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Biomedical subjects

Y Y Park

Publications and source records attributed to Y Y Park.

10 recordsLinked to original sources
PubMed2001

Effects of estrogen on nitric oxide synthase and histological composition in the rabbit clitoris and vagina.

We investigated the functional and histological changes after oophorectomy in the rabbit clitoris and vagina to determine the mechanism responsible for the development of arousal disorder in postmenopausal women. Twenty mature female New Zealand white rabbits were randomly divided into three groups: control; oophorectomy; and estrogen replacement after oophorectomy. We compared the nitric oxide synthase (NOS) activity and the degree of expression of neuronal (nNOS) and endothelial NOS (eNOS) using biochemical and Western blot analysis in clitoral and vaginal tissues. Histological change of smooth muscle and collagen contents in those tissues were also compared using Masson's trichrome staining. NOS activity and the expression of nNOS and eNOS were significantly increased in the oophorectomized group while there was a decrease to the level of the control group in the estrogen replacement group. Histological examination showed that oophorectomy induced a significant increase in collagen and decrease in muscle content in both clitoris and vagina, while the ratio of smooth muscle content was increased significantly after the estrogen replacement. Our results clearly demonstrate that estrogen deficiency induces compensatory NOS production which may be related to decreases in muscle to collagen ratio in female rabbit genital organs.

Animals↗
PubMed2001

Non-Hodgkin's lymphoma & primary biliary cirrhosis with Sjögren's syndrome.

Sjögren's syndrome (SS) is an autoimmune disease characterized by a lymphocytic infiltration of the salivary and lacrimal glands leading to a progressive destruction of these glands due to the production of autoantibodies. This disorder is either isolated (primary SS) or associated with other systemic diseases (secondary SS). The occurrence of B-cell non-Hodgkin's lymphoma (NHL) represents the major complication in the evolution of SS patients. The risk of developing NHL, which is equivalent for both primary and secondary SS, was estimated to be 44 times greater than that observed in a comparable normal population. NHLs in SS patients occur preferentially in the salivary glands and in other mucosa-associated lymphoid tissues (MALT). However, it can also occur in the lymph nodes or bone marrow. We documented a case of low-grade B-cell lymphoma of MALT in the right eyelid and primary biliary cirrhosis (PBC) of a patient with SS. To the best of our knowledge, this is the first case reported in Korea.

Eyelid Neoplasms↗
PubMed2000

Hemodynamic insult by vascular risk factors and pharmacologic erection in men with erectile dysfunction: Doppler sonography study.

To evaluate the penodynamic impact of known vascular risk factors in men with erectile dysfunction, we obtained thorough medical histories covering diabetes, hypertension, heart disease and hypercholesterolemia, alcohol ingestion, and smoking in 265 consecutive patients. We also measured their penile hemodynamic parameters by color duplex ultrasonography after intracavernous prostaglandin E1 injection. In patients with vascular risk factors there was a statistically significant decrease in the peak systolic velocity and increase in the end-diastolic velocity of the cavernosal artery (P < 0.01). Those men who had diabetes had higher average end-diastolic velocities and lower resistance indices (P < 0.01). Smoking and alcohol use also affected penile hemodynamics (P < 0.05). These data confirm that vascular risk factors do increase the likelihood of vasculogenic impotence and that diabetes plays a major role in veno-occlusive dysfunction in the penis.

Adolescent↗
PubMed1999

Is obesity an underlying factor in erectile dysfunction?

OBJECTIVES: We conducted a study to evaluate the impact of obesity on erectile function in men with erectile dysfunction. METHODS: Three hundred and twenty-five consecutive patients with erectile dysfunction were evaluated. We classified the men into 2 groups according to body weight: <120% of the ideal body weight, and >/=120%. We compared several erectile capacities and the findings of penile duplex ultrasonography. RESULTS: There was a statistically significant decrease in the quality of residual erectile function in patients with obesity (penile rigidity grade 1.32 versus 1.62 in the nonobese patients). Obese patients also have an increased prevalence of vascular risk factors based on a review of the medical records and vascular impairment by duplex ultrasound study (43 and 62% in the obese patients versus 30 and 42% in the nonobese patients, respectively, p < 0.05). However, when we focused only on the patients without any vascular risk factors, no significant difference between the 2 groups was noted in the quality of residual erectile function and also the prevalence of penile vascular impairments (p > 0.05). CONCLUSIONS: These data demonstrate that obesity in itself does not seem to be an underlying factor, but does impose a risk to vasculogenic impotence by developing chronic vascular disease.

Adolescent↗
PubMed1997

The impact of aging on penile hemodynamics in normal responders to pharmacological injection: a Doppler sonographic study.

PURPOSE: The change in arterial flow velocity with age in patients with a normal response to pharmacological injection was evaluated. MATERIALS AND METHODS: We studied 64 patients with erectile dysfunction who responded well to intracavernous injection of 10 micrograms. prostaglandin E1 with well sustained penile rigidity for longer than 1 hour and normal cavernous arterial flow velocities on color Doppler ultrasonography. The men were classified into 4 groups according to age younger than 30 years, and 30 to 39, 40 to 49 and 50 years old or older. Flow parameters were compared. RESULTS: The statistically significant decreasing tendency of peak systolic velocity with age was revealed by a simple regression test (p = 0.003). The greatest decrease was observed between patients in the third and fourth decades. When comparing the peak systolic velocity according to timing of measurement, the greatest velocities occurred at later measurements after the fifth decade, while in younger patients these values were reached earlier. CONCLUSIONS: These data demonstrate that cavernous arterial flow during pharmacological erection decreases and the response time of the cavernous artery or tissue to a vasoactive drug becomes longer with age.

Adult↗
PubMed1996

Effects of chronic central administration of losartan on the cardiovascular and hormonal responses to hemorrhage in conscious rats.

Our objective was to assess the effects of chronic central angiotensin II (Ang II) blockade on the basal regulation of blood pressure, heart rate (HR), arginine vasopressin (AVP), renin, epinephrine (EPI), norepinephrine (NE) and on cardiovascular and hormonal responses to hemorrhage in conscious rats. Losartan (4 micrograms/h), or artificial cerebrospinal fluid (aCSF), was chronically infused into a lateral ventricle by using an osmotic minipump for 6 days at a rate of 1 microliter/h. Compared with aCSF controls, chronic losartan treatment significantly decreased the basal level of blood pressure (from 117 +/- 2.3 to 106 +/- 2.2 mmHg, P < 0.01) and increased the HR (from 357 +/- 3.7 to 410 +/- 6.6 beats/min, P < 0.01). Plasma renin concentration increased 3-fold (from 6.1 +/- 0.6 to 19.2 +/- 1.6 ng.ml(-1).h(-1), P < 0.01). Basal levels of AVP, EPI and NE were not different between two groups. Blood pressure immediately after hemorrhage and its compensatory recovery following hemorrhage was not different in both groups. Immediately after hemorrhage, however, in the losartan-treated rats, the HR was distinctly lower than that of aCSF controls, even at 10 min after hemorrhage. Hemorrhage produced a significant increase in the plasma concentrations of AVP, renin, EPI and NE. Chronic losartan treatment markedly augmented the AVP, renin and EPI responses to hemorrhage. These results strongly suggest that Ang II acting through AT1 receptors in the brain plays a significant physiological role in the regulation of basal blood pressure, HR and renin release. In addition, centrally acting Ang II may be one of the important mediators for cardiovascular regulations and hormone releases in response to hemorrhage.

Angiotensin II↗
PubMed1995

Central ANG II-receptor antagonists impair cardiovascular and vasopressin response to hemorrhage in rats.

The role of brain angiotensin II (ANG II) in mediating cardiovascular, vasopressin, and renin responses to hemorrhage was assessed in conscious spontaneously hypertensive rats (SHR) and in normotensive Wistar-Kyoto (WKY) and Wistar rats. Intracerebroventricular administration of losartan (10 micrograms) and saralasin (1 microgram.microliter-1.min-1) produced a markedly greater fall in blood pressure and a reduced tachycardia during and after hemorrhage (15 ml/kg) compared with the artificial cerebrospinal fluid control in SHR and Wistar rats but not in WKY rats. Vasopressin release after hemorrhage was also impaired, but renin release was enhanced by intracerebroventricular ANG II antagonists in SHR and Wistar rats but not in WKY rats. Losartan and saralasin produced remarkably similar effects on the cardiovascular, vasopressin, and renin responses to hemorrhage. These data suggest that brain ANG II acting through AT1 receptors plays an important physiological role in mediating rapid cardiovascular regulation and vasopressin release in response to hemorrhage. The relative importance of brain angiotensin system may vary in different strains of rate.

Angiotensin II↗
PubMed1989

A case of tracheoesophageal cyst in the posterior mediastinum.

We experienced a case of a tracheoesophageal cyst in the posterior mediastinum of a three-year-old girl, who complained of cough and fever. We confirmed this case by computerized tomography and pathologic examination after surgical resection. A brief review of the literature is presented.

Child, Preschool↗
PubMedDate not supplied

Effects of stress on female rat sexual function.

This study was undertaken to investigate whether prolonged stress interferes with sexual behavior and changes biochemical and physiologic mechanisms. Experiments were repeated three times with different rats in each period. In all, 63 female Sprague-Dawley rats were employed, with 21 rats in each period, and the control group was maintained at room temperature with free access to food and water. The stress group was maintained under a scheduled stress condition for 10 days, and seven rats from the group were randomly selected and exposed to the control environment for 10 days as the recovery group. Sexual behavior, hormonal values, and neuronal and endothelial nitric oxide synthase (nNOS and eNOS) expressions of vaginal tissue were analyzed and compared. Serum testosterone levels were significantly elevated in the stress and recovery groups (P<0.05). Female rats in the stress group showed reduced receptivity to their male mates (P<0.05). Western blot analysis demonstrated that nNOS and eNOS expressions were significantly lower in the stress group (P<0.05) than in the other groups. We conclude that chronic physical stress modifies the sexual behavior of female rats through a mechanism believed to involve complex changes in sex hormones, endocrine factors, and neurotransmitters.

Animals↗