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Biomedical subjects

M K Lai

Publications and source records attributed to M K Lai.

At least 73 records · Page 4Linked to original sources
PubMed1996

Post-renal transplant erythrocytosis.

Erythrocytosis is a relatively common phenomenon following renal transplantation. It is not only associated with some special clinical conditions, but also increases the risk of thromboembolism. We therefore studied the clinical manifestations and possible risk factors of erythrocytosis in our renal-transplant patients. Study of 175 patients showed that erythrocytosis, defined as Hct > or = 50%, was found in 17 patients (9.7%), 14 males and 3 females. Among these 17 patients, 13 received cadaveric grafts and the other 4 living-related grafts. True erythrocytosis, defined as erythrocytosis with elevated red blood cell (RBC) mass, was found in 7 patients. Relative erythrocytosis, defined as erythrocytosis with normal RBC mass, was found in the other 10 patients. Six patients developed acquired renal cysts of the native or graft kidneys during the post transplant period. The incidence of acquired renal cysts in the erythrocytosis group was significantly higher than that in the non-erythrocytosis group. The clinical and demographic characteristics were similar in terms of age, gender, serum albumin, and serum creatinine in the erythrocytosis and non-erythrocytosis groups. The incidences of abnormal liver function, and hypertension were similar between the 2 groups. Seventeen of the 161 patients (10.6%) receiving cyclosporine regimen developed erythrocytosis, but none of the 14 patients receiving non-cyclosporine regimen developed erythrocytosis (p > 0.05). Only one patient with true erythrocytosis had an elevated serum erythropoietin (EPO) level and no thromboembolic complications occurred in the erythrocytosis group. We conclude that: (1) the incidence of erythrocytosis in our transplant patients was 9.7%; (2) a higher incidence of acquired renal cysts was found in the erythrocytosis group; (3) most of the patients with erythrocytosis had a normal serum EPO level; (4) no thromboembolic complications occurred in our patients.

Adult↗
PubMed1996

Color Doppler sonogrphy in differentiation between testicular torsion and epididymoorchitis: report of three cases.

Clinical assessment of the testicular torsion and epididymoorchitis is inherently difficult. Inadequate clinical information may prevent differentiation testicular torsion from non-surgical condition. We reported 3 cases with symptoms of acute scrotal condition who had received color Doppler sonography. One man had epididymoorchitis and color Doppler sonography showed profusely increased blood flow in the region of epididymis and testis. Symptoms subsided with one week of medical treatment. Sonography correctly detected absence of testicular perfusion in 2 boys who had sugical exploration of the scrotum. Testicular torsions were confirmed by surgical findings. Absence or markedly decreased testicular blood flow which indicated testicular ischemia or infarction was easily identified. Conversely, hyperemia of the testis and/or epididymis is usually associated with inflammation However, incomplete torsion or detorsion may demonstrate normal testicular flow on color Doppler sonography. Color Doppler sonography provides early diagnosis of acute testicular torsion, and prevents unnecessary scrotal exploration.

Adolescent↗
PubMed1996

Clinical efficacy of prostate-specific antigen testing in patients with prostate disease.

Prostate-specific antigen (PSA) has become the most commonly used marker for the detection of prostatic adenocarcinoma (PCa) in recent years. To understand the clinical value of PSA testing in patients with prostate disease, the preoperative serum PSA values of 562 patients who underwent prostatic surgery from April 1993 to December 1995 were correlated with histologic findings in samples taken during surgery. Histopathologic findings revealed 93 cases of PCa and 469 cases of benign prostatic hyperplasia (BPH). Of the 220 patients with a serum PSA level within the normal range (0-4 ng/mL), PCa was diagnosed in six (2.7%) cases. However, among the 342 patients (61%) who had serum PSA > 4.0 ng/mL, BPH was diagnosed in 225 (75%) patients. With a PSA cutoff value of 4.0 ng/mL, the sensitivity, specificity and positive predictive value of PSA in distinguishing PCa from BPH were 94%, 45% and 25%, respectively. Raising the cutoff value to 10 ng/mL enhanced the specificity (76%) and positive predictive value (42%) with a slight compromise in sensitivity (85%). Of the 469 patients with BPH, 255 (54%) had a serum PSA > 4.0 ng/mL and 107 (24%) had a serum PSA > 10.0 ng/mL. Prostate volume, histologically documented prostatic inflammation and history of urinary retention prior to PSA determination may partly explain the abnormal elevation of serum PSA in patients with BPH. Our data confirmed the sensitivity of PSA in the detection of PCa in a country with a low incidence of PCa. However, a considerable proportion of patients with BPH had elevated serum PSA levels caused by factors unrelated to malignancy. Raising the cutoff value of PSA or employing adjunct parameters derived from PSA determination may be helpful in improving the diagnostic efficacy of PSA.

Aged↗
PubMed1996

Recent advances in the treatment of benign prostatic hyperplasia.

The prevalence of benign prostatic hyperplasia (BPH) in Taiwanese men over the age of 50 years is as high as those in Western countries. BPH significantly affects the life quality of patients. Many theories of the genesis of BPH have been reported and some effective treatments have been designed according to these theories. Adequate preoperative studies can lead to satisfactory treatment results. Medical treatments including alpha-adrenergic blockers and 5-alpha-reductase inhibitors are frequently used as initial steps. Surgical treatment is necessary in more than one-quarter of patients in order to achieve good results. Transurethral resection of the prostate (TURP) remains the gold standard for treatment of BPH, although laser prostatectomy may become as popular as TURP in the future. Transurethral thermotherapy with microwave is also a promising new treatment. There are many other medical or surgical treatments under investigation. Further neuroendocrine research and studies with techniques of molecular biology may offer new concepts in BPH treatment in the future.

Humans↗
PubMed1995

Two-stage orchiopexy with laparoscopic clip ligation of the spermatic vessels in prune-belly syndrome.

A 1-year-old boy with prune-belly syndrome underwent unilateral laparoscopic clip ligation of the spermatic vessels with the hope of developing vasal collateral circulation. Six months later, the patient underwent ipsilateral second-stage orchiopexy on the right testis after division if the ligated spermatic vessels and contralateral Fowler-Stephens orchiopexy on the left testis in combination with major urinary tract reconstructions and abdominoplasty. For the following 1-year period, both testes were growing and comparable in size.

Cryptorchidism↗
PubMed1995

Urologic cancers in uremic patients.

From 1981 through 1990, 21 urologic cancer cases were discovered in 21 uremic patients at our hospital. This constituted 55% (11 of 20) of the total malignancies in nondialyzed uremic patients, 41% (nine of 22) of the total in chronic hemodialysis patients, and 50% (one of two) of those in patients on continuous ambulatory peritoneal dialysis. No cases of urologic cancer were found in kidney transplant recipients. When compared with the general population, the standardized incidence ratio of kidney cancer in chronic hemodialysis patients was found to be 24.1 (P < 0.01) and that of bladder cancer was found to be 16.4 (P < 0.01). Multiple underlying renal diseases contributed to the development of the urologic cancer cases, including four analgesic nephropathy-associated transitional cell carcinoma cases, two acquired cystic kidney disease-associated renal cell carcinoma cases, two chronic pyelonephritis-associated (stone and tuberculosis) squamous cell carcinoma cases, and one xanthogranulomatous pyelonephritis-associated transitional cell carcinoma case. Uremia per se may be an important promoting factor. Hematuria (17 of 21 cases) was the most common presenting feature despite the fact that most of the patients were anuric. The clinical diagnosis of renal parenchymal tumors was based on ultrasonography (five of five cases), whereas most urothelial tumors were detected by cystoscopy or retrograde pyelography (14 of 16 cases). The survival rate of the 17 aggressively treated patients was 82% at 2 years and 45% at 5 years. We conclude that uremic patients are at greater risk of developing urologic cancer.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Tamoxifen enhances the chemosensitivity of bladder carcinoma cells.

PURPOSE: Chemosensitizers, which enhance cellular chemosensitivity and reduce chemoresistance, are expected to substantially improve response rates of systemic chemotherapy for patients with metastatic bladder cancer. Tamoxifen is a nonsteroidal antiestrogen that has been shown to reverse drug resistance in vitro in some cancer models through pathways not related to its antiestrogenic effect. In this study we tried to evaluate its possible effect on chemosensitization of bladder cancer cells. MATERIALS AND METHODS: In vitro chemosensitivity tests were done with 3 bladder cancer cell lines and 4 cytotoxic agents (methotrexate, vinblastine, doxorubicin and cisplatin) in the presence or absence of graded concentrations of tamoxifen. Verapamil was used in parallel experiments to compare the degrees of chemosensitization. The transcript and protein product [P-glycoprotein, (P-gp)] levels of the mdr-1 gene were also examined in the 3 cell lines by reverse-transcription polymerase chain reaction (RT-PCR) and flow cytometric assay, respectively. RESULTS: Tamoxifen at 5 and especially 10 microM. concentrations, which were minimally toxic to the 3 bladder cancer cell lines used, enhanced the chemosensitivity of bladder cancer cells in most drug combinations in a dose-dependent manner. In some combinations 10 microM. tamoxifen did better than 5 microM. in chemosensitization. The effect of chemosensitization was more evident in cells treated with 10 microM. tamoxifen plus methotrexate and vinblastine in which 12.9 to 95.4-fold and 12.4 to 21.3-fold IC50 reduction was observed, respectively. A less prominent, but still significant, effect could be seen in doxorubicin- and cisplatin-treated cells. Verapamil, although used at concentrations up to 10 microM. which are higher than systemically tolerable, was not able to enhance chemosensitivity of the 3 bladder cancer cell lines. By flow cytometric analysis of the P-gp level and by RT-PCR assay of the mdr-1 gene transcript level, it was shown that little if any mdr-1 gene expression could be detected in the 3 cell lines. This implies that the mdr-1 gene function may play a minimal role in drug resistance mechanisms of bladder cancer cells and that tamoxifen exerts its chemosensitization effect through pathways other than mdr-1 gene function modulation. CONCLUSIONS: Tamoxifen was shown to be a good chemosensitizer in a bladder cancer cell model and may well be tried in combination with systemic chemotherapy for metastatic human bladder cancers in the clinical setting.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1995

Primary extramedullary plasmacytoma in cyclosporine-induced gingival overgrowth. A case report.

An unusual solitary extramedullary plasmacytoma developed in the gingiva of a 28 year-old male renal transplant patient with cyclosporine (CyA)-induced gingival overgrowth. On initial presentation, there was no suspicion of a tumor within the lesion. One year later, however, the lesion had increased progressively in size, and its surface was ulcerated. At this time, the lesion was excised by gingivectomy, and histopathological examination revealed plasmacytoma. CyA was discontinued and the patient has been closely observed for 4 years with no recurrence of the gingival lesion.

Adult↗
PubMed1995

[Analysis of 117 cases of hypospadias--its location, operation and complication].

Hypospadias is a common congenital anomaly in male newborns. The incidence is about one in 300 live male births. In the U.S., about 6000 boys with hypospadias are born each year. For this study, we collected 117 recent (with the last 5 years) cases (88 fresh and 29 referred) who received an operation in our department. We calculated the hypospadias location and the complication rate with the desire of finding out the relationships between them. Our overall complication rate is 51.3% which is much higher than other recent studies and may be related to a different distribution of the hypospadias locations.

Adolescent↗
PubMed1995

[Comparison of UW solution and UR (a modified Collins) solution for renal preservation in renal transplantation].

For the storage of human transplanted organs, the benefit of "UW solution" has been proven especially in keeping a longer preservation time for the liver and pancrease; however, the value for kidney preservation was still debated. A total of 293 cases of renal transplantation were performed over 12 years in our hospital and 206 cases were cadaveric transplants. The latter ones were further divided into 3 groups, according to the immunosuppressive medication and preservation solution used. In the CsA treated groups, the ATN rates significantly decreased in those preserved with the UW solution than with the UR solution. Although the UW solution did not improve the graft survival in our series, it did save the cost for postoperative hemodialysis and shorten the hospital stay which made it cost effective.

Adenosine↗
PubMed1995

Relationship between serum prostate specific antigen concentration and prostate volume.

Serum prostate-specific antigen (PSA) levels and prostate volume were evaluated in 553 healthy men aged 40 to 79 years, who entered a study program for benign prostatic hyperplasia from December 1993 to August 1994. Digital rectal examination (DRE), transrectal ultrasonography (TRUS) and serum PSA assay were performed on all participants. After excluding men with suspected prostate cancer and incomplete data, 542 cases qualified for analysis. The mean serum PSA level was 1.4 +/- 1.7 ng/mL which increased with age from 0.8 +/- 0.9 ng/mL in men aged 40 to 49 years to 2.7 +/- 2.8 ng/mL in those aged 70 to 79 years. In this study group, 250 men (46.1%) were documented to have various degrees of benign prostatic hyperplasia (BPH). The prostate volume averaged 22.3 +/- 9.1 mL which increased from 18.5 +/- 6.1 mL in the fifth decade to 27.2 +/- 13.7 mL in the eighth decade. There was a modest correlation between serum PSA level and both age and prostate volume. However, when the prostate volume was adjusted, the PSA level correlated more weakly with age in a multivariate analysis. On the other hand, the serum PSA level correlated more strongly with prostate volume when age was adjusted. Although 5.4% of the men had serum PSA levels > 4 ng/mL, there was no evidence of prostate cancer by DRE and TRUS. Serum PSA levels increased with age and prostate volume, and correlated better with the latter. These factors should be taken into account when determining the significance of a given PSA value in a patient without clinical evidence of prostate cancer.

Adult↗
PubMed1994

Optic internal urethrotomy under transrectal ultrasonographic guide and suprapubic fiberoscopic aid.

Optic internal urethrotomy is the initial treatment of choice for most urethral strictures because of the relatively low morbidity and ease of accomplishment. However, the procedure is difficult and frustrating if a severe stricture or complete disruption of the urethra is encountered. Transrectal ultrasonography of the urethra offers good anatomical visualization, and defines the exact length and extent of bulbous and posterior urethral strictures, which could ensure a more accurate and aggressive incision of the stricture. Eleven patients (8 with posttraumatic and 3 with iatrogenic strictures) with complete obliteration of the bulbous and posterior urethra were successfully treated by optic internal urethrotomy with the aid of transrectal ultrasonography and a suprapubic fiberscope. After 1 year of followup, 5 of the 8 posttraumatic urethral strictures required further management, while the remaining patients had satisfactory results. Although the recurrence rate is high in the posttraumatic patients, transrectal ultrasound and the suprapubic fiberoscope afford a reliable and satisfactory aid during optic internal urethrotomy.

Adolescent↗
PubMed1994

Renal malacoplakia with secondary hepato-duodenal involvement.

Renal parenchymal malacoplakia is uncommon, and coexistence of extensive invasion into the liver and duodenum is extremely rare. Typically, there is an associated long-term urinary tract infection. We report on a 53-year-old woman with a history of diabetes and recurring pyelonephritis, who presented with a renal tumor and upper gastrointestinal bleeding. Surgical intervention included radical nephrectomy, lymphadenectomy, segmental hepatectomy, cholecystostomy, duodenorrhaphy, jejunostomy and appendectomy. There was no surgical morbidity. A pathologist confirmed the diagnosis of malacoplakia. All of the diagnostic criteria, including hematoxylin and eosin stain, iron stain, calcium stain and electron microscopy of Michaelis-Gutmann bodies, were classic. The literature is reviewed.

Duodenal Diseases↗
PubMed1994

Deoxyribonucleic acid flow cytometric study in pheochromocytomas and its correlation with clinical parameters.

OBJECTIVES: To study deoxyribonucleic acid flow cytometry (DNA-FC) in pheochromocytomas and its correlation with clinical parameters. METHODS: Fifty cases of pheochromocytomas of a total of 58 cases were studied for DNA-FC from archival paraffin-embedded tissue blocks and were correlated with clinical parameters (ie, size of tumor, benign or malignant pathologic type, vanillymandelic acid [VMA] level in 24 hour urine, age, sex, duration of symptoms, symptom scores). RESULTS: A total of 19 cases were diploid while 31 cases (62%) showed DNA aneuploidy with 21 cases tetraploid. Four cases were malignant. All of them were tetraploid. However, among the 46 benign cases, 10 were aneuploid and 17 were tetraploid. All 19 cases with DNA diploidy were benign. The DNA-FC did not correlate with other clinical parameters in our study. CONCLUSIONS: We confirmed a high incidence of DNA aneuploidy in pheochromocytomas. All malignant pheochromocytomas were tetraploid and all cases with DNA diploidy were benign. Long-term follow-up of all cases, especially those with DNA aneuploidy (including tetraploidy), is mandatory.

Adrenal Gland Neoplasms↗
PubMed1994

Mutational spectrum in the p53 gene in bladder tumors from the endemic area of black foot disease in Taiwan.

An elevated risk of bladder cancer has been reported in the endemic region of 'black foot disease' on the southwest coast of Taiwan and may be related to high arsenic levels in artesian well water. Thirteen urothelial tumors from this endemic region were examined for mutations in exons 5-8 of the p53 gene to identify the effects of possible exogenous factors at the DNA level. DNA was extracted from archival tissue after microdissection of tumors and analyzed by PCR-SSCP (polymerase chain reaction-based single strand conformation polymorphism), followed by direct sequencing. Eight cases (62%) showed mutations and 9 of the 10 point mutations observed were transitions. The type and position of the mutations were not significantly different when compared with the spectra of p53 mutations previously reported for transitional cell carcinomas (TCCs). However, two of the mutations were CGC-->CAC base changes at codon 175, a mutational hotspot for many tumor types but previously unreported in TCCs except in cases associated with inflammatory agents. Three of the tumors examined were found to contain double mutations, a relatively rare mutagenic event in human cancers. Our results suggest that the agents responsible for the high risk of bladder cancer in the black foot disease region may operate through an inflammation-based mechanism which increases the amount of DNA damage per mutagenic event.

Adult↗
PubMed1994

Clinical experience of posterior urethral valves.

Nine patients with posterior urethral valves were seen at Chang Gung Memorial Hospital from 1985 to 1992. The age at presentation ranged from five days old to 28 years old. The presenting symptoms and signs included abdominal distension, urinary tract infection, respiratory distress, urinary ascites, and weak stream. Patients were examined by voiding cystourethrography and ultrasonography. Surgical management of these patients included primary valve ablation (three cases), cutaneous vesicostomy plus delayed valve ablation (five cases) and primary valve ablation with delayed ureteral reimplantation (one case). For small infants with posterior urethral valves (five cases), temporary vesicostomy and delayed valve ablation offers excellent results in preventing iatrogenic urethral stricture. However, for older children and young adults, the recommended treatment is primary valve ablation. For seven patients with nadir serum creatinine < 1.0 mg/dL, the renal function remained within the normal range, yet during follow-up, one case had renal insufficiency. Vesicoureteral reflux was found in five cases. Spontaneous resolution was noted in two cases after valve ablation, and three cases were controlled with prophylactic antibiotics. The experience of our series suggests that primary valve ablation may be traumatic to the neonatal urethra and temporary diversion would allow greater renal recovery during the neonatal period. With newer delicate instruments, valve ablation may be performed earlier and as a one-stage operation in the future.

Adolescent↗