Marc S. Cohen

Urothelial Hyperplasia and Neoplasia: A Response to Chronic Urinary Tract Infections in Rats

The rat was used as an animal model to examine the effect of foreign bodies and long term infection (24 weeks) on bladder epithelium. Stainless steel wire implants and multiple injections of Escherichia coli were compared to control rat bladders by gross observation, light microscopy and scanning electron microscopy. Hyperplastic alterations, (papilloma, von Brunns nests), dysplasia (squamous metaplasia, microvilli) and early lesions consistent with neoplasia occurred in rats with bladder implants and multiple bacterial injections but not in controls. Epithelial changes were not associated with sterile bladder implants. Bladder papillomata could be observed as early as 2 weeks in rats having both an implant and an infection, but the majority of hyperplastic and early neoplastic-like changes occurred after 6 weeks. Long-term infections, both with and without a bladder implant, can lead to lesions consistent with neoplasia in bladder epithelium.

Urinary Carcinogen [Nitrosamine] Production in a Rat Animal Model for Ureterosigmoidostomy

Tumor development at the site of ureterointestinal anastomosis is a recognized complication in patients undergoing ureterosigmoidostomy. In order to explore the hypothesis that carcinogens (nitrosamines) may be a factor in ureterosigmoidostomy, female Sprague-Dawley rats (n = 125) underwent urethral ligation, bladder dome resection and anastomosis of the bladder trigone to an opening in the anterior rectosigmoid wall. Biweekly nitrosamine determinations were performed on the resultant urine-feces slurry by gas chromatography up to thirty-two weeks post surgery. Nitrosamine (N,N-dimethylnitrosamine) was noted as early as two weeks after surgery in 39% (11/28) of rats. One hundred percent of animals consistently demonstrated nitrosamine by week 14 (32 rats). Nitrosamine levels increased throughout the study with a peak level after thirty-two weeks of 0.275 micrograms./ml. Only a portion (n = 40) of the total animal population was deemed suitable for pathologic examination secondary to animal demise and autolysis at autopsy related to infection and obstruction. In these animals, no adenocarcinoma was found although hyperplastic changes and metaplastic changes were demonstrable at nine days and eight weeks respectively. In one animal a grade I transitional cell papilloma was identified after eight weeks. Control animals demonstrated no nitrosamine production. In vitro combinations of rat urine and feces yielded nitrosamine after six weeks. The absence of adenocarcinoma tumor development is believed indirectly related to animal demise in that not enough time had elapsed to allow significant tumor development. This study lends support to the concept that nitrosamines may play a role in the development of hyperplasia, dysplasia and eventual neoplasia in ureterosigmoidostomy.

The effect of unilateral testicular torsion on the contralateral testicle in prepubertal Chinese hamsters

Recent studies of experimental testicular torsion in rats, rabbits, and guinea pigs have demonstrated conflicting evidence regarding contralateral testicular damage. Those studies in which cellular damage has been found are postulated to result from an immunological mechanism whereby the blood-testis barrier is disrupted with subsequent autoantibody formation. In this study, the histologic and immunologic effects of testicular torsion on the contrateral testicle were investigated in prepubertal Chinese hamsters. Four study groups were established; (1) Left orchiectomy only, (2) sham surgery (scrotal incision), (3) 720° left testicular torsion with left orchiectomy 24 hours later, (4) 720° torsion of left testicle with detorsion after 24 hours. The initial procedure was performed at 1 month of age with subsequent biopsies of the contralateral testicle at 1 week, 1 month, and 6 months after the initial procedure. Testicular tissue was examined for immunofluorescent activity using fluorescent labeled goat antihamster IgG. Positive controls were established by rabbit immunization (rabbit antihamster immunoglobulin) which was subsequently combined with fluorescent labeled goat antirabbit IgG. There was no appreciable difference in immunologic activity between control and experimental animals. Representative sections were examined histologically and no tubular damage was demonstrated and active spermatogenesis was noted at 6 months in all groups. We believe that our results support the premise that testicular torsion in the prepubertal period has no effect on the contralateral testicle.

Urothelial Hyperplasia and Neoplasia. II. Detection of Nitrosamines and Interferon in Chronic Urinary Tract Infections in Rats

In rats with chronic urinary tract infections, urine and blood were examined for two classes of compounds (nitrosamines and interferon) which may lead to the development of urothelial hyperplasia and neoplasia. In vitro, Escherichia coli, a Proteus species or a mixture of both were able to induce high levels of interferon which theoretically could reduce the hosts cellular immune surveillance. These high levels were not detected in vivo in either short-term (5 hr. to 2 wk.) or long-term (2 wk. to 24 wk.) infected rats. In contrast, N, N dimethylnitrosamine was detected in the majority (greater than or equal to 50 per cent) of long term infected rats after 12 wk. although individual rats showed detectable levels as early as 2 wk. post infection. Sterile human or rat urine supported bacterial growth and subsequent production of N, N dimethylnitrosamine, but only after 16 wk. of subculturing in vitro. Gas chromatography was able to detect small amounts of nitrosamines extracted from urine. The mass spectrometer yielded quantitatively and qualitatively better detection. With long term infections, the appearance of a potential carcinogen, N, N dimethylnitrosamine, occurs in vivo and in vitro and correlates with previous findings that describe the development of hyperplastic and early neoplastic changes in the rat urothelium.

Solitary Leiomyoma of the Prostate Presenting as an Encrusted Intravesical Mass

A leiomyoma of the prostate presented as an encrusted intravesical mass on excretory urography. A prostatic leiomyoma usually is benign and is relatively rare with only 41 cases reported previously. Surgical and pathological findings and differential diagnosis are presented.

Calcium phosphate crystal formation in Escherichia coli from human urine: An in vitro study

Escherichia coli with no demonstrable urease activity was inoculated into filter sterilized urine obtained from a healthy volunteer subject with no history of stone disease and then incubated at 37 degrees C. Bacteria were recovered at intervals between 1 and 10 days. Urinary pH was stable as compared to control urines and spontaneous crystal precipitation was not noted in controls. Recovered organisms were analyzed by x-ray powder diffractometry. An uncharacterized mineral phase (UMP) was first evident after 6 days. Calcium phosphate in the form of brushite and hydroxyapatite was apparent at 7 and 10 days respectively. This suggests a role for bacteria in calcium phosphate crystal formation in urine apart from urease activity and may contribute to the calcium phosphate component of urinary calculi.

Bladder reconstruction in rabbits with glutaraldehyde-stablilized amniotic membranes☆

Glutaraldehyde-treated human amniotic membranes were used to repair rabbit bladders after supratrigonal cystectomies. The membranes maintained the integrity of the bladders until healing and reepithelialization occurred. There was no significant loss of bladder capacity or decreased renal function postoperatively. Calcification did not occur on the membranes but was noted on chromic sutures retaining the membranes in 7 of 27 bladders. These findings suggest that glutaraldehyde-stabilized amnion is well tolerated by the urothelium and may serve as a suitable material for replacement of genitourinary tissues.

Intracellular crystal formation in bacteria from human urines: A contributing factor in urinary calculi

SummaryUnderstanding of the bacterial contribution to urinary calculi has been limited to those organisms capable of altering the urine through urease activity. Sterilized urines from stone forming and non-stone forming individuals were inoculated with bacteria having either strong, weak, or no urease activity. All organisms grown in unbuffered urines produced crystallization (calcite or apatite) as demonstrated by X-ray diffraction. Bacteria grown in conventional medium (Heart Infusion broth) did not demonstrate crystal formation. Unstained specimens revealed electron-dense deposits within bacteria grown in urine. Deposits were not present in organisms grown in conventional media. Analysis revealed increased levels of calcium within these deposits as compared to extracellular levels. These findings support the hypothesis that both urease producing and non-urease producing organisms may accumulate calcium crystals intracellularly and form nidi for calculus formation.

Total and Specific Immunoglobulin Response to Acute and Chronic Urinary Tract Infections in a Rat Model

Total and specific levels of immunoglobulins IgG, A and M were determined by an enzyme-linked immunosorbent assay (ELISA) in a rat model of urinary tract infections (cystitis) during the early and late phases of infection. The early response was characterized by rapid rise in IgM in serum and urine. This response decreased rapidly and was undetectable in urine after eight weeks. Correlation between total serum and urine levels of IgM was not found although a chronological relationship was observed. Total and specific serum and urine IgA responses were erratic. Concentrations of IgA were low and this antibody class was undetectable in urine until the infection had been established for six weeks. In contrast, total serum and urine IgG increased in concentration at five days post infection and reached total maximum by weeks four to eight, then declined, but remained detectable over 24 weeks. Specific IgG titers remained elevated in serum but declined in urine between four and 10 weeks. A correlation between total serum and total urine IgG was found. Also, bacteria generated a concomitant nonspecific response, a part of which was detected against a common antigen expressed on E. coli J5 strain that cross-reacts with a number of gram negative genera. The results show that IgM chronologically is the first antibody to appear in increased amounts in the serum and urine, followed by IgG. The data also suggests a relationship exists between total serum IgG and total urine IgG which may affect the hosts ability to eliminate urinary infection.

Serum and urinary immunoglobulin in the rat model of acute urinary tract infection

Total levels of urine and serum immunoglobulin IgM, IgG and IgA, and the E. coli-specific bacterial immunoglobulin response were determined by enzyme-linked immunosorbent assay (ELISA) in a rat model of acute urinary tract infection. High levels of urinary IgM were detected as early as day 3 post infection and then decreased to statistically insignificant levels. Peak levels of IgG occurred in the serum and urine on day 14. Urine and serum IgA levels remained low throughout the study period. The results demonstrate that in the rat model of acute urinary tract infection, IgM appears first in the urine and serum, and rapidly decreases. IgG then appears in the serum and urine followed by a late E. coli-specific immunoglobulin serum and urine response. Also, a non-specific component of the immunoglobulin response was noted in both the serum and urine. In the rat, IgA appears to play little or no role in the urine or in the serum response to the infection.