Renal Corticomedullary Junction Research Articles

Linear Calcification along the Renal Corticomedullary Junction.

Linear Calcification along the Renal Corticomedullary Junction.

Quantification of vascular damage in acute kidney injury with fluorine magnetic resonance imaging and spectroscopy.

To design a fluorine MRI/MR spectroscopy approach to quantify renal vascular damage after ischemia-reperfusion injury, and the therapeutic response to antithrombin nanoparticles (NPs) to protect kidney function. A total of 53 rats underwent 45 min of bilateral renal artery occlusion and were treated at reperfusion with either plain perfluorocarbon NPs or NPs functionalized with a direct thrombin inhibitor (PPACK:phenyalanine-proline-arginine-chloromethylketone). Three hours after reperfusion, kidneys underwent ex vivo fluorine MRI/MR spectroscopy at 4.7 T to quantify the extent and volume of trapped NPs, as an index of vascular damage and ischemia-reperfusion injury. Microscopic evaluation of structural damage and NP trapping in non-reperfused renal segments was performed. Serum creatinine was quantified serially over 7 days. The damaged renal cortico-medullary junction trapped a significant volume of NPs (P = 0.04), which correlated linearly (r = 0.64) with the severity of kidney injury 3 h after reperfusion. Despite global large vessel reperfusion, non-reperfusion in medullary peritubular capillaries was confirmed by MRI and microscopy, indicative of continuing hypoxia due to vascular compromise. Treatment of animals with PPACK NPs after acute kidney injury did not accelerate kidney functional recovery. Quantification of ischemia-reperfusion injury after acute kidney injury with fluorine MRI/MR spectroscopy of perfluorocarbon NPs objectively depicts the extent and severity of vascular injury and its linear relationship to renal dysfunction. The lack of kidney function improvement after early posttreatment thrombin inhibition confirms the rapid onset of ischemia-reperfusion injury as a consequence of vascular damage and non-reperfusion. The prolongation of medullary ischemia renders cortico-medullary tubular structures susceptible to continued necrosis despite restoration of large vessel flow, which suggests limitations to acute interventions after acute kidney injury, designed to interdict renal tubular damage. Magn Reson Med 79:3144-3153, 2018. © 2017 International Society for Magnetic Resonance in Medicine.

Mesenchymal Stem Cells Contribute to Improvement of Renal Function in a Canine Kidney Injury Model.

The kidney excretes waste materials and regulates important metabolic functions, and renal disorders constitute a significant medical problem and can result in fatalities. In the present study, mesenchymal stem cells derived from canine umbilical cord blood (cUCB-MSCs) were isolated and evaluated for their ability to improve renal function in a canine model of acute kidney injury (AKI). The canine AKI model was developed by i.v. injection of cisplatin and gentamycin into 14 male beagle dogs. cUCB-MSCs were administered into the renal corticomedullary junction following AKI induction. Survival time, clinical signs, blood analysis and histological parameters were analyzed. The group treated with AKI plus cUCB-MSCs had decreased blood urea nitrogen and creatinine levels, and showed an extended life-span and improved histological manifestations. MSCs were detected around the tubules of these kidneys at the histological level. Taken together, our findings suggest that cUCB-MSCs could be an alternative therapeutic agent for canine AKI.

Evaluation of renal cortical thickness by non-contrast-enhanced MR imaging with spatially selective IR pulses: comparison between cirrhotic and non-cirrhotic patients.

To compare renal cortical thicknesses between patients with and without cirrhosis with normal renal function based on serum creatinine using non-contrast-enhanced steady-state, free precession (SSFP) MRI with spatially selective inversion recovery (IR) pulses and to discuss the clinical implications of measuring renal cortical thickness in patients with cirrhosis. 40 patients with and without cirrhosis who had normal renal function based on serum creatinine and underwent non-contrast-enhanced SSFP imaging with spatially selective IR pulses were included. The renal cortical thickness, renal width, renal cortical width ratio, serum creatinine levels and estimated glomerular filtration rates (eGFRs) were compared between cirrhotic and non-cirrhotic groups. The mean renal cortical thickness was significantly lower in the cirrhotic group (3.6 ± 0.9 mm) than in the non-cirrhotic group (4.9 ± 0.8 mm; p < 0.001). The mean renal cortical width ratio was significantly lower in the cirrhotic group (0.07 ± 0.02) than in the non-cirrhotic group (0.10 ± 0.02; p < 0.001). The mean serum creatinine and mean eGFR did not show significant differences between the two groups. Measurement of renal cortical thickness by means of non-contrast-enhanced SSFP MRI with spatially selective IR pulses may help evaluate renal function accurately in patients with cirrhosis, in whom it may be overestimated by serum creatinine and eGFR. (1) The renal corticomedullary junction was clearly depicted by non-contrast-enhanced SSFP MRI with spatially selective IR pulses in all patients with and without cirrhosis. (2) The mean renal cortical thickness measured on the optimal SSFP image with spatially selective IR pulses was significantly lower in the cirrhotic group (3.6 ± 1.0 mm) than in the non-cirrhotic group (4.9 ± 0.8 mm) (p < 0.001), although the mean eGFR did not show a significant difference between the two groups.

Coccidial dispersion across New World marsupials: Klossiella tejerai Scorza, Torrealba & Dagert, 1957 (Apicomplexa: Adeleorina) from the Brazilian common opossum Didelphis aurita (Wied-Neuwied) (Mammalia: Didelphimorphia).

Klossiella tejerai Scorza, Torrealba & Dagert, 1957 is a primitive coccidian parasite reported from the New World marsupials Didelphis marsupialis (Linnaeus) and Marmosa demerarae (Thomas). The current work describes K. tejerai from the Brazilian common opossum Didelphis aurita (Wied-Neuwied) in Southeastern Brazil, evidencing the coccidial dispersion across opossums of the same family. The sporocysts recovered from urine samples were ellipsoidal, 20.4×12.7µm, with sporocyst residuum composed of scattered spherules and c.13 sporozoites per sporocyst, with refractile bodies and nucleus. Macrogametes, microgametes, sporonts, sporoblasts/sporocysts were identified within parasitophorous vacuoles of epithelial cells located near the renal corticomedullary junction. Didelphis marsupialis should not have transmitted K. tejerai to D. aurita because they are not sympatric; however M. demerarae is sympatric with D. marsupialis and D. aurita. Therefore, D. aurita becomes the third host species for K. tejerai in South America.

Probiotic dietary supplementation in a dog with chronic kidney disease

A 7-year-old spayed female English Cocker Spaniel dog presented with polyuria (PU), polydipsia (PD), intermittent vomiting, and weight loss. Physical examination revealed pale, tacky mucous membranes and severe emaciation. Hematological and biochemical examinations revealed moderate normocytic normochromic non-regenerative anemia and moderate azotemia. Abdominal ultrasonography demonstrated bilaterally small lumpy-bumpy kidneys with hyperechoic parenchyma as well as loss of renal corticomedullary junction. Based on clinical history and examinations, the dog was diagnosed with chronic kidney disease (CKD). The dog was treated with supportive care including fluid therapy, phosphate-binding agent, and histamine H2-receptor antagonist. Darbepoetin Alfa was administered to control renal secondary non-regenerative anemia. Prescribed diet with low-protein and low-phosphorus was fed to alleviate CKD signs. Further, dietary probiotics were supplemented. This case demonstrates that oral probiotic supplementation helped reduce blood urea-nitrogen (BUN) levels. This case indicates that dietary probiotics can be a potential alternative therapeutic agent for management of renal failure.

Age‐related change in renal corticomedullary differentiation: Evaluation with noncontrast‐enhanced steady‐state free precession (SSFP) MRI with spatially selective inversion pulse using variable inversion time

To evaluate age-related change in renal corticomedullary differentiation and renal cortical thickness by means of noncontrast-enhanced steady-state free precession (SSFP) magnetic resonance imaging (MRI) with spatially selective inversion recovery (IR) pulse. The Institutional Review Board of our hospital approved this retrospective study and patient informed consent was waived. This study included 48 patients without renal diseases who underwent noncontrast-enhanced SSFP MRI with spatially selective IR pulse using variable inversion times (TIs) (700-1500 msec). The signal intensity of renal cortex and medulla were measured to calculate renal corticomedullary contrast ratio. Additionally, renal cortical thickness was measured. The renal corticomedullary junction was clearly depicted in all patients. The mean cortical thickness was 3.9 ± 0.83 mm. The mean corticomedullary contrast ratio was 4.7 ± 1.4. There was a negative correlation between optimal TI for the best visualization of renal corticomedullary differentiation and age (r = -0.378; P = 0.001). However, there was no significant correlation between renal corticomedullary contrast ratio and age (r = 0.187; P = 0.20). Similarly, no significant correlation was observed between renal cortical thickness and age (r = 0.054; P = 0.712). In the normal kidney, noncontrast-enhanced SSFP MRI with spatially selective IR pulse can be used to assess renal corticomedullary differentiation and cortical thickness without the influence of aging, although optimal TI values for the best visualization of renal corticomedullary junction were shortened with aging.

Effects of impaired functional domains of osteopontin on renal crystal formation: Analyses of OPN transgenic and OPN knockout mice

Osteopontin (OPN) has been described as playing a nonredundant role in renal crystal formation. Here we investigated the effects of impaired domains of OPN, namely, the Arg-Gly-Asp (RGD) sequence and two calcium-binding sites on crystal formation. We used wild-type mice (WT group), OPN knockout mice (KO group), and OPN knockout mice carrying either a transgene in which the RGD sequence had been modified to Arg-Gly-Glu (RGE group) or whose two calcium-binding sites had been deleted (CaX group). Following intraperitoneal injection of glyoxylate for 9 days, the changes occurring in three parameters of crystal formation--localization, number, and microstructure--were analyzed. In the WT group, crystal deposits increased gradually at the renal corticomedullary junction in an orderly fashion, whereas those in the KO group were observed sporadically in the renal cortex. In both the CaX and RGE groups, deposits were localized near the corticomedullary junction. Crystal deposition was greatest in the WT group and least in the KO group. The number of deposits in the RGE group was nearly equal to that in the KO group. Microscopic observations revealed that the crystal nuclei in the CaX group were stratified and occurred in a disordered pattern; this pattern was dissimilar to that in the WT group, in which a rosette petal-like radial pattern was observed. In the RGE group, the nuclei exhibited a radial pattern similar to that in the WT group. The results indicated the possibility that each domain contributes to the mechanism by which OPN stimulates crystal formation.

Adrenal and renal corticomedullary junction iron deposition in red cell aplasia

Iron deposition can occur in the kidneys as a result of hemolysis or extensive iron overload from transfusions. With T2* MRI, renal iron deposition can be visualized. In this report, renal corticomedullary junction iron deposition is noted using T2* MRI in a boy with red cell aplasia. The renal corticomedullary junction iron deposition is an indication of the severity of his iron overload. This is an unusual finding and brings clinical attention to the boy's renal function for further evaluation.

KLOSSIELLA QUIMRENSIS (APICOMPLEXA: KLOSSIELLIDAE) CAUSES RENAL COCCIDIOSIS IN WESTERN BARRED BANDICOOTS PERAMELES BOUGAINVILLE (MARSUPIALIA: PERAMELIDAE) IN WESTERN AUSTRALIA

Previous studies have described a range of Klossiella species parasitic in marsupial hosts. Klossiella quimrensis is the etiologic agent of renal coccidiosis in the peramelid marsupial hosts Isoodon obesulus and Perameles gunnii in Eastern Australia, but there is no previous report of klossiellosis in Western Australian peramelids. This study describes klossiellosis diagnosed by histology of renal tissue sections collected during necropsy of 20 Perameles bougainville between 2000 and 2005. Sporonts, sporoblasts, and macrogametes were identified within parasitophorous vacuoles of epithelial cells located near the renal corticomedullary junction. The prevalence of renal coccidiosis in P. bougainville diagnosed by renal histology is estimated at 30%. Only a single unsporulated sporocyst was detected by examination of cystocentesis-collected urine, indicating that microscopic evaluation of urine samples is an insensitive diagnostic test for detection of K. quimrensis in P. bougainville. This infection in P. bougainville is indirectly associated with mild multifocal interstitial lymphohistiocytic nephritis and is likely to be only minimally pathogenic in otherwise healthy individuals. Our study also extends the host and geographic range of K. quimrensis to include P. bougainville and Western Australia.

A1adenosine receptor knockout mice exhibit increased mortality, renal dysfunction, and hepatic injury in murine septic peritonitis

Sepsis is a leading cause of multiorgan dysfunction and death in hospitalized patients. Dysregulated inflammatory processes and apoptosis contribute to the pathogenesis of sepsis-induced organ dysfunction and death. A(1) adenosine receptor (A(1)AR) activation reduces inflammation and apoptosis after ischemia-reperfusion injury. Therefore, we questioned whether A(1)AR-mediated reduction of inflammation and apoptosis could improve mortality and organ dysfunction in a murine model of sepsis. A(1)AR knockout mice (A(1) knockout) and their wild-type (A(1) wild-type) littermate controls were subjected to cecal ligation and double puncture (CLP) with a 20-gauge needle. A(1) knockout mice or A(1) wild-type mice treated with 1,3-dipropyl-8-cyclopentylxanthine (a selective A(1)AR antagonist) had a significantly higher mortality rate compared with A(1) wild-type mice following CLP. Mice lacking endogenous A(1)ARs demonstrated significant elevations in plasma creatinine, alanine aminotransferase, aspartate aminotransferase, keratinocyte-derived chemokine, and tumor necrosis factor-alpha 24 h after induction of sepsis compared with wild-type mice. The renal corticomedullary junction from A(1) knockout mice also exhibited increased myeloperoxidase activity, intercellular adhesion molecule-1 protein, and mRNA encoding proinflammatory cytokines compared with renal samples from A(1) wild-type littermate controls. No difference in renal tubular apoptosis was detected between A(1) knockout and A(1) wild-type mice. We conclude that endogenous A(1)AR activation confers a protective effect in mice from septic peritonitis primarily by attenuating the hyperacute inflammatory response in sepsis.

Persistent karyomegaly caused byPenicilliumnephrotoxins in the rat

Continuous or intermittent consumption by rats of food moulded by Penicillium aurantiogriseum induced prominent and extensive histopathological changes within several weeks seen specifically at the renal cortico-medullary junction. Many cells of the P3 segment of proximal tubules contained either giant nuclei or multiple enlarged nuclei, described in this text as karyomegaly, but also included within a cytomegalic change. The changes contrasted with the tubular cell necrosis and concomitant mitosis elicited after only four days consumption of nephrotoxic mould. Unilateral nephrectomy enabled persistence of histopathological changes to be assessed directly after detailed histology at an earlier stage. After ten days consumption of food with a 100-fold excess of fungal extract containing the amphoteric nephrotoxins, the typical acute histopathology evolved, over a period of three weeks on normal diet, into the bizarre karyomegalic histopathology, implying a latent effect. Karyomegaly persisted for at least twelve months after nephrotoxin dosage ceased. P. aurantiogriseum karyomegaly was much more striking than that induced by a relatively high chronic dose of another Penicillium nephrotoxin, ochratoxin A. Although the study does not attempt to measure relative potencies, qualitatively similar ultrastructural changes (enlarged nuclei, proliferation of smooth endoplasmic reticulum and thickening of proximal tubule basement membranes) were induced by the two types of nephrotoxin. The broadly toxic ochratoxin A is the popular putative aetiological agent in the mysterious and insidious Balkan endemic nephropathy and associated urinary tract tumours. As the renal carcinogenicity of ochratoxin A in rats follows karyomegaly, the striking karyomegaly induced by P. aurantiogriseum in the proximal tubules of the kidney must be considered as a potential factor in human chronic renal disease.

Renal Corticomedullary Junction

Inability to demonstrate the renal corticomedullary junction (CMJ) on magnetic resonance (MR) images has been reported in connection with several medical renal diseases. T1-weighted spin echo pulse sequences have been advocated to demonstrate a signal intensity difference between cortex and medulla. This study was undertaken to determine which of several T1-weighted spin echo (SE) and gradient echo (GE) sequences are better for delineation of the CMJ. The MR studies were performed at 0.5 Tesla on 27 normal volunteers. Multi-slice axial images of both kidneys were obtained in all subjects at each of the following five pulse sequences: SE 250/20, SE 500/30, SE 900/30, and GE 300/15 with 80 degrees and 64 degrees flip angles. Contrast/noise ratios were calculated for the signal intensity differences between cortex and medulla; the average standardized contrast/noise ratios ranked as follows: GE 300/15/80 degrees = 3.01 +/- 0.74, GE 300/15/64 degrees = 2.72 +/- 0.74, SE 250/20 = 2.02 +/- 0.33, SE 500/30 = 1.96 +/- 0.51, and SE 900/30 = 1.71 +/- 0.39. In addition, the five sequences for each patient were randomized and the images were independently ranked for delineation of CMJ by three MR radiologists. The cumulative subjective ranking for all observers from best to worst is as follows: SE 500/30, GE 300/15/80 degrees, GE 300/15/64 degrees, SE 900/30, SE 250/20. Although better contrast/noise ratios are achieved with the GE sequences and the more T1-weighted SE sequences, as a practical matter this does not seem to be the only significant factor when compared with the visual image evaluation by independent observers.(ABSTRACT TRUNCATED AT 250 WORDS)

Isolation of Staphylococcus Hyicus from Seborrheic Dermatitis in a Pygmy Goat

Microscopic examination of hematoxylin and eosin (HE)stained skin sections showed marked hyperkeratosis with parakeratosis of the epidermis. There also were numerous extensive foci of polymorphonuclear leukocytes aggregated in the hyperkerototic debris (Fig. 1). A few mononuclear inflammatory cells were sprinkled in the dermis but the major inflammatory changes were confined to the stratum comeum of the epidermis. No ectoparasites or mycotic organisms were detected in the skin sections. The renal corticomedullary junction vasculature showed infiltrates of leukocytes that were predominantly neutrophilic. There also were leukocytic casts and very few randomly scattered oxalate crystals in the medullary tubules. The liver showed mild centrilobular hepato

Immunologic and clinicopathologic evaluation of adult dogs inoculated with Encephalitozoon cuniculi.

Beagle dogs inoculated intravenously with 1.75 x 10(9) viable Encephalitozoon cuniculi spores at 12.5 months of age were monitored for 18 months to assess infection in the adult dog. Parameters monitored included packed cell volume, total and differential leukocyte counts, and humoral and cellular responses to infection. Immunoglobulin M and G antibodies directed against the parasite tegument were present throughout the 18 months. Peripheral blood monocytes treated with lymphokines, either antigen specific (E. cuniculi) or nonspecific (concanavalin A), killed E. cuniculi spores in vitro. Pretreatment of E. cuniculi spores with normal dog serum or infected dog serum enhanced the killing of the parasite (normal dog serum less than infected dog serum) by canine monocytes. Histologic examination of selected tissues revealed microfocal plasma cell and lymphocyte aggregates at the renal corticomedullary junction and in the medullary interstitium. The results of these experiments suggest that the adult dog is able to mount an effective defense to infection, to minimize host tissue damage, and to eliminate the parasite through complex interactions between monocytes-macrophages and lymphocytes.

The feeding of diets containing up to 4% monosodium glutamate to rats for 2 years

Charles River CD rats were fed diets containing either 2.05% w/w sodium propionate or 1, 2 or 4% w/w monosodium glutamate (MSG) for 104 weeks. There were no adverse effects upon bodyweight gain, economy of food consumption, haematology, blood chemistry, organ weights or mortality by comparison with control rats receiving the basal diet. Water consumption, urinary volume and sodium excretion were increased at 2.05% sodium propionate or 4% MSG, and this appeared to be reflected in an increased incidence and earlier onset of spontaneous subepithelial basophilic deposits in the renal pelvis among treated rats. Focal mineralization at the renal corticomedullary junction occurred with equal frequency in all groups, including untreated controls. There were no other histological findings of significance.