Glomerular Density in Renal Biopsy Specimens Predicts the Long-Term Prognosis of IgA Nephropathy

Background and objectives: An early histopathologic predictor of the renal prognosis, before the occurrence of advanced glomerular sclerosis/interstitial fibrosis and/or apparent renal dysfunction, remains to be established in IgA nephropathy (IgAN). This study aimed to determine whether the glomerular density (GD; nonsclerotic glomerular number per renal cortical area) of biopsy specimens obtained at an early stage of IgAN could predict the long-term renal outcome.Design, setting, participants, & measurements: The predictive value of the factors at biopsy, including the GD, on the renal outcome was retrospectively analyzed for 98 patients who had IgAN with an estimated GFR of ≥60 ml/min per 1.73 m² at biopsy (87 ml/min per 1.73 m² on average).Results: The individual value of GD in biopsy ranged from 1.2 to 8.1/mm² (i.e., approximately a seven-fold variation), and the GD showed a close inverse correlation with mean glomerular volume. Among the various clinicopathologic factors involved, both a cellular/fibrocellular crescent and the GD were found to be significant predictors of progression in multivariate analyses. A low GD in the biopsy specimens was frequently associated with a steeper slope of the renal function and a synergistically enhanced risk for progression with the presence of cellular/fibrocellular crescent. The renal function, proteinuria, degrees of glomerulosclerosis, and interstitial fibrosis at biopsy were not independent predictors of the prognosis in these patients.Conclusions: A strong predictive relationship of low GD with progression observed in this study suggests that GD may serve as an early histopathologic marker of long-term renal prognosis in IgAN.The outcome of IgA nephropathy (IgAN) is highly variable among individuals (1–4). Some patients maintain only isolated urinary symptoms for many years, whereas other patients progress to ESRD. Previous studies have consistently identified various clinicopathologic parameters at the time of diagnosis, especially heavy proteinuria, reduced renal function, advanced glomerular sclerosis, or tubulointerstitial fibrosis, as independent risk factors for progression (4–7); however, these findings characterize already advanced renal injury rather than reflect the progression rate of renal diseases. The factors that may allow prediction of progression in early stage of IgAN remain to be fully elucidated.We recently performed a study using pairs of serial biopsy specimens from 18 patients with progressive IgAN (8). In these patients, renal biopsies were performed both before and after the establishment of impaired renal function. We found a low glomerular density (GD; the number of nonsclerotic glomeruli per renal cortical area) in the first biopsy to be associated with both the already enlarged glomeruli and an increased susceptibility to subsequent renal scarring and a more rapid progression. A high GD in the first biopsy was associated with a relatively slow progression despite a large increase in the glomerular size in the second biopsy. These results were consistent with the currently proposed concept that kidneys with a reduced nephron number, presumably having less of a functional reserve, may cause glomerular enlargement, thereby becoming more susceptible to subsequent renal injury and functional decline (9–11). We therefore hypothesized that the GD in the early stage of “potentially progressive” renal diseases, such as IgAN, can predict subsequent renal adaptation and/or scarring and thus serve as an early marker of renal prognosis.By analyzing a larger number of patients, this study aimed to clarify the relationship between GD and the long-term renal outcome of patients with IgAN and without any apparent renal dysfunction at the time of biopsy. In addition to the patients who showed a progressive loss of renal function, this study included patients whose renal function had been stable for a long time.     

Surgical resection of gastrointestinal stromal tumor of esophagus following preoperative imatinib treatment: a case report

We report a case of esophagectomy after a primary esophageal gastrointestinal stromal tumor (GIST) was preoperatively treated with imatinib mesylate. A 71-year-old woman was diagnosed with an esophageal submucosal tumor by upper gastrointestinal endoscopy at her health checkup. The tumor was located at the lower thoracic esophagus immediately above the esophagogastric junction and measured 4.5 cm in size. It was diagnosed as GIST of the esophagus for reasons of its high susceptibility to imatinib mesylate. Preoperative treatment with imatinib was performed in an attempt to preserve the esophagus. Although the tumor size was decreased by 36% after the 6-month treatment, transhiatal esophagectomy was required for complete resection, and esophageal preservation could not be accomplished.     

A case of metastatic esophageal tumor from breast cancer

A 58-year-old woman was admitted to our hospital with the complaint of dysphagia that had developed 37 months after initiation of treatment for breast cancer. Endoscopy revealed severe stenosis 32 cm from the incisors through which the endoscope could not pass. No mucosal irregularities were observed, and biopsies of the stenotic lesion were negative for malignancy. Computed tomography showed wall thickening of the midthoracic esophagus and left pleural effusion, which had increased metabolic activity as detected by ¹⁸F-fluorodeoxyglucose positron emission tomography. Cytological examination of the pleural effusion showed adenocarcinoma compatible with metastasis from a prior lobular carcinoma of the breast. Vinorelbine effectively relieved her symptoms, and the disease stabilized for approximately 1 year. However, she died 16 months after the diagnosis of metastatic esophageal tumor from the preceding breast cancer.     

Evaluation of the genotoxic potential of single-wall carbon nanotubes by using a battery of in vitro and in vivo genotoxicity assays

The genotoxic potential of a high purity sample of single-wall carbon nanotubes (SWCNTs) was evaluated using a battery of in vitro and in vivo genotoxicity assays. These comprised a bacterial reverse mutation test (Ames test), an in vitro chromosomal aberration test, and an in vivo mouse bone marrow micronucleus test. The SWCNTs exerted no genotoxicity in Salmonella typhimurium TA97, TA98, TA100, and TA1535, or in Escherichia coli WP2 uvrA/pKM101, whether in the absence or presence of metabolic activation and at concentrations of 12.5–500 μg/plate. In the chromosomal aberration test, at 300–1000 μg/mL, the SWCNTs did not increase the number of structural or numerical chromosomal aberrations, whether the test was conducted with or without metabolic activation. In the in vivo bone marrow micronucleus test, doses of 60 mg/kg and 200 mg/kg SWCNTs did not affect the proportions of immature and total erythrocytes, nor did it increase the number of micronuclei in the immature erythrocytes of mice. The results of these studies show that the high purity and well-dispersed sample of SWCNTs are not genotoxic under the conditions of the in vitro bacterial reverse mutation assay, chromosomal aberration assay, or in vivo bone marrow micronucleus test, and thus appear not to pose a genotoxic risk to human health in vivo.     

Recombinant human hepatocyte growth factor (HGF), but not rat HGF,elicits glomerular injury and albuminuria in normal rats via an immune complex‐dependent mechanism

1. Hepatocyte growth factor (HGF) has the therapeutic potential to improve renal fibrosis and proteinuria in rodents with chronic kidney disease. In contrast, long‐term administration of human HGF to normal rats reportedly elicits proteinuria. Thus, the role of HGF during proteinuria remains contentious. The aim of the present study was to demonstrate that human HGF is antigenic to rodents and that immune complex formation causes proteinuria. 2. We administered either human or rat HGF to normal rats for 28 days. Albuminuria was evaluated by sodium dodecyl sulphate–polyacrylamide gel electrophoresis. The renal phenotypes of the two HGF treatments were examined using histological techniques. 3. Administration of human HGF (1 mg/kg per day, i.v.) to rats led to severe albuminuria and glomerular hypertrophy in association with increased blood levels of anti‐human HGF IgG and IgG deposition in mesangial areas. Furthermore, an immune complex between human HGF and anti‐human HGF IgG stimulated the production of proteinuric cytokines (including transforming growth factor‐β) in rat cultured mesangial cells. In contrast, treatment of healthy rats with rat HGF for 4 weeks caused neither mesangial IgG deposition nor elevated anti‐HGF IgG in the blood. Overall, rat HGF did not provoke albuminuria. 4. We conclude that human HGF produces pseudotoxic effects in normal rat kidneys via an immune complex‐mediated pathway, whereas syngenic HGF is safe due to less deposition of glomerular IgG. Our results affirm the safety of the repeated use of syngenic HGF for the treatment of chronic organ diseases, such as renal fibrosis and liver cirrhosis.     

Bacteria isolated from surgical infections and its susceptibilities to antimicrobial agents--special references to bacteria isolated between April 2009 and March 2010

Bacteria isolated from surgical infections during the period from April 2009 to March 2010 were investigated in a multicenter study in Japan, and the following results were obtained. In this series, 671 strains including 16 strains of Candida spp. were isolated from 174 (79.1%) of 220 patients with surgical infections. Four hundred and eleven strains were isolated from primary infections, and 244 strains were isolated from surgical site infection. From primary infections, anaerobic Gram-negative bacteria were predominant, followed by aerobic Gram-negative bacteria, while from surgical site infection aerobic Gram-positive bacteria were predominant, followed by anaerobic Gram-negative bacteria. Among aerobic Gram-positive bacteria, the isolation rate of Enterococcus spp. was highest, followed by Streptococcus spp., and Staphylococcus spp. in this order, from primary infections, while Enterococcus spp. was highest, followed by Staphylococcus spp. from surgical site infection. Among aerobic Gram-negative bacteria, Escherichia coli was the most predominantly isolated from primary infections, followed by Klebsiella pneumoniae, Enterobacter cloacae and Pseudomonas aeruginosa, in this order, and from surgical site infection, E. coli was most predominantly isolated, followed by P. aeruginosa and E. cloacae. Among anaerobic Gram-positive bacteria, the isolation rate of Eggerthella lenta was the highest from primary infections, followed by Parvimonas micra, Streptococcus constellatus and Finegoldia magna, and from surgical site infection, E. lenta was most predominantly isolated. Among anaerobic Gram-negative bacteria, the isolation rate of Bilophila wadsworthia was the highest from primary infections, followed by Bacteroides fragilis, Bacteroides ovatus and Bacteroides thetaiotaomicron, and from surgical site infection, B. fragilis was most predominantly isolated, followed by B. ovatus, B. wadsworthia and B. thetaiotaomicron, in this order. In this series, we noticed no vancomycin-resistant Gram-positive cocci, nor multidrug-resistant P. aeruginosa. We should carefully follow up B. wadsworthia which was resistant to various antibiotics, and also Bacteroides spp. which was resistant to many beta-lactam antibiotics.     

Biopersistence of inhaled MWCNT in rat lungs in a 4-week well-characterized exposure

It is important to conduct a risk assessment that includes hazard assessment and exposure assessment for the safe production and handling of newly developed nanomaterials. We conducted an inhalation study of a multi-wall carbon nanotube (MWCNT) as a hazard assessment. Male Wistar rats were exposed to well-dispersed MWCNT for 4 weeks by whole body inhalation. The exposure concentration in the chamber was 0.37?±?0.18?mg/m3. About 70% of the MWCNTs in the chamber were single fiber. The geometric mean diameter (geometric standard deviation, GSD) and geometric mean length (GSD) of the aerosolized MWCNTs in the chamber were 63?nm (1.5) and 1.1 μm (2.7), respectively. The amounts of MWCNT deposited in the rat lungs were determined by the X-ray diffraction method and elemental carbon analysis. The average deposited amounts at 3 days after the inhalation were 68 μg/lung by the X-ray diffraction method and 76 μg/lung by elemental carbon analysis. The calculated deposition fractions were 18% and 20% in each analysis. The amount of retained MWCNT in the lungs until 3 months after the inhalation decreased exponentially and the calculated biological half times of MWCNT were 51 days and 54 days, respectively. The clearance was not delayed, but a slight increase in lung weight at 3 days after the inhalation was observed.     

Inhibitory effect of chitosan-containing lotion on scratching response of hairless mice with atopic dermatitis-like dry skin

In this study, using a special diet-induced mouse model of atopic dermatitis, we tested the effect of chitosan-containing lotion (CL) on itch-related scratching associated with barrier-disrupted dry skin. HR-1 hairless mice fed a special diet exhibited apparent dry skin symptoms characterized by decreased skin hydration and increased transepidermal water loss. In the special diet-fed mice, scratching behavior was markedly enhanced for 60 min after oral administration of ethanol. When CL was applied once immediately after ethanol administration, the enhanced scratching response was significantly suppressed, but this effect was abolished within 30-40 min; when applied twice immediately and at 30 min, CL almost completely blocked scratching throughout 60 min. Comparison of CL and the chitosan-free vehicle showed that CL inhibited scratching more strongly and persistently than the vehicle, which transiently suppressed scratching only for 10 min after application. Although the decreased skin hydration was improved even by the vehicle, the increased transepidermal water loss was resolved only by CL. Skin surface temperature was much more reduced in CL-treated mice than in vehicle-treated mice. Collectively, CL has an antipruritic effect, which could be partly explained by recovery of skin barrier function and cooling of the skin.     

Biodegradable CpG DNA hydrogels for sustained delivery of doxorubicin and immunostimulatory signals in tumor-bearing mice

Immunostimulatory CpG DNA was self-assembled to form DNA hydrogels for use as a sustained delivery system for both intercalated doxorubicin (DXR) and immunostimulatory CpG motifs for cancer treatment. X-shaped DNA (X-DNA) was designed as a building unit, and underwent ligation to form DNA hydrogels. Two types of X-DNA were constructed using four oligodeoxynucleotides each, one containing six potent CpG motifs (CpG X-DNA) and the other with none (CpG-free X-DNA). CpG X-DNA was more effective than its components or the CpG-free counterpart in terms of the production of tumor necrosis factor-α from murine macrophage-like RAW264.7 cells, as well as maturation of the murine dendritic DC2.4 cells. The cytotoxic effects of X-DNA, DXR and their complexes were examined in a co-culture system of colon26/Luc cells, a murine adenocarcinoma clone stably expressing firefly luciferase, and RAW264.7 cells. DXR/CpG X-DNA showed the highest ability to inhibit the proliferation of colon26/Luc cells. DXR was slowly released from CpG DNA hydrogels. Injections of DXR/CpG DNA hydrogels into a subcutaneous colon26 tumor effectively inhibited tumor growth. These results show that CpG DNA hydrogels are an effective sustained system for delivery of immunostimulatory signals to TLR9-positive immune cells and DXR to cancer cells.