Unilateral renal cystic disease--report of one case and review of literature

Clinical presentation of unilateral renal cystic disease (URCD) is characterized by multiple simple cysts in only 1 kidney. Involvement of other intra-abdominal organs is not found. Renal function is usually preserved despite the existence of multiple cysts. No genetic background can be delineated up to the present. We present 1 patient with URCD, who was evaluated for his right flank pain. Urinalysis and biochemical tests showed normal renal function (BUN 5.03 mmol/l, creatinine 110.5 micromol/l). Ultrasonographic examination was done and it revealed 2 right renal stones. Furthermore, multiple renal cysts over the juxta-medullary area were noted. His left kidney was intact. Computed tomography (CT) of both kidneys confirmed this finding. 99mTc-DTPA renal scan showed that the glomerular filtration rate of both kidneys was not significantly different. There was no family history of renal diseases. His parents, grandparents and siblings were examined for possible kidney lesions, but none of them had any renal cystic lesion. This patient was followed for only a relatively short period of time (3 years) and his renal function did not deteriorate. Follow-up image studies with sonography and CT were not different from the previous ones.

Ardisiaquinones from Ardisia teysmanniana

Bioassay-guided fractionation of a CHCl(3) extract from the leaves of Ardisia teysmanniana Scheff. (Myrsinaceae) has led to the isolation of three new alkyldibenzoquinone derivatives that showed inhibitory activity in an in vitro assay for UDP-MurNac synthesis. The structures of ardisiaquinone G, H and I were established using MS and NMR spectroscopic methods.

Differential effects of FMLP-activated neutrophils from patients with IgA nephropathy enhanced endothelin 1 production of glomerular mesangial cells

BACKGROUND

Neutrophil infiltration in the glomeruli is common in patients with IgA nephropathy (IgAN). The pathogenetic roles of the infiltrated neutrophils and their relationship with glomerular mesangial cells, however, are not clear.

METHODS

We examined the effects of coculture with N-formyl-methionyl-leucyl-phenylalanine (FMLP) activated neutrophils on the viability, endothelin 1 (ET-1) production, and ET-1 mRNA expression of rat glomerular mesangial cells. Neutrophils were isolated from 15 IgAN patients, from 13 patients with non-IgA mesangial proliferative glomerulonephritis (MsPGN), and from 10 normal controls.

RESULTS

The ET-1 production by mesangial cells was significantly higher after stimulation with FMLP-activated neutrophils from IgAN patients than that of MsPGN patients and normal controls, and this effect was significantly abolished by pretreating mesangial cells with superoxide dismutase and partly abolished by catalase. The ET-I mRNA expression of mesangial cells showed a parallel increase with ET-1 protein. The trypan blue exclusion test showed significant mesangial cell death after stimulation with FMLP-activated neutrophils as compared with quiescent neutrophils, and the cell death was also prevented by superoxide dismutase but not catalase. The FMLP-activated neutrophils from IgAN patients produced more superoxide than those of MsPGN patients and normal controls.

CONCLUSION

The FMLP-activated neutrophils from patients with IgAN have differential effects in enhancing the cell death and the ET-1 production of glomerular mesangial cells through the release of superoxide.

Advanced glycation end product-induced proliferation in NRK-49F cells is dependent on the JAK2/STAT5 pathway and cyclin D1

Advanced glycation end products (AGEs) are important in the pathogenesis of diabetic nephropathy, which leads to renal fibrosis. Previously, we found that the janus kinase (JAK)/signal transducers and activators of transcription (STAT) signaling pathway is necessary for AGE-induced cellular proliferation in normal rat kidney interstitial fibroblast (NRK-49F) cells. However, a direct link between JAK/STAT and cell-cycle progression has not been well established. In this regard, STAT5 has been found to induce cyclin D1 and proliferation in hematopoietic cells. Therefore, we examined effects of AGE on STAT5 and cell-cycle-dependent mitogenesis in NRK-49F cells. We found that AGE increased cyclin D1 expression and cyclin-dependent kinase (cdk)4 activity while decreasing p21(WAF1/CIP1) expression. We also found that AGE (100 microg/mL) induced STAT5 tyrosine phosphorylation. Meanwhile, AGE induced STAT5 protein-DNA binding activity, which was reversed by AG-490 (a specific JAK2 inhibitor) and STAT5 decoy oligodeoxynucleotide (ODN). In addition, STAT5 decoy ODN reversed AGE-induced cell-cycle-dependent cellular proliferation and cyclin D1 protein expression. We concluded that AGE induced cell-cycle-dependent cellular proliferation by inducing the JAK2-STAT5-cyclin D1 and cdk4 pathways in NRK-49F cells.

Induction of cellular toxicity in cultured porcine corneal keratocytes by endothelin-1

The effect of endothelin-1 (ET-1) on corneal cells is not well understood. We investigated the biochemical changes of cultured porcine corneal keratocytes under exposure to ET-1. The results indicate that ET-1 has remarkable effects to inhibit corneal keratocytes on 3H-thymidine, 3H-leucine, 3H-uridine uptakes and cellular migration. It is in a dose-dependent manner at concentrations ranging from 10(-7) M to 10(-9) M. The 50% inhibitory dose (ID50) for ET-1, as measured by 3H-thymidine uptake, 3H-uridine uptake and 3H-leucine uptake, were 10(-7) M, 10(-0.52) M and 10(-11.8) M, respectively. The dead and living cells were estimated with MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide) assay that was converted tetrazolium dye of living cells only into insoluble purple formazan crystals within mitochondria. In the presence of ET-1, the cellular MTT values were also decreased. The ID50 for ET-1 with cell migration assay and MTT assay were measured at 10(-7.86) M and 10(-5.1) M. Endothelin-1 (10(-6) M) promptly changed cellular morphology and attenuated adhesion observed with laser scanning cytometer. Endothelin-1-induced characteristic apoptosis cells were observed using a TUNEL assay that detected fragmented DNA of apoptosis. Western blot assay revealed that endothelin-1 induced proteolysis and decreased in fibronectin protein. These findings indicate that endothelin-1 may lead keratocytes to death resulting from induction of apoptosis and functional loss.

Xanthones from Garcinia parvifolia

Nine new xanthones, parvixanthones A-I (1-9), isolated from the dried bark of Garcinia parvifolia, were found to have a common 1,3,6,7-oxygenated pattern for their xanthone nucleus, but various oxygenated isoprenyl or geranyl substituent groups. The structures were determined by spectroscopic methods.

Toxic effects of mitomycin-C on cultured ciliary process cells and trabecular meshwork cells

Mitomycin-C has recently become an adjunct medication for inhibition of fibroblast proliferation in glaucoma filtering procedures. Prolonged postoperative ocular hypotony has been a frequent complication of trabeculectomy with mitomycin-C. In order to characterize the hypotony mechanism, we compared the toxic effects of mitomycin-C on cultured rabbit ciliary process cells and trabecular meshwork cells. The results indicate that mitomycin-C has a more marked effect on ciliary process cells on 3H-thymidine uptake than on trabecular meshwork cells at concentrations ranging from 10(-1) to 10(-5) mg/ml after 3-, 5- and 60-min treatment, respectively. The living cells after mitomycin-C treatment were estimated with MTT assay that was converted tetrazolium dye of living cells only into insoluble purple formazan crystals within mitochondria. In the presence of mitomycin-C for 3, 5, and 60 min, the cellular MTT values in ciliary process cells were more decreased than in trabecular meshwork cells. Depolarization of the trabecular meshwork cells with 50 mM KCl led to an increase in intracellular calcium concentration, whereas application of mitomycin-C at 10(-3) mg/ml resulted in decrease of KCl-induced intracellular calcium increase. Mitomycin-C (10(-3) mg/ml) decreased cAMP concentration in ciliary process cells following 3- and 5-min treatment; however, it did not significantly affect the cellular cAMP concentration after only a 1-min exposure. Mitomycin-induced marked ladder pattern of DNA fragmentation was observed in ciliary process tissues after treatment with 10(-1) mg/ml of mitomycin-C for 3 and 5 min. However, the DNA pattern in trabecular meshwork tissues was not obviously affected by mitomycin-C. These findings from our results indicate that mitomycin-induced ocular hypotony may result from damage to both ciliary process and trabecular meshwork tissues.

Endothelin-induced changes of secondary messengers in cultured corneal endothelial cells

The effect of endothelins on corneal endothelial cells is not well understood. We have investigated the effects of endothelin-1 (ET-1), endothelin-2 (ET-2) and endothelin-3 (ET-3) on bovine corneal endothelial cellular proliferation and the secondary messenger changes in cells in the presence of ET-1. It was found that the 3H-thymidine uptake was enhanced by ET-1 significantly, whereas ET-2 and ET-3 had no effect. ET-1 remarkably affects the increase of corneal endothelial cells on 3H-thymidine, 3H-leucine, and 3H-uridine uptakes in a dose-dependent manner. The 50% effective concentrations (EC50) for ET-1, as measured by 3H-thymidine uptake, 3H-uridine uptake, and 3H-leucine uptake were 10(-8.78) M, 10(-8.53) M and 10(-8.04) M, respectively. It was found that endothelin-1 increased intracellular calcium concentration by using the method of preloading with Fura-2-AM and assaying with spectrophotometry. The cellular IP1, IP2, and IP3 were also stimulated in the presence of ET-1. Moreover, ET-1 enhanced the basal cellular cAMP and cGMP concentrations in corneal endothelial cells in a dose-dependent manner. Immunofluorescent staining revealed that ET-1 increased the fibronectin protein concentration and changed protein distribution in corneal endothelial cells. These findings indicate that endothelin-1 increases in cell proliferation and biological changes may be involved in changing intracellular calcium mobility, increasing intracellular phosphoinositides, enhancing intracellular cGMP and cAMP accumulation, and fibronectin protein synthesis.

Differential effects of circulating IgA isolated from patients with IgA nephropathy on superoxide and fibronectin production of mesangial cells

BACKGROUND

IgA nephropathy (IgAN) is characterized by predominant deposition of IgA in the glomerular mesangium. Serum IgA is often elevated in patients with IgAN, and it has been postulated that it is responsible for the mesangial lesions. However, the direct effect of circulating IgA on mesangial cells is not clear.

METHODS

We investigated the effects of sera and IgA which were isolated from patients with IgAN on thymidine uptake, superoxide and fibronectin production and fibronectin mRNA expression of cultured rat mesangial cells, and we compared the findings to the effects of IgA isolated from patients with non-IgA mesangial proliferative glomerulonephritis (MsPGN) and normal controls. IgA was isolated with affinity chromatography using cyanogen bromide activated Sepharose 4B coupled to sheep antihuman IgA antiserum.

RESULTS

Our results demonstrated that both sera and IgA from patients with IgAN dose-dependently increased mitogenesis of mesangial cells as measured by (3)H-labeled thymidine uptake. The thymidine uptake by sera and IgA isolated from patients with IgAN was significantly higher than that of sera and IgA isolated from patients with MsPGN and normal controls. Sera and IgA from patients with IgAN significantly enhanced superoxide and fibronectin production and fibronectin mRNA expression of mesangial cells. The superoxide and fibronectin production was also significantly higher as compared with patients with MsPGN and normal controls.

CONCLUSIONS

Our results indicate that circulating IgA isolated from patients with IgAN is different from that of patients with MsPGN and normal controls and may potentially induce oxidative injury and production of extracellular matrix of glomerular mesangial cells in IgAN.

Critical evaluation of the current indications for transition zone biopsies

OBJECTIVES

Two primary indications for the performance of anteriorly directed transition zone (TZ) biopsies are (a) an elevated prostate-specific antigen (PSA) level and an enlarged, non-nodular prostate and (b) prior negative sextant biopsies of the prostate. These indications are, however, based on a study population evaluated early in the PSA era (1989 to 1992). The current analysis targeted a more contemporary series of patients (1995 to 2000) presenting with these two indications for TZ biopsies, who underwent ultrasound scanning and biopsies by the same examiner and with the same equipment as in the earlier series.

METHODS

We evaluated 390 men, 274 (70.3%) of whom underwent sextant plus TZ biopsies for elevated PSA levels and an enlarged, non-nodular prostate; 116 (28.7%) underwent this biopsy strategy because of an elevated or rising PSA in whom prior sextant biopsies had not revealed cancer.

RESULTS

Of the 274 patients who underwent initial sextant biopsies plus anterior biopsies for an enlarged, non-nodular prostate, 49 (17.9%) were found to have adenocarcinoma and in only 4 (1.5%) did only the TZ biopsies reveal cancer. Of the 116 patients who underwent TZ biopsies after prior negative sextant biopsies, 36 (31.0%) were found to have prostate cancer and in 11 (9.5%) only the TZ biopsies demonstrated cancer.

CONCLUSIONS

The cancer detection rate for sextant plus TZ biopsies in this contemporary series of patients presenting with enlarged, non-nodular prostates was substantially lower than the rate in earlier reports (1.5% compared with 36.9%), despite the consistency in the equipment and examining physician. This may have been due to the stage migration of prostate cancer, which has been observed as a result of the widespread use of PSA measurement for early detection. Sextant plus TZ biopsies are more productive in patients with prior negative biopsies who have a persistent clinical suspicion for prostate cancer on the basis of an elevated and/or rising PSA level.

Role of receptor for advanced glycation end-product (RAGE) and the JAK/STAT-signaling pathway in AGE-induced collagen production in NRK-49F cells

Advanced glycation end-product (AGE) is important in the pathogenesis of diabetic nephropathy (DN), and captopril (an angiotensin converting enzyme inhibitor) is effective in treating this disorder. We have shown that the Janus kinase (JAK)/signal transducers and activators of transcription (STAT) cascade is responsible for AGE-induced mitogenesis in NRK-49F (normal rat kidney fibroblast) cells, but its role in renal fibrosis in DN remains unknown. Therefore, we have sought to determine whether JAK/STAT is involved in AGE-regulated collagen production in NRK-49F cells. We found that AGE time (1-7 days) and dose (10-200 microg/ml)-dependently increased collagen production in these cells. Additionally, AGE increased RAGE (receptor for AGE) protein expression. AGE-induced RAGE expression was dose-dependently inhibited by antisense RAGE oligodeoxynucleotide (ODN) and captopril. AGE-induced type I collagen production and JAK2-STAT1/STAT3 activation were decreased by AG-490 (a specific JAK2 inhibitor), antisense RAGE ODN and captopril. Meanwhile, STAT1 and STAT3 decoy ODNs also suppressed the induction of collagen by AGE. We concluded that RAGE and the JAK2-STAT1/STAT3 pathway were involved in AGE-induced collagen production in NRK-49F cells. Furthermore, captopril was found to reverse AGE-induced collagen production, probably by attenuating RAGE expression and JAK2-STAT1/STAT3 activities.

Role of receptor for advanced glycation end-product (RAGE) and the JAK/STAT-signaling pathway in AGE-induced collagen production in NRK-49F cells

Advanced glycation end-product (AGE) is important in the pathogenesis of diabetic nephropathy (DN), and captopril (an angiotensin converting enzyme inhibitor) is effective in treating this disorder. We have shown that the Janus kinase (JAK)/signal transducers and activators of transcription (STAT) cascade is responsible for AGE-induced mitogenesis in NRK-49F (normal rat kidney fibroblast) cells, but its role in renal fibrosis in DN remains unknown. Therefore, we have sought to determine whether JAK/STAT is involved in AGE-regulated collagen production in NRK-49F cells. We found that AGE time (1-7 days) and dose (10-200 microg/ml)-dependently increased collagen production in these cells. Additionally, AGE increased RAGE (receptor for AGE) protein expression. AGE-induced RAGE expression was dose-dependently inhibited by antisense RAGE oligodeoxynucleotide (ODN) and captopril. AGE-induced type I collagen production and JAK2-STAT1/STAT3 activation were decreased by AG-490 (a specific JAK2 inhibitor), antisense RAGE ODN and captopril. Meanwhile, STAT1 and STAT3 decoy ODNs also suppressed the induction of collagen by AGE. We concluded that RAGE and the JAK2-STAT1/STAT3 pathway were involved in AGE-induced collagen production in NRK-49F cells. Furthermore, captopril was found to reverse AGE-induced collagen production, probably by attenuating RAGE expression and JAK2-STAT1/STAT3 activities.

Alterations of glomerular and extracellular glutathione peroxidase levels in patients and rats with focal segmental glomerulosclerosis

Glutathione peroxidase (GPX) is an important antioxidant that effectively scavenges hydrogen peroxide. Recent studies have revealed that plasma GPX activity is decreased in patients with chronic kidney failure. However, there have been no reports on renal and urinary GPX levels in patients with kidney disorders. Therefore in this study we have measured the plasma and urinary GPX levels and glomerular GPX immunostaining in patients with focal segmental glomerulosclerosis (FSGS) and normal kidney function as compared with those in patients with minimal change disease (MCD) and those in normal control subjects. Rats with puromycin aminonucleoside-induced FSGS were also studied. The results showed that the plasma GPX level was significantly lower in FSGS patients than in either MCD patients or normal control subjects (both P <.01). The urinary GPX level was also significantly lower in FSGS patients than in either MCD patients (P <.05) or normal control subjects (P <.01). The immunostaining score of glomerular GPX was significantly lower in FSGS patients than in normal control subjects (both P <.05). Serial examinations of glomerular GPX immunostaining in FSGS rats also demonstrate a decrease in the score with the progression of disease. Our results indicate that all the plasma, urinary, and glomerular GPX levels are decreased in FSGS patients, indicating a decreased antioxidant defense in the early stages of chronic glomerular diseases.

Plasma and urinary endothelin-1 in focal segmental glomerulosclerosis

The kidney is an important site of endothelin-1 (ET-1) production and is particularly susceptible to ET-1 action. Infusion of ET-1 in rats induces both functional and morphological alterations in the kidneys. Increased plasma level of ET-1 has been reported in patients with chronic renal failure. However, there are still no reports on the plasma and urinary ET-1 levels in patients with focal segmental glomerulosclerosis (FSGS). In the present study, we have measured the plasma concentration and urinary excretion rate of ET-1 in 15 patients with nephrotic syndrome due to FSGS, and observed the serial changes of plasma and urinary ET-1 in nephrotic rats with FSGS, induced by repeated injection with puromycin aminonucleoside (PAN). ET-1 was measured with radioimmunoassay. The results showed that plasma ET-1 concentration in FSGS patients was significantly higher than in normal controls (P < 0.05), and that urinary ET-1 excretion rate was also significantly higher in FSGS patients than in normal controls (P < 0.01). In FSGS patients, the plasma and urinary ET-1 was significantly correlated (P < 0.05), and the urinary ET-1 excretion rate was significantly correlated with the amount of proteinuria (P < 0.05) and the glomerular sclerosing score (P < 0.01). In the ten rats with PAN-induced FSGS, serial examination showed a significant increase in plasma ET-1 after 8 weeks of injections, while the urinary ET-1 excretion rate showed a biphasic increase that showed a peak after 4 to 6 weeks. The same changes in plasma and urinary ET-1 levels were not observed in control rats injected with normal saline at the same frequency. Our results suggest that ET-1 may be involved in the pathogenesis of FSGS in both humans and rats.

High prevalence of selective immunoglobulin A deficiency in peritoneal dialysis patients

We encountered two hemodialysis (HD) patients with recurrent infections and complete immunoglobulin A deficiency (IgAD). To survey the possibility of a similar occurrence in other populations, we conducted the present study. We used nephelometry to examine the levels of immunoglobulins G (IgG), A (IgA), and M (IgM) in 42 continuous ambulatory peritoneal dialysis (CAPD) patients, 246 HD patients, 56 chronic renal failure (CRF) patients, and 250 normal adults. Four CAPD patients (9.5%) and five HD patients (2.0%) were found to be completely IgA deficient (IgA < 6.67 mg/dL). Peritoneal dialysis patients therefore had a significantly higher prevalence of IgAD compared with HD and CRF patients. The underlying diseases leading to dialysis therapy in the IgAD patients varied. Their dialysis durations also varied. The occurrence rate of peritonitis in CAPD patients with IgAD was no higher than in patients without IgAD. The clinical significance of IgAD was focused on mucosal immunity, but the exact prevalence of infection was difficult to define. However, these patients' medical records did suggest more frequent respiratory tract infections and cellulitis events than did the records of patients without IgAD. Two PD patients with IgAD died of pneumonia. Immunodiffusion and indirect ELISA methods were used to detect the presence of auto-antibodies, successfully identifying them in three patients. Further research is needed to study other mechanisms of IgAD.

Effects of drugs on cellular proliferation in cultured iris pigment epithelial cells and retinal pigment epithelial cells

In this study, iris and retinal pigment epithelial cells were cultured from porcine and various drugs including methionine-enkephalin, isoproterenol, dibutyryl cAMP, endothelin-1, dexamethasone and phorbol 12-myristate 13-acetate (PMA) were used to investigate their effects on both cellular proliferation in cultured porcine iris and retinal pigment epithelial cells. Cellular proliferation was estimated with 3H-thymidine uptake. It is indicated that both pigment epithelial cells possess epithelial-like morphology and abundant pigment granules in cells obviously. Following the iris pigment epithelial cells being treated with endothelin-1, the 3H-thymidine uptake in the cells was increased to 126% as compared with the control. However, the cellular proliferation was decreased to 83% when the cells were treated with isoproterenol. In the case of methionine-enkephalin, dibutyryl cAMP, dexamethasone and phorbol 12-myristate 13-acetate (PMA), the thymidine uptake in the iris pigment epithelial cells was not affected by above drugs. In the retinal pigment epithelial cells, the 3H-thymidine uptakes were increased to 145% and 146% when the cells were incubated with methionine-enkephalin, and isoproterenol, respectively. In the presence of dibutyryl cAMP, dexamethasone and phorbol ester (PMA), the cellular proliferation was inhibited to 83%, 73% and 85% respectively. However, endothelin-1 did not affect the cellular proliferation in retinal pigment epithelial cells. These results show that the morphological shapes of iris pigment epithelial cells are similar to retinal pigment epithelial cells. However, the cellular proliferation in both cells may be regulated by distinct mechanisms.

Insulin and heparin suppress superoxide production in diabetic rat glomeruli stimulated with low-density lipoprotein

Patients with diabetic nephropathy frequently show increased levels of circulating low-density lipoprotein (LDL) and oxidized LDL, which have been reported to be related to the generation of oxygen-free radicals. In the present study, we evaluated the effects of insulin and heparin on the superoxide production of glomeruli, which were isolated from rats with streptozotocin-induced diabetes for one week, one month, and three months, respectively, and the glomeruli were stimulated with native and oxidized LDL. LDL was isolated from normal subjects with normolipidemia, and the superoxide was measured by using a spectrophotometer. The results demonstrated that the poorly controlled diabetic rat glomeruli showed a significantly higher production of superoxide than normal glomeruli under basal status and after stimulation, and this production increased further with the progression of diabetes. Insulin suppressed both the basal and stimulated production of superoxide in diabetic glomeruli, but not in normal glomeruli. Heparin suppressed superoxide production of diabetic glomeruli stimulated by either native or oxidized LDL, and it also partly suppressed superoxide production of normal glomeruli stimulated by oxidized LDL. Our results suggest that glomerular injury in diabetics with hyperlipidemia may be mediated through enhanced generation of oxygen-free radicals, which can be partially attenuated by insulin and heparin.

Significance of salivary epidermal growth factor in peptic ulcer disease in hemodialysis patients

BACKGROUND/AIMS

Hemodialysis (HD) patients are prone to developing peptic ulcers. However, of all the risk factors associated with peptic ulcers, none have been shown to be more prevalent in HD patients than in the general population. However, salivary epidermal growth factor (EGF) may play a role in peptic ulcer diseases.

METHODS

Salivary EGF levels and bioactivities were assayed in 47 maintenance HD patients and 30 normal controls, and the molecular weights of EGF were assessed using high-performance liquid chromatography (HPLC).

RESULTS

Salivary EGF levels were not different between both groups of subjects (4.2 +/- 0.34 vs. 5 +/- 0.54 ng/mg protein, NS), and HPLC revealed that salivary EGF in both groups had similar molecular weights. However, salivary EGF bioactivity was significantly depressed in the HD patients as compared to the normal controls (0.59 +/- 0.08 vs. 1.55 +/- 0.15 ng/mg protein, p < 0.01). Stepwise multiple regression showed that the low salivary EGF levels were associated with female gender (p < 0.05), while low salivary EGF bioactivity was associated with HD per se (p < 0.05). In the 22 HD patients who underwent gastric endoscopy, salivary EGF bioactivity was significantly lower in those with peptic ulcers than in those without (0.38 +/- 0.08 vs. 0.69 +/- 0.08 ng/mg protein, p < 0.05).

CONCLUSION

Decreased salivary EGF bioactivity may contribute to peptic ulcer disease among maintenance HD patients.

Fluorodeoxyglucose positron emission tomography studies in diagnosis and staging of clinically organ-confined prostate cancer

OBJECTIVES

To determine the value of 18-fluoro-2-deoxyglucose (FDG) positron emission tomography (PET) studies in the evaluation of patients with organ-confined prostate cancer. This imaging method has previously found little usefulness in localized prostate tumors because of excretion of the isotope into the urine, masking any lower urinary tract lesions. We evaluated this imaging modality using hydration, furosemide, and bladder emptying before the procedure to evacuate the nonspecific isotope in the urine.

METHODS

FDG PET scans were performed on 24 patients diagnosed with clinically organ-confined prostate cancer. No patient had received any prior treatments for the cancer. FDG PET scans were performed 1 hour after injection of 15 mCi of F-18 deoxyglucose. Patients were scanned from the base of the skull through the inguinal region (including the pelvis). Additional signal attenuation-corrected images of the inguinal region were acquired 30 minutes after intravenous injection of 40 mg of furosemide. The final diagnosis was made by histologic examination, correlative imaging studies, and/or clinical follow-up.

RESULTS

FDG PET studies were negative in 23 of the 24 organ-confined prostate cancers and the study was only faintly positive in 1 tumor (4.0% sensitivity).

CONCLUSIONS

FDG PET is not a useful test in the evaluation of clinically organ-confined prostate cancer.

Bilateral orbital pseudotumor with suprasellar and pulmonary involvement: report of a case

A 39-year-old man had bilateral proptosis and blurred vision for I week. Computed tomography and magnetic resonance imaging showed signs of bilateral orbital pseudotumor, a suprasellar mass, and pulmonary infiltration. Biopsies from retrobulbar and bronchial sites showed similar inflammatory tissue. His disease resolved with pulsed corticosteroid therapy.

Cytotoxic prenylated depsidones from Garcinia parvifolia

Leaf extracts of Garcinia parvifolia provided relatively high yields of four novel, cytotoxic prenylated depsidones. The structures were determined mainly by detailed NMR spectral analysis and X-ray crystallography.

Altering expression of alpha3beta1 integrin on podocytes of human and rats with diabetes

The adhesion molecule integrin alpha3beta1 is the major receptor of podocyte to the glomerular capillary basement membrane (GBM). Since progressive alteration of the glomerular extracellular matrix (ECM) compartment leading to GBM thickening is common in diabetic nephropathy, we investigated the cellular distribution of alpha3beta1 integrin in podocytes of patients with diabetic nephropathy and streptozotocin-induced diabetic rats, and we evaluated the effects of high glucose on the cultured rat podocytes. Both human and rat kidneys were stained using the immunoelectron microscopy and immunoperoxidase technique with mouse monoclonal antibodies to human integrin alpha3 subunit. The results showed that both the number of immunogold particles and the staining of integrin alpha3 subunit on podocytes were weaker in patients with diabetic nephropathy than those of control kidneys. The staining of alpha3 on podocytes in the poorly-controlled diabetic rats was also weaker after one and three months of hyperglycemia. However, the staining was identical to controls in rats with only one week of hyperglycemia. High glucose (25 mM) but not streptozotocin in vitro suppressed the alpha3 expression of cultured rat podocytes. Our results demonstrated that the expression of integrin alpha3beta1 on podocytes was suppressed in both human and rats with diabetes, possibly due to the effects of hyperglycemia, and the suppression became more severe with the duration of diabetes.