Cortical and papillary absorptive defects in gentamicin nephrotoxicity

Cortical and papillary absorptive defects in gentamicin nephrotoxicity. Renal function was examined in rats given daily injections of gentamicin (100 to 150 mg/kg) for 10 to 14 days. Whole kidney inulin clearance fell and urine volume increased. Single nephron GFR of surface nephrons varied. Some nephrons had no filtration, some had low rates, and some had high rates. Abnormal renal tubular epithelial inulin permeability was demonstrated by microinjection. Micropuncture of individual nephrons early and later in their course demonstrated reduced fluid reabsorption along the proximal convoluted tubule of superficial nephrons. Rates of fluid delivery to the late proximal and distal tubule were elevated. The rate of fluid reabsorption in the superficial loop of Henle was increased. Maximal urine osmolality and papillary tissue content of urea was reduced. The polyuria, therefore, results from decreased fluid reabsorption by proximal tubules and, probably, by papillary collecting ducts. The decrease in proximal fluid reabsorption is probably secondary to impaired solute reabsorption. A decrease in collecting duct fluid absorption can be attributed to the observed decrease in papillary solute concentration.Anomalies d'absorption corticale et papillaire dans la néphrotoxicité par la gentamicine. La fonction rénale a été examinée chez des rats recevant des injections journalières de gentamicine (100 à 150 mg/kg) pendant 10 à 14 jours. La clearance de l'inuline du rein entier a chuté, et le volume urinaire a augmenté. Le débit de filtration glomérulaire néphronique individuel des néphrons superficiels a varié. Certains néphrons n'avaient pas de filtration, certains avaient des débits faibles et certains avaient des débits élevés. Une perméabilité anormale de l'épithélium tubulaire rénal à l'inuline a été démontrée par micro-injection. Des microponctions du début et de la fin de néphrons individuels ont démontré une diminution de réabsorption de fluide le long du tubule contourné proximal des néphrons superficiels. Les débits de fluide délivré au tubules proximal tardif et distal étaient élevés. Le débit de réabsorption de fluide dans l'anse de Henlé superficielle était augmenté. L'osmolalité urinaire maximale et le contenu tissulaire papillaire en urée étaient diminués. De la sorte, la polyurie est dûe à une diminution de la réabsorption de fluide par les tubules proximaux, et probablement par les canaux collecteurs papillaires. La diminution de la réabsorption proximale de fluide est probablement secondaire à une anomalie de la réabsorption des solutés. Une diminution de l'absorption de fluide dans le canal collecteur peut être attribuée à la diminution observée de la concentration papillaire en solutés

Am I my brother's keeper?: fratricide in the kidney

Experimental acute kidney injury (AKI) is accompanied by the death of renal tubule epithelial cells, necrosis and apoptosis of the terminal portion of the proximal tubule, and apoptosis in the distal nephron. While immune competent cells invading the kidney play a role in such cell death, intervention in these processes only partially ameliorates the extent of cell death. Given the results of Linkermann et al. in this issue of KI, an epithelium-derived component of immune mediated cell death must now be strongly considered

Chronic Kidney Disease and GWAS: “The Proper Study of Mankind Is Man”

Genome-wide association studies (GWAS) have been applied to complex diseases such as diabetes and hypertension, successfully uncovering strong gene associations of potential pathophysiologic significance. Recently, two studies (Köttgen et al., 2010; Chambers et al., 2010) have been applied to uncover genes relevant to the pathophysiology of chronic kidney disease (CKD)

Positive effect of the induction of p21WAF1/CIP1 on the course of ischemic acute renal failure

Positive effect of the induction of p21WAF1/CIP1 on the course of ischemic acute renal failure.BackgroundThe p21 protein is found in the nucleus of most cells where it modulates cell cycle activity. At low levels, p21 stabilizes interactions between D cyclins and their cyclin-dependent kinases (cdks), but at high levels after induction by several different stress pathways, it causes cell cycle arrest. The p21 mRNA is induced in murine kidney after several types of acute renal failure, including cisplatin administration, ischemia-reperfusion, and ureteral obstruction. We reported that after cisplatin injection, mice with a p21 gene deletion developed much more severe renal damage than wild-type mice. To dissociate the effects of cisplatin-induced DNA damage and subsequent initiation of DNA damage-dependent cell death pathways from effects of acute renal failure, we have now examined mice after ischemia-reperfusion, a model of renal failure not associated with genotoxin-induced DNA damage early after the injury.MethodsWild-type and p21(-/-) mice were made ischemic by clamping both renal hila for 30 or 50 minutes. At various times after reflow, mortality and parameters of renal function and morphology were quantified. Also, the nuclear proteins p21 and proliferating cell nuclear antigen (PCNA) were localized in kidney sections by immunohistochemistry.ResultsKidney function was more impaired and mortality increased significantly in p21(-/-) mice as compared with p21(+/+) mice. We found more cell cycle activity, indicated by increased number of mitotic cells and nuclear PCNA-positive cells, in kidney of p21(-/-) mice.ConclusionsIn this study, p21(-/-) mice were more susceptible to ischemia-induced acute renal failure, with similarly elevated levels of parameters of cell cycle activity. We propose that the increased and inappropriate cell cycle activity in kidney cells is responsible for the increased kidney impairment and mortality

View point on social media use in interventional cardiology.

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Allergic bronchopulmonary aspergillosis with coexistant aspergilloma: a case report

<p>Abstract</p> <p>Introduction</p> <p>The coexistence of allergic bronchopulmonary aspergillosis and aspergilloma is rare.</p> <p>Case presentation</p> <p>We present the case of a 56-year-old Caucasian man who worked as a farmer, with infiltrates in the right lower and middle lung lobes, partial consolidation of the middle lobe and with previous diagnosis of chronic obstructive bronchitis. Evaluation of our patient led to the diagnosis of allergic bronchopulmonary aspergillosis with coexistent aspergilloma in the right lower lobe. He was treated with oral methylprednisolone and itraconazole. At the five-year follow-up he is without any sign of recurrence.</p> <p>Conclusion</p> <p>Aspergillus infection after the inhalation of spores in the form of a hypersensitivity reaction and saprophytic colonization can be coexistent.</p

Monocyte chemoattractant protein-1 promotes macrophage-mediated tubular injury, but not glomerular injury, in nephrotoxic serum nephritis

Monocyte chemoattractant protein-1 (MCP-1) is upregulated in renal parenchymal cells during kidney disease. To investigate whether MCP-1 promotes tubular and/or glomerular injury, we induced nephrotoxic serum nephritis (NSN) in MCP-1 genetically deficient mice. Mice were analyzed when tubules and glomeruli were severely damaged in the MCP-1–intact strain (day 7). MCP-1 transcripts increased fivefold in MCP-1–intact mice. MCP-1 was predominantly localized within cortical tubules (90%), and most cortical tubules were damaged, whereas few glomerular cells expressed MCP-1 (10%). By comparison, there was a marked reduction (>40%) in tubular injury in MCP-1–deficient mice (histopathology, apoptosis). MCP-1–deficient mice were not protected from glomerular injury (histopathology, proteinuria, macrophage influx). Macrophage accumulation increased adjacent to tubules in MCP-1–intact mice compared with MCP-1–deficient mice (70%, P < 0.005), indicating that macrophages recruited by MCP-1 induce tubular epithelial cell (TEC) damage. Lipopolysaccharide-activated bone marrow macrophages released molecules that induced TEC death that was not dependent on MCP-1 expression by macrophages or TEC. In conclusion, MCP-1 is predominantly expressed by TEC and not glomeruli, promotes TEC and not glomerular damage, and increases activated macrophages adjacent to TEC that damage TEC during NSN. Therefore, we suggest that blockage of TEC MCP-1 expression is a therapeutic strategy for some forms of kidney disease.published_or_final_versio

Prevalence of asthma, aspirin sensitivity and allergy in chronic rhinosinusitis: data from the UK National Chronic Rhinosinusitis Epidemiology Study

Background: Chronic rhinosinusitis (CRS) is a common disorder associated with other respiratory tract diseases such as asthma and inhalant allergy. However, the prevalence of these co-morbidities varies considerably in the existing medical literature and by phenotype of CRS studied. The study objective was to identify the prevalence of asthma, inhalant allergy and aspirin sensitivity in CRS patients referred to secondary care and establish any differences between CRS phenotypes. Methods: All participants were diagnosed in secondary care according to international guidelines and invited to complete a questionnaire including details of co-morbidities and allergies. Data were analysed for differences between controls and CRS participants and between phenotypes using chi-squared tests. Results: The final analysis included 1470 study participants: 221 controls, 553 CRS without nasal polyps (CRSsNPs), 651 CRS with nasal polyps (CRSwNPs) and 45 allergic fungal rhinosinusitis (AFRS). The prevalence of asthma was 9.95, 21.16, 46.9 and 73.3% respectively. The prevalence of self-reported confirmed inhalant allergy was 13.1, 20.3, 31.0 and 33.3% respectively; house dust mite allergy was significantly higher in CRSwNPs (16%) compared to CRSsNPs (9%, p < 0.001). The prevalence of self- reported aspirin sensitivity was 2.26, 3.25, 9.61 and 40% respectively. The odds ratio for aspirin sensitivity amongst those with AFRS was 28.8 (CIs 9.9, 83.8) p < 0.001. Conclusions: The prevalence of asthma and allergy in CRS varies by phenoytype, with CRSwNPs and AFRS having a stronger association with both. Aspirin sensitivity has a highly significant association with AFRS. All of these comorbidities are significantly more prevalent than in non-CRS controls and strengthen the need for a more individualised approach to the combined airway