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Biomedical subjects

L Baert

Publications and source records attributed to L Baert.

At least 109 records · Page 6Linked to original sources
PubMed1994

Accuracy of combined computerized tomography and fine needle aspiration cytology in lymph node staging of localized prostatic carcinoma.

The sensitivity and accuracy rate of computerized tomography (CT) in lymph node staging of localized prostatic carcinoma is commonly considered to be low. Fine needle aspiration cytology of pathological lymph nodes seen on radiological staging can enhance this low accuracy rate. We prospectively investigated the accuracy of CT and fine needle aspiration cytology in lymph node evaluation of 285 patients with clinically locally confined prostatic carcinoma. The sensitivity, specificity and accuracy rates of this combined method were 77.8%, 100% and 96.5%, respectively. False-negative staging results were found in only 10 patients with minimal nodal disease. Although in contrast with previous reports, combined CT and fine needle aspiration cytology in our hands seems to be a highly efficient staging method for lymph node involvement. This method could be considered as an alternative to surgical lymphadenectomy in the preoperative evaluation of the nodal status of patients with localized prostatic carcinoma who are scheduled for radical prostatectomy or curative radiotherapy.

Aged↗
PubMed1994

Immunohistochemical localization of prostate-specific markers within the accessory male sex glands of Cowper, Littre, and Morgagni.

OBJECTIVES: The aim of the study was to explore possible production of prostate-specific markers by the embryologically and physiologically related accessory male sex glands, other than the prostate. METHODS: The accessory male sex glands of Cowper, Littre, and Morgagni were studied systematically in 10 whole-mount autopsy and 5 surgical cystoprostatourethrectomy specimens. Immunohistochemistry was applied with the avidin-biotin-peroxidase method and commercially available monoclonal antibodies raised against prostate-specific antigen (PSA) and prostate-specific acid phosphatase (PSAP). RESULTS: All specimens showed clear microscopic identification of these glands except for Cowper's glands, which were not found in most of the surgical cystoprostatourethrectomy specimens but were found coincidentally in one. Localization of the prostate-specific markers PSA and PSAP was demonstrated for the first time in three Cowper's glands, but they were a consistent finding in Littre's and Morgagni's glands when immunohistochemical identification was performed in a systematic fashion. CONCLUSIONS: PSA and PSAP are mostly produced by prostatic tissue, but not exclusively. These findings may have an impact on the specificity and sensitivity of PSA serum levels after radical prostatectomy because they support the hypothesis of extraprostatic sources of PSA.

Acid Phosphatase↗
PubMed1994

In vivo fluorescence detection of human bladder carcinoma without sensitizing agents.

The diagnosis of transitional cell bladder carcinoma and especially carcinoma in situ of the bladder in spinal cord disordered persons is often made difficult by catheters, infections or stone-induced chronic inflammation. Fluorescence tagging of tumors by sensitizing agents such as hematoporphyrin derivatives enhances visualization but presents a number of drawbacks for the patients, even at low doses. We have developed a cystoscopic fiber optic instrument, based on a mercury arc lamp, for in vivo detection of human bladder carcinoma without sensitizing agents. The tissue autofluorescence upon UV excitation (365 nm) is detected and a demarcation contrast ratio for carcinoma in situ and transitional cell carcinoma of 2.6 and 3.2 respectively is obtained. This demarcation ratio is 60 percent higher than the contrast ratio obtained after photosensitizer injection. The integration of a reliable diagnostic method with a known efficient therapeutic technique (Nd YAG laser irridiation) opens the way for cost-effective preventive care of high-risk patients.

Biopsy↗
PubMed1994

Mucin-secreting adenocarcinoma of the prostate with neuroendocrine differentiation and Paneth-like cells.

We present an unusual variant of prostatic adenocarcinoma with obvious mucinous and neuroendocrine features, arising in the transition zone. The neuroendocrine component is largely represented by Paneth-like cells (PLCs). These cells correspond to previously described eosinophilic cells and are amphicrine. We could demonstrate immunohistochemically the presence of calcitonin in some of these PLCs. The prognostic significance of these special characteristics is not well known, but it is most likely that this type of prostate cancer will not respond well to hormonal therapy.

Adenocarcinoma, Mucinous↗
PubMed1994

Fluorescence imaging of bladder cancer.

Fluorescence tagging of tumors by sensitizing agents such as hematoporphyrin derivatives is an efficient method for diagnosing tumors but presents, even at low doses, a number of serious drawbacks for the patients. We demonstrate a fiberoptic instrument for the diagnosis of bladder cancer, based on a tripled frequency Nd YAG laser, without need for sensitizing agents, based on the autofluorescence of tissues. The contrast demarcation obtained for CIS and TCC respectively is 2.2 and 2.7, which is about 30% higher than what can be obtained after photosensitizing. The integration of the diagnostic method with a reliable therapeutic technique for tumor cell destruction, opens the way for cost-effective preventive care of high risk patients.

Carcinoma in Situ↗
PubMed1994

Nocturnal penile tumescence evaluation before and after corporeal plication for Peyronie's disease.

A prospective study was done on 76 patients who underwent surgical correction by corporeal plication of the penile deformity secondary to Peyronie's disease. Nocturnal penile tumescence and rigidity were recorded by RigiScan during three consecutive nights, before and after the operation. A significant number of patients developed erections of better quality especially at the tip, after this corporeal plication procedure. These data indicate that corporeal plication does significantly enhance the quality of erectile episodes, by increasing penile rigidity.

Adolescent↗
PubMed1994

A histopathological study of deep dorsal penile vein in venogenic impotence.

We have studied the histopathology of 87 dorsal penile veins, obtained from patients who underwent a resection of the deep dorsal penile vein because of proven venous leakage. The amount of muscle tissue and of collagenous connective tissue has been numerically quantified. Special attention has been focused on the muscular/collagenization ratio. We show that this ratio is not correlated to age neither with the outcome of the operation and that no differences exist between veins in venous leakage patients and in potent patients. This study confirms that the reduction of venous outflow-the so called corporeal veno-occlusive mechanism-is probably a secondary passive phenomenon, due to smooth muscular relaxation, and mainly located within the corpora cavernosa, between the expanding sinusoidal wall and the noncompliant tunica albuginea. Our findings also strongly refute the hypothesis that polsters or other venous wall characteristics contribute to the normal physiology of the deep dorsal penile vein.

Adult↗
PubMed1994

Adenocarcinoma of the rectum with a solitary metastasis to the urethra in a female.

Adenocarcinoma of the urethra is extremely rare, constituting 10 to 20% of all primary urethral malignancies in women. As in men, the squamous carcinoma accounts for 70% of all urethral tumours. Adenocarcinomas are mostly primary lesions, originating from the paraurethral glands. A case is reported about a female patient, presenting with a mucinous urethral adenocarcinoma, presumably secondary to a primary rectal adenocarcinoma.

Adenocarcinoma, Mucinous↗
PubMed1994

Urethral squamous cell carcinoma associated with urethral stricture and urethroplasty.

We reviewed the few published cases of male urethral squamous cell carcinoma after urethroplasty. A new case report is added. Considering the known facts we conclude that urethral cancer following urethroplasty, performed to cure urethral stricture, is a rare complication. One must be aware of possible evolution to malignancy when this surgical procedure is not fully successful, i.e. in the case of recurring urinary obstruction or disturbed wound healing. Alarming symptoms are fistulization, abscess formation, ulceration and induration. Histopathological examination is needed, firstly before urethroplasty to exclude already existing malignant changes of the urethral mucosa and secondly whenever suspicion is raised after surgery. It is of utmost importance to diagnose a urethral carcinoma as early as possible because the cure rate in advanced stage is minimal.

Carcinoma, Squamous Cell↗
PubMed1994

[Hormone therapy before radical prostatectomy. Effects on surgical method and resection margins. Belgian Uro-Oncological Study Group (B.U.O.S.)].

127 patients with a clinical stage T2b and T3 prostate cancer were randomized in order to undergo either a radical prostatectomy alone or a radical prostatectomy after hormonal treatment (560 mg of estramustine phosphate daily for 6 weeks) in a prospective multi-center study. The clinical or radiological evaluation of an eventual downstaging being extremely difficult, the authors compared in the 2 groups the influence on the surgical act and the number of positive surgical margins at pathological examination of the resected specimen. There was no significant difference between the 2 groups concerning the surgery (duration of the procedure, blood transfusion, degree of difficulty). For clinical T2 prostate tumors the number of positive surgical margins was significantly lower in the group that had preoperative hormonal treatment. In the group with clinical T3 prostate cancer this difference was not found. The influence of positive margins on the later development of local or systemic recurrence and on survival still has to be awaited. At this moment one could conclude that only patients with a T2 prostate cancer benefit of a preoperative hormonal treatment.

Estramustine↗
PubMed1993

Clinical fluorescence diagnosis of human bladder carcinoma following low-dose Photofrin injection.

A point-monitoring fluorescence diagnostic system based on a low-energy pulsed laser, fiber transmission optics, and an optical multichannel analyzer was used for diagnosis of patients with bladder malignancies. Twenty-four patients with bladder carcinoma, carcinoma in situ, and/or dysplasia were injected with hematoporphyrin derivative, Photofrin, 0.35 or 0.5 mg/kg body weight, forty-eight hours prior to the investigation. The ratio between the red sensitizer emission and the bluish tissue autofluorescence provided excellent demarcation between papillary tumors and normal bladder wall. Certain cases of dysplasia also could be differentiated from normal mucosa. Benign exophytic lesions such as malakoplakia appeared different from malignant tumors in fluorescence. Flat suspicious bladder mucosa such as seen in infectious diseases or after radiation therapy appeared normal on fluorescence.

Adult↗
PubMed1993

Long-term consequences of urethral stents.

The results of the self-expandable urethral stent (Wallstent) in the treatment of urethral strictures were evaluated in 7 patients with a followup of 23 to 31 months. The 4 failures were caused by exuberant fibrotic proliferation in the lumen of the stent, which required further endoscopic treatment in 2 patients and even surgical removal of the stent in 1. In the other 2 patients the fibrotic proliferation was progressive and will require further treatment. In 1 patient there is slowly progressive proliferation and a diminishing urine flow rate, and in 2 the fibrotic proliferation seems to be stable. Early reports on the stent suggest that its use will obviate the necessity for complex surgery of urethral stricture. Strictures involving layers deeper than the urothelium and traumatic strictures are not good indications for the self-expandable stent. As this technology continues to evolve, we must continue to follow these patients closely and be attentive to the possible long-term consequences.

Aged↗
PubMed1993

High pressure versus low pressure electromagnetic extracorporeal lithotripsy.

A low pressure and an upgraded high pressure electromagnetic lithotriptor were compared for the treatment of calculi within the ureter. The upgrading allows for increased energy density onto the stone surface. We targeted 139 ureteral calculi (average diameter 8.1 mm.) with the low pressure system. The mean number of shock waves was 7,308, 9,226 and 5,304 for calculi in the upper, mid and lower ureter, respectively, and the energy density corresponded to 0.222, mJ./mm.2, 0.224 mJ./mm.2 and 0.223 mJ./mm.2, respectively. Immediate fragmentation was achieved in 39 of 51 upper (77%), 21 of 42 mid (50%) and 22 of 46 lower (49%) ureteral calculi. The upgraded shock wave tube was used in 52 calculi (average diameter 6.1 mm.). The mean number of shock waves was 6,250, 14,150 and 3,400 for calculi in the upper, mid and lower ureter, respectively, and the energy density corresponded to 0.32 mJ./mm.2, 0.33 mJ./mm.2 and 0.30 mJ./mm.2, respectively. Immediate fragmentation was achieved in 11 of 16 upper (69%), 4 of 6 mid (67%) and 7 of 30 lower (23%) ureteral calculi. The comminution rate did not significantly increase, which implies that the focal energy density is not the only decisive parameter in fragmentation by extracorporeal shock wave lithotripsy.

Adolescent↗
PubMed1993

Mitomycin C in combination with orchiectomy for newly diagnosed metastatic prostate cancer: preliminary results on a randomized trial.

The preliminary results of a randomized trial comparing orchiectomy versus orchiectomy and mitomycin C in 119 newly diagnosed metastatic prostate cancer patients are presented. Of 109 evaluable patients 57 were treated with orchiectomy alone and 52 received adjuvant intravenous mitomycin C. Mean interval to progression was 13 months in the orchiectomy group versus 11 months in the mitomycin C group. Preliminary analysis did not demonstrate a favorable effect of the combination with this chemotherapeutic agent compared to orchiectomy alone (p = 0.3).

Aged↗
PubMed1993

In situ light dosimetry during whole bladder wall photodynamic therapy: clinical results and experimental verification.

Photodynamic therapy (PDT) using Photofrin IIR (PII) as a photosensitizer is currently being evaluated as a new treatment modality for superficial bladder cancer. An optimum therapeutic ratio requires uniform illumination of the whole bladder wall and accurate light dosimetry. The first clinical light dosimetry results (16 patients) are reported, obtained using a system which allows in situ measurement and control of the light fluence at the bladder wall. The true light fluence at the bladder wall (i.e. non-scattered incident light plus scattered light) appeared to be on the average a factor beta = 4.8 +/- 1.2 (mean +/- SD) larger than the non-scattered incident light fluence. The latter is often, but incorrectly, used in reporting light fluence. The factor beta varied between patients with extremes of 2.5 and 7.1. Because such large variations were unexpected, but may have significant clinical consequences, experiments in plastic bladder models were performed to study separately the various factors (e.g. bladder shape, air bubble) affecting the dosimetry in clinical treatments. The results imply that the clinical variations are most likely to be the result of variations in optical properties of the bladder wall mucosa, probably due to the disease and prior treatments. If light dosage is based on non-scattered light only (without in situ light dosimetry, according to a current clinical protocol) the present results indicate variations in the true (total) light fluence between patients by a factor of at least 2. At the least this may cause unnecessary discomfort to a number of patients.

Female↗