Mustafa Emre Bakircioglu

Homologous acellular matrix graft for urethral reconstruction in the rabbit : Histological and functional evaluation

OBJECTIVE To evaluate urethral replacement by a free homologous graft of acellular urethral matrix in a rabbit model. MATERIALS AND METHODS In 30 male New Zealand rabbits, a 0.8 to 1.1 cm. segment of the urethra was resected, replaced with an acellular matrix graft of 1.0 to 1.5 cm. (mean 1.3 cm.), and placed on an 8F feeding tube. Additionally 4 animals underwent sham operation. At varying intervals before sacrifice (from 10 days to 8 months), the animals underwent urodynamic evaluation and retrograde urethrography (for which 4 untreated rabbits served as control). The grafted specimens were prepared for evaluation histologically and by reverse-transcription polymerase chain reaction (RT-PCR). RESULTS In all animals, the acellular matrix graft remained in its original position. Histological examination showed complete epithelialization and progressive vessel infiltration. At 3 months, smooth muscle bundles were first observed infiltrating the matrix at the end-to-end anastomosis; after 6 months, the smooth muscle bundles had grown into one-third of the matrix. Urodynamics did not detect any difference between the control and matrix-grafted animals in bladder volume, leak-point pressure and residual volume. RT-PCR detected an increase in IGF mRNA in the graft between week 3 and month 6 and in HB-EGF mRNA after day 10 through month 3. TGF-alpha mRNA was not detected; TGF-beta mRNA was unchanged from normal urethral tissue. By 8 months, the host and implant could not be differentiated by urethrography. CONCLUSION The acellular urethral matrix allows single-stage urethral reconstruction. All tissue components were seen in the grafted matrix after 3 months, with further improvement over time; however, the smooth muscle in the matrix was less than in normal rabbit urethra and was not well oriented. RT-PCR revealed the importance of time-dependent growth factor influences during regeneration.

The effect of adeno-associated virus mediated brain derived neurotrophic factor in an animal model of neurogenic impotence

PURPOSE We tested the hypothesis that transfecting penile tissue with brain derived neurotrophic factor may facilitate neural recovery and erectile capability after cavernous nerve injury. MATERIALS AND METHODS Of the 34 Sprague-Dawley rats used 10 underwent sham operation and 24 underwent bilateral cavernous nerve freezing and intracavernous injection of adeno-associated virus-LacZ (12) or adeno-associated virus-brain derived neurotrophic factor (12). Erectile function was assessed by cavernous nerve electrostimulation at 4 and 8 weeks, and samples of penile tissue and the major pelvic ganglia were evaluated histologically. RESULTS In the brain derived neurotrophic factor group mean maximal intracavernous pressure plus or minus standard deviation was significantly higher than in the LacZ group at 4 and 8 weeks (58.5 +/- 11.7 cm. water versus 28.4 +/- 5.5 and 61.3 +/- 12.5 versus 37.7 +/- 7.9, respectively). In addition, in the brain derived neurotrophic factor group reduced nicotinamide adenine dinucleotide phosphate diaphorase staining and neuronal nitric oxide synthase immunostaining revealed significantly more positive nerve fibers in the dorsal nerves and cavernous tissue than in the LacZ group at each time point and the percent of neuronal nitric oxide synthase positive neurons in the major pelvic ganglia was also significantly greater. Moreover, in the LacZ group most neurons showed a light staining pattern with irregular contours and numerous vacuoles in the cytoplasm. CONCLUSIONS Intracavernous injection of adeno-associated virus-brain derived neurotrophic factor may prevent the degeneration of neuronal nitric oxide synthase containing neurons in the major pelvic ganglia and facilitate the regeneration of neuronal nitric oxide synthase containing nerve fibers in penile tissue, thus, enhancing the recovery of erectile function after bilateral cavernous nerve injury.

DECREASED TRABECULAR SMOOTH MUSCLE AND CAVEOLIN-1 EXPRESSION IN THE PENILE TISSUE OF AGED RATS

PURPOSE Because decreased trabecular smooth muscle content is reportedly associated with vasculogenic impotence in men, we performed a rodent study to investigate the effect of aging on trabecular smooth muscle content and caveolin-1 protein expression in penile smooth muscle cells. MATERIALS AND METHODS In 6 young (age 3 months) and 6 old (age 24 months) rats erectile function was evaluated by cavernous nerve stimulation. At sacrifice penile tissue samples were collected for Western blot analysis, Massons trichrome staining, caveolin-1 immunostaining and electron microscopy. The percent of smooth muscle in the trabecular tissue was assessed by computer assisted image analysis. RESULTS In the aged rats mean intracavernous pressure plus or minus standard deviation was decreased (70 +/- 8.8 versus 107 +/- 12.3 cm. water) and the latency period was increased (7.8 +/- 1.2 versus 4.5 +/- 0.5 seconds) significantly compared to values in the young rats (p <0.001). The mean ratio of trabecular smooth muscle-to-connective tissue was also significantly altered in old versus young rats (27% +/- 2.9% versus 42.1% +/- 5.1%, p <0.001). Immunostaining for caveolin-1 was noted in each group in the sarcolemma of smooth muscle cells and endothelium of trabecular sinusoids but the staining pattern was less intense and the percent of smooth muscle positive for caveolin-1 was decreased in aged versus young rats (17.9% +/- 2.5% versus 27.5% +/- 3.6%, p <0.001). Moreover, young trabecular smooth muscle cells had more caveolae in the sarcolemma on electron microscopy and a higher expression of caveolin-1 protein on Western blot analysis. In contrast, higher endothelial nitric oxide synthase protein expression was noted in the penile tissue of old rats. CONCLUSIONS In these aged rats the decreased ratio of trabecular smooth muscle-to-collagen and the reduced expression of caveolin-1 may contribute to erectile dysfunction.

The effect of pregnancy and delivery on the function and ultrastructure of the rat bladder and urethra

Objective To examine the effect of pregnancy and delivery on the function and ultrastructure of the bladder and urethra in rats.

HETEROLOGOUS ACELLULAR MATRIX GRAFT FOR RECONSTRUCTION OF THE RABBIT URETHRA: HISTOLOGICAL AND FUNCTIONAL EVALUATION

PURPOSE In a rabbit model we evaluated urethral replacement by a free heterologous dog acellular matrix graft and compared these results with those of a homologous graft with the exclusion of antigenicity as a major goal. MATERIALS AND METHODS In 14 male New Zealand rabbits a 0.8 to 1.1 cm. segment of urethra was resected and replaced with a tubular acellular 1.0 to 1.5 cm. (mean 1.3) urethral matrix graft placed on an 8Fr feeding tube. Seven animals received a rabbit graft, 7 received a canine graft and 3 untreated rabbits served as controls. All animals underwent urethral pressure profile determination and retrograde urethrography before 8 and 6 were sacrificed at 6 and 8 months, respectively. Grafted and normal specimens were evaluated by histological testing. RESULTS In all animals the acellular matrix graft remained in its original position. Histological examination showed complete epithelialization and progressive vessel infiltration. At 6 months more than a third of the homologous grafts had smooth muscle bundles but the heterologous grafts had only poorly disseminated smooth muscle. Picrosirius red stain demonstrated a shift in the ratio of collagen types I-to-III with an increase in type III in the processed homologous and heterologous matrices that did not change significantly postoperatively. At 8 months the urethral pressure profile detected no difference in control and matrix grafted animals, and urethrography did not readily differentiate host from implant. CONCLUSIONS In the heterologous matrix all tissue components were present after 6 months with no signs of rejection and even gradual improvement with time. However, regenerated smooth muscle did not equal that in normal rabbit urethra and it was not well oriented. Even after 8 months only a few disseminated smooth muscle cells were evident. Most alpha-actin positive cells were surrounding the vessels. Although function was normal, the alteration in the collagen ratio effected by matrix production indicated that the matrix collagen appeared not to have been replaced by host collagen. The increase in collagen type III may explain the lack of stricture in the grafted animals on normal retrourethrography.

THE EFFECTS OF COLCHICINE ON A PEYRONIE'S-LIKE CONDITION IN AN ANIMAL MODEL

PURPOSE We have developed an animal model of Peyronies disease by injecting transforming growth factor beta (TGF-beta) into the rat penis. Our objective is to study the effects of colchicine on the Peyronies condition in an animal model. MATERIALS AND METHODS Thirty-six adult male Sprague-Dawley rats received TGF-beta injections into the tunica albuginea and were divided into two groups (n = 18 each). Rats in the first group were divided into three subgroups (n = 6 each). Each rat in the three subgroups received the following: Subgroup 1 received colchicine, subgroup 2 received ibuprofen, and subgroup 3 received regular water. The rats were euthanized after 6 weeks. Rats in the second group were also divided into three subgroups. These rats received the same treatments as the rats in the first group, but treatments began 6 weeks after TGF-beta injection. These rats were euthanized after 12 weeks. Tunical tissue samples were collected and examined using Hart and trichrome stains, electron microscopy (EM), and western blot analysis for TGF-beta detection. RESULTS In the first group, the colchicine-treated rats exhibited less collagen deposition and less elastic fiber fragmentation than the untreated or ibuprofen-treated rats. EM confirmed the results and showed normal distribution and shape of both collagen and elastic fibers in the colchicine-treated group. In the second group, the colchicine-treated rats exhibited less crowding of the collagen fibers. However, the elastic fibers remained fragmented and scarce. Western blot analysis showed significant down-regulation of TGF-beta expression (5/6) in the colchicine-treated group after 6 weeks. Down-regulation was observed in only 1/6 in both ibuprofen and non-treated groups. After 12 weeks 2/6, 1/6, and 1/6 rats displayed down regulation in the colchicine treated, ibuprofen treated, and non-treated groups, respectively. CONCLUSION Early colchicine treatment may suppress a Peyronies like condition in the rat animal model.

Klinefelter syndrome: does it confer a bad prognosis in treatment of nonobstructive azoospermia?

OBJECTIVE To determine the effectiveness of microsurgical testicular sperm extraction (micro-TESE) and intracytoplasmic sperm injection (ICSI) for men with Klinefelter syndrome (KS). DESIGN Retrospective clinical study. SETTING Private IVF center. PATIENT(S) Men with nonmosaic KS (n = 106), and men with nonobstructive azoospermia (NOA) and normal karyotypes (n = 379). INTERVENTION(S) Micro-TESE on the day of oocyte retrieval. MAIN OUTCOME MEASURE(S) Sperm recovery, fertilization, pregnancy, and spontaneous abortion rates. RESULT(S) Sperm was successfully recovered in 50 of 106 (47%) men in the KS group and 188 of 379 (50%) in the NOA group. The fertilization rate was higher in the NOA group than the KS group (65% vs. 57%, respectively); however, pregnancy (55% vs. 53%) and abortion rates (12% vs. 11.5%) did not differ statistically significantly between groups. In the KS group, 23 pregnancies resulted in 29 live births; the 21 children who underwent genetic evaluation had normal karyotypes. CONCLUSION(S) Sperm recovery rates in men with KS were similar to those of men with NOA and normal karyotypes. The fertilization rate was statistically significantly lower for men with KS than men with NOA, but pregnancy and abortion rates were similar. We observed good sperm recovery and ICSI outcomes for patients with KS.

Effect of a Chinese herbal medicine mixture on a rat model of hypercholesterolemic erectile dysfunction

PURPOSE We examine the effect of a Chinese herbal medicine mixture on erectile function in a rat model of hypercholesterolemic erectile dysfunction. MATERIALS AND METHODS In this study 32, 3-month-old Sprague-Dawley rats were used. The 8 control animals were fed a normal diet and the remaining 24 were fed 1% cholesterol diet for 4 months. After 2 months herbal medicine was added to the drinking water of the treatment group of 16 rats but not the cholesterol only group of 8. Of the 16 rats 8 received 25 mg./kg. per day (group 1) and 8 received 50 mg./kg. per day (group 2) of Chinese herbal medicine mixture. Serum cholesterol levels were measured at 2 and 4 months. At 4 months erectile function was evaluated with cavernous nerve electrostimulation in all animals. Penile tissues were collected for electron microscopy, and to perform Western blot for endothelial nitric oxide synthase, neuronal nitric oxide synthase, basic fibroblast growth factor (bFGF) and caveolin-1. RESULTS Serum cholesterol levels were significantly higher in animals fed the 1% cholesterol diet compared to controls at 2 and 4 months. Nevertheless, there was no significant difference among group 1 (145 +/- 30 mg./dl.), group 2 (157 +/- 20) and the cholesterol only group (143 +/- 15). Systemic arterial pressure was not significantly different between the animals that were fed the 1% cholesterol diet and the controls. During electrostimulation of the cavernous nerve peak sustained intracavernous pressure was significantly lower in the cholesterol only group (50 +/- 23 cm. H2O) compared to the control group. Conversely erectile function was not impaired in the herbal medicine treated rats. Electron microscopy showed many caveolae with fingerlike processes in the cavernous smooth muscle and endothelial cell membranes in control and treated rats but not in the cholesterol only group of rats. Western blot did not show a difference among groups in protein expression for endothelial nitric oxide synthase and neuronal nitric oxide synthase in penile tissue but caveolin-1 and bFGF protein expression was significantly higher in groups 1 and 2 than in the cholesterol only and control groups. CONCLUSIONS Rats developed erectile dysfunction after being fed a 1% cholesterol diet for 4 months. Although serum cholesterol levels were similar in the cholesterol only rats and those treated with Chinese herbal medicine mixture, erectile response was significantly better in the treated group. The mechanism of the herbal medicine is unknown. High levels of bFGF and caveolin-1 expression in the treated group may protect the cavernous smooth muscle and endothelial cells from the harmful effect of high serum cholesterol.

Gonadotrophin therapy in combination with ICSI in men with hypogonadotrophic hypogonadism

The aim of this study was to evaluate the impact of gonadotrophin therapy in combination with intracytoplasmic sperm injection (ICSI) in men with hypogonadotrophic hypogonadism (HH). Twenty-five azoospermic men were diagnosed with HH due to low FSH, LH and total testosterone concentrations. These patients were treated with human chorionic gonadotrophin for 1 month plus recombinant FSH the following month. Total testosterone concentrations were measured in the first and third months. Semen analyses were performed monthly after the third month of treatment. ICSI was performed when sperm production commenced. Total testosterone concentration and testicular volume were significantly increased after gonadotrophin therapy (P < 0.001). On average, spermatozoa were detected in the ejaculate after 10 months. Spontaneous pregnancies were achieved in four couples. Twenty-two ICSI cycles were performed in 18 couples using ejaculated or testicular spermatozoa, and 12 pregnancies (54.5% per cycle) were achieved. These results showed that HH could be treated successfully with hormonal therapy combined with ICSI using ejaculated spermatozoa. The use of ICSI made it possible to achieve pregnancy when spermatozoa appeared in the ejaculate, and shortened the duration of gonadotrophin therapy.

Tunica albuginea acellular matrix graft for penile reconstruction in the rabbit: a model for treating Peyronie's disease

Objective To evaluate the use of an acellular matrix graft of the tunica albuginea for functional penile reconstruction in severe cases of Peyronies disease.