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Biomedical subjects

Y S Tsai

Publications and source records attributed to Y S Tsai.

At least 19 recordsLinked to original sources
PubMed2001

Age-associated changes in collagen content and its subtypes within rat corpora cavernosa with computerized histomorphometric analysis.

OBJECTIVES: To study the age-associated changes in the percentage of collagen and subtypes I, III, and IV within the corpora cavernosa in a rat model. METHODS: The corpora cavernosa tissues were obtained from 30 male Wistar rats at three different ages. Processed with Masson's trichrome staining for collagen and with immunohistochemical staining for the collagen subtypes, the values of the collagen percentage, the percentage of area, and relative proportion of each collagen subtype within the rat corpora cavernosa were measured using an automatic image analysis system. The relationships between an increase in age and these parameters were analyzed. RESULTS: The percentage of collagen within the corpora cavernosa was higher in the old rats (80 weeks) than in the young (20 weeks) and intermediate-age (40 weeks) rats (P = 0.02 and P = 0.25, respectively) and significantly increased with age (P = 0.021). The values of the percentage of area of collagen subtypes III and IV also increased significantly with age (P = 0.039 and P = 0.019, respectively). The value of the percentage of area of collagen subtype I was not significantly increased (P = 0.159). Also, no significant differences were found in the relative proportions of all three collagen subtypes with age among the three age groups. CONCLUSIONS: The percentages of collagen within rat corpora cavernosa significantly increased, but not strongly, with age, especially collagen subtypes III and IV. However, the relative proportion of each subtype did not change with age. Therefore, we conclude that the amount of collagen may only partly contribute to erectile dysfunction in the aging process of the rat.

Aging↗
PubMed2001

Transurethral microwave thermotherapy for symptomatic benign prostatic hyperplasia: long-term durability with Prostcare.

OBJECTIVE: To evaluate the long-term durability of transurethral microwave thermotherapy (TUMT) with Prostcare for symptomatic benign prostatic hyperplasia (BPH). PATIENTS AND METHODS: From August 1993 to July 1994, a total of 65 patients with symptomatic BPH who underwent TUMT using the Prostcare apparatus (Bruker Spectospin, Wissembourg, France) with low-energy protocol (maximal power 52 W) were enrolled into a short-term evaluation. Subsequent follow-up information was collected in July 1999. If patients had had any further therapy for BPH, the date of retreatment was considered as an endpoint of TUMT efficacy. If no further therapy for BPH had been needed, they were re-assessed for overall satisfaction. RESULTS: The median follow-up period was 49 months. Twenty patients were excluded for various reasons, including 17 with loss of follow-up and 3 with new diseases that could affect the voiding status. Thirty-eight (84.4%) of 45 valuable patients had received further therapy for BPH, including medication (n = 21, 46.7%), and endoscopic surgery (n = 17, 37.7%). The times to pharmacologic or endoscopic retreatment after TUMT were 8.9+/-11.1 and 23.0+/-14.4 months, respectively (p = 0.0003, log rank test). Only 7 (15.5%) patients had no further treatment, with 3 having satisfactory improvements, but 4 feel dissatisfied yet not needing any further therapy. In addition, 2 patients complained of erectile dysfunction after TUMT and 1 was diagnosed with prostate cancer 50 months after TUMT. In addition, there was no significant difference for all baseline values among three groups with no retreatment or retreatment with medication or endoscopic surgery. CONCLUSION: At the 5-year follow-up, the long-term durability of low-energy TUMT with Prostcare is only exhibited in a few patients and the overall retreatment rate was 84.4%. Thus, patient should be informed of the high probability of supplementary treatment after TUMT.

Aged↗
PubMed2000

Evaluation of pharmacokinetics and pharmacodynamics of captopril from transdermal hydrophilic gels in normotensive rabbits and spontaneously hypertensive rats.

The purpose of this investigation was to assess the pharmacokinetics (plasma concentration) and pharmacodynamics (heart rate, blood pressure (BP), and plasma renin activity (PRA)) of captopril experimental gel in normotensive rabbits and spontaneously hypertensive rats (SHRs) by reference to a short duration intravenous administration of the drug. In normotensive rabbits, the blood concentration versus time course of captopril after transdermal administration could be described well by a two-compartment model, and the maximum plasma concentration (5. 68+/-2.05 microg ml(-1)) was achieved in about 7 h. The increase in plasma captopril concentration led to increases in PRA and reductions in BP. A simple E(max) model adequately described the relationship between the percentage change of mean blood pressure (MBP) and the blood concentration of the captopril. The maximum reduction in MBP (E(max)) was 36.23% and the concentration at half maximum effect (EC(50)) was 0.24 microg ml(-1). The captopril was continuously released from the gel formulation and protected the SHRs in lower BP throughout the period of transdermal therapy. These results indicated that the development of captopril transdermal drug delivery system was possible. Further research was warranted on a modified formulation of captopril, which was optimized for transdermal delivery of the drug.

Administration, Cutaneous↗
PubMed2000

Biphasic changes in autonomic nervous activity during pregnancy.

To understand the sequential response of the autonomic nervous system to pregnancy, we studied heart rate variability in 23 first trimester, 23 second trimester and 21 third trimester pregnant women. Twenty non-pregnant women were recruited as controls. Time and frequency domain measures of heart rate variability in three recumbent positions were compared. We found that normalized high-frequency power in the supine position increased significantly in the first trimester (42.2 (95% confidence interval (CI) 5.4) nu (normalized unit); P < 0.05) compared with non-pregnant controls (33.0 (6.0) nu), and then decreased progressively in the second (27.3 (6.7) nu) and third (21.8 (6.0) nu; P < 0.05) trimesters. The low-/high-frequency power ratio in the supine position decreased significantly in the first trimester (0.8 (0.3); P < 0.05) compared with that of non-pregnant controls (1.1 (0.3)) and increased progressively in the second (1.5 (0.4)) and third (2.1 (0.8); P < 0.05) trimesters. When the position was changed from the supine to the right lateral decubitus, the percentage change in normalized high-frequency power correlated significantly and negatively with normalized high-frequency power in the supine position in non-pregnant controls (r = -0.56, P = 0.01) and in pregnant women in the first (r = -0.44, P = 0.034), second (r = -0.68, P < 0.001) and third (r = -0.68, P < 0.001) trimesters. These results indicate that autonomic nervous activity shifted towards a lower sympathetic and higher vagal modulation in the first trimester, and changed towards a higher sympathetic and lower vagal modulation in the third trimester as gestational age increased. The balance between the haemodynamic changes of pregnancy and aortocaval compression caused by the enlarging gravid uterus may be responsible for the biphasic changes in autonomic nervous activity during pregnancy.

Adult↗
PubMed2000

Safety and efficacy of alprostadil sterile powder (S. Po., CAVERJECT) in diabetic patients with erectile dysfunction.

OBJECTIVES: To evaluate the long-term efficacy and safety of intracavernosal alprostadil (CAVERJECT((R))) in diabetic patients with erectile dysfunction (ED). PATIENTS AND METHODS: This study included 31 diabetic men (aged 44-75 years) with ED of >/=4 months duration. All patients were initially instructed in the self-injection technique at the investigator's clinic. The optimal dose was determined for each patient and set at one of the following: 5, 10, 20, 30, 40, 50, or 60 microg. After the optimal dose was determined and the patient was well trained, the self-injection home phase was followed for 6 months. The efficacy and adverse events were documented. RESULTS: An optimal dose was determined for 29 men (93.5%) and in 16 men (55%) it was >/=20 microg. During the home phase, 76.5% of injections assessed by the patients resulted in satisfactory sexual activity and 72.5% of injections assessed by partners resulted in satisfactory intercourse. A total of 16 patients dropped out during the titration phase (n = 2) and the home phase (n = 14). The most common reasons included lack of efficacy (n = 3, all in the home phase), intolerable penile pain (1 in the titration phase, 2 in the home phase) and dissatisfaction with the higher dosage (n = 2). Penile pain occurred in 19 (61%) of 31 patients. Most were tolerable, and the incidence decreased with time. Prolonged erection occurred in 2 men (6.5%), and no priapism was noted. Penile fibrosis occurred in 1 patient (3. 2%). None of the systemic medical events were related to the study mediction. However, 1 patient suffered from right putaminal hemorrhage in the last month, and this was considered to be caused by underlying hypertension and not drug-related. CONCLUSION: Despite the high incidence of penile pain, most of the occurrences were tolerable. Despite a higher withdrawal rate in this study, intracavernosal alprostadil is still considered as a relatively effective and safe treatment in some diabetic patients with ED if the individual dose is established by titration and patients are trained in the self-injection technique with period supervision.

Adult↗
PubMed2000

Transurethral microwave thermotherapy for symptomatic benign prostatic hyperplasia: short-term experience with Prostcare.

PURPOSE: To assess our short-term experience with transurethral microwave thermotherapy (TUMT) for symptomatic benign prostatic hyperplasia (BPH). PATIENTS AND METHODS: From August 1993 through July 1994, in total 65 patients with symptomatic BPH were enrolled into this study. The patients' ages ranged from 56 to 95 years with a mean of 70 years. Under local anesthesia with intraurethral instillation of Xylocaine jelly only, all patients received one session of TUMT for up to 60 min with Prostcare equipment. Uroflowmetry was performed and international prostatic symptom score (IPSS) determined before 3 and 6 months after TUMT for assessment of efficacy. All adverse events were recorded and evaluated for clinical relevance. RESULTS: At 3 and 6 months following TUMT, the mean IPSS decreased from 19.7 +/- 6.8 (baseline) to 12.8 +/- 8.2 (-46%) and to 15.5 +/- 9.0 (-21%), respectively; the maximal urine flow rate at 3 and 6 months increased from 9.1 +/- 4.8 ml/s (baseline) to 11.0 +/- 4.9 ml/s (+21%) and to 10.9 +/- 5.6 ml/s (+19%), respectively. During TUMT, burning sensation was the most frequent complaint (38.5%), followed by urethral discomfort (29.2%) and urgency (9.2%). Two patients (3.1%) interrupted TUMT, because of intolerable pain. Following TUMT micturition pain (73.8%) and gross hematuria (45.9%) were the most adverse events. Most of these adverse events disappeared within 2 weeks. One patient suffered from skin erosion over the penoscrotal junction 1 week later. None had retrograde ejaculation; 1 patient complained of erectile dysfunction. CONCLUSION: Although the efficacy of TUMT with Prostcare became less prominent 6 months after TUMT, TUMT was still a tolerable, safe alternative treatment of BPH, especially in patients who were not suitable for transurethral resection of the prostate or anesthesia.

Aged↗
PubMed2000

Postoperative administration of interleukin-12 significantly enhances the anti-tumor immune response of MBT-2 bladder cancer bearing mice.

This study, using the MBT-2 murine bladder tumor model, mainly investigated the role of interleukin-12 (IL-12) in the specific antitumor immune response of a tumor-bearing host when systemically administrated after surgery. Day 17 tumor-bearing mice (D17TBM) along with non-tumor bearing naive mice were treated with daily intraperitoneal (i.p.) injection of IL-12 (0.25 microg/mouse) from day 18 to day 24 for a total of 7 doses. Their splenocytes were obtained on Day 31 for natural killer cells (NK), lymphokine activated killer cells (LAK) and cytotoxic T lymphocyte (CTL) activity assay and lymphocyte subsets phenotypic analysis. The tumor suppression effect of systemic IL-12 administration was evaluated based on the tumor outgrowth of the higher number of tumor cells rechallenged 24 hours after resectioning of the primary tumor. After evaluation on Day 31, the result of in vitro cytotoxicity assay revealed that systemic administration of IL-12 mainly enhanced the splenic LAK and CTL activities in non-tumor-primed naive mice, and the NK activity in tumor-primed D17TBM, respectively. However, in vivo administration of IL-12 with or without IL-2 failed to upgrade the proportions of either CD4+ CD44+ or CD8+ CD44+ T cells subsets in the spleens and regional inguinal lymph nodes (LNs) of both the D17TBM and naive mice. However, the splenic CD8+ CD44+ T-cell subset in the IL-12-treated D17TBM increased prominently after further culturing in the presence of IL-2 400 units/ml plus IL-12 25 ng/ml for 4 days. The fact that systemic administration of IL-12 significantly suppressed the outgrowth of Day-18 challenged tumor cells, especially in D17TBM, clearly indicates that the established specific antitumor immunity in tumor-primed D17TBM was efficiently augmented. From the results of this study, we conclude that, after surgical resection of a primary tumor, systemic administration of IL-12 can be an effective adjuvant therapy because it demonstrates a significant augmentation effect on the tumor-specific immune response in the tumor-primed host.

Animals↗
PubMed2000

Ipsilateral distal radius and scaphoid fractures.

Simultaneous fractures of the distal radius and scaphoid are uncommon. Previous reports have outlined a variety of treatment methods for this condition. We describe the results in eight patients with simultaneous fractures of the distal radius and scaphoid, who were treated at National Taiwan University Hospital from 1987 to 1998. Treatments for the distal radius fractures included pin-in-cast in one patient, casting in one, external fixation in one, external fixation after pinning in three, and open reduction with internal fixation in two. All scaphoid fractures occurred at the scaphoid waist, and were treated with long-arm thumb spica in three patients, Herbert screw fixation in two, and percutaneous pinning in three. All of the fractures united, and none of the patients developed scaphoid avascular necrosis. One patient suffered from superficial radial nerve injury during external fixation. The functional results of the wrist were good in five patients and fair in three. To prevent the possible over-distraction of the scaphoid fracture, fixation of the scaphoid should be performed if a distraction force is to be applied during the treatment of the distal radius fracture. If no distraction force is to be applied, a thumb spica may provide adequate fixation for the scaphoid fracture.

Adult↗
PubMed2000

Influential factors affecting prognosis of snakebite patients management: Kaohsiung Chang Gung Memorial Hospital experience.

BACKGROUND: The objective of this study was to determine the most influential factors affecting the prognosis of snakebite patients in Kaohsiung Chang Gung Memorial Hospital. METHODS: A thorough review of the medical records of poisonous snakebite from June 1986 to November 1999 was carried out in this retrospective study. RESULTS: Of the identified snakes in 39 bite victims, 70% of these cases were hemorrhagic type: Trimeresurus stejnegeri 20/27, T. mucrosquamatus 6/27, and Agkistrodon acutus 1/27; 28% were neurotoxic type: Naja naja atra 6/11 and Bungarus multicinctus 5/11; and 2% was mixed type: Vipera russelli formosensis 1/39. Three of four acute renal failure victims were bitten by T. mucrosquamatus. Two of the 5 victims bitten by B. multicinctus required endotracheal intubation to maintain their respiration. Five patients received skin grafting, 3 of whom were bitten by Naja naja atra. Most of our patients (55%) received only a single dose of antivenin, and 83% (29/35) of the antivenin was given within 6 hours after the bite; the antivenin infusion was finished in less than 2 hours in most cases (33/36). CONCLUSION: Bites from Trimeresurus stejnegeri are the most common poisonous snakebite recorded in our emergency department. T. mucrosquamatus is prominent in causing bleeding tendency and acute renal failure. Bungarus multicinctus is more prominent than Naja naja atra in causing acute respiratory failure. The dosage of antivenin used to treat patient bitten by cobra was less than that recommended by the poison control center, and the complication of skin necrosis requiring skin grafting was more severe than that of the other species.

Adolescent↗
PubMed1999

Comparison of supine and upright positions on autonomic nervous activity in late pregnancy: the role of aortocaval compression.

In order to understand the effect of aortocaval compression on autonomic nervous activity, we compared the effects of supine and upright postures on measures of heart rate variability in late pregnancy. Thirty-two women in late pregnancy and 23 nonpregnant age-matched women were studied. Both time and frequency domain heart rate variability measures were compared between the supine and upright positions, and between pregnant women and controls. The pregnant women had smaller mean RR interval, standard deviation of RR intervals and normalised high-frequency power, and a larger low- to high-frequency power ratio than nonpregnant women in the supine position. When the position was changed from upright to supine in nonpregnant women, the percentage change in the mean RR interval and normalised high-frequency power were increased, whereas the percentage change in the coefficient of variation of RR interval and low- to high-frequency power ratio were decreased. In contrast, the percentage change in normalised high-frequency power was decreased and the percentage change in low- to high-frequency power ratio was increased in pregnant women when the position was changed from upright to supine. These results indicate that the vagal enhancing effect seen in normal subjects when changing position from upright to supine was reversed in women in late pregnancy. Aortocaval compression in the supine position in pregnant women might be responsible for this reversal in the autonomic response to lying down.

Adult↗
PubMed1999

Return of autonomic nervous activity after delivery: role of aortocaval compression.

We have compared measures of heart rate variability (HRV) in 15 women in late pregnancy before and 3 months after delivery and in 20 non-pregnant controls, to study the effect of aortocaval compression on autonomic nervous activity. Normalized high-frequency power was used as an index of vagal activity and the low-/high-frequency power ratio as index of sympathovagal balance. We found that the decrease in vagal activity and increase in sympathovagal balance before delivery returned to normal 3 months after delivery. Percentage changes in vagal activity and sympathovagal balance 3 months after delivery in the left lateral decubitus position were least among three recumbent positions. The relief of aortocaval compression as a result of delivery of the fetus may be the main cause of return of autonomic nervous activity 3 months after delivery. Postpartum hormonal changes may also contribute to return of autonomic nervous activity after delivery.

Adult↗
PubMed1998

Preparation of a novel streptokinase mutant with improved stability.

The novel mutant streptokinase, SK-K59E, can activate human plasminogen as efficiently as the purified commercially available streptokinase. Several peptide bonds including Lys59-Ser60 in native streptokinase were hydrolyzed in reaction with plasmin and peptides of small molecular masses were generated. The plasminogen activator activity of native streptokinase in reaction with human plasmin declined to 25% of the original activity in a 120-min incubation. On the other hand, the NH2-terminal peptide of SK-K59E remained intact in reaction with plasmin and the activator activity of streptokinase decreased to 75% of the original activity in 120 min. The major degraded peptide fragments of native streptokinase in reaction with plasmin had molecular masses of 36 and 30 kDa. However, two major peptide fragments of 42 and 34 kDa were observed in the reaction of SK-K59E with human plasmin. The 42 kDa peptide fragment, which contained NH2-terminal of streptokinase, could activate human plasminogen as efficiently as the native streptokinase. SK-K59E can induce greater degree of caseinolysis and fibrinolysis than the native streptokinase. In conclusion, the results demonstrate that the prevention of cleavage at Lys59 of streptokinase prolongs the half-life of streptokinase in complex with plasmin and that the NH2-terminal of streptokinase (Ile1-Lys59) plays an important role in maintaining its stability.

Enzyme Stability↗
PubMed1997

Retropharyngeal and epidural abscess from a swallowed fish bone.

Retropharyngeal abscess is not uncommon, but the incidence of epidural extension of a retropharyngeal abscess is very rare. Intraspinal involvement of the deep neck infection should be suspected if the patient has neurologic deficits. Emergent surgical drainage and aggressive antibiotic treatment are necessary. The outcome is strongly associated with the level of neurologic function at the time of diagnosis. Contrast-enhanced computed tomography is an excellent diagnostic method for any deep neck infection. A case is presented in which a perforating pharyngeal foreign body (fish bone) induced a retropharyngeal and epidural abscess. The literature is reviewed to improve the early recognition and treatment of this complication of deep neck infection.

Brain Abscess↗
PubMed1997

The effect of position on autonomic nervous activity in late pregnancy.

We investigated the effect of three different recumbent positions on autonomic nervous activity in late pregnancy. Thirty pregnant and 24 nonpregnant aged-matched women were studied, and measures of heart rate variability in both time and frequency domains were compared using supine, right and left lateral decubitus positions. In the nonpregnant women, the normalised high-frequency power was greatest in the right lateral decubitus position. In the pregnant women, the normalised high-frequency power was lowest and the low/high-frequency power ratio was greatest in the supine position. Both the percentage decrease of normalised high-frequency power and the percentage increase of low/high-frequency power ratio in the supine and right lateral positions were greater than those in the left lateral position. For women in late pregnancy, the left lateral decubitus position may be beneficial because cardiac vagal activity is least suppressed and cardiac sympathetic activity is least enhanced. Aortocaval compression might be the mechanism underlying the change in cardiac autonomic nervous activity when supine and right lateral decubitus positions are assumed in late pregnancy.

Adult↗
PubMed1997

An expert-guided decision tree construction strategy: an application in knowledge discovery with medical databases.

With the steady growth in electronic patient records and clinical medical informatics systems, the data collected for routine clinical use have been accumulating at a dramatic rate. Inter-disciplinary research provides a new generation of computation tools in knowledge discovery and data management is in great demand. In this study, an expert-guided decision tree construction strategy is proposed to offer an user-oriented knowledge discovery environment. The strategy allows experts, based on their expertise and/or preference, to override inductive decision tree construction process. Moreover, by reviewing decision paths, experts could focus on subsets of data that may be clues to new findings, or simply contaminated cases.

Algorithms↗
PubMed1997

Unilateral pulmonary edema during general anesthesia--report of two cases.

Unilateral presentation of pulmonary edema, though well known to occur, is an uncommon entity. Previous reviews of this subject have discussed the different etiologies, which include rapid reexpansion of collapsed lung, down lung syndrome (gravitational edema), systemic-to-pulmonary arterial shunts, heart failure, compression or occlusion of pulmonary vasculatures, obstruction of a bronchus and an acute manifestation of neuropulmonary reaction (neurogenic pulmonary edema). Occurrence of this complication during surgery, however, is even rarer. We report 2 cases of unilateral pulmonary edema occurring during general anesthesia for elective surgery.

Adult↗
PubMed1996

Supplementation with vitamins C and E enhances cytokine production by peripheral blood mononuclear cells in healthy adults.

The effect of supplementation with vitamins C and E on cytokine production of healthy adult volunteers was studied in a single-blind trial. Ten subjects in each group received daily vitamin C (1 g ascorbic acid), vitamin E (400 mg dl-alpha-tocopheryl acetate), or vitamins C and E for 28 d. Plasma concentrations of alpha-tocopherol, ascorbate, and lipid peroxides as well as the production of cytokines by peripheral blood mononuclear cells (PBMCs) were measured before, during, and at the end of the supplementation and 1 wk later. PBMCs were cultured in the presence of absence of lipopolysaccharide for 24 h. The interleukin 1 (IL-1), interleukin 6 (IL-6), and tumor necrosis factor alpha (TNF-alpha) in the culture supernates were assayed by enzyme-linked immunosorbent assay methods. Production of IL-1 beta and TNF-alpha in the group supplemented with vitamins C and E was significantly higher (P < 0.05) than that of the groups given vitamin E or vitamin C alone. The enhancing effect of supplementation with a combination of vitamins E and C coincided with peak plasma alpha-tocopherol and ascorbate concentrations and the lowest plasma lipid peroxide concentrations (P < 0.05) on day 14. In addition, an in vitro experiment with PBMCs showed that vitamins E and C reduced lipopolysaccharide-induced prostaglandin E2 production and enhanced TNF-alpha production. These results indicate that combined supplementation with vitamins C and E is more immunopotentiating than supplementation with either vitamin alone in healthy adults.

Adult↗