Acute kidney injury (AKI) is classified into three types according to its pathophysiology: prerenal, intrinsic renal, and post-renal AKI. Experimental models of AKI can be divided into two categories: in vivo and in vitro. Models can be further subdivided according to how AKI is simulated. The pathophysiology of intrinsic renal and post-renal AKI has been investigated using animal models. Most studies have been conducted in murine models using male mice or rats, while large mammals like sheep, pigs, and monkeys have been used in a limited number of studies. The intrinsic renal AKI model is divided into septic vs. aseptic AKI. Aseptic AKI is subdivided into ischemic vs. nephrotoxic AKI. Lipopolysaccharides (LPS) injection or cecal ligation and puncture (CLP) have been used to simulate the septic AKI model in rodents. Ischemic AKI is the most extensively investigated field to date because ischemic AKI is the most common and serious cause of AKI in both native kidneys and renal allografts. Ischemia-reperfusion injury (IRI) surgery has been used to induce ischemic AKI. There are two different methods of IRI surgery: laparotomy vs. flank approach. Warm temperature and male sex are critical to induction of sufficient grade of renal injury in this model. Many nephrotoxicants pertinent to human disease have been used to reproduce nephrotoxic AKI in rodent models. Cisplatin, a common chemotherapeutic agent, has many pathophysiologic features that overlap with IRI. Other nephrotoxicants such as gentamicin or glycerol were studied in the past, whereas much more attention has recently been devoted to environmental nephrotoxicants such as cadmium. However, variant susceptibility to different doses of nephrotoxicants is a big hurdle to set up a reproducible and consistent model of nephrotoxic AKI. Post-renal AKI is simulated with ureteral obstruction surgery, whereas the unilateral ureteral obstruction (UUO) model has frequently been used. Although some novel findings have been reported through numerous studies using murine AKI models, AKI still remains a challenging condition that lacks specific diagnostic or therapeutic tools because of species barriers or experimental settings. Animal AKI models using mammals genetically closer to human like monkeys would be valuable to simulate human AKI more appropriately.
Acute Kidney Injury* ; Allografts ; Animals* ; Cadmium ; Cisplatin ; Gentamicins ; Glycerol ; Haplorhini ; Humans ; In Vitro Techniques ; Kidney ; Laparotomy ; Ligation ; Lipopolysaccharides ; Male ; Mammals ; Mice ; Models, Animal* ; Models, Theoretical ; Punctures ; Rats ; Reperfusion Injury ; Rodentia ; Sheep ; Swine ; Ureteral Obstruction

Megalocytic interstitial nephritis is a rare form of kidney disease caused by chronic inflammation. We report a case of megalocytic interstitial nephritis occurring in a 45-yrold woman who presented with oliguric acute kidney injury and acute pyelonephritis accompanied by Escherichia coli bacteremia. Her renal function was not recovered despite adequate duration of susceptible antibiotic treatment, accompanied by negative conversion of bacteremia and bacteriuria. Kidney biopsy revealed an infiltration of numerous histiocytes without Michaelis-Gutmann bodies. The patient's renal function was markedly improved after short-term treatment with high-dose steroid.
Acute Disease ; Acute Kidney Injury/complications/*drug therapy/pathology ; Anti-Bacterial Agents/therapeutic use ; Azithromycin/therapeutic use ; Bacteremia/*drug therapy/microbiology/pathology ; Cefotaxime/therapeutic use ; Creatinine/blood ; Escherichia coli ; Escherichia coli Infections/*drug therapy/microbiology/pathology ; Female ; Humans ; Kidney/pathology ; Methylprednisolone/therapeutic use ; Middle Aged ; Nephritis, Interstitial/*drug therapy/immunology/pathology ; Pyelonephritis/complications/*drug therapy/pathology ; Renal Dialysis ; Shock, Septic/drug therapy/microbiology

Ischemic acute kidney injury (AKI) is a common medical problem with significant mortality and morbidity, affecting a large number of patients globally. Ischemic AKI is associated with intrarenal inflammation as well as systemic inflammation; thus, the innate and adaptive immune systems are implicated in the pathogenesis of ischemic AKI. Among various intrarenal immune cells, T cells play major roles in the injury process and in the repair mechanism affecting AKI to chronic kidney disease transition. Importantly, T cells also participate in distant organ crosstalk during AKI, which affects the overall outcomes. Therefore, targeting T cell-mediated pathways and T cell-based therapies have therapeutic promise for ischemic AKI. Here, we review the major populations of kidney T cells and their roles in ischemic AKI.

Progressive ptosis and headache developed in a 50-year-old woman with non-small cell lung cancer. Although brain magnetic resonance imaging showed improved cerebellar metastasis after prior radiotherapy without any other abnormality, the follow-up examination taken 6 months later revealed metastasis to the cavernous sinus. The diagnosis of metastasis to the cavernous sinus is often difficult because it is a very rare manifestation of lung cancer, and symptoms can occur prior to developing a radiologically detectable lesion. Therefore, when a strong clinical suspicion of cavernous sinus metastasis exists, thorough neurologic examination and serial brain imaging should be followed up to avoid overlooking the lesion.
Brain ; Carcinoma, Non-Small-Cell Lung ; Cavernous Sinus ; Caves ; Female ; Follow-Up Studies ; Headache ; Humans ; Lung Neoplasms ; Magnetic Resonance Imaging ; Middle Aged ; Neoplasm Metastasis ; Neuroimaging ; Neurologic Examination

BACKGROUND: Lung cancer is responsible for substantial proportions of cutaneous metastasis from internal malignancies. The aim of this study was to evaluate the clinical manifestations and outcomes of cutaneous metastasis in Korean lung cancer patients. METHODS: On a retrospective basis, we analyzed medical records of all patients diagnosed with lung cancer from 2000 to 2006. RESULTS: Cutaneous metastases were found in 10 of 4,385 patients. The number of cases was highest for squamous cell carcinoma. However, there was no metastasis from 754 cases of small cell carcinomas. Cutaneous metastasis was detected during staging work-up in 4 patients and it was the presenting sign of recurrence post-operative in 2 patients. Average time from the diagnosis to discovery of cutaneous metastasis was 16.3 months and median survival was 8.5 months (range, 1.8~19.1 months). CONCLUSION: Physicians should be acquainted with clinical manifestations and outcomes of cutaneous metastasis from lung cancer to detect new, recurrent cancer, or disease progression, and to administer appropriate and prompt management.
Carcinoma, Small Cell ; Carcinoma, Squamous Cell ; Disease Progression ; Humans ; Lung ; Lung Neoplasms ; Medical Records ; Neoplasm Metastasis ; Recurrence ; Retrospective Studies ; Skin Neoplasms

An intramedullary spinal cord metastasis (ISCM) rarely develops in systemic cancer but is indicative of a poor prognosis. A 56-year-old man was admitted due to weakness of the lower extremities. He had received radiotherapy 3 months prior for a brain metastasis that had developed 1 year after achieving a complete response from chemotherapy for extended stage small cell lung cancer. Although the brain lesion had improved partially, ISCM from the cervical to lumbar-sacral spinal cords, which was accompanied by a leptomeningeal dissemination, was diagnosed based on magnetic resonance imaging of the spine and cerebrospinal fluid cytology. Finally, he died of sudden cardiac arrest during treatment. This is the first case of ISCM involving the whole spinal segments. Physicians should be aware of the subsequent development of ISCM in lung cancer patients with a previously known brain metastasis who present with new neurological symptoms.
Brain ; Death, Sudden, Cardiac ; Humans ; Lower Extremity ; Lung ; Lung Neoplasms ; Magnetic Resonance Imaging ; Middle Aged ; Neoplasm Metastasis ; Prognosis ; Small Cell Lung Carcinoma ; Spinal Cord ; Spine

A 48-year-old man presented with acute right flank pain. A computed tomography scan revealed right renal infarction. Because he had no thrombosis in the renal vessels and no clear embolic source, a further examination was performed to find the cause of the renal infarction. On transesophageal echocardiography, a right-to-left shunt during the Valsalva maneuver established a diagnosis of patent foramen ovale. This is a case of paradoxical embolism through a PFO leading to renal infarction.
Echocardiography, Transesophageal ; Embolism, Paradoxical ; Flank Pain ; Foramen Ovale, Patent ; Humans ; Infarction ; Middle Aged ; Thrombosis ; Valsalva Maneuver

PURPOSE: Urinary angiotensinogen (AGT) has been reported as an important marker reflecting the activity of intrarenal renin-angiotensin system (RAS) in chronic glomerulonephritis patients. We investigated urinary AGT excretion and intrarenal AGT expression in patients with minimal change disease (MCD). METHODS: In 20 patients with biopsy-proven MCD, urinary and plasma AGT was measured using a sandwich ELISA and intrarenal AGT expression was measured with immunohistochemistry. Urine samples from normal healthy volunteers and patients with biopsy-proven thin basement membrane disease (TBM) were used as control groups. RESULTS: MCD patients showed a wide range of natural logarithm of the urinary AGT/creatinine [ln (urinary AGT/Cr)] and the ln (urinary AGT/Cr) was higher in MCD patients compared with normal controls and TBM controls (normal control vs. TBM vs. MCD, 1.2+/-0.25 vs. 0.9+/-0.34 vs. 3.2+/-0.40). Intrarenal AGT expression was diverse in MCD patients (intrarenal AGT, arbitrary unit, 27.39-78.52 in TBM, 0.00-145.80 in MCD). Ln (urinary AGT/Cr) did not show a direct correlation with intrarenal AGT expression, plasma AGT, or urinary protein/creatinine ratio. CONCLUSION: Urinary AGT excretion and intrarenal AGT expression are enhanced in some MCD patients, suggesting that intrarenal RAS is activated in these patients.
Angiotensinogen ; Basement Membrane ; Corneal Dystrophies, Hereditary ; Enzyme-Linked Immunosorbent Assay ; Glomerulonephritis ; Humans ; Immunohistochemistry ; Nephrosis, Lipoid ; Plasma ; Proteinuria ; Renin-Angiotensin System

Uninephrectomy (uNx) in young rats causes salt-sensitive hypertension (SSH). Alterations of sodium handling in residual nephrons may play a role in the pathogenesis. Therefore, we evaluated the adaptive alterations of renal sodium transporters according to salt intake in uNx-SSH rats. uNx or sham operations were performed in male Sprague-Dawley rats, and normal-salt diet was fed for 4 weeks. Four experimental groups were used: sham-operated rats raised on a high-salt diet for 2 weeks (CHH) or on a low-salt diet for 1 week after 1 week's high-salt diet (CHL) and uNx rats fed on the same diet (NHH, NHL) as the sham-operated rats were fed. Expression of major renal sodium transporters were determined by semiquantitative immunoblotting. Systolic blood pressure was increased in NHH and NHL groups, compared with CHH and CHL, respectively. Protein abundances of Na+/K+/2Cl- cotransporter (NKCC2) and Na+/Cl- cotransporter (NCC) in the CHH group were lower than the CHL group. Expression of epithelial sodium channel (ENaC)-gamma increased in the CHH group. In contrast, expressions of NKCC2 and NCC in the NHH group didn't show any significant alterations, compared to the NHL group. Expressions of ENaC-alpha and ENaC-beta in the NHH group were higher than the CHH group. Adaptive alterations of NKCC2 and NCC to changes of salt intake were different in the uNx group, and changes in ENaC-alpha and ENaC-beta were also different. These altered regulations of sodium transporters may be involved in the pathogenesis of SSH in the uNx rat model.
Animals ; Blood Pressure ; Diet ; Diet, Sodium-Restricted ; Epithelial Sodium Channels ; Handling (Psychology) ; Humans ; Hypertension ; Immunoblotting ; Male ; Nephrectomy ; Nephrons ; Rats ; Rats, Sprague-Dawley ; Salicylamides ; Social Control, Formal ; Sodium ; Sodium Chloride Symporters ; Sodium-Potassium-Chloride Symporters