Biomedical subjects

Kwangsung Park

Publications and source records attributed to Kwangsung Park.

6 recordsLinked to original sources

PubMed2004

Intracavernosal injection of vascular endothelial growth factor improves erectile function in aged rats.

OBJECTIVES: To investigate whether intracavernosal injection of vascular endothelial growth factor (VEGF) can restore erectile function in the aging rat. MATERIALS AND METHODS: Ten young (4-5 months) and 30 old (24 months) Sprague-Dawley male rats were used. The old rats were divided into 3 groups: vehicle-only (phosphate buffered saline plus 0.1% bovine serum albumin; n = 10), VEGF 1 microg/kg (n = 10), and VEGF 10 microg/kg (n = 10). At 2 and 4 weeks after treatment, erectile function and histology were evaluated by hemodynamic study, histomorphometric analysis, and immunohistochemistry. RESULTS: After 4 weeks of treatment, the ratio of peak intracavernosal pressure to systemic arterial blood pressure in response to neurostimulation was significantly higher in both the VEGF 1 microg/kg (79.9 +/- 7.7%) and the VEGF 10 microg/kg group (76.8 +/- 5.8%) compared to the vehicle-only group (63.1 +/- 8.5%; p < 0.05). The percentage of cavernosal smooth muscle was significantly higher in the VEGF 10 microg/kg group (16.1 +/- 1.4%) compared to the vehicle-only group (12.8 +/- 2.2%; p = 0.047). VEGF treatment in old rats increased e-NOS and VEGF expression in both treatment groups. CONCLUSION: Intracavernosal injection of VEGF appears to restore smooth muscle integrity and improve erectile function in aged rats.

Angiogenesis Inducing Agents↗

PubMed2004

Intrascrotal extratesticular arteriovenous malformation.

We describe a case of intrascrotal-extratesticular arteriovenous malformation in an adult that presented as a hard scrotal mass mimicking post-traumatic hematoma. This is the first reported case of an arteriovenous malformation at the intrascrotal-extratesticular region.

Adult↗

PubMed2004

Penile strangulation treated with the modified string method.

Penile strangulation by a nonmetallic or thin metallic ring is easily overcome by severing the object, but a heavy metal ring causing penile strangulation is very difficult to sever. Here we report 2 cases of penile strangulation by metal rings, involving a 38-year-old man and a 44-year-old man, both of whom were treated with the modified string method and glandular puncture.

Adult↗

PubMed2003

Reperfusion of ischemic corporal tissue: physiologic and biochemical changes in an animal model of ischemic priapism.

OBJECTIVES: To assess the physiologic and biochemical changes resulting from ischemia and reperfusion. Effective therapy for ischemic priapism reestablishes corporal venous outflow and arterial inflow and results in increased corporal partial pressure of oxygen. Data are limited concerning reperfusion injury of ischemic erectile tissue associated with reactive oxygen species (ROS) and the potential role of ROS scavengers in the clinical therapy of ischemic priapism. METHODS: Anesthetized adult New Zealand white male rabbits (n = 7) were exposed to a low oxygen tension breathing gas to achieve hypoxia within the corpora cavernosa. This resulted in a mean systemic oxygen saturation of 60%. The pelvic nerve was electrically stimulated to induce penile erection, and the base of the erect penis was clamped. After varying durations of ischemia, the clamp was removed to allow reperfusion. We determined the intracavernosal oxygen tension, histologic changes, myeloperoxidase activity, and lipid peroxidation. RESULTS: Corporal partial pressure of oxygen progressively decreased as the duration of priapism increased. A statistically significant increase was noted in myeloperoxidase activity and lipid peroxidation with corporal reperfusion. Polymorphonuclear leukocyte infiltration was documented in the ischemic reperfused tissue. CONCLUSIONS: In the management of ischemic priapism, reperfusion causes erectile tissue injury owing to the presence of ROS. There is a need to investigate the utility of ROS scavengers and antioxidants in the management of ischemic priapism.

Animals↗

PubMed2002

Diabetes induced alteration of clitoral hemodynamics and structure in the rabbit.

PURPOSE: We investigated the effect of diabetes on clitoral hemodynamics and structures in the rabbit. MATERIALS AND METHODS: A total of 25 New Zealand White female rabbits weighing 3 to 3.5 kg. were divided into 2 groups, including 5 in the control and 20 in the experimental group. Experimental animals received intravenous injection of alloxan hydrochloride (Sigma Chemical Co., St. Louis, Missouri) (100 mg./kg.). The development of diabetes was verified by measuring body weight and blood glucose levels. After 12 weeks clitoral cavernous blood flow in ml. per minute per 100 gm. tissue was measured with a laser Doppler flowmeter. Cross sections of the clitoris were used for histochemistry and histomorphometric image analysis. RESULTS: After 12 weeks 5 animals were included in the diabetes group. Mean baseline flaccid and peak clitoral cavernous blood flow plus or minus standard deviation significantly decreased in the diabetic group compared with the control group (3.9 +/- 1.6 and 5.8 +/- 2.2 versus 7.2 +/- 2.5 and 12.9 +/- 5.8 ml. per minute per 100 gm. tissue, respectively, p <0.05). Histology revealed diffuse clitoral fibrosis in the diabetic group. On histomorphometry the mean proportion of clitoral cavernous smooth muscle in the diabetic group was significantly decreased compared with the control group (51.9% +/- 4.9% versus 62.3% +/- 3.1%, p < 0.05). CONCLUSIONS: These results show that diabetes mellitus produces significant adverse effects on the hemodynamic mechanism of clitoral engorgement and leads to diffuse clitoral cavernous fibrosis. It implies that decreased sexual arousal in diabetic women may result from structural changes in the clitoris.

Animals↗

PubMed2002

Efficacy of virtual glasses in audio-visual sexual stimulation during penile color duplex Doppler ultrasonography.

OBJECTIVE: To examine whether audio-visual sexual stimulation (AVSS) with virtual glasses is effective in improving the recording of penile hemodynamics during penile color duplex Doppler ultrasonography. PATIENTS AND METHODS: A total of 64 consecutive patients with erectile dysfunction underwent penile color duplex Doppler ultrasonography after intracavernosal injection of 10-20 microg prostaglandin El and subsequent genital stimulation. AVSS with virtual glasses and earphones was applied when peak systolic velocities (PSV) were less than 35 cm/s or end diastolic velocities (EDV) were more than 5 cm/s. PSV, EDV and the resistive index of both cavernosal arteries were continuously monitored. Clinical erectile response was assessed with visual inspection and manual palpation. RESULTS: AVSS with virtual glasses was performed on 40 of 64 patients. AVSS improved the clinical erectile response in 26 (65%) of 40 patients. Doppler ultrasonography without AVSS identified 11 (27.5%), 5 (12.5%), and 24 (60%) patients with arteriogenic, veno-occlusive, and mixed-type impotence, respectively. However, after real-time AVSS 15 (37.5%), 7 (17.5%), 8 (20%), and 10 (25%) patients demonstrated non-vasculogenic, arteriogenic, veno-occlusive, and mixed-type impotence, respectively. Real-time AVSS improved the Doppler wave forms in 65% of cases. CONCLUSION: AVSS with virtual glasses improves the recording of physiologic erectile response and may be used as a valuable tool during penile color duplex Doppler ultrasonography.

Adult↗