The trigger-maintenance model of persistent mild to moderate hyperoxaluria induces oxalate accumulation in non-renal tissues.

Persistent mild to moderate hyperoxaluria (PMMH) is a common side effect of bariatric surgery. However, PMMH's role in the progression to calcium oxalate (CaOx) urolithiasis and its potential effects on non-renal tissues are unknown. To address these points, a trigger + maintenance (T + Mt) model of PMMH was developed in rats (Experiment 1).

Partitioning of 14C-oxalate excretion in rats during a persistent oxalate challenge.

This study was done to resolve published discrepancies in oxalate excretion between humans and rats and to characterize oxalate partitioning in rats during persistent severe hyperoxaluria, such as that seen in many bariatric patients. Osmotic minipumps dispensing 360 micromole/day KOx + 3.9 +/- 0.

Maturing the sperm: unique mechanisms for modifying integral proteins in the sperm plasma membrane.

The epididymis has been understudied, in part due to its cancer resistance and the development of effective technologies for sperm injection and in vitro fertilization. However, it is worthy of study because--absent advanced reproductive technology--its proper function is essential for conceiving children: sperm leaving the testis are immature and nonfertile. Epididymal functions can be divided into several general categories (1) concentration of sperm; (2) functional maturation; (3) storage in a quiescent state until ejaculation; (4) removal of degenerating sperm; (5) provision of appropriate conditions for survival; (6) transport by the myoid cells; (7) protection; (8) maintenance of the blood epididymal barrier.

Intraprostatic lymphocyte profiles in aged wistar rats with estradiol induced prostate inflammation.

Purpose: We report LS phenotypes in aged Wistar rats (Charles Rivers, Wilmington, Massachusetts) with EPI.

Materials And Methods: EPI was induced in 36 to 40-week-old male rats by castration with subcutaneous injections of 17beta-estradiol (0.25 mg/kg daily) plus dihydrotestosterone propionate (2.

Gene expression in the LNCaP human prostate cancer progression model: progression associated expression in vitro corresponds to expression changes associated with prostate cancer progression in vivo.

Identification of the genes involved in prostate cancer (PCa) progression to a virulent and androgen-independent (AI) form is a major focus in the field. cDNA microarray was used to compare the gene expression profile of the indolent, androgen sensitive (AS) LNCaP PCa cell line to the aggressively metastatic, AI C4-2. Thirty-eight unique sequences from a 6388 cDNA array were found differentially expressed (> or =2-fold, 95% CI).

Continuous infusion of oxalate by minipumps induces calcium oxalate nephrocalcinosis.

It is hypothesized that oxalate plays an active role in calcium oxalate (CaOx) nephrocalcinosis and oxalate driven nephrolithiasis by interacting with the kidney. We developed an adjustable, nonprecursor, continuous infusion model of hyperoxaluria and CaOx nephrocalcinosis to investigate this hypothesis. Minipumps containing PBS or KOx (60-360 micromol/day; n = 5-7/dose) were implanted subcutaneously in male Sprague-Dawley rats on D0 and D6.

A simple procedure for isolating microgram quantities of biologically active bikunin from human urine.

Objective: To report a simple, relatively rapid protocol to isolate biologically active bikunin from human urine using ion-exchange-trypsin affinity chromatography. Bikunin is a protease inhibitor which has been shown to play a role in various processes, including inhibition of calcium oxalate crystallization, the regulation of proliferation and modulation of carcinogenesis. The unavailability of the purified protein has hampered studies on bikunin's expanding role in these processes.

The healthy rat prostate contains high levels of natural killer-like cells and unique subsets of CD4+ helper-inducer T cells: implications for prostatitis.

Purpose: Chronic nonbacterial prostatitis spontaneously develops in aged Lewis and Wistar rats but not in Sprague-Dawley rats. We report the unique profile of lymphocyte subsets present in the healthy Sprague-Dawley rat prostate.

Materials And Methods: We compared enzymatic and mechanical methods of intraprostatic lymphocyte isolation in healthy 8 to 10-week-old Sprague-Dawley rats.

Minipump induced hyperoxaluria and crystal deposition in rats: a model for calcium oxalate urolithiasis.

Purpose: Unraveling the mechanisms leading to clinically active calcium oxalate (CaOx) stone disease and the development of effective medical therapies to treat it have been hampered by the lack of appropriate animal models. To address this problem we developed a model of hyperoxaluria and calcium oxalate crystal deposition by implanting osmotic minipumps subcutaneously into male rats, that is minipump induced hyperoxaluria and crystal deposition in rats.

Materials And Methods: Male Harlan-Sprague Dawley rats (225 to 290 gm) were implanted subcutaneously with 1-week 2 ml osmotic minipumps containing 1.

Decreased renal expression of the putative calcium oxalate inhibitor Tamm-Horsfall protein in the ethylene glycol rat model of calcium oxalate urolithiasis.

Purpose: Tamm-Horsfall protein is believed to inhibit calcium oxalate crystallization, aggregation or adhesion to the renal epithelium. We determined whether ethylene glycol induced urolithiasis changes the expression of renal and urinary Tamm-Horsfall protein. For comparison the expression of another calcium oxalate inhibitor, osteopontin, was also analyzed.