Biomedical subjects

R Dahiya

Publications and source records attributed to R Dahiya.

At least 55 records · Page 3Linked to original sources

PubMed1999

Bladder acellular matrix graft: in vivo functional properties of the regenerated rat bladder.

The purpose of this study was to determine whether the rat urinary bladder augmented by an acellular matrix graft can restore the bladder's low-pressure reservoir function and preserve normal micturition. After partial cystectomy (> 50%) and grafting with the bladder acellular matrix graft (BAMG), storage and voiding functions were monitored in 20 rats by means of a specially designed "micturition cage," leak-point cystography, and cystometry. After 4 months, sections (n = 6) were examined histologically to evaluate regeneration of bladder wall components within the BAMG. Bladder capacity and compliance increased progressively and were significantly higher in the grafted animals than in controls (partial cystectomy only), and volumes per void were significantly higher than in either control or normal animals. At 4 months, the regenerated urothelium, smooth muscle, blood vessels and nerves within the BAMG were qualitatively identical to normal bladder wall. Augmentation cystoplasty with the homologous BAMG leads to morphologic and functional rat bladder regeneration, thus enhancing low-pressure reservoir function and preserving normal micturition.

Animals↗

PubMed1999

Effect of thermal variables on human breast cancer in cryosurgery.

There is a growing interest in the use of cryosurgery to treat breast cancer, following recent breakthroughs in noninvasive imaging and in cryotechnology, as well as the recent success of cryosurgery in treating various types of cancer. However, since haphazard freezing does not guarantee tissue destruction, in order to apply this technique effectively it is essential to determine the thermal parameters that produce complete destruction of malignant tissue. This study seeks to quantitatively identify the relationship between thermal variables and the degree of freezing damage to human breast cancer cells. In order to do this, human breast cancer and normal cells were frozen with controlled thermal parameters using a directional solidification apparatus. Cell viability was determined after thawing using trypan blue, and correlated to the thermal variables used during freezing. Cellular damage is observed to increase with increasing cooling rates, due to the higher probability of intracellular ice formation. A double freeze thaw cycle significantly increases the extent of cell damage, and is sufficient to ensure complete cell destruction at final freezing temperatures of -40 degrees C for a 25 degrees C/min cooling rate, and -20 degrees C for a 50 degrees C/min cooling rate. The correlations between cell death and thermal parameters are qualitatively identical for all the cell types in this study, although there is some variation from one cell type to another in the overall susceptibility to freezing damage. The correlations established in this study can be used to design systematic and optimal breast cryosurgery protocols.

Breast Neoplasms↗

PubMed1999

Effects of diabetes on nitric oxide synthase and growth factor genes and protein expression in an animal model.

Erectile dysfunction occurs frequently in humans with diabetes mellitus; the molecular basis of this phenomenon is not known. We investigated the effects of diabetes on penile erection, nitric oxide synthase and growth factors expression in an animal model. Forty male rats were divided into two groups: the experimental group (n = 30) received intraperitoneal injection of Streptozotocin (STZ) dissolved in citrate buffer to induce diabetes; ten age-matched control rats received injection of citrate buffer vehicle only. Before euthanization at eight weeks, erectile function was assessed by electrostimulation of the cavernous nerves. NADPH diaphorase staining was used to identify NOS and immunostaining technique was used to identify nNOS in the penile nerve fibers. RT-PCR was used to identify mRNA expression of nNOS, eNOS, iNOS, ER-beta, ER-alpha, NGF, IGF-I, TGF-beta 1, and AR. Western blot was used to identify nNOS, IGF-I, NGF, and TFG-beta protein expressions. In the diabetic group, there was: (1) a significant decrease in NOS containing nerve fibers in the dorsal and intracavernosal nerves; (2) a significant lower maximal intracavernosal pressure. RT-PCR showed down-regulation of nNOS (large form), iNOS and ER-beta mRNA expression, Immunoblot showed down-regulation of nNOS protein expression and nNOS immunostaining showed less positive staining in the dorsal and intracavernous nerves in the diabetic group. These molecular changes may provide the basis for further studies to explore the association between diabetes and impotence.

Animals↗

PubMed1999

Differential gene expression of growth factors in young and old rat penile tissues is associated with erectile dysfunction.

The molecular mechanisms of erectile dysfunction with aging are unclear. Recent studies have suggested that growth factors may play a role in the etiology of erectile dysfunction. This present study was designed to test the hypothesis that gene expression of various growth factors such as TGF alpha, TGF beta 1, TGF beta 2, TGF beta 3, IGF and NGF modulate with aging in rat penile tissues. For this purpose, total RNA was extracted from young and old rat penile tissues and the gene expression for these growth factors was determined by differential reverse-transcriptase-polymerase chain reaction (RT-PCR) using specific oligonucleotide primers. mRNA levels of growth factors were quantified by using beta-actin as an internal standard. The results of these experiments suggest that: (1) young and old rat penile tissues expressed mRNA transcripts for TGF alpha, TGF beta 1, TGF beta 2, TGF beta 3, IGF and NGF; (2) TGF beta 1 gene expression was significantly increased in old rat penile tissues as compared to young; (3) mRNA transcripts for NGF and TGF beta 3 were significantly lower in old rat penile tissues as compared to young; and (4) TGF alpha, TGF beta 2 and IGF mRNA expression did not change in young and old rat penile tissues. These results suggest that the differential gene expression for various growth factors in young and old rat penile tissues may be important in understanding the pathophysiology of erectile dysfunction associated with aging.

Aging↗

PubMed1999

Temporal bone fractures: otic capsule sparing versus otic capsule violating clinical and radiographic considerations.

OBJECTIVE: To assess the practicality and utility of the traditional classification system for temporal bone fracture (transverse vs. longitudinal) in the modern Level I trauma setting and to determine whether a newer system of designation (otic capsule sparing vs. otic capsule violating fracture) is practical from a clinical and radiographic standpoint. METHODS: The University of Massachusetts Medical Center Trauma Registry was reviewed for the years 1995 to 1997. Patients identified as sustaining closed head injury were reviewed for basilar skull fracture and temporal bone fracture. Clinical and radiographic records were evaluated by using the two classification schemes. RESULTS: A total of 2,977 patients were treated at the trauma center during this time. Ninety (3%) patients sustained a temporal bone fracture. The classic characterization of transverse versus longitudinal fracture (20% vs. 80%, respectively) was unable to be determined in this group; therefore, clinical correlation to complications using that paradigm was not possible. By using the otic capsule violating versus sparing designation, an important difference in clinical sequelae and intracranial complications became apparent. Compared with otic capsule sparing fractures, patients with otic capsule violating fractures were approximately two times more likely to develop facial paralysis, four times more likely to develop CSF leak, and seven times more likely to experience profound hearing loss, as well as more likely to sustain intracranial complications including epidural hematoma and subarachnoid hemorrhage. CONCLUSION: The use of a classification system for temporal bone fractures that emphasizes violation or lack of violation of the otic capsule seems to offer the advantage of radiographic utility and stratification of clinical severity, including severity of Glasgow Coma Scale scores and intracranial complications such as subarachnoid hemorrhage and epidural hematoma.

Cerebrospinal Fluid Otorrhea↗

PubMed1999

Loss of two new loci on chromosome 8 (8p23 and 8q12-13) in human prostate cancer.

Inactivation of tumor suppressor genes due to allelic loss is thought to be an important mechanism of gene alterations in prostatic carcinogenesis. Loss of sequences on the short arm of chromosome 8 (8p) has been reported in human cancers, especially of 8p22 and 8p12-21 in prostate cancer. By using PCR analysis of polymorphic microsatellite repeat markers at four 8p loci and three 8q loci in 60 tumors, we observed deletion of sequences at two other deletion domains (8p23, and 8q12-13). There was loss in 51 of 60 cases (85%) with at least one marker. Four distinct regions of loss detected were: i) at 8p23, at locus D8S262; ii) at 8p22, on locus D8S259; iii) at 8p12, on loci D8S255 and D8S285; iv) at 8q12-13, on loci between D8S260 and D8S528. We found that 29% of the tumors showed LOH at 8p23; 19% LOH on 8p22; 54% had LOH at 8p12; and 48% had LOH at 8q12-13. There was higher frequency of LOH at 3 or more loci in samples of T3 stage (62%) as compared to T2 stage (13.3%) which suggests higher incidence of LOH in advanced stage of prostate cancer. We report deletion of two novel loci at 8p23 and 8q12-13, these regions may contain putative tumor suppressor genes in prostate cancer.

Chromosome Mapping↗

PubMed1999

The effects of colchicine on a Peyronie's-like condition in an animal model.

PURPOSE: We have developed an animal model of Peyronie's disease by injecting transforming growth factor beta (TGF-beta) into the rat penis. Our objective is to study the effects of colchicine on the Peyronie's 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 Peyronie's like condition in the rat animal model.

Animals↗

PubMed1998

Bladder acellular matrix graft in rats: its neurophysiologic properties and mRNA expression of growth factors TGF-alpha and TGF-beta.

To assess the neurophysiologic properties and molecular mechanisms of the bladder acellular matrix graft (BAMG), we performed cystometric and neurophysiologic studies in male Sprague-Dawley rats (n = 46) at varying intervals. The animals were assigned to 3 groups: 1) normal, 2) partial cystectomy (>50%), and 3) partial cystectomy (>50%) and grafting with a BAMG of equal size. Additionally, matrix-grafted and host bladders were processed for analysis of mRNA expression of transforming growth factor (TGF)-alpha, TGF-beta1, TGF-beta2, and TGF-beta3 by reverse transcriptase polymerase chain reaction. Matrix-grafted bladders showed a significantly higher bladder capacity at 3 and 6 weeks and 4 months than those with partial cystectomy alone, and a significantly higher bladder capacity at 4 months than in normal controls (P < or = 0.01). Residual urine volume was significantly increased at 4 months. Electrostimulation of the pelvic nerve provoked generalized bladder contractions, a response that was reduced by atropine and hexamethonium. Variable induction of TGF-alpha, TGF-beta1, TGF-beta2, and TGF-beta3 gene transcription was evident in the BAMG, with prominent mRNA expression of TGF-alpha and TGF-beta1 6 months after surgery. These cystometric results and detrusor responses to stimulation provide further evidence that graft components do not interfere with host components. Matrix-grafted rat bladders generate, although not increased over time, adequate intravesical pressure responses to produce sustained voiding. Gene expression of different growth factors may be significant in understanding their role in the development and differentiation of the BAMG for partial bladder replacement.

Animals↗

PubMed1998

Possible molecular mechanisms of cryoablation-induced impotence in a rat model.

OBJECTIVES: Cryoablation of the prostate has been reported to induce impotence as a consequence of cavernosal nerve injury. This study is designed to investigate the early and late effects of cavernosal nerve cryoablation on growth factor expression and erectile function in a rat model. METHODS: Forty male rats were divided into two groups (n=20 each). The first group underwent unilateral cavernosal nerve freezing (experimental group). Before their euthanization at 1 and 3 months (10 rats each), erectile function was assessed by electrostimulation of the cavernous nerves. The second group served as the control and was killed at the same time points. Western blot and reverse transcriptase-polymerase chain reaction (RT-PCR) techniques were used to identify protein and gene expression of nerve growth factor (NGF), transforming growth factor-alpha (TGF-alpha), epidermal growth factor (EGF), and insulin-like growth factor-1 (IGF-1) in the rat penis and pelvic ganglia. RESULTS: Electrostimulation of the frozen nerve after 3 months revealed a significantly higher maximal intracavernosal pressure and a shorter latency period than in the 1-month group. At 3 months, immunoblot showed upregulation of NGF, TGF-alpha, and the precursor form of IGF-1 protein expression in the penile tissue; RT-PCR showed downregulation of NGF gene expression in the pelvic ganglia of the frozen side. CONCLUSIONS: The results show that erectile function decreased at 1 month and then partially recovered 3 months after cavernosal nerve freezing. This alteration in erectile function was associated with differential gene and protein expression of the growth factors (NGF, TGF-alpha, EGF, and IGF-1). Further studies are required to elucidate the potential role of these growth factors in the prevention and treatment of cryoablation-induced impotence.

Animals↗

PubMed1998

Molecular prognostic markers in breast cancer.

Based on the scientific literature, there are several molecular markers which might be used for the prognosis of breast cancer. Possible molecular prognostic markers are: BRCA-1, BRCA-2, p53, erbB oncogenes, loss of heterozygosity (LOH), chromosomal aberrations, microsatellite instability, transforming growth factor alpha (TGFalpha), and the multiple drug resistance (MDR) gene. In this chapter, we discuss the possible role of these prognostic markers in breast cancer.

BRCA2 Protein↗

PubMed1998

Interactions between adult human prostatic epithelium and rat urogenital sinus mesenchyme in a tissue recombination model.

Tissue recombinants composed of adult human prostatic epithelium (hPrE) and rat urogenital sinus mesenchyme (rUGM) were grafted beneath the renal capsule of athymic rodent hosts. The pseudostratified human epithelium initially became multilayered, solid epithelial cords emerged, grew into the surrounding mesenchyme and canalized to regenerate a pseudostratified epithelium. Basal cells expressed cytokeratins 5 and 14, while luminal cells expressed cytokeratins 8 and 18, prostate specific antigen and prostatic acid phosphatase. The rat mesenchymal component differentiated into thick sheets of smooth muscle, characteristic of the human but not the rat prostate. These findings indicate that epithelial-mesenchymal interactions were reciprocal. Rat UGM induced adult hPrE to form new ductal-acinar tissue, involving epithelial proliferation, ductal branching morphogenesis and functional cytodifferentiation. Concurrently the epithelium dictated smooth muscle differentiation and patterning. Species-specific reverse transcriptase polymerase chain reaction SC (RT-PCR) analysis of the tissue recombinants was performed to separately examine the expression of epidermal growth factor (EGF), transforming growth factor-alpha (TGF-alpha), epidermal growth factor receptor (EGFR), TGF-beta 1, and TGF-beta 3 in the epithelium, stroma and host components of the graft. All of these genes, except TGF-beta 1, were expressed in all three tissues. Human TGF-beta 1 was not detected, indicating that this gene was not expressed in human prostatic epithelium but was present in stroma.

Adult↗

PubMed1998

Functional rat bladder regeneration through xenotransplantation of the bladder acellular matrix graft.

OBJECTIVE: To determine the decreased antigenicity of the bladder acellular matrix graft (BAMG) through xenotransplantation and to assess the in vivo and in vitro functional properties of the rat urinary bladder thus regenerated. MATERIALS AND METHODS: After partial cystectomy (> 50%), BAMGs prepared from hamster, rabbit and dog urinary bladders were grafted to male and female Sprague-Dawley rats; 10 control rats underwent partial cystectomy only. Urinary storage and voiding function were monitored in 15 animals using a specially designed 'micturition cage' and cystometry. After 4 months, organ-bath studies and histological techniques were used to evaluate bladder regeneration in vitro in the grafted animals. RESULTS: Clinically relevant antigenicity was not evident; no animal died from rejection and all bladder wall components regenerated in all BAMG xenografts. However, the degree and quality of regeneration varied. Muscularization, peak pressure, and bladder capacity were higher in the hamster BAMG-grafted animals, whereas in vitro contractility and compliance were best in the dog BAMG-regenerated bladders. All grafted bladders had significantly better capacity and compliance than the autoregenerated bladders after partial cystectomy alone. CONCLUSIONS: The present in vivo and in vitro studies show that BAMG-augmentation cystoplasty can lead to morphological and functional regeneration of the rat bladder, preserving its low-pressure reservoir function. Because BAMG-regenerated bladders show functional innervation that is similar to normal bladders, they can work in coordination with the host bladder components, thus generating adequate intravesical pressure to produce sustained voiding. The decreased antigenicity makes heterologous BAMG transplants feasible without immunosuppression.

Animals↗

PubMed1998

Composition and biomechanical properties of the bladder acellular matrix graft: comparative analysis in rat, pig and human.

OBJECTIVE: To compare the composition and mechanical properties of the newly developed bladder acellular matrix graft (BAMG) with the normal urinary bladder in rat, pig and human. MATERIALS AND METHODS: Rat, pig and human urinary bladders were harvested and divided into control and experimental groups. For the latter, BAMGs were prepared, and light and transmission electron microscopic studies performed. Strips from the normal bladders and the BAMGs (10 in each group) were tested under tension, and the ultimate tensile strength, maximum strain, and elastic modulus were determined from stress/strain curves. RESULTS: Both types I and III collagen, as well as elastic fibres, were observed as major components of the matrix scaffold. There were more collagen type I fibres in the rat than in the pig and human BAMGs, whereas the pig, and particularly the human, both showed higher levels of type III collagen and elastic fibres. These different matrix scaffold patterns were confirmed by electron microscopy. Results from biomechanical testing showed no significant differences for strength, strain or elastic modulus between BAMG and control bladder strips, except in the rat where the maximum strain values were significantly lower. CONCLUSION: There are variations in the acellular matrix structure with similar biomechanical properties between the BAMG and the normal urinary bladder in three different species. These results may underscore the potential of the BAMG. Furthermore, this in vitro model provides a suitable method to study the mechanical properties of the urinary bladder and may serve as a diagnostic tool for various investigations.

Animals↗

PubMed1998

A novel p53 mutation hotspot at codon 132 (AAG-->AGG) in human renal cancer.

Mutations of p53 tumor suppressor gene are the most common genetic alterations in a variety of human carcinomas. The sites of p53 mutations, however, vary in different cancers. The present study was designed to characterize p53 mutations in 40 primary human renal cancer specimens using hot-start-PCR-single-strand conformation polymorphism (SSCP) analysis, sequencing of PCR product and immunohistochemistry. DNA extracted from microdissected paraffin-embedded sections was amplified by hot-start-PCR using oligonucleotide primers specific for exons 4-9 of p53. The mutations were analyzed by PCR-SSCP technique and the generated fragments were denatured and analyzed by 6% polyacrylamide gel electrophoresis. The samples showing a band shift were denatured and sequenced using the Sequenase Version 2.0 DNA Sequencing Kit (US Biochemical, Cleveland, Ohio). Genomic DNA from control samples containing wild-type p53 alleles was sequenced in parallel for confirming mutations in samples that were positive for p53 in the PCR-SSCP analysis. The results of these experiments demonstrate that: (1) there were mutations in p53 exon 5 and 8 in 35% (14 out of 40 samples) of human renal cancer tissues as revealed by PCR-SSCP analysis; (2) DNA sequencing of samples showing frame-shift have hot spot of p53 mutation on exon 8 at codon 244 (GGC-->TGC) and exon 5 at codon 132 [AAG (Lys)-->AGG (Arg)]. This mutation in p53 exon 5 at codon 132 is novel and has not yet been reported; (3) immunohistochemical staining of p53 in renal cancer tissue using mouse anti-human p53 monoclonal antibody, clone PAb 1801, correlated with the p53 mutation assessed by PCR-SSCP. No correlation was found between p53 mutations and tumor stage and grade of renal cancer.

Carcinoma↗

PubMed1998

Species-specific detection of growth factor gene expression in developing murine prostatic tissue.

The aim of the present study was to develop a method by which the expression of paracrine signaling molecules could be localized to either epithelial or stromal cells of developing prostatic tissue. Heterospecific tissue recombinants composed of mouse urogenital epithelium (mouse UGE) plus rat urogenital mesenchyme (rat UGM) and the reciprocal tissue recombinants, rat urogenital epithelium (rat UGE) plus mouse urogenital mesenchyme (mouse UGM), were grafted under the renal capsule in intact, athymic male mouse and rat hosts. After 2 wk of growth, RNA from the grafts was analyzed by species-specific reverse transcription-polymerase chain reaction for the expression of the mRNA for the following molecules: transforming growth factors beta1, beta3, and alpha; epidermal growth factor; epidermal growth factor receptor; and keratinocyte growth factor. The species of expression of these growth factor and receptor gene products within the heterospecific tissue recombinants was identified, allowing determination of the cell layer in which the genes were expressed. Identification of the tissue-specific expression of the growth factor and growth factor receptor profiles of the epithelium and mesenchyme of this in vivo model provides a basis for understanding the autocrine and paracrine mediators of cell-cell interactions in prostatic development.

Animals↗

PubMed1998

The effect of surgical trauma on rat tunica albuginea.

PURPOSE: Increased TGF-beta1 protein expression in tunica albuginea has been found to be associated with Peyronie's disease. The present study is designed to investigate whether surgical trauma induces TGF-beta up-regulation and histological changes in rat penis. MATERIALS AND METHODS: Thirty-two adult male Sprague-Dawley rats were divided into two groups. The first group (n=24) underwent incision and suture repair of the tunica albuginea of the penis. The second group (n=8) received sham surgery (incision of the penile skin and underlying fascia) as the control group. The trauma-induced group was divided into four subgroups in which the rats were euthanized at 6 hours (n=6), 1 day (n=6), 3 days (n=6), and 8 weeks (n=6). Two sham-operated (control) animals were also euthanized at each of the above time points. All tunical tissues from the trauma-induced and sham-operated rats were collected and examined histologically using Trichrome and Hart elastic fiber stain. Electron microscopy was used to study the ultrastructural changes of both trauma induced and control specimens. Western blotting technique was performed to study TGF-beta protein expression in both experimental and sham-operated groups. RESULTS: Tissue edema and hemorrhage between collagen bundles are noted in the experimental groups after 6 hours, 1 day and 3 days. At 8 weeks the most prominent changes observed were inflammatory cellular infiltration and disorganization of the collagen bundles. In the control group the tunica albuginea retains normal wavy regular appearance in all rats. This histological analysis is similar to the reported description of histological features of the acute phase of Peyronie's disease. Electron microscopy showed packed collagen bundles in the trauma-induced group with normal appearing elastic fibers. No abnormal change was detected in the control group. Immunoblot results revealed remarkable TGF-beta1 protein expression in 1, 5, 3, and 0 rats of trauma induced subgroups after 6 hours, 1 day, 3 days, and 8 weeks respectively. No TGF-beta1 protein expression in any rats in the control group was detected. No significant TGF-beta2 or TGF-beta3 protein expression was observed either in the trauma induced group or in the control group. CONCLUSION: Trauma can induce histological changes similar to the acute phase of Peyronie's disease but not the overt picture of the chronic phase of Peyronie's disease. It can also result in an early but transient up-regulation of TGF-beta1 protein expression in the rat penis. We conclude that surgical incisional trauma does not result in Peyronie's disease-like changes in the tunica.

Animals↗

PubMed1998

In vitro functional properties of the rat bladder regenerated by the bladder acellular matrix graft.

PURPOSE: To assess the response of rat urinary bladder regenerated by the homologous bladder acellular matrix graft (BAMG) to in vitro electrical and pharmacologic stimuli. MATERIALS AND METHODS: In Sprague-Dawley rats, partial cystectomy (>50%) was performed, followed by BAMG augmentation cystoplasty. After 4 months, organ bath studies of tissue strips in 10 were used to compare the contractility of the BAMG regenerates and the corresponding host detrusor smooth muscle. RESULTS: The BAMG regenerates exhibited contractile activity to electrical field stimulation and a qualitatively identical pattern of response to muscarinic, purinergic, alpha- and beta-adrenergic drug administration and nitric oxide. At 4 months after surgery, the maximum forces of contraction of the BAMG regenerates to carbachol stimulation amounted to close to 80% of the host bladder response. With electrical field stimulation, they equaled 44% and 62% of the host bladder response after 2.5 and 4 months, respectively. Histological and immunohistochemical studies confirmed the presence of receptors for neurotransmitters that these functional in vitro studies implied. CONCLUSIONS: The present study provides further evidence that augmentation cystoplasty with the BAMG leads to functional regeneration of the rat bladder detrusor smooth muscle.

Animals↗

PubMed1998

Effect of cavernous nerve freezing on protein and gene expression of nitric oxide synthase in the rat penis and pelvic ganglia.

PURPOSE: Cryoablation of the prostate has been reported to induce impotence as a result of cavernous nerve injury. This study is designed to investigate the early and late effects of cavernosal nerve cryoablation on erectile function and nitric oxide synthase (NOS) containing nerves in the rat penis and pelvic ganglia. MATERIALS AND METHODS: Forty male rats were divided into two groups (n = 20 each). The first group underwent unilateral cavernous nerve freezing (experimental group). Before their euthanization at 1 and 3 months (10 rats each), erectile function was assessed by electrostimulation of the cavernous nerves. The second group served as a control and was euthanized at the same time points. Nicotinamide adenine dinucleotide phosphate (NADPH) diaphorase staining was used to identify NOS in the penile nerve fibers of the mid-shaft segment and neurons of the pelvic ganglia. Western blot, RT-PCR and immunostaining techniques were used to identify protein and gene expression of eNOS, iNOS, and nNOS. RESULTS: One month after unilateral cavernosal nerve freezing, there was a significant decrease in NOS-containing nerve fibers in the dorsal and intracavernosal nerves and ipsilateral pelvic ganglia as compared with the intact side. At three months, the number of NOS containing nerve fibers in the above-mentioned nerves and ganglia showed a significant increase on the frozen side but not the intact side. Electrostimulation of the frozen nerve after three months revealed a significantly higher maximal intracavernosal pressure and a shorter latency period than the one-month group. At three months, immunoblot showed up-regulation of eNOS and nNOS protein expression in the penile tissue. RT-PCR showed up-regulation of nNOS gene expression in the pelvic ganglia of the frozen side. Immunostaining confirmed the results of western blot and showed significant increase of the nNOS positive staining in the frozen side of the penile tissue after three months. There was no difference in iNOS after three months between both sides. Our repeated eNOS immunostaining was not successful. CONCLUSIONS: The results show that intracavernous pressure response to neurostimulation markedly decreased at one month and then partially recovered three months after cavernosal nerve freezing. A similar pattern of changes of the NOS-containing nerve fibers in dorsal nerves, intracavernosal nerves, and pelvic ganglia were observed. This alteration in erectile function and NOS-containing nerves was associated with differential gene and protein expression of the three subtypes of NOS.

Animals↗