Hyalinizing trabecular adenoma is an uncommon benign thyroid tumor that is recently described in the literature. This tumor is easily confused with medullary carcinoma on surgical specimens and with papillay carcinoma on cytologic specimens. Herein we report the cytologic characteristics of a case of histologically proven hyalinizing trabecular adenoma of the thyroid gland. Cytologically, the aspirate showed trabecular or individually dispersed polygonal cells with finely stippled chromatin pattern, nuclear grooves, and eosinophilic nuclear pseudoinclusions. No colloid materials were noted in the background.
Adenoma ; Animals ; Carcinoma, Medullary ; Chromatin ; Colloids ; Eosinophils ; Hyalin ; Mediastinum ; Puromycin Aminonucleoside* ; Puromycin* ; Rats* ; Thyroid Gland

PURPOSE: The aim of this study is to investigate the effect of glomerular cyclooxygenase-2 (COX-2) overexpression on podocyte injury by puromycin aminonucleoside (PAN) in nephrin-driven COX-2 transgenic mice. METHODS: We administrated PAN intravenously on day-1 (15 mg/100 g body weight) and day-3 (30 mg/100 g body weight) in wild type (male B6/D2 mice) and COX-2 transgenic mice. An additional group received a selective COX-2 inhibitor (SC58236) with PAN. The animals from each group were sacrificed at the end of day-3 and 10. We investigated albuminuria, foot process effacement and glomerular COX-2 and nephrin expression. RESULTS: PAN induced albuminuria only in COX-2 transgenic mice, with the peak on day-3. Selective COX-2 inhibition significantly reduced albuminuria. EM examination demonstrated foot process effacement, which was improved partially by selective COX-2 inhibition, in COX-2 transgenic mice treated with PAN on day-3. Glomerular COX-2 expression increased significantly on day-3 in COX-2 transgenic mice treated with PAN, whereas expression of nephrin showed a tendency to decrease on day-3. These changes of expression of COX-2 and nephrin were partly attenuated by selective COX- 2 inhibition. Unlike COX-2 transgenic mice, wild-type mice did not show any changes even after PAN treatment. CONCLUSION: In COX-2 transgenic mice, PAN induced albuminuria, podocyte injury and up-regulation of glomerular COX-2, which were ameliorated by selective COX-2 inhibitor. These results suggest that COX-2 may play an important role in increasing susceptibility of podocytes to injury and selective COX-2 inhibition may ameliorate podocyte injury.
Albuminuria ; Animals ; Cyclooxygenase 2* ; Foot ; Mice* ; Mice, Transgenic ; Podocytes* ; Puromycin Aminonucleoside ; Puromycin* ; Up-Regulation

PURPOSE: This experimental study was conducted to determine serial morphological changes of rat's kidney with chronic puromycin aminonucleoside (PAN) nephropathy. Special emphasis was given to the occurrence of glomerular hypertrophy and its relationship to the subsequent development of focal segmental glomerulosclerosis(FSGS). METHODS: Sprague-Dawley rats weighing 200-230g were used and divided into control(n=9) and experimental group(n=15). Rats were given subcutaneous injections of PAN at a dose of of 2mg/100g body weight, or an equivalent volume of normal saline and six injection were given over a period of 9 weeks, at weeks 0, 1, 3, 5, 7 and 9. At weeks 4, 8 and 11, rats were sacrificed and kidney weight, kidney weight/body weight(%) and various laboratory tests including serum protein and albumin were determined. Renal tissues were prepared with Histochoice(R) fixative and paraffin embedding for morphologic study. RESULTS: Kidney weight and kidney weight/body weight(%) were increased significantly in experimental group compared to controls at 4, 8 and 11 weeks. Heavy proteinuria along with lowering of serum protein and albumin and elevation of serum cholesterol was seen in experimental group at week 4 and this change became more marked on weeks 8 and 11. The frequency of FSGS in experimental animal, at week 4, 8 and 11 were 0.6%, 10.6% and 26.2% respectively(p<0.05) and the development of FSGS was more marked in juxtamedullary glomeruli compared to cortical glomeruli. Glomerular surface area showed significant increase in experimental animals compared to controls(p<0.01), the percentage of increase being 12.0, 14.7 and 12.3% at week 4, 8 and 11. And the surface areas of juxtamedullary glomeruli were larger than those of cortical glomeruli throughout the study period. CONCLUSION: In summary, present study indicates that glomerular hypertrophy occurs and precedes the development of FSGS in rats with chronic PAN nephropathy and juxtamedullary glomeruli are more susceptible to developing FSGS compared to cortical glomeuli.
Animals ; Body Weight ; Cholesterol ; Hypertrophy* ; Injections, Subcutaneous ; Kidney ; Paraffin Embedding ; Proteinuria ; Puromycin Aminonucleoside* ; Puromycin* ; Rats* ; Rats, Sprague-Dawley ; Sclerosis*

PURPOSE: To examine the renal injury by albumin infusion, which has been widely used to correct severe nephrotic edema, in puromycin aminonucleoside(PAN) induced nephrotic-range proteinuric rats. MATERIALS AND METHODS: Sixty Sprague-Dawley rats were divided into 3 experimental groups, control group(PAN only, n=20), low-dose albumin group (PAN+25% albumin 1g/kg, n=20) and high-dose albumin group(PAN+25% albumin 4g/kg, n=20). PAN was peritoneally injected on day #1 and #7 to all experimental rats and 25% albumin was peritoneally injected from day #3 for three weeks. Twenty-four hour urine protein, serum creatinine and serum albumin were measured weekly. Histopathologic and ultrastructural examination using transmission EM, and immunohistochemical stainings of CD68, pan T, and L26 were done at 3 and 8 week. RESULTS: Twenty-four hour urine proteins at 2 and 3 weeks were significantly increased in high- dose albumin group compared to control and low- dose albumin group. Serum creatinine at 3 week in high-dose albumin group was 0.9+/-0.54mg/dL which was significantly higher than 0.6+/-0.31mg/dL of control group and 0.6+/-0.43mg/dL of low-dose albumin group. Serum creatinine at 8 week in high-dose albumin group was 1.2+/-0.85mg/dL which was significantly higher than 0.6+/-0.24mg/dL of control group and 0.6+/-0.21mg/dL of low-dose albumin group. Serum albumin was not different among groups. Percent(%) glomerular sclerosis at 8 week in high-dose albumin group was 9.4+/-5.8% which was significantly higher than 3.5+/-1.7% of control group. Interstitial mononuclear cell infiltration was increased according to albumin dose and most of them was CD68(+) macrophages. Vacuolar degeneration of podocytes, accumulation of protein reabsorption droplets in the cytoplasm of podocytes and proximal tubule and lipid droplets in the cytoplasm of proximal tubules were increasd according to albumin dose. CONCLUSION: Albumin infusion in PAN induced proteinuric rats load accelerate the decline in renal function by progressive glomerular and tubulo-interstitial injury. Albumin infusion in clinical nephrotic edema shoud be used very carefully.
Animals ; Control Groups ; Creatinine ; Cytoplasm ; Edema ; Macrophages ; Podocytes ; Puromycin Aminonucleoside* ; Puromycin* ; Rats* ; Rats, Sprague-Dawley ; Sclerosis ; Serum Albumin

Sodium retention is a hallmark of nephrotic syndrome. We investigated whether sodium retention is associated with changes of natriuretic peptide system at different stages (i.e., a sodium retaining stage and a compensatory stage) of nephrotic syndrome. At day 7 after PAN (puromycin aminonucleoside) injection, the urinary excretion of sodium was decreased, along with the development of ascites and positive sodium balance. The plasma and urinary ANP (atrial natriuretic peptide) immunoreactivities were increased. ANP mRNA expression was increased in the heart and kidney, whereas that of NPR (natriuretic peptide receptor)-A and NPR-C mRNA was decreased in the kidney. The expression of NEP was decreased in the kidney. At day 14, urinary excretion of sodium did not differ from the control. The plasma ANP level and heart ANP mRNA expression returned to their control values. The expression of ANP mRNA in the kidney was increased in association with increased urinary ANP immunoreactivities. The expression of NPR-A in the kidney became normal, whereas that of NPR-C kept decreased. The expression of NEP (neutral endopeptidase) remained decreased. These findings suggest that the increased renal ANP synthesis in association with decreased metabolism via NEP and NPR-C may play a compensatory role against the development of sodium retention in nephrotic syndrome. The decreased of NPR-A expression in the kidney may contribute to the ANP resistance at day 7. The subsequent recovery of NPR-A expression may play a role in promoting sodium excretion in later stage (at day 14).
Animals ; Ascites ; Atrial Natriuretic Factor ; Heart ; Kidney ; Nephrotic Syndrome ; Plasma ; Puromycin ; Puromycin Aminonucleoside ; Rats ; Retention (Psychology) ; RNA, Messenger ; Sodium

Proteinuria is a major promoter that induces tubulointerstitial injury in glomerulopathy. Dietary salt restriction may reduce proteinuria, although the mechanism is not clear. We investigated the effects of dietary salt restriction on rat kidneys in an animal model of glomerular proteinuria. Male Sprague-Dawley rats were used and divided into 3 groups: vehicle-treated normal-salt controls, puromycin aminonucleoside (PA)-treated normal-salt rats, and PA-treated low-salt rats. PA was given at a dose of 150 mg/kg BW at time 0, followed by 50 mg/kg BW on days 28, 35, and 42. Sodium-deficient rodent diet with and without additional NaCl (0.5%) were provided for normal-salt rats and low-salt rats, respectively. On day 63, kidneys were harvested for histopathologic examination and immunohistochemistry. PA treatment produced overt proteinuria and renal damage. Dietary salt restriction insignificantly reduced proteinuria in PA-treated rats, and PA-treated low-salt rats had lower urine output and lower creatinine clearance than vehicle-treated normal-salt controls. When tubulointerstitial injury was semiquantitatively evaluated, it had a positive correlation with proteinuria. The tubulointerstitial injury score was significantly increased by PA treatment and relieved by low-salt diet. ED1-positive infiltrating cells and immunostaining for interstitial collagen III were significantly increased by PA treatment. These changes appeared to be less common in PA-treated low-salt rats, although the differences in PA-treated normal-salt versus low-salt rats did not reach statistical significance. Our results suggest that renal histopathology in PA nephrosis may potentially be improved by dietary salt restriction. Non-hemodynamic mechanisms induced by low-sodium diet might contribute to renoprotection.
Animals ; Collagen ; Creatinine ; Diet ; Diet, Sodium-Restricted ; Humans ; Immunohistochemistry ; Kidney ; Male ; Models, Animal ; Nephrosis ; Proteinuria ; Puromycin ; Puromycin Aminonucleoside ; Rats ; Rats, Sprague-Dawley ; Rodentia

PURPOSE: To test whether the expression of beta-catenin, a component of podocyte as a filtration molecule, would be altered by puromycin aminonucleoside (PAN) in the cultured podocyte in vitro. METHODS: We cultured rat glomerular epithelial cells (GEpC) with various concentrations of PAN and examined the distribution of beta-catenin by confocal microscope and measured the change of beta-catenin expression by Western blotting and reverse transcriptase-polymerase chain reaction (RT-PCR). RESULTS: We found that beta-catenin relocalized from peripheral cytoplasm to inner cytoplasm, therefore, intercellular separations were seen in confluently cultured cells by high concentrations of PAN in immunofluorescence views. In Western blotting of GEpC, PAN (50 microg/mL) decreased beta-catenin expression by 34.9% at 24 hrs and 34.3% at 48 hrs, compared to those in without PAN condition (P<0.05). In RT-PCR, high concentrations (50 microg/mL) of PAN also decreased beta-catenin mRNA expression similar to protein suppression by 25.4% at 24 hrs and 51.8% at 48 hrs (P<0.05). CONCLUSION: Exposure of podocytes to PAN in vitro relocates beta-catenin internally and reduces beta-catenin mRNA and protein expression, which could explain the development of proteinuria in experimental PAN-induced nephropathy.
Animals ; Ascorbic Acid ; beta Catenin ; Blotting, Western ; Cells, Cultured ; Cytoplasm ; Epithelial Cells ; Filtration ; Fluorescent Antibody Technique ; Glycyrrhetinic Acid ; Podocytes ; Proteinuria ; Puromycin ; Puromycin Aminonucleoside ; Rats ; RNA, Messenger

BACKGROUND: It is known that non-steroidal antiinflammatory drugs (NSAIDs) reduce the amount of proteinuria in nephrotic syndrome. It is based on the facts that the NSAIDs block the production of prostaglandins. Therefore selective cyclooxygenase-2 (COX-2) inhibitor may be expected to play a role in reduction of the proteinuria in nephrotic syndrome. METHODS: Twenty-seven Sprague-Dawley rats were divided into 3 groups. After 3 to 5 days of adaptation, we gave puromycin aminonucleoside to groups A and B via intraperitoneal route. The third group C was a normal control group. Selective COX-2 inhibitor was orally given to group A for 2 weeks. Each group was divided again into 3 subgroups by the day of experiment: 1, 14 and 21-day subgroups. We checked the changes in the serum and urine creatinine, albumin concentrations, creatinine clearances, the amount of proteinuria and the pathologic findings. The differences between groups were tested by 2-way ANOVA and Dunnett T-test, and the changes of proteinuria were tested by Repeated measures ANOVA. RESULTS: The changes of 24-hour urine protein excretion were significantly different between three groups (p<0.01). Protein excretion of group A was significantly decreased, especially between 14 and 21 days (p<0.05). The changes of creatinine clearance were significantly different between three groups (p<0.05), between 1 and 21 days (p<0.05). Electron microscopy showed morphological recovery of foot processes after administration of selective COX-2 inhibitor in PAN nephropathy rats (group A). CONCLUSION: It is suggested that selective COX- 2 inhibitors may be effective in reducing proteinuria and protecting the renal function in nephrotic syndrome.
Animals ; Anti-Inflammatory Agents, Non-Steroidal ; Creatinine ; Cyclooxygenase 2* ; Cyclooxygenase Inhibitors ; Foot ; Microscopy, Electron ; Nephrotic Syndrome ; Prostaglandins ; Proteinuria ; Puromycin Aminonucleoside* ; Puromycin* ; Rats* ; Rats, Sprague-Dawley

PURPOSE: To test whether the expression of P-cadherin, a component of slit diaphragms between podocyte foot processes, would be altered by puromycin aminonucleoside (PAN) in a cultured podocyte in vitro. METHODS: Rat glomerular epithelial cells (GEpC) were cultured with various concentrations of PAN. The distribution of P-cadherin was examined with a confocal microscope. Western blotting and reverse transcriptase-polymerase chain reaction (RT-PCR) were used to measure the change in P-cadherin expression. RESULTS: This study found that P-cadherin was concentrated in the inner and peripheral cytoplasm with high concentrations of PAN under immunofluorescence views. Western blotting of GEpC revealed that PAN induced a decrease of P-cadherin in dose- and time-dependent manners. A high dose (50 microg/mL) of PAN decreased P-cadherin expression by 21.9% at 24 h (P<0.05) and 31.9% at 48 h (P<0.01) compared to those without PAN. In RT-PCR, high concentrations (50 microg/mL) of PAN also decreased P-cadherin mRNA expression, similar to protein suppression, by 23.5% at 48 h (P<0.05). CONCLUSION: Podocytes exposed to PAN in vitro concentrated P-cadherin internally, and reduced P-cadherin mRNA and protein expression. This could explain the development of proteinuria in experimental PAN-induced nephropathy.
Animals ; Ascorbic Acid ; Blotting, Western ; Cadherins* ; Cytoplasm ; Diaphragm ; Epithelial Cells ; Fluorescent Antibody Technique ; Foot ; Glycyrrhetinic Acid ; Podocytes* ; Proteinuria ; Puromycin Aminonucleoside* ; Puromycin* ; Rats ; RNA, Messenger

An ultrastructural study was done on puromycin aminonucleoside (PAN) nephropathy which was induced in a group of Sprague-Dawley rats by a single intraperitoneally injected dose. To study the ultrastructural alteration of glomerular anionic sites renal tissue was stained with polyethyleneimine (PEI) as a cationic probe. The PEI method seemed to selectively stain heparan sulfate proteoglycan in the basement membrane and has been widely used to evaluate the changes of the basement membrane in human diseases as well as in experimental work. The experimental rats developed proteinuria three days after the PAN injection. Electron microscopic studies of glomeruli showed the loss of epithelial foot processes, formation of cytoplasmic vacuoles, microvillous formation, and increased numbers of lysosomes in the cytoplasm of podocytes. The anionic sites on the basement membrane with foot process fusion were mostly indistinguishable from those seen in control rats, but focal areas of loss or disarray of anionic sites were noted. The anionic sites were not seen on the basement membrane where the overlying epithelium was detached. The results suggest that proteinuria in PAN nephrosis may be primarily due to a glomerular epithelial lesion, leading to focal disarray of anionic sites or focal defects in the epithelial covering of the basement membrane. The loss of anionic sites in the basement membrane may result partially from the foot process fusion, but mostly from the epithelial detachment.
Animals ; Basement Membrane ; Cytoplasm ; Epithelium ; Foot ; Heparan Sulfate Proteoglycans ; Humans ; Lysosomes ; Nephrosis ; Podocytes ; Polyethyleneimine ; Proteinuria ; Puromycin Aminonucleoside* ; Puromycin* ; Rats ; Rats, Sprague-Dawley ; Vacuoles