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Heart failure
Published in Henry J. Woodford, Essential Geriatrics, 2022
SGLT2 inhibitors include dapagliflozin and empagliflozin. They were initially developed as drugs for type 2 diabetes (see page 439) but have since been found to have a role in the management of HFrEF. One of their actions is a diuretic effect through inhibiting sodium reabsorption in the proximal convoluted tubule.9
Pathophysiologic Mechanisms of Acute Renal Failure
Published in Robin S. Goldstein, Mechanisms of Injury in Renal Disease and Toxicity, 2020
Other features of impaired renal function, such as impaired reabsorption of sodium chloride or water and impaired secretion of hydrogen ions, for example, are best ascribed to direct injury of the cells responsible for those transport activities.18 In this regard, Hanley19 studied ion and water transport by isolated tubule segments from rabbits subjected to 60 min of renal ischemia. Proximal convoluted tubule segments showed a reduction in fluid reabsorption of 77%, and proximal straight tubular segments showed a reduction in fluid reabsorption of 88%.19 The proximal nephron segments showed morphologic changes consistent with ischemic injury, although the distal segments did not. Nevertheless, the thick ascending limb of Henle’s loop also had an impaired ability to lower perfusate chloride after ischemia by 60%. Diluting ability by this segment was reduced by 49%. In addition, the cortical collecting tubule showed a 59% reduction in antidiuretic hormone-dependent osmotic water permeability.19 Thus, ischemia induced marked changes in ion and water transport in tubular segments which showed morphologic changes in the brush border membrane as well as in segments that had no gross histologic changes.
Urolithiasis
Published in Manit Arya, Taimur T. Shah, Jas S. Kalsi, Herman S. Fernando, Iqbal S. Shergill, Asif Muneer, Hashim U. Ahmed, MCQs for the FRCS(Urol) and Postgraduate Urology Examinations, 2020
Thomas Johnston, James Armitage, Oliver Wiseman
Cystinuria like most inborn errors of metabolism is inherited in an autosomal recessive pattern with the gene defect located on Chromosome 2. It has been classified into three types (I, II and III) according to the specific gene mutation although this differentiation is of little clinical relevance. The incidence of heterozygous cystinuria is about 1 in 20,000 and these individuals are at high risk of recurrent cystine urolithiasis. Patients with cystinuria have defective absorption in the jejunum of cystine, and the other dibasic amino acids ornithine, lysine and arginine. The reabsorption of these amino acids in the proximal convoluted tubule of the kidney is also abnormal leading to high levels in the urine. Cystine, in contrast to ornithine, lysine and arginine, is relatively insoluble at physiological urine pH and has a pKa of 8.3. At pH < 7.0 the solubility of cystine is approximately 250 mg/L but at pH > 7.5 its solubility increases considerably to more than 500 mg/L [12]. Patients with heterozygous cystinuria excrete <200 mg/day and usually do not form stones whereas cystine excretion in homozygous cystinurics is typically 600–1400 mg/day.
Resveratrol: a panacea compound for diazinon-induced renal toxicity
Published in Toxin Reviews, 2023
Maryam Esfahani, Amir Hossein Rahbar, Sara Soleimani Asl, Fereshteh Mehri
Histopathological assessments of the H&E stained of the kidney tissue are shown in Figure 1(A–E). In the present study, the structure of the kidney and Bowman’s capsule was normal in the control group. The urinary space was not dilated, and the distal convoluted tubule and the proximal convoluted tubule were intact (Figure 1(A)). DZN rats had renal damage compared with control rats. The urinary space, the distal convoluted tubule, and the proximal convoluted tubule were dilated. Vascular congestion and cell infiltration were evident and the epithelial cohesion of the Bowman’s capsule was lost (Figure 1(B)). Based on the findings, the severity of lesions reduced in the DZN + different doses of Res groups. The Bowman’s capsule epithelium was more cohesive, and the dilatation of the urinary space and distal convoluted tubule represented a reduction. These changes were observed in parallel with the increasing dose of Res (Figure 1(C–E)). Accordingly, the TI index in the control group was zero and was not observed geological cases. Due to the presence of atrophy and vacuolation of the epithelium as well as cell infiltration and calcium crystals, the damage was in the severe in diazinon group. Injury rate decreased in the resveratrol groups, so that it was moderate in the low and medium dose groups and mild in the high dose group. Evaluation in regarding the extent of kidney tissue damage was used using studies conducted by Toblli et al. (1999).
Treatment with human umbilical cord blood serum in a gentamicin-induced nephrotoxicity model in rats
Published in Drug and Chemical Toxicology, 2022
Naser Mirazi, Fatemeh Baharvand, Reza Moghadasali, Alireza Nourian, Abdolkarim Hosseini
Prior to the implementation of eosin and hematoxylin staining, from the kidney tissues, 5 µ-size sections were deparaffinized and rehydrated. The reagents and stains were bought from Sigma (St. Louis, MO, USA). An Olympus BX-50 microscope, with the integration of a color digital camera (Olympus, Japan, DP-72), was utilized for observing the histological sections. Protective effects of hUCBS on kidney were quantitatively assessed by measuring the glomerular surface area (GA), glomerular volume (GV) and number of proximal tubular cell nuclei (PTN). For each group, 20 superficial cortical glomeruli were selected according to the following criteria: 1) presence of afferent or efferent arterioles at the glomerular vascular pole; 2) presence of the beginning of proximal convoluted tubule at the glomerular urinary pole. GA was measured by outlining a perimeter along the glomerular periphery (Gilbert et al.1991) using image analysis software (Image J v1.53). Assuming glomeruli as spheres, we calculated GV using the following formula: GV = 1.2545 × GA (Rangan and Tesch 2007). PTN was counted in 10 proximal convoluted tubular sections close to the renal corpuscles on which the glomerular measurements were performed. The numbers of epithelial cells were calculated as number of nuclei per 100 µm of perimeter of proximal convoluted tubules using Olympus DP2-BSW application software (v2.2). The images were all taken with a magnification of ×400 from H&E-stained renal tissue sections.
Grape seed extract protects against amiodarone - induced nephrotoxicity and ultrastructural alterations associated with the inhibition of biomarkers of inflammation and oxidative stress in rats
Published in Ultrastructural Pathology, 2021
Refaat A. Eid, Mohamed Samir Ahmed Zaki, Mubarak Al-Shraim, Muhammad Alaa Eldeen, Mohamed A. Haidara
Examinations of the renal samples of the control and GSE-treated rat groups showed a glomerulus with its capillary basement membranes, endothelium mesangial and podocytes with foot processes (Figures 3a&4a). Higher magnification of the glomerulus displayed the three layers of the glomerular basement membrane, an inner layer (the lamina rarainterna), an outer layer (the lamina raraexterna), and a dense central layer (the lamina dinsa) with thin diaphragms (Figure 2b & 3b). A cross-section of a proximal convoluted tubule illustrated epithelial cells lining the tubule resting on the basement membrane and brush border in the tubular lumen. itochondria, nucleus and infolding membranes were also seen (Figure 3c & 4c). A cross-section of a distal convoluted tubule showed epithelial cells with short microvilli resting on lumina membrane . Note mitochondria, nucleus, infolding membranes were also seen (Figure 2d & 3d).