The effect of susceptibility of gadolinium contrast media on diffusion-weighted imaging and the apparent diffusion coefficient

RATIONALE AND OBJECTIVES

The development of parallel magnetic resonance imaging has resulted in the frequent use of diffusion-weighted imaging (DWI) in clinical medicine, which usually involves the use of contrast medium. However, gadolinium (Gd) contrast medium may have some effect on DWI and the apparent diffusion coefficient (ADC). The present study was performed to determine whether the magnetic susceptibility of contrast medium alters the DWI signal and the value of ADC in some imaging techniques.

MATERIALS AND METHODS

Nonfat suppression DWI, short-time inversion recovery (STIR) combination, and chemical shift selective (CHESS) combination DWI were performed to examine 10 phantoms with gadolinium-meglumine gadopentetate (Gd-DTPA) dissolved at concentrations from 0.0005 to 0.1 mmol in physiologic saline as a contrast medium. The average pixel value and ADC of each method were determined.

RESULTS

ADC showed no differences between before and after treatment with contrast medium for all imaging techniques with Gd considered distributed over the whole tumor. The signal intensity did not change on nonfat suppression or CHESS combination DWI, but deteriorated on STIR.

CONCLUSIONS

ADC was not influenced by the magnetic susceptibility of contrast medium. In addition, it was suggested that the ability of tumor detection may be reduced if STIR is used as fat suppression.

Polybrominated diphenyl ethers in human serum and sperm quality

Polybrominated diphenyl ethers (PBDEs) are widely used flame retardants; currently, they are identified as ubiquitous environmental contaminants. Several studies indicate that PBDEs might affect male fertility. We present the results of a pilot study on the relationship between human serum PBDEs and sperm quality. The PBDE levels in Japan are comparable to those found in European countries. Strong inverse correlations were observed between the serum concentration of 2,2',4,4',5,5'-hexabromodiphenyl ether and sperm concentration (r = -0.841, p = 0.002) and testis size (r = -0.764, p = 0.01). Extensive studies on the relationship between PBDEs and sperm quality are required.

Pontine hypoplasia in children with periventricular leukomalacia

BACKGROUND AND PURPOSE

The brain stem in patients with periventricular leukomalacia (PVL) appears smaller than normal on MR imaging, but few reports have described this feature, and the number of patients has been relatively small. The present study was conducted to examine the hypothesis that the pons in patients with PVL is smaller than normal.

MATERIALS AND METHODS

Using MR imaging, we examined 80 children (43 boys and 37 girls) with PVL and 80 age-matched control children (41 boys and 39 girls). The control children were diagnosed as neurologically and developmentally normal by pediatric neurologists and also showed normal MR imaging findings. MR imaging was performed at a corrected age range of 0-5 years in both groups. We measured the anteroposterior diameter of the whole pons, the tegmentum and the basis, and the corpus callosal length by using midline T1-weighted sagittal images and compared each parameter between the PVL groups and the control groups.

RESULTS

Pontine diameters in all of the regions were significantly smaller in the PVL group than in the control group (mean +/- SD, whole pontine diameters, 1.66 +/- 0.21 and 1.87 +/- 0.23 cm [P < .001]; basis diameters, 0.42 +/- 0.10 and 0.51 +/- 0.14 [P < .001]; tegmentum diameters, 1.23 +/- 0.20 and 1.36 +/- 0.19 [P < .001], respectively). The respective corpus callosal lengths were 5.02 +/- 0.90 and 5.51 +/- 0.76 (P < .001). There was no significant difference in the basis/tegmentum ratio between the PVL group and the control group. When the age-related pontine diameter differences were examined, there was already a significant difference at 0 years of age between the 2 groups. There was a significant correlation between whole pontine diameter and corpus callosal length in the PVL group (correlation coefficient, 0.52; P < .001) and the control group (correlation coefficient, 0.63; P < .001).

CONCLUSION

We have proven that pontine diameter in patients with PVL is significantly smaller than that in normal control subjects, including each diameter of basis and tegmentum.

Phase II study of radiation therapy combined with weekly nedaplatin in locally advanced uterine cervical carcinoma (LAUCC): Kitasato Gynecologic Radiation Oncology Group (KGROG 0501)--initial analysis

OBJECTIVE

Locally advanced uterine cervical carcinoma (LAUCC) treated with chemoradiotherapy is considered to be the standard treatment regimen. However, no evidence of its efficacy and safety has been obtained from the Japanese population. Furthermore, the total dose of Japanese radiation therapy protocol is less than that of the USA which indicated that chemoradiotherapy for LAUCC is better than radiation therapy alone by phase III clinical trials. Thus, the current phase II study was designed to evaluate chemoradiotherapy with a lower radiation dose for LAUCC using weekly nedaplatin effectively and safely in the Japanese population. Nedaplatin is a platinum drug and no hydration is required to infuse patients because it is less toxic on renal function. If this phase II trial is successful, chemoradiotherapy for LAUCC in out-patient clinics could be possible.

PATIENTS AND METHODS

Patients registered in the current study were found to have LAUCC based on the following criteria i) pathologically proven squamous cell carcinoma or adenocarcinoma, ii) FIGO clinical Stage Ib, IIa, IIb with bulky tumor (diameter > 40 mm assessed by pelvic magnetic resonance imaging) or pelvic lymph node swelling (diameter > 10 mm assessed by pelvic computed tomography); iii) FIGO clinical Stage IIIa, IIIb and IVa with no paraaortic lymph node swelling (diameter > 10 mm) observed by abdominal computed tomography; iv) age: 20-75 years; v) performance status: 0-2. The treatment protocol was as follows: Radiation therapy in a combination of external beam radiation therapy (total dose: 50 Gy-52 Gy/25-27 fractions with central shielding after 30-32 Gy) with high-dose rate intracavitary irradiation (24-30 Gy/4-6 fractions to point A). Chemotherapy applied in the current study was weekly nedaplatin infused intravenously (30 mg/mm2/time, once a week, total 150 mg/mm2/5 weeks). Sample size in the current study was 45 LAUCC patients recruited for three years at a single institution. This protocol was permitted by the ethics committee of Kitasato University Hospital.

RESULTS

Ten patients were registered in this study between June 2005 and March 2006. The median age was 57.5 years (range 36-73). PS0 was five and PS1 was five. As for clinical stage, nine were IIIb and only one was IIb. Nine patients were proven to have squamous cell carcinoma and one adenocarcinoma. The median maximum tumor diameter was 62.5 mm (range 30-100 mm). As for initial response, eight had CR and two had PR (100% response rate). As for hematological acute morbidity, three were grade 2, six were grade 3, and one was grade 4.

CONCLUSIONS

This initial analysis of the phase II study confirmed that concurrent chemoradiotherapy using nedaplatin is safe and efficacious, thus we decided to undergo further studies.

Bisphenol A (BPA) and its source in foods in Japanese markets

The determination of bisphenol A (BPA) and/or bisphenol A diglycidyl ether (BADGE) in foods sold in Japanese markets and in water leached from six epoxy resin cans with similar diameters was carried out using high-performance liquid chromatography (HPLC) with electrochemical detection (LC/ECD), LC-mass spectrometric detection (LC/MS) and LC-tandem mass spectrometric detection (LC/MS/MS). BPA concentrations were 0-842 ng g(-1) for 48 canned foods, 0-14 ng g(-1) for 23 foods in plastic containers, and 0-1 ng g(-1) for 16 foods in paper containers. No BADGE was detected in three canned foods. There was no difference in leaching concentrations of BPA into glycine buffers at pHs 8 and 11, and water. The amounts of BPA leached into water from six epoxy resin cans held at 121 degrees C for 20 min were almost the same as the cans' contents and were much higher than the amounts leached from cans held at or below 80 degrees C for 60 min. The amount leached depended on the type of can, but not on the amount of BADGE leached from the cans. Considerably more BPA than BADGE leached to water from six cans. Two cans whose contents had high concentrations of BPA showed no BADGE leaching even at 121 degrees C, suggesting the different kinds of epoxy resin can linings from others. The results imply that the main source of human exposure to BPA is food from cans with linings that contain high percentages of BPA as an additive or an unforeseen contaminant.

Effectiveness of concurrent radiation therapy combined with peroral chemotherapy (UFT or TS-1 ) for T2N0 glottic cancer in Japanese population

16538

Background: The current study retrospectively reviewed 147 T2N0 glottic cancer patients treated at Kitasato University Hospital to compare concurrent radiation therapy combined with chemotherapy (most of them: UFT or TS-1, peroral anti-cancer drugs), with conventional radiation therapy. Methods: One-hundred and forty-seven patients with T2N0 glottic cancer treated with radiation therapy alone or radiation therapy combined with peroral (UFT or TS-1)or intravenous chemotherapy between 1974 and 2005 at Kitasato University Hospital. The median age of all patients was 64 years (range; 45–86 years). As for gender, 145 were males and the others were females. As for radiation therapy protocol, all except one were treated with 2 Gy per fraction, 5 fractions per week and a total of 60 Gy. Only one patient was treated with 1.8 Gy per fraction, 5 fractions per week and a total of 61.2 Gy. As for chemotherapy protocol, 83 patients were concurrently given UFT, (UFT group). 24 patients given TS-1, (TS-1 group) and 23 patients underwent intravenous chemotherapy using mainly cisplatin (Pt. group). The other 23 patients underwent no chemotherapy. Results: The median follow-up time was 61 months (range; 3–372 months). The 5-year local control rates of all patients was 83.4 %. Stratified by radiation therapy alone group (RT group) and concurrent chemoradiation therapy (CCRT group), The 5-year local control rates of RT group and CCRT group were 82.7%, 83.4%, respectively (p=NS). Stratified by chemotherapy regimens of CCRT group, 3-year local control rates of UFT group, TS-1 group and Pt. group were 90.1%, 100.0% and 73.4%, respectively, which indicated the peroral chemotherapy was not inferior to intravenous chemotherapy. As for morbidity, 2 patients of UFT group experienced severe enteritis . Conclusion: Concurrent radiation therapy combined with UFT or TS-1 for T2N0 glottic cancer might be the one of standard treatments in Japanese Population. Furthermore, concurrent use of TS-1 might perform break-through for T2N0 glottic cancer in terms of local control rate, overall survival and burdens of treatment on patients.

No significant financial relationships to disclose.

Stereotactic bradiotherapy (SRT) for operable stage I non-small cell lung cancer: Is SRT comparable to surgery?

7623

Background: Stereotactic radiotherapy (SRT) has been aggressively performed as a radical treatment for stage I non-small cell lung cancer (NSCLC) in Japan, however most cases were medically inoperable. In a large Japanese multi-institutional experience, we reviewed the treatment outcome of SRT for medically operable stage I NSCLC cases with the patients’ refusal to surgery. Methods: In 1995–2004, 86 medically operable patients with stage I NSCLC (median age, 74 years; 62 T1N0M0; 24 T2N0M0) were treated with SRT alone in 14 reliable institutions. Stereotactic three-dimensional treatment was performed using non-coplanar dynamic arcs or multiple static ports. A total dose of 20 to 72.5 Gy at the isocenter was administered in 1 to 10 fractions. Median calculated biological effective dose (BED) was 115 Gy (range, 100–153 Gy). The data was collected and analyzed in a retrospective manner. Results: During follow-up (median, 43 months), pulmonary complications of above grade 2 arose in 4 patients (5.8%). Local control rates at 3 and 5-year post SRT were 88.1% and 85.5%, respectively. Three and 5-year overall survival rates were 80.7% and 71.3%, respectively. Five-year overall survival rate for patients whose age was over 70 years (n=27) and under 70 years (n=58) were 74.3% and 69.6%, respectively. Five-year overall survival rate for stage IA (n=62) and IB (n=24) cases were 72.3% and 68.4%, respectively. Conclusions: SRT is safe and promising as a radical treatment for operable stage I NSCLC. The survival rate of SRT is potentially comparable to that of surgery.

No significant financial relationships to disclose.

Solitary myofibroma of the lumbar vertebra: adult case

We present the first known adult case of solitary myofibroma of bone, which affected a lumbar vertebra in a 33-year-old male. Radiography identified a purely lytic lesion with a sclerotic rim in the right pedicle of L1. CT showed an expansile lytic lesion with a sclerotic rim. MRI of the lesion revealed an isointense signal on T1-weighted images, an inhomogeneously hyperintense signal on T2-weighted images, and marked enhancement with gadolinium. Pathological study showed a mixed picture of nodular proliferation of spindle-shaped myoid cells and hemangiopericytomatous proliferation of short spindle/small round cells. The tumor cells were immunoreactive for smooth muscle actin and immunonegative for desmin. This case of solitary myofibroma of bone is exceptionally rare because of its occurrence in an adult older than 20 years of age and its location at an extra-craniofacial site.

Should we discard the graft? Analysis of the renal grafts with a total ischemia time of more than 24 hours donated after cardiac death

The objective is to investigate the outcome of transplantation using kidney grafts from donors after cardiac death (DCDs) with a total ischemia time (TIT) longer than 24 h. All 373 kidneys were procured from DCDs. They were procured using the in-situ regional cooling technique. Grafts were classified into two groups according to TIT. Fifty-three grafts had a TIT longer than 24 h (group 1), and the other 320 grafts (group 2) were less than 24 h. The numbers of never functioning grafts (PGF) were 3 in group 1 (5.7%) and 17 in group 2 (5.3%), a nonsignificant difference. Graft survival rates at 3, 5 and 10 years posttransplant were 84.9%, 73.0% and 64.1% in group 1, and 76.3%, 69.9% and 57.1% in group 2, which demonstrate no significant difference. The significant risk factors for graft failure were donor age, serum creatinine level on hospitalization and WIT. However, TIT longer than 24 h was not employed. Multivariate logistic regression indicated that only WIT was associated with an increase in the risk of PGF. Our results demonstrate that kidneys from DCDs, even if their TIT is more than 24 h, should be considered a worthwhile source of renal grafts.

Atypical, bidirectional regulation of cadmium-induced apoptosis via distinct signaling of unfolded protein response

Cadmium is a widely distributed nephrotoxic metal that causes renal tubular injury. In this report, we investigated involvement of endoplasmic reticulum (ER) stress and individual unfolded protein responses in cadmium-initiated apoptosis of tubular epithelial cells. Cadmium chloride (CdCl(2)) induced expression of endogenous ER stress markers, GRP78, GRP94 and CHOP in vitro and in vivo, and subsequently caused cytological changes typical of apoptosis. Attenuation of ER stress by transfection with ER chaperone GRP78 or ORP150 suppressed CdCl(2)-triggered apoptosis. In response to CdCl(2), phosphorylation of RNA-dependent protein kinase-like ER kinase (PERK) and eukaryotic translation initiation factor 2alpha (eIF2alpha) was observed. Enhanced phosphorylation of eIF2alpha attenuated, whereas inhibition of eIF2alpha exacerbated CdCl(2)-induced apoptosis. Activating transcription factor 6 (ATF6) was also activated by CdCl(2) and blockade of this process suppressed induction of CHOP and thereby improved cell survival. CdCl(2) also triggered activation of the inositol-requiring ER-to-nucleus signal kinase 1 (IRE1)-X-box-binding protein 1 (XBP1) pathway and inhibition of XBP1 attenuated apoptosis independent of GRP78 and CHOP. c-Jun N-terminal kinase (JNK), another molecule downstream of IRE1, was also phosphorylated by CdCl(2) and its inhibition attenuated apoptosis. These results evidenced bidirectional regulation of apoptosis in cadmium-exposed cells. The ATF6 and IRE1 pathways cooperatively caused apoptosis via induction of CHOP, activation of XBP1 and phosphorylation of JNK, and the PERK-eIF2alpha pathway counteracted the proapoptotic processes.

Up-Regulation of Osteopontin, Chemokines, Adhesion Molecule, and Heat Shock Proteins in 1-Hour Biopsy From Cardiac Death Donor Kidneys

AIMS

Since April 1979, 471 kidneys were retrieved from donors after cardiac death (DCD) using an in situ regional cooling technique, with excellent renal function and good long-term graft survival. However, the precise cascade of events following transplantation of DCD kidneys and the influence of ischemia-reperfusion injury remain unclear. In this study, we performed gene expression profiling using 1-hour biopsy samples from DCD kidneys versus those from living sources.

METHODS

All kidney grafts were procured at our center using an in situ regional cooling technique from DCD. Living donor kidneys (LD) were harvested by open nephrectomy. All graft biopsies were performed 1 hour after reperfusion (DCD n = 8, LD n = 9). We analyzed the expression profile of 20,173 genes.

RESULTS

One hundred seventy eight genes were up-regulated (>2-fold difference and DCD/LD > 1.5) and 120 down-regulated (<1/2-fold and LD/DCD > 1.5) in DCD kidneys. Expression of osteopontin (22.5 +/- 2.6-fold DCD vs 7.7 +/- 1.7 LD; P < .001), chemokines (CCL4 4.4 +/- 0.7 vs 2.5 +/- 0.3; P < .01), (CCL2 6.0 +/- 1.3 vs 2.8 +/- 0.5), CXCL1 (9.5 +/- 0.4 vs 2.0 +/- 0.2), and CXCL2 (16.7 +/- 5.3 vs 4.8 +/- 1.3; P < .05), adhesion molecule (ICAM-1 4.7 +/- 0.7 vs 2.5 +/- 0.4; P < .05), and heat shock proteins (HSPA1L 6.7 +/- 0.7 vs 1.6 +/- 0.3, HSPA1A 17.7 +/- 2.6 vs 2.4 +/- 0.5, HSPA1B 13.3 +/- 0.2 vs 3.0 +/- 0.7, HSPA5 6.7 +/- 0.8 vs 3.2 +/- 0.3, HSPB1 2.9 +/- 0.2 vs 1.0 +/- 0.1, and HSPH1 19.4 +/- 3.0 vs 5.9 +/- 1.1; P < .001) were up-regulated in the kidneys from DCD.

CONCLUSION

This report analyzed global gene expression using 1-hour biopsy samples from DCD kidneys. These results may provide new insight into the identification of novel target genes for the development of therapeutic approaches and for determining graft viability of kidneys from DCD.

Should We Discard the Renal Allografts From Cardiac Death Donors That Have Total Ischemic Time Longer Than 24 Hours?

PURPOSE

The objective of this study was to investigate the outcome of transplantation using kidney grafts donated after cardiac death (DCD) with a total ischemic time (TIT) longer than 24 hours.

PATIENTS AND METHODS

We followed 373 kidneys recovered from DCD donors and transplanted at 41 centers. All kidneys were procured from uncontrolled DCD donors. Grafts were classified into two groups according to TIT. We recorded renal function and duration of the survival period for each graft.

RESULTS

Fifty-three grafts had a TIT longer than 24 hours (group 1). The other 320 grafts had a TIT less than 24 hours (group 2). The number of never functioning grafts were three in group 1 (5.7%) and 17 in group 2 (5.3%). Delayed graft function (DGF) occurred in 44 group 1 (83.0%) and 254 group 2 kidneys (79.4%) for intervals of 13.5 +/- 12.6 versus 10.9 +/- 12.6 days, respectively. Graft survival rates at 3, 5, and 10 years posttransplant were 84.9%, 73.0%, 64.1% for group 1, and 76.3%, 69.9%, 57.1% for group 2. In a Cox proportional hazards model, TIT longer than 24 hours was not a significant independent risk factor.

CONCLUSION

Our results showed that even kidneys with TITs of over 24 hours yielded comparable results despite a higher incidence of DGF.

Is Pulsatile Perfusion Necessary for Renal Transplantation Engrafting Kidneys From Cardiac Death Donors?

BACKGROUND

There has been a considerable literature describing the use of pulsatile perfusion (PP) to evaluate the efficacy of organs from deceased donors. Since 1979, we recovered 469 kidneys from deceased donors after cardiac death (DCDs), using an in situ regional cooling technique and preservation by simple cold storage. In this study, the posttransplantation outcomes as well as long-term survivals of renal grafts from DCDs were compared with PP data in the recent literature.

MATERIALS AND METHODS

We compared our recent data with 176 kidneys recovered between 1993-2002 using an in situ regional cooling technique. Patient and graft survivals were compared with those from the Scientific Registry of Transplant Recipients (SRTR) database.

RESULTS

Following transplantation, 4.5% of the grafts never recovered; 10.3% of the grafts showed immediate renal function; 85.2% of the grafts had delayed graft function (DGF) with an average acute tubular necrosis (ATN) period of 13.1 days compared with 54.3% DGF from DCD using PP. Graft survival rates at 1, 3, 5, and 10 years were 90.8%, 86.5%, 77.8%, and 69.0%, respectively, compared with 89% at 1 year and 80% at 3 years reported for DCD by the SRTR in which almost 30% of the grafts underwent PP.

CONCLUSIONS

Although PP seemed to have some advantage to decrease the DGF ratio, an in situ regional cooling technique with simple cold storage may provide excellent graft function and long-term graft survival as well as having benefits in cost and transportation.

Cine MR imaging of uterine peristalsis in patients with endometriosis

Endometriosis is one of the most important causes of infertility; however the precise mechanism by which it affects female fertility is unclear. The objective of this study was to study the functional aspects of the uterus by evaluating uterine contractility in patients with endometrial cysts of the ovary. The study population was recruited from two institutes and consisted of 26 women (periovulatory (10), luteal (13), and menstrual phase (3); age range: 19-51 years) with untreated endometriosis; the control group consisted of 12 healthy women (age range: 22-41 years). Cine MR imaging obtained by a 1.5T magnet was visually evaluated at 12x faster than real speed, focusing on the presence of uterine peristalsis, the direction and frequency of peristalsis, and the presence of sustained uterine contractions. Uterine peristalsis was identifiable in 3/10, 3/13, and 3/3 of the endometriosis patients in each menstrual cycle, respectively, and in 11/12, 3/12, and 5/12 of their control subjects. Peristaltic detection rate and frequency were significantly less for the endometriosis group than for the controls in the periovulatory phase only (p<0.05). Sustained contractions were recognized in 19/36 control subjects and in 13/26 endometriosis patients, but the difference was not significant. Uterine peristalsis appears to be suppressed during the periovulatory phase in patients with endometriosis, which may have an adverse effect on sperm transport.

Dynamic helical CT mammography of breast cancer

PURPOSE

The purpose of this study was to determine whether dynamic helical computed tomography (CT)-mammography could assist in selecting the most appropriate surgical method in women with breast cancer.

MATERIALS AND METHODS

Preoperative contrast-enhanced helical CT scanning of the breast was performed on 133 female patients with suspicion of breast cancer at the same time as clinical, mammographic, and/or ultrasonographic examinations. The patients were scanned in the prone position with a specially designed CT-compatible device. A helical scan was made with rapid intravenous bolus injection (3 ml/s) of 100 ml of iodine contrast material. Three-dimensional maximum intensity projection (MIP) images were reconstructed, and CT findings were correlated with surgical and histopathological findings.

RESULTS

Histopathological analysis revealed 84 malignant lesions and seven benign lesions. The sensitivity, specificity, and accuracy levels of the CT scanning were 94.6%, 58.6%, and 78.9%. Helical scanning alone revealed additional contralateral carcinomas in three of four patients and additional ipsilateral carcinomas in three of five patients. However, the technique gave false-positive readings in 24 patients. The preoperative CT-mammogram altered the surgical method in six patients.

CONCLUSION

Dynamic helical CT-mammography in the prone position may be one of the choices of adjunct imaging in patients with suspected breast cancer scheduled for surgery.

Screening and identification of substances that regulate nephrin gene expression using engineered reporter podocytes

Downregulation of nephrin in podocytes leads to development of proteinuria in human and experimental kidney diseases. However, little is understood about pathophysiologic substances that regulate nephrin expression. In this report, we established conditionally immortalized reporter podocytes REPON for sensitive, continuous monitoring of nephrin gene expression. A murine podocyte cell line harboring a temperature-sensitive simian virus 40 large T antigen was stably transfected with a gene encoding secreted alkaline phosphatase (SEAP) under the control of the 5.4 or 8.3 kb nephrin gene promoter. The established reporter cells REPON5.4 and REPON8.3 were exposed to various pathophysiologic substances, and culture media were subjected to SEAP assay to identify regulators of nephrin gene expression. Among the bioactive substances tested, three physiological ligands of nuclear receptors including all-trans-retinoic acid, 1,25-dihydroxyvitamin D3, and dexamethasone significantly activated the nephrin gene promoter in a dose-dependent manner. These effects were observed in both REPON5.4 and REPON8.3 and were associated with upregulation of nephrin mRNA. The effects of these substances were synergistic, and the maximum effect was observed by combination of three agents. In contrast, inflammatory cytokines interleukin-1beta (IL-1beta) and tumor necrosis factor-alpha as well as phorbol ester significantly downregulated the activity of the nephrin promoter as well as nephrin gene expression. These results elucidated the bidirectional regulation of nephrin by distinct pathophysiologic substances and may provide molecular bases for explaining how proteinuria is induced under pathologic situations and why some ligands for nuclear receptors have the anti-proteinuric potential.