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Biomedical subjects

J L Chin

Publications and source records attributed to J L Chin.

At least 73 records · Page 4Linked to original sources
PubMed1986

Transrectal needle aspiration versus transperineal needle biopsy in diagnosis of carcinoma of prostate.

Transrectal needle aspiration of the prostate was compared to transperineal biopsy in 28 patients with suspected carcinoma of the prostate. This technique was found to have a high sensitivity and specificity for diagnosing carcinoma of the prostate, and no complications were seen. The addition of Nuclear Flow DNA analysis may give further prognostic information from needle aspiration and core biopsy specimens. Transrectal needle aspiration of the prostate is a safe, inexpensive, and accurate method of diagnosing carcinoma of the prostate.

Biopsy, Needle↗
PubMed1986

Nuclear magnetic resonance assessment of renal perfusion and preservation for transplantation.

The feasibility of using proton nuclear magnetic resonance (NMR) relaxation measurement to monitor organ perfusion and preservation was studied using a rat model. Intact kidneys were assessed with NMR following various periods of cold storage. Bilateral en bloc donor nephrectomy was performed on Sprague-Dawley rats with prior in situ flushing with Euro-collins', dextrose and other test solutions via a plastic cannula in the aorta. A paramagnetic agent, gadolinium-DPTA, dissolved in perfusion fluid was then injected into the renal vasculature. NMR analysis was repeated and the kidneys were reflushed with perfusion fluid to remove the gadolinium, followed by another NMR analysis. By sequential flushing and NMR measurement after 24, 48 and 72 hours of cold storage, the thoroughness of flushing, the patency of intrarenal vasculature and capillary integrity could be assessed. With the D5W, the T1 relaxation of kidneys dropped 56% with prolonged cold storage, indicating gadolinium accumulation in the interstitium, in effect loss of capillary integrity. With the Euro-collins', the T1 showed a small drop (23%) and almost complete flush-out, indicating superior tissue preservation and patency of vasculature. The addition of trifluoperazine, (TFP, a calmodulin inhibitor) to the Euro-collins' resulted in only a 9% drop in T1 after 72 hours. This possibly indicates TFP has additional protective action on cold ischemic damage. Using the small animal model presented here, proton NMR spectroscopy appears to be a sensitive technique in assessing renal vascular patency after cold storage and provides a useful tool for the investigation of other agents for organ preservation for transplantation.

Animals↗
PubMed1986

Microvascular surgery as an adjunctive tool in renal transplantation.

There has been a serious shortage of suitable kidneys for transplantation since this procedure became the treatment of choice for many patients with end-stage renal failure. Some harvested kidneys are discarded due to complicated or injured renal vasculature and some potential living related donors are judged unsuitable because their kidneys have multiple vessels. The authors review the basic microsurgical techniques they have used in such situations to salvage kidneys for transplantation. They emphasize the ex-vivo, "bench", microsurgical method for protecting the kidney from prolonged warm ischemia time (as with multiple complicated in-situ anastomoses). Several illustrative case reports from their recent experience are presented. The authors conclude that microvascular surgery is an important adjunct to the armamentarium of the transplant surgeon.

Adult↗
PubMed1985

Flow cytometric analysis of DNA content in human bladder tumors and irrigation fluids.

Flow cytometry (FCM) was used to study the DNA distribution of 99 tumor biopsy specimens and 41 bladder irrigation samples from patients with transitional cell carcinoma of the bladder. For tumor biopsy and cystectomy specimens, the frequency of aneuploidy increased with advancing tumor stage and grade. All T0 tumors were diploid. Twenty-seven percent of T1, 71.4% of T2, and 75% of T3 and T4 tumors were aneuploid. All Grade I tumors were diploid. Thirty percent of Grade II and 76.9% of Grade III tumors were aneuploid. The frequency of aneuploidy of tumors in the early stages (Ta, T1) is similar to the incidence of subsequent progression by these tumors described in the literature. For irrigation fluids, the relationship between grade and stage and the frequency of aneuploidy was similar to the relationship seen with tumor specimens. All four patients with only carcinoma in situ had aneuploid cells in their irrigations. The comparison of FCM data of bladder biopsy and bladder irrigation from the same cystoscopic evaluation suggests adequate representation of tumor cells in the irrigation fluids for almost all cases. The authors conclude that DNA ploidy analysis by FCM appears useful in a clinically important group of patients with aneuploid superficial tumors of moderate or high grade. Bladder irrigation analysis appears useful in the follow-up of patients with a history of carcinoma in situ and those with aneuploid tumors.

Carcinoma, Transitional Cell↗
PubMed1985

Vaginal recurrence after cystectomy for bladder cancer.

The records of 14 patients with vaginal recurrence following cystectomy were reviewed in an attempt to find factors responsible for the local failure. Comparison was made with female patients who underwent cystectomy for bladder cancer during the same period but who did not have vaginal recurrence. Patients with previous surgery and radiation to the pelvic organs appear to be at risk for local recurrence, probably because of the difficulties associated with surgical removal of the bladder. Patients with tumors other than transitional cell carcinoma, especially those located at the bladder neck and urethra, also appear to be at high risk. Proper surgical technique with en bloc cystourethrectomy, including excision of the anterior vaginal wall, is of paramount importance to avoid local recurrence.

Aged↗
PubMed1985

The effect of nitrofurantoin on bladder tumor cell lines: in vitro growth and implantation in the cauterized mouse bladder.

Nitrofurans compounds and derivatives demonstrate antineoplastic activity in vitro as well as in vivo. Nitrofurantoin caused in vitro growth inhibition of a FANFT-induced murine bladder tumor (MBT2) and a human transitional cell carcinoma cell line (GIBB) in concentrations of 125 microM, 250 microM and 500 microM. The implantation and growth of MBT2 in the cauterized mouse bladder was inhibited by 250 microM nitrofurantoin. The bladder mucosa of two groups of C3Hf/HeHa female mice was electrically cauterized. In group I, 1 X 10(6) MBT2 cells were injected into the bladders of 42 mice, while in group II 1 X 10(6) MBT2 cells in 250 microM nitrofurantoin solution were injected into the bladders of 51 mice. Positive tumor implantation was seen in 25 bladders (59.5 per cent) of group I as compared to 15 bladders (29.5 per cent) of group II. All tumors in group I were large, occupying more than 50 per cent of bladder cross sectional area with 24 per cent showing extravesical extention. Sixty-six per cent of tumors in groups II were less than 25 per cent of bladder cross sectional area and 13.4 per cent had extravesical extention.

Animals↗
PubMed1985

Flow cytometric deoxyribonucleic acid analysis of primary and metastatic human renal cell carcinoma.

The deoxyribonucleic acid profiles of 54 renal cell carcinoma specimens (43 primary and 11 metastatic tumors) from 50 patients are reported. Deoxyribonucleic acid ploidy and the proportion of cells in the S phase (S index) were determined by flow cytometry. Of the patients 44 had advanced disease (stages III and IV). The frequency of deoxyribonucleic acid aneuploidy (presence of a distinct aneuploid stemline) was 74.1 per cent for all tumors and 77.3 per cent for stages III and IV tumors. The percentage of aneuploid tumors did not vary significantly among the various histological types, between stages III and IV tumors, or between primary and metastatic tumors. S indexes for aneuploid tumors were significantly higher than for diploid tumors. When deoxyribonucleic acid ploidy of the tumor alone was considered with respect to survival, there appeared to be a slight survival advantage for patients with diploid tumors compared to those with aneuploid tumors. However, a larger patient population (especially patients with early stage disease) and a longer followup will be required to determine the prognostic role of flow cytometry deoxyribonucleic acid analysis of renal cell carcinoma. Flow cytometry analysis of 4 primary renal tumors and their subsequent metastases revealed concordance in ploidy in 3 specimens. In 1 patient the primary tumor showed a diploid pattern whereas the subsequent metastasis showed 2 aneuploid stemlines. Possible explanations for this observation are listed. Further flow cytometry studies of deoxyribonucleic acid profiles in renal cell carcinoma are warranted and should improve our understanding of the biological and clinical behavior of this tumor.

Aneuploidy↗
PubMed1985

Relationship between DNA ploidy, glandular differentiation, and tumor spread in human prostate cancer.

DNA ploidy was evaluated by flow cytometry for 45 human prostate carcinomas (34 prostatectomy specimens and 11 biopsies). Twenty tumors (44.4%) contained a distinct aneuploid stem line. All 11 tumors confined to the prostate gland (pathological Stage B) were diploid. The frequency of aneuploidy increased with advancing stage, and most tumors with distant metastases were aneuploid. The degree of glandular differentiation was characterized by the Gleason score. One-third of tumors with a Gleason score of 5 to 6 were aneuploid, whereas over 70% of poorly differentiated tumors with a Gleason score of 9 to 10 were aneuploid. Among diploid tumors, 45.5% were localized carcinomas (Stage B), 36.4% were characterized by invasion outside the prostate (Stage C), and 18.2% formed pelvic nodal or distant metastases (Stages D1 and D2). In nearly two-thirds of patients with aneuploid tumors, pelvic nodal or distant metastases were found. When tumors were classified according to both DNA ploidy and degree of glandular differentiation, then subgroups of tumors with the highest and lowest degree of malignant potential became apparent. Only 7.1% of diploid tumors with a Gleason score of 5 to 6 formed metastases, but 80% of aneuploid tumors with a higher Gleason score (7 to 10) formed metastases. Diploid tumors with higher Gleason scores and aneuploid tumors with lower Gleason scores had intermediate frequencies of metastases. The presence of an aneuploid stem line in prostate carcinomas indicated that the tumor had spread outside the prostate gland or had metastasized. DNA ploidy may be an important prognostic factor for human prostate cancer. DNA ploidy and the degree of glandular differentiation considered together may improve prognostic evaluation of prostate carcinomas.

DNA, Neoplasm↗
PubMed1983

The anti-adherence effect of heparin: a visual analysis.

The various intrinsic bladder mucosal defenses against bacterial invasion, including the anti-adherence action of the surface mucopolysaccharide layer, have been documented in recent years. Studies have suggested Heparin, a mucopolysaccharide, may have anti-adherence action. We used scanning electron microscopy to visually evaluate the effects of intravesical HCl, Heparin and Protamine on the interaction between E. coli and rat bladders. Our findings concurred with previous statistical analyses using radio-isotope labelled bacteria, suggesting a beneficial anti-adherence effect of Heparin which can be negated by Protamine. We also noted a white coating on the bacteria in bladders treated with Heparin. We suggest this may represent minute amounts of Heparin coating the bacteria, thus decreasing bacterial adherence to bladder mucosa. Analogues of Heparin, without anti-coagulant properties, may be useful in prophylaxis against urinary tract infections.

Animals↗
PubMed1983

Diagnostic considerations in working with Asian-Americans.

It is generally accepted that ethnic differences can no longer be regarded as extraneous variables in diagnosis. Yet, how to work with these differences often remains unclear. Asian-American cultural views and values are discussed with respect to their influence on the assessment of intellectual and personality functioning. It is proposed that the diagnostic process include a focus on the adaptive potential of particular forms of cultural behavior.

Asian↗
PubMed1982

Renal angiomyolipoma not associated with tuberous sclerosis.

Six cases of renal angiomyolipoma not associated with the tuberous sclerosis complex illustrate the common presenting clinical picture of this relatively rare hamartoma. The authors discuss the traditional and newer diagnostic studies used, particularly ultrasonography and computerized axial tomography and their applications in the diagnosis of angiomyolipoma. Special emphasis is placed on differentiation of renal angiomyolipoma from renal cell carcinoma. Although the newer imaging techniques are valuable diagnostic aids, treatment of these renal mass lesions should not be based entirely on results of such studies.

Adenocarcinoma↗