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Biomedical subjects

Y M Lin

Publications and source records attributed to Y M Lin.

At least 37 records · Page 2Linked to original sources
PubMed2000

Identification of novel polymorphisms in the AXIN1++ and CDX-2 genes.

Axin and Cdx-2 play important roles in the tumorigenesis of human liver and colon. We have identified seven novel single-nucleotide polymorphisms (SNPs) in the AXIN1 gene and three in the CDX-2 gene. The identification of SNPs in these cancer-associated genes establishes a basis for future investigations to detect losses of heterozygosity in tumors; these SNPs may also provide genetic background information associated with cancer risk.

Alleles↗
PubMed2000

Novel image analysis of corpus cavernous tissue in impotent men.

OBJECTIVES: To objectively evaluate the contents of corpus cavernous tissue in impotent men using an automated novel image analysis system. METHODS: Thirty-three impotent men and 2 normal potent men (controls) underwent corpus cavernous biopsies. The procedures were performed using a Biopty gun under local anesthesia. The obtained specimens were stained with Masson's trichome technique, and the collagen fiber contents were evaluated by a computerized morphometric analysis method. In addition, we estimated the intraobserver and interobserver reliability of this automated image analysis system. RESULTS: No major complication was noted during or after the biopsies. Of the 33 impotent patients, 3 were diagnosed as having psychogenic, 11 as having arteriogenic, 13 as having venogenic, 1 as having neurogenic, and 5 as having idiopathic impotence. The collagen fiber percentages in the 35 men were as follows: normal potent: 48.2% +/- 1.4%, psychogenic 55.2% +/- 11.6%, arteriogenic 73.2% +/- 4.4%, venogenic 66.5% +/- 4.2%, neurogenic 76.9%, and idiopathic 77.4% +/- 4.2%. Significant differences were found between the normal potent and arteriogenic groups (P <0.05) and between the normal potent and idiopathic groups (P <0.05). Patients older than 60 years had a higher collagen fiber content (70.4% +/- 3.7%) than those younger than 50 years old (58.6% +/- 5.2%). The interobserver and intraobserver variances were both negligible for this automated image analysis system. This method significantly reduced the amount of variation introduced by the intra-rater reliability of a technician compared with the manual method. CONCLUSIONS: The present automated image analysis system is believed to be a reliable, accurate quantitative measurement tool for studies of penile tissue. Cavernous biopsy is a rapid, safe, and representative modality to study penile disease. An increase in cavernous collagen fibers (or corporal fibrosis) is considered an important factor in impaired erectile function.

Adult↗
PubMed2000

Transitional cell carcinoma in dialysis patients.

OBJECTIVE: The aim of our study was to determine whether there is an increased incidence of urothelial cancer, especially transitional cell carcinoma (TCC), in uremic patients on dialysis. METHODS: Retrospective chart analyses were completed for 1,910 uremic patients undergoing maintenance dialysis between January 1987 and December 1997. The incidence of urinary tract cancer was assessed. Only the patients with cancers diagnosed after start of dialysis were enrolled in the study. RESULTS: Of the 1,910 patients, 70 had concomitant urinary tract cancers. Nineteen patients (0.99%), including 17 patients with TCC and 2 patients with renal cell carcinoma, were diagnosed after the initiation of dialysis. The average duration from dialysis to TCC diagnosis was 38.3 (range 2-144) months. Painless gross hematuria was the cardinal symptom in 16 of the 17 patients with TCC. In the 17 patients with TCC, no distant metastases were found at the time of diagnosis. Fourteen patients (82.3%) were stage 0 or A, and 1 patient was stage B1. CONCLUSIONS: The 0.89% incidence of TCC in our dialysis patients was high as compared with that of the general population. The risks of developing urinary TCC in dialysis patients were examined, and we suggest that immunosuppressive stage, dialysis procedure, and chronic bladder irritation (decreased urinary wash effect) may play a part in the development of urinary TCC in dialysis patients. Early detection of hematuria due to regular visits and decreased exposure of urinary tract epithelium to carcinogens from urine may explain why early-stage TCC was seen in most of our patients.

Aged↗
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

Studies and syntheses of siderophores, microbial iron chelators, and analogs as potential drug delivery agents.

Siderophores (microbial iron chelators) play an extremely important role in microbial pathogenicity. Microbial uptake of siderophore-iron complexes through active transport systems allow microbes to survive and proliferate even under iron deficient environments during invasion of a host. Due to their structural complexity, unique iron (III) chelation, acquisition properties, and their therapeutic potential, siderophores have attracted much attention in a broad range of disciplines. Tremendous progress has been made in siderophore syntheses, in determination of the structures and functions of outer membrane receptors (e.g. FhuA and FepA), and in the mechanistic insight into siderophore-iron-mediated active transport processes. One of the important practical applications of this active transport system is development of species-selective active drug transport (the Trojan Horse approach) to potentially treat infections due to drug resistant strains of microbes. Siderophore-drug conjugates have shown great potential in active drug delivery to target pathogenic microbes.

Drug Carriers↗
PubMed2000

Percutaneous epididymal sperm aspiration versus microsurgical epididymal sperm aspiration for irreparable obstructive azoospermia--experience with 100 cases.

PURPOSE: This study investigated the sperm retrieval success rates, fertilization rates, pregnancy rates, and complications of percutaneous epididymal sperm aspiration (PESA) and microsurgical epididymal sperm aspiration (MESA) in cases of irreparable obstructive azoospermia. METHODS: During a period of 36 months, 100 men with irreparable obstructive azoospermia underwent 109 cycles of sperm retrieval procedures and intracytoplasmic sperm injection (ICSI). We routinely performed PESA first in each retrieval cycle; MESA and/or testicular sperm extraction (TESE) were performed if PESA failed. The sperm retrieval success rates, mean fertilization rates, and pregnancy rates of PESA and MESA were evaluated. RESULTS: PESA was performed in all 109 retrieval cycles with a successful sperm retrieval rate of 61%. When PESA failed to retrieve a sufficient number of viable sperm, MESA was subsequently performed with a sperm retrieval rate of 93%. Three cases, which had failed retrieval with both the PESA and MESA procedures, received TESE successfully. The rates of fertilization and pregnancy were 56% and 39% in the 66 PESA-ICSI cycles, respectively, and 47% and 45% in the 40 MESA-ICSI cycles. No significant differences were found in fertilization rates or pregnancy rates among the various sperm retrieval methods and obstruction etiologies. The overall mean fertilization rate and pregnancy rate were 51% and 41%, respectively. CONCLUSION: Both PESA and MESA can be used successfully to obtain sufficient sperm for ICSI. PESA cannot replace MESA in some cases as some epididymal pathologies prevent its success. The results of this study indicate that PESA should be the treatment of choice for patients with ductal obstruction distal to the epididymis, owing to its higher initial success rate. In contrast, patients with irreparable epididymal obstruction might achieve better success rates with MESA.

Epididymis↗
PubMed1999

A pilot study of three-dimensional conformal radiotherapy in unresectable hepatocellular carcinoma.

BACKGROUND: The purpose of this study was to determine the potential role of three-dimensional (3-D) conformal radiotherapy (RT) in treatment of unresectable hepatocellular carcinoma (HCC). METHODS: Thirteen patients were included in this study, which was conducted between 1993 and 1996. Nine patients (group A) were treated with 3-D conformal RT alone because of main portal vein thrombosis, inferior vena cava thrombosis, obstructive jaundice and failure of previous transcatheter arterial chemoembolization (TACE) to control the disease. The remaining four patients (group B) were treated with a combination of TACE and 3-D conformal RT. RESULTS: The greatest dimension of the main tumour in the whole group of patients ranged from 6 to 25 cm (median 15 cm). The radiation dose ranged from 40 to 60 Gy. The tumour response was evaluated by computed tomography scans of the liver 6-8 weeks after completion of radiotherapy. Partial response was observed in 58% of the patients (seven of 12) and minimal response in another 25% of patients (three of 12). One patient could not be evaluated because of the development of hepatic failure 1 month after completion of RT. All patients in group B lived for more than 1 year (range 16-40 months). In group A, one patient who had a large tumour (11 x 10 x 21 cm) with portal vein thrombosis was converted to become resectable after 45 Gy of radiation. The resection specimen revealed no residual cancer cells. This patient is alive longer than 15 months after treatment without the evidence of disease. CONCLUSIONS: Our experience indicates that HCC is more radiosensitive than it was traditionally expected. Three-dimensional reconstruction of tumour and surrounding organs helps to avoid excessive exposure of the liver and adjacent organs to RT and makes it a safer treatment modality for unresectable HCC. Our preliminary data show promise and are worthy of further study to explore the potential role of radiotherapy in the treatment strategy for HCC at various stages of involvement.

Aged↗
PubMed1999

Antiviral activities of biflavonoids.

Biflavonoids such as amentoflavone (1), agathisflavone (2), robustaflavone (3), hinokiflavone (4), volkensiflavone (5), rhusflavanone (7), succedaneflavanone (9), all isolated from Rhus succedanea and Garcinia multiflora, as well as their methyl ethers and acetates, volkensiflavone hexamethyl ether (6), rhusflavanone hexaacetate (8), and succedaneflavanone hexaacetate (10) were evaluated for their antiviral activities. The inhibitory activities against a number of viruses including respiratory viruses (influenza A, influenza B, respiratory syncytial, parainfluenza type 3, adenovirus type 5, and measles) and herpes viruses (HSV-1, HSV-2, HCMV, and VZV) were investigated. The results indicated that robustaflavone exhibited strong inhibitory effects against influenza A and influenza B viruses with EC50 values of 2.0 micrograms/ml and 0.2 microgram/ml, respectively, and selectivity index values (SI) of 16 and 454, respectively. Amentoflavone and agathisflavone also demonstrated significant activity against influenza A and B viruses. Amentoflavone and robustaflavone exhibited moderate anti-HSV-1 anti-HSV-2 activities with EC50 values of 17.9 micrograms/ml (HSV-1) and 48.0 micrograms/ml (HSV-2) and SI values of > 5.6 (HSV-1) and > 2.1 (HSV-2) for amentoflavone; EC50 values of 8.6 micrograms/ml (HSV-1) and 8.5 micrograms/ml (HSV-2), and SI values of > 11.6 (HSV-1) and > 11.8 (HSV-2) for robustaflavone. Rhusflavanone demonstrated inhibitory activities against influenza B, measles, and HSV-2 viruses with SI values of 9.3, 8 and > 6.4, respectively. Succedaneaflavanone exhibited inhibitory activities against influenza B virus and VZV with SI values of 15 and < 3.0, respectively.

Antiviral Agents↗
PubMed1999

Unilateral pulmonary artery agenesis with presentation of hemoptysis: a case report.

Unilateral pulmonary artery agenesis (UPAA), a rare congenital anomaly frequently associated with other cardiovascular abnormalities, is usually diagnosed and surgically treated in childhood. Those who do not suffer other cardiac anomalies (isolated UPAA) have only minor or no symptoms and survive into adulthood. Isolated UPAA in adult patients may present as recurrent respiratory tract infection, dyspnea on exertion, hemoptysis or an incidental finding of an abnormal chest radiograph. We present the case of a 38-year-old man with a congenital absence of the right pulmonary artery (PA) and recurrent hemoptysis. The diagnosis was confirmed by cardiac catheterization, which disclosed an absence of the right PA and systemic collaterals to the right lung from the right internal thoracic artery and posterior intercostal arteries.

Adult↗
PubMed1998

Robustaflavone, a potential non-nucleoside anti-hepatitis B agent.

Robustaflavone, a naturally occurring biflavanoid isolated from Rhus succedanea, was found to be a potent inhibitor of hepatitis B virus (HBV) replication in 2.2.15 cells, with an effective concentration (EC50) of 0.25 microM, and a selectivity index (SI, IC50/EC90) of 153. Robustaflavone hexaacetate inhibited HBV replication with an EC50 of 0.73 microM, but exhibited no cytotoxicity at concentrations up to 1000 microM. Combinations of robustaflavone with penciclovir and lamivudine displayed synergistic anti-HBV activity, having the most pronounced effects when the combination ratios were similar to the ratio of EC50 potencies. Thus, a 1:1 combination of robustaflavone and penciclovir exhibited an EC50 of 0.11 microM and an SI of 684, while a 10:1 combination of robustaflavone and lamivudine exhibited an EC50 of 0.054 microM and an SI of 894. Statistical analyses of the combination data using the Combostat program confirmed that robustaflavone exhibited synergism with both penciclovir and lamivudine.

Acyclovir↗
PubMed1998

Radiostrontium analytical method using crown-ether compound and Cerenkov counting and its applications in environmental monitoring.

The radiostrontium content in environmental samples was determined by chemical analysis by means of the fuming nitric acid method and ion exchange method with low-level beta counting and the newly developed method using crown-ether compound. Counting was performed with a low-background counter and a liquid scintillation counter together; the latter was the Cerenkov counting method. All results obtained by these three methods were in good agreement. The time for chemical separation of radiostrontium, using crown-ether compound, is much faster than fuming nitric acid and ion exchange methods. However, due to the high background of the liquid scintillation counter, the detection limit for Cerenkov counting is about two times higher than that for low-background counting.

Chromatography, Ion Exchange↗
PubMed1998

Measurement of equilibrium factor and unattached fraction of radon progeny in Kaohsiung, Taiwan.

To reasonably estimate the population dose from radon, equilibrium factor, Fp, and unattached fraction, fp, of radon progeny are important parameters. A Lucas cell and a working level monitor was used for most Fp measurement. The unattached fraction was measured by SARAD EQF3020. A detached house was chosen to measure the Fp in different rooms. The Fp value depended mainly on the ventilation rate and surface to volume ratio of the rooms. Fp and fp were measured in bedrooms of 14 other dwellings. Two hospitals were also chosen for measurement of Fp in the working place using rooms located in the basement. The average Fp for dwellings was about 0.5 and the average unattached fraction was about 0.055. The radon levels in the hospitals were higher than those in the dwellings but the equilibrium factors in the hospital were very low (about 0.06). The low Fp was attributed to the use of a dehumidifier in the hospitals. Dehumidifiers are popular for reducing fungi problem induced by the high humidity in Taiwan.

Air Pollution, Indoor↗
PubMed1997

Activity concentrations and population dose from radium-226 in food and drinking water in Taiwan.

The purpose of this study was to determine the radioactivity of 226Ra in environmental samples in Taiwan. Fish, pork, rice, flour, chicken, vegetable, milk, fruit, egg and water samples were collected and pretreated by radiochemical procedure to extract the 226Ra, and the activity concentrations of 226Ra were determined using a liquid scintillation counter. The 226Ra content of groundwater was 12.0 mBq l-1. The 226Ra contents of the food ranged from 0.02 Bq kg-1 fresh to 0.17 Bq kg-1 fresh. The annual internal dose from ingestion of 226Ra from food and drinking water per caput was evaluated to be 7.5 microSv.

Environmental Exposure↗
PubMed1997

In vitro anti-HIV activity of biflavonoids isolated from Rhus succedanea and Garcinia multiflora.

Eleven biflavonoids, including amentoflavone (1), agathisflavone (2), robustaflavone (3), hinokiflavone (4), volkensiflavone (5), morelloflavone (7), rhusflavanone (9), succedaneaflavanone (10), GB-1a (11), GB-1a 7"-O-beta-glucoside (13), and GB-2a (14) isolated from Rhus succedanea and Garcinia multiflora, as well as their methyl ethers, volkensiflavone hexamethyl ether (6), morelloflavone heptamethyl ether (8), and GB-1a hexamethyl ether (12), were evaluated for their anti-HIV-1 RT activity. The results indicated that compounds 3 and 4 demonstrated similar activity against HIV-1 reverse transcriptase (RT), with IC50 values of 65 microM. Compounds 1, 2, 7, 11, and 14 were moderately active against HIV-1 RT, with IC50 values of 119 microM, 100 microM, 116 microM, 236 microM, and 170 microM, respectively. Morelloflavone (7) also demonstrated significant antiviral activity against HIV-1 (strain LAV-1) in phytohemagglutinin-stimulated primary human peripheral blood mononuclear cells at an EC50 value of 6.9 microM and a selectivity index value of approximately 10. The other biflavonoids were either weakly active, inactive, or not selective against HIV-1 in human lymphocytes.

Anti-HIV Agents↗
PubMed1997

Small changes in essential amino acid concentrations alter diet selection in amino acid-deficient rats.

The rat's sensitivity to changes in the dietary limiting amino acid concentration (LAA) was examined on the basis of dietary selection. Rats were adapted to purified low protein basal (Basal) diets in which threonine (Thr) was the LAA (0.188-0.212% wt/wt of diet). In Experiment 1, rats made a clear selection for their adaptation diet over a diet containing 0.012% less threonine after 2-3 d of choice. Rats made no clear dietary selection when given a choice between their adaptation diet and a diet containing 0.012% more threonine. Experiment 2 was conducted to examine the rat's sensitivity to small decreases in the LAA concentration. Rats adapted to a 0.200% Thr-Basal diet clearly responded to decreases as small as 0.009% in the concentration of threonine and selected against the more deficient diet when given a choice between it and the 0.200% Thr-Basal adaptation diet. Because plasma and brain amino acid concentrations are important for detection of other amino acid deficiencies, these variables were measured to determine whether they were affected by such small changes in dietary amino acid concentration. In Experiments 3 and 4, rats were adapted to the 0.200% Thr-Basal diet and then fed 0.188, 0.200 or 0.212% Thr-Basal diets for 6 h, or 0.188 and 0.212% Thr-Basal for 54 h. Amino acid concentrations in plasma, prepiriform cortex and anterior cingulate cortex were not significantly different among treatments. Norepinephrine concentration in the prepiriform cortex was not affected by dietary treatment. We conclude that small decreases in LAA concentration can cause selection against the more deficient diet, but that detection of such deficiencies does not require significant changes in plasma and brain amino acid concentrations.

Amino Acids↗