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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
PubMed2001

AZFa candidate gene deletions in Taiwanese patients with spermatogenic failure.

BACKGROUND AND PURPOSE: Deletions of the azoospermia factor subregion a (AZFa) genes in proximal Yq11 are not frequently reported. The majority of AZFa deletions are thought to be associated with more severe testicular phenotypes, such as Sertoli cell-only syndrome. There is a lack of data on AZFa gene deletions in East Asian populations. In this study, we investigated the deletion status of AZFa genes in Taiwanese men with spermatogenic failure. METHODS: One hundred and eighty-three consecutive men with severe oligozoospermia or non-obstructive azoospermia were enrolled in this study. Genomic DNA was extracted from peripheral blood samples and polymerase chain reaction (PCR) was performed using primers specific to four AZFa genes: AZFaT1, DFFRY, DBY, and UTY. Sequence-tagged site markers (sY740, sY630, sY86, sY85, sY87, sY709, and sY88) were used to define the position of deletions. One hundred and twenty fertile men with normal spermatogenesis were enrolled as controls. RESULTS: Of the 183 patients, two showed single AZFa gene deletions, resulting in an overall frequency of 1.1%. One of these two patients had DFFRY deletion and the other had DBY deletion; their testicular phenotypes were Sertoli cell-only syndrome and hypospermatogenesis, respectively. Neither patient had deletions extending from AZFa through AZFb or AZFc. CONCLUSION: Our results suggest that AZFa gene deletion is infrequent in Taiwanese patients with severe oligozoospermia or non-obstructive azoospermia.

Gene Deletion↗
PubMed2000

Y-chromosome microdeletion and its effect on reproductive decisions in taiwanese patients presenting with nonobstructive azoospermia.

OBJECTIVES: To investigate the position, extent, and frequency of Y chromosome microdeletions in Taiwanese patients presenting with nonobstructive azoospermia, and to investigate the effect of microdeletions on reproductive decisions. METHODS: We studied 176 consecutive men with azoospermia in our urology clinic. Polymerase chain reaction tests were performed in 94 patients with nonobstructive azoospermia, and a series of 27 sequence-tagged sites (STSs) mapped within intervals 5 and 6 of Yq11 was selected for analysis. Clinical genetics counseling was provided to couples with microdeletions, and these couples made their own choices about further treatment modalities. RESULTS: Among 94 patients screened for microdeletion, 11 (11.7%) showed microdeletions of one or more STSs. One had a deletion confined to the azoospermia factor b (AZFb) region (encompassing the RBM gene). Two were found to have deletions of both the AZFb and AZFc regions. Eight patients had deletions in the AZFc region (encompassing the DAZ gene). Five had deletions distal to the DAZ gene family. One had multiple, noncontiguous deletions. In 8 patients with testicular histology available, a lack of genotype/phenotype correlation was noted. Of the 11 couples with deletions, 3 thought microdeletion was a serious defect and opted for an artificial insemination of donor or adoption, 5 chose intracytoplasmic sperm injection, and the other 3 decided to undergo treatment with Chinese medicinal herbs. CONCLUSIONS: The most commonly deleted region in the Taiwanese population is AZFc. The genes implicated in Taiwanese spermatogenesis defects are the DAZ and RBM gene families. Twenty-seven percent of couples with microdeletions deferred assisted reproductive technologies because of concern about their underlying genetic defects.

Adoption↗
PubMed2000

Significant down-regulation of alpha-albumin in human hepatoma and its implication.

The potential association of alpha-albumin (ALF) with hepatocellular carcinoma (HCC) was investigated. Expression of ALF was significantly reduced in HCC tumor tissue as compared with the paired peritumor tissue from 16 patients and in four HCC cell lines as compared with normal hepatocytes. ALF mRNA was also down-expressed in circulating HCC cells compared to circulating normal hepatocytes. The proliferation of Hep3B cells was inhibited by over-expression of ALF. Taken together, ALF is significantly down-regulated in HCC, and this might facilitate the proliferation of HCC. Thus, detection of ALF mRNA, in addition to that of alpha-fetoprotein (AFP) mRNA, might help to distinguish normal or malignant hepatocytes in peripheral blood.

Albumins↗
PubMed2000

Local radiotherapy with or without transcatheter arterial chemoembolization for patients with unresectable hepatocellular carcinoma.

PURPOSE: To evaluate the treatment outcome, patterns of failure, and prognostic factors for patients with unresectable hepatocellular carcinoma (HCC) treated with local radiotherapy alone or as an adjunct to transcatheter arterial chemoembolization (TACE). METHODS AND MATERIALS: From March 1994 to December 1997, 25 patients with unresectable HCC underwent local radiotherapy to a portion of the liver. Twenty-three patients were classified as having cirrhosis in Child-Pugh class A and 2 in class B. Mean diameter of the treated hepatic tumor was 10.3 cm. Mean dose of radiation was 46.9 +/- 5.9 Gy in a daily fraction of 1.8-2 Gy. Sixteen patients were also treated with Lipiodol and chemotherapeutic agents mixed with Ivalon or Gelfoam particles for chemoembolization, either before and/or after radiotherapy. Percutaneous ethanol injection therapy (PEIT) was given to one patient. All patients were monitored for treatment-related toxicity and for survival and patterns of failure. RESULTS: In a median follow-up period of 23 months, 11 patients were alive and 14 dead. The median survival duration from treatment was 19.2 months with a 2-year survival of 41%. Only 3 of 25 patients had local progression of the treated hepatic tumor. The recurrences were seen within the liver or extrahepatic. The 2-year local, regional, and extrahepatic progression-free survival rates were 78%, 46%, and 39%, respectively. The local control ranked the highest. Patients with Okuda Stage I disease had significantly longer survival than those with Stage II and III (p = 0.02). Patients with T4 disease (p = 0.02) or treated with radiotherapy alone (p = 0.003) had significantly shorter survival. T4 disease (p = 0.03) and pretreatment alpha-fetoprotein level of more than 200 ng/ml (p = 0. 03) were associated with significantly worse regional progression-free survival. A significant difference was observed in both regional progression-free survival (p = 0.0001) and extrahepatic progression-free survival (p = 0.005) between patients with and without portal vein thrombosis before treatment. The presence of satellite nodules had a significantly worse impact on regional progression-free survival (p = 0.04) and extrahepatic progression-free survival (p = 0.03). Patients with hepatic tumor more than 6 cm in diameter or portal vein thrombosis tended to have shorter survival. Radiation-induced liver disease (RILD) and gastrointestinal bleeding were the most common treatment-related toxicities. CONCLUSION: Radiotherapy is effective in the treatment of patients with unresectable HCC. Its effect appeared to be more prominent within the site to which radiation was given. The combination of TACE and radiation was associated with better control of HCC than radiation given alone, probably due to the selection of patients with favorable prognosis for the combined treatment. A dose-volume model should be established in the next phase of research in the treatment of unresectable HCC.

Adult↗
PubMed2000

Potent induction of long-term CD8+ T cell memory by short-term IL-4 exposure during T cell receptor stimulation.

An important goal of vaccination is to achieve long-term survival of functional memory T cells. Using a MHC-compatible adoptive transfer system, we show here that a short, 3-day IL-4 but not IL-2 or IL-12 exposure during in vitro T cell receptor stimulation of naive CD8(+) T cells induced long-lasting in vivo memory. Such long-term memory CD8(+) T cells expressed antigen-specific cytotoxicity and the potential for IFN-gamma and IL-4 production. Our results support the concept that functional T cell longevity can be regulated by cytokines during initial antigen encounter and provide a rational foundation for vaccine development. They also may have implications in formulating optimal therapeutic regimens of ex vivo expanded autologous cancer- and HIV-specific CD8(+) T cells. In addition, the availability of large numbers of memory CD8(+) T cells generated through our high-efficiency system should facilitate progress in the molecular dissection of CD8(+) T cell memory development.

Adoptive Transfer↗
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↗