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L S Marks

Publications and source records attributed to L S Marks.

At least 37 records · Page 2Linked to original sources
PubMed1996

Serum prostate specific antigen levels after transurethral resection of prostate: a longitudinal characterization in men with benign prostatic hyperplasia.

PURPOSE: We studied the long-term effects of adenomectomy on serum levels of prostate specific antigen (PSA) in men with benign prostatic hyperplasia (BPH). MATERIALS AND METHODS: A consecutive series of 82 men undergoing adenomectomy for BPH between 1990 and 1992 was studied. PSA levels were determined before and serially after operation for as long as 5 years. RESULTS: Mean PSA decreased from 4.6 ng/ml. preoperatively to 0.7 ng./ml. 6 months postoperatively. These low levels were maintained throughout the 5-year observation period. The PSA decrease correlated with grams of tissue removed (r = 0.54, p < 0.001) and averaged 0.11 ng./ml./gm. Postoperatively mean PSA velocity was 0.01 ng./ml. per year, that is essentially flat, and it was not influenced by patient age, race, type of operation, grams of tissue removed, baseline PSA, PSA density of T1a lesions (7). One to 5 years after adenomectomy 6 of the 82 men had invasive prostatic carcinoma, and PSA levels and velocities remained low. CONCLUSIONS: These data support the concept of transition zone primacy in determining serum PSA. Furthermore, they suggest a possible need for a modified reference range when using PSA to screen for prostatic carcinoma in the estimated 3 million men alive in the United States who previously underwent adenomectomy for BPH.

Adult↗
PubMed1995

Prostatic aperture resulting from visual laser ablation: classification system based on follow-up endoscopy.

To study the evolving prostatic aperture created by visual laser ablation (VLAP), we performed 38 video-endoscopies in 24 men with prostatism at various intervals 2 weeks to 1 year after treatment. Complete healing was generally observed within 3 to 4 months, never before 6 weeks; and in some patients, tissue sloughing was still apparent beyond 6 months. By review of the cystoscopic findings and video hard copies, three independent observers classified the healed prostatic apertures with great uniformity into one of four categories: (I) minimal change (lateral lobes still meet in midline throughout gland length) (N = 3); (II) minor aperture (opening less than 50% of cystoscopic field over less than 50% of gland length) (N = 5); (III) major aperture (opening more than 50% of cystoscopic field over more than 50% of gland length) (N = 11); and (IV) full ablation (nearly complete replacement of lobar configuration with a general concavity) (N = 5). Clinical outcomes (symptom scores, uroflow rates) matched with follow-up cystoscopic categories but not with any other readily identifiable measures. The four-category system proved to be simple, reproducible, and clinically relevant. If a standardized tissue aperture is the ultimate aim of new methods to ablate the prostate, the proposed system for classifying the aperture could have a considerable future application.

Aged↗
PubMed1994

Morphometry of the prostate: I. Distribution of tissue components in hyperplastic glands.

OBJECTIVES: Morphometry, or quantitative image analysis, offers great promise in characterizing the various histologic types of benign prostatic hyperplasia (BPH), but to date, a systematic study of the tissue components is lacking. Thus we employed morphometry to examine the distribution of primary BPH tissues throughout whole human prostates. METHODS: The prostate glands of 20 men with BPH were removed for low-volume carcinoma and subjected to a uniform, comprehensive, systematic quantification of the primary BPH tissue components using the technique of digitization and point-count morphometry. RESULTS: We found the following average volumes among the 20 glands: epithelium, 19.9% (S.D. 5.1%, range 11.7% to 30.8%); fibromuscular stroma, 50.4% (S.D. 9.4%, range 32.2% to 74.4%); glandular lumina, 29.7% (S.D. 8.9%, range 11.9% to 47.5%). Within the individual prostates, we found symmetry in primary BPH tissue distribution, except that the outer prostate was on average 25% richer in epithelium than the inner prostate (p < 0.05). When tissue composition was determined in simulated biopsy specimens, corrected for radial (ie, inner vs outer gland) orientation, the correlation with whole-organ composition was statistically significant for "percentage epithelium" (r = 0.72, p < 0.01) and for "stromal/epithelial ratio" (r = 0.63, p < 0.01). CONCLUSIONS: Major differences in primary tissue composition may separate different hyperplastic prostates. Primary BPH tissues are rather symmetrically distributed within individual prostates. Quantitative histologic differences between prostates, potentially important in clinical decision-making may be accurately diagnosed by morphometry of radially oriented biopsy specimens.

Aged↗
PubMed1993

Serial endoscopy following visual laser ablation of prostate (VLAP)

Visual laser ablation of the prostate (VLAP) was evaluated by serial video-endoscopy and six months of clinical correlation in 7 men suffering from advanced prostatism and urinary retention. Images of the prostatic urethra were obtained before and at various intervals from two to nineteen weeks after the procedure. A substantial tissue defect evolved within three months; complete healing required an even longer period. Except in the 1 patient with middle lobe obstruction, spontaneous urination was restored in all patients (including 2 cancer patients additionally treated with androgen deprivation). No operative complications were encountered. Thus, a safe and visually successful prostatectomy was the usual result of VLAP in the present patients. As a minimally invasive method to remove an obstructing prostate, laser treatment warrants further study.

Aged↗
PubMed1992

Value of balloon dilation in treatment of youthful patients with prostatism.

Forty-three youthful patients with uncomplicated prostatism were prospectively evaluated to test the safety and efficacy of transurethral balloon dilation (TUDP). Treatment consisted of cystoscopic placement of an intraprostatic balloon inflated to 25 mm diameter at 3 atm pressure for ten minutes. At longest follow-up (9.8 months, average; 3-24 months, range), 88 percent of patients were satisfied with overall treatment results. The average improvements in voiding symptom score and peak uroflow were 77 percent and 73 percent, respectively. Mean improvements over pretreatment levels were statistically significant at one month (p less than 0.01) and remained so for the entire follow-up period. No incontinence, impotency, retrograde ejaculation, sepsis, or serious bleeding developed. An intraprostatic fissure, which spared the bladder neck, was a uniform finding and the most likely mechanism of lasting action of TUDP. In the relief of uncomplicated prostatism in youthful patients, TUDP compares favorably with other treatment alternatives.

Aged↗
PubMed1980

Use of saralasin to detect renovascular hypertension in childhood.

Current methods to evaluate renovascular hypertension in the pediatric population often requires a general anesthetic. Saralasin, an angiotensin II competitive inhibitor, is a safe, noninvasive technique which can be utilized at the bedside in a salt-depleted child off antihypertensive medication. Two illustrative cases are presented.

Aldosterone↗
PubMed1980

The diagnostic and therapeutic uses of saralasin in renal transplant hypertension.

Saralasin was used as a functional test of the renin-angiotensin axis in 4 renal transplant patients with hypertension. Blood pressure was recorded by an automatic recording device and plasma renin activity was measured by radioimmunoassay of angiotensin I. A positive saralasin test suggested renin-mediated hypertension despite normal peripheral renin levels in a 40-year-old man whose original kidney disease was nephrosclerosis. Since the blood pressure was refractory to intravenous sodium nitroprusside saralasin was used for 14 hours to control blood pressure before and after arteriography in the patient. Removal of the native kidneys markedly ameliorated the hypertension. A 35-year-old woman with transplant hypertension was responsive to angiotensin blockade only during a period of abrupt worsening of blood pressure associated with an acute rejection episode. Finally, 2 patients with advanced chronic rejection responded to saralasin administration. These studies confirm that 1) angiotensin blockade is a useful tool in the diagnosis of renin-dependent hypertension even when plasma renin levels are not elevated, 2) saralasin can be used to control renin-dependent forms of hypertension that are refractory to intravenous sodium nitroprusside therapy and 3) transplant hypertension associated with acute and chronic rejection appears to be renin-dependent.

Adult↗
PubMed1977

Predictive value of renin determinations in renal artery stenosis.

The prognostic value of renal vein and peripheral renin levels was analyzed in 66 patients with unilateral renal artery stenosis who underwent corrective surgery. Patient selection for operation was independent of renin results. Fifty-three percent of those with confirmed renovascular hypertension had renal vein renin ratios less than 2.0, ie, within the 95% confidence limit for the control group of 82 patients with essential hypertension. Thirty-four patients with clearly lateralizing renin data (ipsilateral:contralateral greater than or equal to 1.5 and contralateral:peripheral less than or equal to 1.3) were benefited by operation, but 23 additional patients with nonlateralizing data also benefited. No proposed scheme for renin data analysis detected more than 75% of those with renovascular hypertension. Although lateralizing renin data are highly predictive of operative benefit, nonlateralizing data do not necessarily herald operative failure and should not be dogmatically used to exclude surgical intervention.

Adult↗
PubMed1977

Unilateral renal hypoplasia with associated venous anomaly and hypertension. A study of the juxtaglomerular cells.

A child with unilateral renal hypoplasia, high plasma renin levels and hypertension was found to have large numbers of juxtaglomerular granular cells in the affected kidney. They were seen adjacent to and sometimes in the interior of hyalinized glomeruli or, in loose nests scattered in the interstitium. Ultrastructurally they contained large numbers of crystalline protogranules in the Golgi region and also displayed other features suggestive of hyperactivity. Atrophic tubules, smooth muscle and mast cells were present in considerable numbers. Well-preserved renal cortex remained in the affected kidney with no demonstrable juxtaglomerular granularity. After unilateral nephrectomy the patient became normotensive and plasma renin levels became normal. Thus it appears that the juxtaglomerular cells are able to produce and release renin independent of the structural integrity of the juxtaglomerular apparatus and renal glomerulus.

Child↗
PubMed1977

Non-renin-mediated renovascular hypertension: A new syndrome?

In two hypertensive patients with renal-artery stenosis, overactivity of the renin-angiotensin system was ruled out by investigations of renin and aldosterone concentrations and by the lack of a vasodepressor response to angiotensin blockade with saralasin. Nevertheless, hypertension was cured by renal revascularisation. The date suggest that there is a form of renovascular hypertension which is not mediated by the renin-angiotensin system.

Adult↗
PubMed1977

Angiotensin blockade in renovascular hypertension: a controlled, prospective study.

Saralasin, a specific competitive inhibitor of angiotensin II, was administered in a controlled, prospective study designed to test the hypothesis that this agent is a useful tool for the detection of renovascular hypertension. 13 patients, 11 with renovascular hypertension and 2 with high-renin essential hypertension, showed a gross, readily apparent decrease in blood pressure after receiving saralasin. 8 patients with essential hypertension and normal or low renin levels exhibited no depressor response to the drug. In the patients with renovascular hypertension, blood pressure response during angiotensin blockade compared favourably with renal vein renin determinations as a predictor of operative results. Because saralasin testing has resulted in few if any falsely positive or negative results when considered as a diagnostic procedure for renin-mediated hypertension, and because it is safe, it may become an ideal initial screening procedure. The saralasin test (either bolus injection or sustained infusion) is completely valid only if the patient is mildly salt-depleted, is not taking other antihypertensive medication, and is genuinely hypertensive at the time of the test.

Adult↗
PubMed1977

Renin, sodium, and vasodepressor response to saralasin in renovascular and essential hypertension.

Saralasin (1-sar-8-ala-angiotensin II), a competitive inhibitor of angiotensin II, was administered to 32 patients with renovascular or essential hypertension before (Day 1) and after (Day 2) they were mildly sodium depleted by furosemide (1 mg/kg body weight). A blood pressure lowering effect of saralasin was observed in 16 of 17 patients with renovascular hypertension on Day 2, but in only 10 of the 17 on Day 1. Of the 15 patients with essential hypertension, only the four with high renin levels exhibited a vasodepressor response on Day 2; three responded similarly on Day 1. The Average net sodium loss between the 2 days was greater for patients who responded to the drug on Day 2 (170 meq) than those who did not (129 meq) (P less than 0.05); however, there was no correlation between blood pressure response and either net sodium loss or urinary sodium excretion at the time of testing. Plasma renin activity correlated with saralasin responses (r=-0.74, P less than 0.01). Saralasin testing during a state of modest sodium depletion compares favorably with renin measurements in the detection of renin-mediated hypertension.

Adult↗
PubMed1976

Detection of renovascular hypertension: saralasin test versus renin determinations.

Angiotensin blockade was established in hypertensive patients with the competitive inhibitor saralasin and the blood pressure response was compared to prior renin determinations. Two patients with subsequently confirmed renovascular hypertension had normal peripheral renin and non-lateralizing renal vein renin ratios, yet both showed a clear-cut lowering of blood pressure after administration of the blocking agent, indicating the presence of renin-mediated hypertension. Thus, direct in vivo testing with saralasin appears to offer certain advantages over renin determinations.

Angiotensin II↗
PubMed1976

Renovascular hypertension: does the renal vein renin ratio predict operative results?

Renal vein renin ratios from 56 hypertensive patients who were operated upon for unilateral stenosis of a main renal artery were compared to blood pressure response to a corrective operation. In patients with renal vein renin ratios greater then 2.0, the upper limits of normal for essential hypertension (95 per cent confidence limits), the cure/improvement rate approximated 90 per cent. However, in patients operated upon despite lesser ratios the cure/improvement rate was also high--83 per cent in our series and 57 per cent in collected reports from the literature. Thus, the test may be falsely negative in a high percentage of patients. Renal vein renin ratios would appear to be most useful in confirming but not necessarily in denying the functional significance of a renal artery stenosis.

Adult↗