Accumulation of Nucleolar Inorganic Polyphosphate Is a Cellular Response to Cisplatin-Induced Apoptosis

The chemotherapeutic drug cisplatin, which targets DNA, serves as one of the main staples in cancer treatment. Yet, the therapeutic application of cisplatin is limited by two major challenges: the occurrence of reversible and irreversible side effects due to non-specific toxicity, and the intrinsic or developing resistance of tumor cells toward cisplatin. Here we demonstrate that cancer cells respond to cisplatin treatment with the nucleolar accumulation of inorganic polyphosphate (polyP), a universally conserved high-energy compound. PolyP accumulation positively correlates with the levels of activated caspase-3, suggesting a novel role of polyP in cisplatin-mediated apoptosis. In support of this finding, we discovered that administration of exogenous polyP increases cisplatin-induced toxicity in select cancer cell lines, raising the exciting possibility that enhancing endogenous polyP levels might be a novel mechanism to sensitize cancer cells to cisplatin treatment.

Tissue ingrowth in penile implants and its effect on repeat penile surgery

Penile implant malfunction is usually treated by removal of the original malfunctioning implant followed by replacement with a new device. During replacement, the original implant can be explanted without any difficulty, as it is not adherent to the surrounding tissue. Herein, we describe two cases of tissue ingrowth into the implant that produced difficulty during explantation and suggest ways in which this condition can be managed.

Chronic cigarette smoking induces an oxidantantioxidant imbalance in the testis

OBJECTIVES

We have previously demonstrated the harmful effect of chronic inhalation of cigarette smoke on the testis in Sprague-Dawley rats. The aim of the present study was to investigate the role of free oxygen radicals and reactive oxygen species in inducing testicular damage in Sprague-Dawley rats following exposure to cigarette smoke.

MATERIALS AND METHODS

Sprague-Dawley rats, 25 days old, were exposed daily to cigarette smoke by the Walton smoking machine for a period of 15, 30, and 45 days. Age-matched Sprague-Dawley rats were exposed to room air with the smoking machine and served as controls. Rats were sacrificed from each group at 15, 30, and 45 days and the testes were removed. The testicular tissue levels of glutathione and lipid peroxidation product malonaldehyde (MDA) were measured colorimetrically using the Bioxytech GSH-400 and LPO-586 kits, respectively. The activity of glutathione peroxidase was assessed colorimetrically using the Bioxytech GPx-340 kit. Statistical analysis was performed using ANOVA followed by the t test.

RESULTS

There was a 47.8% increase in the MDA in the treated rat testis compared with the control rat after 45 days of exposure to cigarette smoke or air, respectively (p < 0.05). This was associated with a parallel significant decrease in the level of glutathione and glutathione peroxidase activity in the treated rat testis, 38.2% and 29.1%, respectively, after 45 days of cigarette smoke exposure (p < 0.05). No significant difference was noted in the levels of glutathione, glutathione peroxidase, and lipid peroxidation end products after 15 and 30 days of treatment.

CONCLUSIONS

Chronic cigarette smoke inhalation is associated with an increase in the level of oxidants and a simultaneous decrease in the level of antioxidants in the rat testis. This abnormality of the oxidant-antioxidant balance may be one of the mechanisms leading to testicular tissue damage and abnormal spermatogenesis in the rat testis following chronic inhalation of cigarette smoke.

Morphometric analysis of rat testis following chronic exposure to cigarette smoke

PURPOSE

To assess the effect of chronic exposure to cigarette smoke on spermatogenesis in Sprague-Dawley rats.

MATERIALS AND METHODS

Twenty 5-day-old Sprague-Dawley rats were exposed daily to cigarette smoke by the Walton smoking machine for a period of 15, 30, and 45 days. Age-matched Sprague-Dawley rats exposed to room air with the smoking machine served as controls. Rats were sacrificed from each group at 15, 30, and 45 days and the testes were removed. Fifty seminiferous tubules were assessed in each group. Morphometric and histopathologic analyses of the testes were carried out. The following parameters were studied: (1) Number of germ cells (step 7 spermatids), (2) seminiferous tubule diameter, (3) height of germinal epithelium, (4) presence of degenerating or sloughed cells, (5) failure of release of spermatids into the tubular lumen, and (6) degeneration of Leydig cells. Statistical analysis was performed using ANOVA followed by the t test.

RESULTS

There was a significant decrease in the germ cell count (step 7 spermatids) in the rats exposed to cigarette smoke for 30 days (93.19 versus 98.15 step 7 spermatids in the control animals (p < 0.001). This decrease persisted in the rats exposed to cigarette smoke for 45 days (82.47 versus 103.01 step 7 spermatids in control animals, p < 0.001). The mean seminiferous tubule diameter was significantly reduced only in the rats exposed to cigarette smoke for 45 days (0.283 microm versus 0.299 microm in the control animals, p < 0.001). There was no significant difference in the height of the germinal epithelium, and no degenerating cells were noted in either group.

CONCLUSIONS

Cigarette smoke adversely affects spermatogenesis in pubertal Sprague-Dawley rats.

Lipid peroxidation and antioxidant activities in rat testis after chronic cocaine administration

OBJECTIVES

Our recent study has shown that cocaine has adverse action on spermatogenesis and fertility in male rats. Adverse effects of cocaine on the testes may be mediated by oxidative damage and subsequent lipid peroxidation. Glutathione is a cellular antioxidant and is found in high concentrations in the rat testes. In this study, the effects of chronic cocaine administration on the activities of glutathione peroxidase, the level of testicular reduced glutathione, and lipid peroxidation were investigated.

METHODS

Thirty-day-old male Sprague-Dawley rats were given cocaine hydrochloride (15 mg/kg body weight) subcutaneously daily for 90 days. Control animals received equal volumes of normal saline daily for 90 days. Testes were removed at 15, 30, 60, and 90 days after cocaine injection. Tissues were washed and homogenized in ice-cold metaphosphoric acid solution or Tris-HCI buffer. Reduced glutathione, glutathione peroxidase, and malonaldehyde levels were determined by colorimetric assay. Statistical analysis was performed using analysis of variance.

RESULTS

Testicular reduced glutathione and glutathione peroxidase were significantly decreased in the treatment testes 15, 30, 60, and 90 days after chronic cocaine injection compared with controls (P <0.05). The testicular malonaldehyde level was 20.8% (P <0.05), 22.1% (P <0.05), 31.2% (P <0.05), and 24.7% (P <0.05) above the control value on days 15, 30, 60, and 90, respectively.

CONCLUSIONS

Our findings demonstrate that chronic administration of cocaine to male rats induces a depletion of reduced glutathione and glutathione peroxidase. Adverse effects of cocaine on the testes are at least in part due to impairment of the function of the antioxidant defense and further enhancement of lipid peroxidation.

Penile implant success in patients with corporal fibrosis using multiple incisions and minimal scar tissue excision

OBJECTIVES

To establish the efficacy of "minimal scar tissue excision" in the treatment of penile fibrosis.

METHODS

Thirty-four patients with extensive penile fibrosis who underwent placement of penile implant from October 1989 to April 1998 were evaluated by a chart review of the patient's follow-up data. Function of the implant was evaluated at follow-up visits. The follow-up ranged from 4 to 84 months (mean 23.7, median 22). All patients had undergone minimal scar tissue excision of the fibrous tissue in the penis.

RESULTS

All patients underwent successful introduction of the penile implant, and in no patient was the procedure abandoned because of technical difficulty. Intraoperatively, 1 patient developed a tear in the crus. It was not recognized during the initial operation but was repaired at a subsequent date by Gore-Tex grafting. The Uniflate prosthesis of another patient failed 2 years after the initial surgery and was replaced with the Mentor alpha-1 implant. None of the patients developed infection. All the patients had a functioning implant at the time of last review.

CONCLUSIONS

Minimal scar tissue excision is a safe and effective method in the management of extensive penile fibrosis.

Cocaine induced apoptosis in rat testes

PURPOSE

Exposure of rats to chronic cocaine results in disruption of spermatogenesis including reduction of germ cells. However, the cellular mechanism responsible for the testicular damage in testes is still unknown. We have studied the role of apoptosis in cocaine induced testicular damage.

MATERIALS AND METHODS

Thirty-day-old male Sprague-Dawley rats were given cocaine hydrochloride (15 mg./kg. body weight) subcutaneously daily for 90 days. Control animals received equal volumes of normal saline daily for 90 days. Testes were removed at 15, 30, 60, and 90 days of cocaine administration. In situ detection of germ cells with DNA strand breaks in paraffin-embedded testicular section (5 microm.) was achieved by the terminal deoxynucleotidyl transferase (TdT)-mediated dUTP in situ nick end-labeling (TUNEL) method. DNA fragmentation was also determined by gel electrophoresis.

RESULTS

Apoptotic cells were found in the spermatocytes and spermatogonia of germinal epithelium. Less than 7% of seminiferous tubule cross sections showed a high level of apoptosis (> or =3 apoptotic cells per tubule) in control animals compared with experimental group where 25% of the tubules showed a high level of apoptosis (p<0.05). The number of apoptotic cells was significantly increased by 15 days, peaked at 30 days and persisted up to 90 days of cocaine exposure when compared with controls (p<0.05). DNA isolated from the cocaine treated testes displayed a clear ladder pattern whereas the DNA from controls did not.

CONCLUSIONS

The experimental results presented here suggest that cocaine exposure leads to significant apoptosis in rat testes and the mechanism of cocaine induced testicular injury may be related to the induction of apoptosis.

Assessment of psychosexual adjustment after insertion of inflatable penile prosthesis

OBJECTIVES

To evaluate the psychosexual benefit obtained from multicomponent penile implant surgery in patients with erectile dysfunction.

METHODS

A psychosexual questionnaire was given to 35 patients undergoing penile prosthesis implantation before surgery and at 3 months, 6 months, and 1 year after surgery. The questionnaire consisted of 13 questions scored on a scale from 1 through 5. Results of the questionnaire were statistically analyzed for differences among the preoperative, 3-month postoperative, 6-month postoperative, and 1-year postoperative period.

RESULTS

The general linear model evaluation showed a significant difference for each overall combination of the following pairs: preoperative versus 3 months postoperative (P=0.0005) and 3 months postoperative versus 6 months postoperative (P=0.002). There was no overall difference between psychosexual total score at 6 months after surgery and 1 year after prosthesis implantation (P=0.85). The patients perceived improvement in their erectile ability and libido. Concern about obtaining and maintaining an erection during intercourse was significantly alleviated. There was an increase in the frequency of sexual activity and an improvement in satisfaction with sex life. A decrease in feelings of sadness, depression, anxiety, anger, frustration, and embarrassment related to sexual activity was also noted.

CONCLUSIONS

The current study demonstrates significant improvement in the psychosexual well being of multicomponent penile implant recipients, with attainment of a high level of patient satisfaction up to 1 year after surgery.

Antibacterial activity of antibiotic coated silicone grafts

PURPOSE

Postoperative infection remains one of the most serious complications of implantation of penile prostheses. Attempts to reduce the rate of infection by spraying the prosthesis with an antibiotic solution prior to implantation, along with perioperative antibiotics, have failed to eradicate infection. No published studies have evaluated the effect of antibiotic coating of penile prostheses. In this study, we evaluate the antibacterial effect of antibiotic-coated silicone strips as a surrogate for the penile prosthesis.

MATERIALS AND METHODS

Strips coated with several different antibiotics were dipped in bacterial solutions containing Staphylococcus epidermidis or S. aureus and implanted subcutaneously in adult Sprague-Dawley rats. After a week, the strips were removed, and the number of bacteria on the strips and in the surrounding tissue were determined. The in vitro antibiotic activity of the antibiotic-coated strips against the same organisms was also determined.

RESULTS

In the group of rats that received silicone strips contaminated in vitro with S. epidermidis, six of nine control rats yielded strips and tissues containing heavy bacterial growth. None of six strips coated with rifampin/minocycline yielded bacterial growth, nor did any of the seven strips coated with vancomycin. One of seven rats that received amikacin-coated strips had infection of the strip. The tissue results were similar to the strip results. In the group using S. aureus as the contaminating bacterium, the strips and tissues from eight of nine control rats yielded bacteria. None of the six rifampin/minocycline-coated strips yielded bacteria, while two of seven vancomycin-treated strips and two of six amikacin-coated strips were infected with S. aureus. The difference in bacterial growth between controls and antibiotic-coated strips reached a level of statistical significance for the rifampin/minocycline and vancomycin groups and was highly significant for the rifampin/minocycline groups.

CONCLUSION

The experimental results presented here suggest that coating silicone graft material with antibiotics, particularly rifampin/minocycline, can reduce the incidence of graft colonization in contaminated wounds in rats, even in the absence of systemic antibiotics. These graft materials may prove useful in preventing the infection of penile prostheses.