medium-Scale Enterprise, Business Proposals, Principal Component

Improving Admissions into Technical and Vocational Institutions Through a Statistical Classification Technique

Polytechnic education at the Tertiary level is part of the the crowning achievement or the capstone of the traditional educational structure. It is the hub of human development worldwide. Therefore the system of admissions into these institutions anywhere is an area of research interest.  Many factors are considered before students are admitted into programmes at the tertiary level of education and this differs from country to country. However, a growing conflict is the entry requirements into the traditional universities on one hand and the polytechnic and the vocational institutions on the other hand. According to Stubbs (Stubbs, 1998), at least half of the differences in students’ academic performance could be attributed to the students’ social background and prior attainment rather than the school they attended. Using Ghana’s example as a case study, the multivariate classification tool of linear Discriminant Analysis was conducted on students’ academic performance with entry grades as the predictors and the classes they obtain at the end of their study at the Polytechnic level as the response variable.  Exploratory data analytical tools of normality, multicolinearity, homocedasticity amongst others were employed on the data. Further analysis on the transformed data using linear discriminant analysis revealed that the elective subjects as predictors have far stronger discriminating powers than the core subjects. This suggests that the current entry requirement policy into the polytechnics that focuses on the core subjects must be looked at again. The current entry regime which is more like that of the universities tends to turn away many otherwise very good technical and vocational education materials because of fails in one or two core courses. Keywords: Discriminant Analysis, Multicollinearity, Homocedasticity, Centroids, Eigen value, Normalit

The utilization of positron emission tomography in the evaluation of renal health and disease

Purpose: Positron emission tomography (PET) is a nuclear imaging technique that uses radiotracers to visualize metabolic processes of interest across different organs, to diagnose and manage diseases, and monitor therapeutic response. This systematic review aimed to characterize the value of PET for the assessment of renal metabolism and function in subjects with non-oncological metabolic disorders. Methods: This review was conducted and reported in accordance with the PRISMA statement. Research articles reporting “kidney” or “renal” metabolism evaluated with PET imaging between 1980 and 2021 were systematically searched in Medline/PubMed, Science Direct, and the Cochrane Library. Search results were exported and stored in RefWorks, the duplicates were removed, and eligible studies were identified, evaluated, and summarized. Results: Thirty reports met the inclusion criteria. The majority of the studies were prospective (73.33%, n = 22) in nature. The most utilized PET radiotracers were 15O-labeled radio water (H215O, n = 14) and 18F-fluorodeoxyglucose (18F-FDG, n = 8). Other radiotracers used in at least one study were 14(R,S)-(18)F-fluoro-6-thia-heptadecanoic acid (18F-FTHA), 18F-Sodium Fluoride (18F-NaF), 11C-acetate, 68-Gallium (68Ga), 13N-ammonia (13N-NH3), Rubidium-82 (82Rb), radiolabeled cationic ferritin (RadioCF), 11C‐para-aminobenzoic acid (11C-PABA), Gallium-68 pentixafor (68Ga-Pentixafor), 2-deoxy-2-F-fluoro-d-sorbitol (F-FDS) and 55Co-ethylene diamine tetra acetic acid (55Co-EDTA). Conclusion: PET imaging provides an effective modality for evaluating a range of metabolic functions including glucose and fatty acid uptake, oxygen consumption and renal perfusion. Multiple positron emitting radiolabeled racers can be used for renal imaging in clinical settings. PET imaging thus holds the potential to improve the diagnosis of renal disorders, and to monitor disease progression and treatment response

Underlying Kidney Diseases and Complications for COVID-19: A Review

There is mounting evidence supporting that patients with kidney diseases are particularly vulnerable to coronavirus disease-2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). The review was conducted to examine the risk and complications of COVID-19 among patients with confirmed cases of underlying kidney disease. A search of Google Scholar, PubMed and Science direct databases to August 2020 was conducted using search terms pertaining to kidney diseases, renal insufficiency, kidney injury, angiotensin receptors, hemodialysis, and kidney transplant. We briefly reviewed COVID-19 in the context of kidney diseases. A significant proportion of hospitalized patients for COVID-19 have acute kidney injury, which further deteriorates their prognosis. COVID-19 increases morbidity and mortality among people already diagnosed with kidney disorders and obesity due to multiple organ injury caused by the SARS-CoV-2. This review supports the need for clinicians to carefully manage and monitor all patients with renal disorders in order to minimize acute kidney injuries. Although some therapeutic drugs have been suggested by some studies, treatment should be administered cautiously not to worsen the condition of the kidney. Further studies are required to highlight the efficient management of patients with underlying kidney diseases, who are infected with SARS-CoV-2. With proactive systematic screening and triaging, close monitoring and prompt management of coexisting other infections, the COVID-19 disease burden among these patients could be reduced

The Beneficial Effects of Bariatric-Surgery-Induced Weight Loss on Renal Function

Obesity represents an independent risk factor for the development of chronic kidney disease (CKD), leading to specific histopathological alterations, known as obesity-related glomerulopathy. Bariatric surgery is the most effective means of inducing and maintaining sustained weight loss. Furthermore, in the context of bariatric-surgery-induced weight loss, a reduction in the proinflammatory state and an improvement in the adipokine profile occur, which may also contribute to the improvement of renal function following bariatric surgery. However, the assessment of renal function in the context of obesity and following marked weight loss is difficult, since the formulas adopted to estimate glomerular function use biomarkers whose production is dependent on muscle mass (creatinine) or adipose tissue mass and inflammation (cystatin-c). Thus, following bariatric surgery, the extent to which reductions in plasma concentrations reflect the actual improvement in renal function is not clear. Despite this limitation, the available literature suggests that in patients with hyperfiltration at baseline, GFR is reduced following bariatric surgery, whereas GFR is increased in patients with decreased GFR at baseline. These findings are also confirmed in the few studies that have used measured rather than estimated GFR. Albuminuria is also decreased following bariatric surgery. Moreover, bariatric surgery seems superior in achieving the remission of albuminuria and early CKD than the best medical treatment. In this article, we discuss the pathophysiology of renal complications in obesity, review the mechanisms through which weight loss induces improvements in renal function, and provide an overview of the renal outcomes following bariatric surgery

The utilization of positron emission tomography in the evaluation of renal health and disease

PurposePositron emission tomography (PET) is a nuclear imaging technique that uses radiotracers to visualize metabolic processes of interest across different organs, to diagnose and manage diseases, and monitor therapeutic response. This systematic review aimed to characterize the value of PET for the assessment of renal metabolism and function in subjects with non-oncological metabolic disorders.MethodsThis review was conducted and reported in accordance with the PRISMA statement. Research articles reporting “kidney” or “renal” metabolism evaluated with PET imaging between 1980 and 2021 were systematically searched in Medline/PubMed, Science Direct, and the Cochrane Library. Search results were exported and stored in RefWorks, the duplicates were removed, and eligible studies were identified, evaluated, and summarized.ResultsThirty reports met the inclusion criteria. The majority of the studies were prospective (73.33%, n = 22) in nature. The most utilized PET radiotracers were 15O-labeled radio water (H215O, n = 14) and 18F-fluorodeoxyglucose (18F-FDG, n = 8). Other radiotracers used in at least one study were 14(R,S)-(18)F-fluoro-6-thia-heptadecanoic acid (18F-FTHA), 18F-Sodium Fluoride (18F-NaF), 11C-acetate, 68-Gallium (68Ga), 13N-ammonia (13N-NH3), Rubidium-82 (82Rb), radiolabeled cationic ferritin (RadioCF), 11C‐para-aminobenzoic acid (11C-PABA), Gallium-68 pentixafor (68Ga-Pentixafor), 2-deoxy-2-F-fluoro-D-sorbitol (F-FDS) and 55Co-ethylene diamine tetra acetic acid (55Co-EDTA).ConclusionPET imaging provides an effective modality for evaluating a range of metabolic functions including glucose and fatty acid uptake, oxygen consumption and renal perfusion. Multiple positron emitting radiolabeled racers can be used for renal imaging in clinical settings. PET imaging thus holds the potential to improve the diagnosis of renal disorders, and to monitor disease progression and treatment response.</p

Renal Sinus Fat Is Expanded in Patients with Obesity and/or Hypertension and Reduced by Bariatric Surgery Associated with Hypertension Remission

Renal sinus fat is a fat depot at the renal hilum. Because of its location around the renal artery, vein, and lymphatic vessels, an expanded renal sinus fat mass may have hemodynamic and renal implications. We studied whether renal sinus fat area (RSF) associates with hypertension and whether following bariatric surgery a decrease in RSF associates with improvement of hypertension. A total of 74 severely obese and 46 lean controls were studied with whole-body magnetic resonance imaging (MRI). A total of 42 obese subjects were re-studied six months after bariatric surgery. RSF was assessed by two independent researchers using sliceOmatic. Glomerular filtration rate (eGFR) was estimated according to the CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration). Patients with obesity accumulated more RSF compared to lean controls (2.3 [1.7-3.1] vs. 1.8 [1.4-2.5] cm(2), p = 0.03). Patients with hypertension (N = 36) had a larger RSF depot compared to normotensive subjects (2.6 [2.0-3.3] vs. 2.0 [1.4-2.5] cm(2), p = 0.0007) also after accounting for body mass index (BMI). In the pooled data, RSF was negatively associated with eGFR (r = -0.20, p = 0.03), whereas there was no association with systolic or diastolic blood pressure. Following bariatric surgery, RSF was reduced (1.6 [1.3-2.3] vs. 2.3 [1.7-3.1] cm(2), p = 0.03) along with other markers of adiposity. A total of 9/27 of patients achieved remission from hypertension. The remission was associated with a larger decrease in RSF, compared to patients who remained hypertensive (-0.68 [ -0.74 to -0.44] vs. -0.28 [ -0.59 to 0] cm(2), p = 0.009). The accumulation of RSF seems to be involved in the pathogenesis of hypertension in obesity. Following bariatric surgery, loss of RSF was associated with remission from hypertension