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Biomedical subjects

D Chopin

Publications and source records attributed to D Chopin.

At least 127 records · Page 7Linked to original sources

[Proper use of prostate specific antigen].

Prostate specific antigen (PSA) has become the best marker for prostatic carcinoma. PSA is secreted by the glandular cells of prostatic epithelium and is specific for any normal, hyperplasic and tumoral prostatic tissue. PSA is excreted in blood that render its dosage accessible for clinical purpose. Two different tests are now used: Tandem test R is a radioimmunological test (N1:0-4 ng/mL), and Pros check test uses an immunoenzymatic method and is considered to be more sensitive (N1: < 2.5 ng/mL). PSA increases of 35 ng/mL for every other gram of hyperplastic prostatic tissue and of 3.5 ng/mL by gram of prostatic cancer. This test allows detection of prostate carcinoma with a positive predictive value of 49% when PSA > 4 ng/mL and 75% when PSA > 10 ng/mL. However, only biopsies will confirm the diagnostic of prostate cancer. For the patients with an increased PSA and no cancer founded by random biopsies, an increase of PSA level in the next year suggests prostate carcinoma. When the diagnostic of prostate cancer has been made, a PSA < 15 ng/mL suggests a low stage carcinoma (B1 or B2). When PSA > 75 ng/mL, there is a high probability that this cancer is node positive. Between this values, PSA cannot make the difference between stage B, C or D. The more sensitive test (Pros check) must give undetectable level after radical prostatectomy. For high stage lesion treated by hormonotherapy, or chemotherapy or radiation therapy, PSA is a good indicator of response to therapy and recurrence after therapy.

Adenocarcinoma↗

Usefulness of MIB1 monoclonal antibody in assessing the proliferative index in human bladder carcinoma: comparison with Ki-67 antibody.

The reactivity of MIB1 antibody on routinely processed paraffin sections was compared with that of Ki-67 antibody on frozen sections of 80 transitional cell carcinomas of the bladder. The percentage of labelled cells was expressed as the labelling index. MIB1 labelling indices were higher than those of Ki-67 but for each case the two values were strongly correlated (r = 0.91). Ki-67 and MIB1 indices were also correlated to tumour grade and stage (P < or = 0.001). MIB1 indices determined after both formaldehyde and ethanol based Bouin's fluid fixatives did not show any significant difference. MIB1 antibody staining after microwave oven heating of tissue sections is a simple technique for assessing the proliferative fraction of bladder tumours on fixed material. The use of MIB1 antibody permits retrospective studies and should determine whether the proliferation index in bladder carcinoma has the same prognostic value as demonstrated in other types of neoplasms.

Adult↗

[Assessment of the use of the Graf ligamentoplasty in the surgical treatment of lumbar spinal stenosis. Apropos of a series of 26 patients].

PURPOSE OF THE STUDY: The aim was to determine the usefulness of a flexible stabilization system associated with neural decompression in the treatment of lumbar spinal stenosis. 2 points were especially studied: low back pain at follow up and Graf system ability to prevent postoperative instability. PATIENTS AND METHODS: 26 patients were screened retrospectively with an average follow up of 29 months. Clinical results were appreciated on the functional Beaujon's score. Preoperatively all of the patients had static and dynamic standard X-rays. The evaluation of sagital olisthesis was done by using displacement of the posterior border of the vertebral body (Wiltse and Winter method's). On the dynamic X-Rays we accepted as criteria of instability an olisthesis of 2 mm or more, an angular displacement equal or superior to 14.3 degrees in L2 L3, 15.5 degrees in L3 L4 and 18 degrees in L4 L5 according to the Dvorak's criteria, or a rotatory dislocation. Neurological compression was studied from CT scan and dynamic and static myelogram. RESULTS: According to our classification results were excellent in 8 cases, good in 6 cases, fair in 9 cases and poor in 3 cases. Generally results were good on the neurological symptoms (neurological claudication, radiculalgia at rest or at exertion) and fair on the low back pain. Only one half of our patients had improvement of back pain and 15 per cent were worsened. A postoperative destabilization occurred in 27 per cent of our patients (7 levels, 7 patients). The dynamic preoperative X-rays of these destabilized levels detected always 2 or 3 criteria of instability: hypermobility, olisthesis of 2 mm or more on the flexion X-rays or rotatory subluxation. For the remaining cases only one criteria of instability was found (hypermobility or olisthesis on flexion X-rays). CONCLUSIONS: Concerning the postoperative low back pain using of a flexible system associated with a neural decompression did not improve the results. Concerning the prevention of postoperative instability the Graf system did not avoid the slipping of the most instable levels.

Female↗

[Training of surgeons for laboratory research].

A degree in surgical research has been set up in 1986 in France. It includes a one-year full time work in a research laboratory, and seminars (one to three days long, each). General surgical research objectives are gathered in a first seminar. Then, candidates select one among four optional subjects: biomaterials-artificial organs, transplantation, oncology, and neurosciences. Two prerequisites are necessary in order to register. The first is to write a research project according to standardized rules, and the second is to attend two seminars, one dealing with scientific communication and the other with methodology in clinical research. A nation-wide valid Academic degree is delivered to candidates who pass an oral presentation of their research report and who attended all seminars according to the optional subject that they selected. From 1986 to 1993, 434 students attended the formation. They came from different regions of France, proving the nation-wide characteristic of the degree, and some from foreign countries. Seminars were held in different French University towns. An increasing number of students become Ph.D.

Education, Medical, Graduate↗

The effects of focused extracorporeal pyrotherapy on a human bladder tumor cell line (647 V).

UNLABELLED: Human transitional cell bladder carcinoma cell-line 647 V has been used to evaluate the effects on tumor cells in vitro of a new technique: focused extracorporeal pyrotherapy (F.E.P.). The device is made of multi-sources of piezoelectric ceramics focused at 320 mm. The focal area is 10 mm. high on 1.5 mm. width, and shots of 0.25 to 0.50 seconds were delivered on 4 groups of cell pellets placed in a polyurethane tube at the focus. Trypan blue MTT cell growth curve and Colony forming tests were used. There was a significant reduction (Student's t test) of the cell variability rate on the Trypan Blue test, 5% (in the treated Group) against 95% (control Group). The growth curve was flattened whether 0.50 second shots were single or repeated. The colony formation test was also significantly altered: 5.7% (treated group) against 70% (control group). CONCLUSION: focused extracorporeal pyrotherapy is able to alter or kill tumor cells in vitro.

Carcinoma, Transitional Cell↗

Antibodies to bladder-tumor-associated antigens as prognosis probes in the flow-cytometric analysis.

Monoclonal antibodies directed against bladder tumor cells (10D1, 7C12, 6D1, 3C6, G4 and E7) and human leukocyte antigen (HLe1) were tested by flow cytometry on 68 bladder tumors involving 10 grade I, 29 grade II and 29 grade III tumors (WHO classification). According to their evolution stage, these tumors can be subdivided into 17 stage Pa, 34 stage P1, 7 stage P2 and 10 stage P3. Fifteen normal bladder samples were used as a control. Analysis of DNA content revealed a first group of 31 tumors with a unimodal DNA profile. In the second groups of 37 tumors, the DNA profile was bimodal. Cells from grade I tumors were labelled with 10D1 and 6D1 antibodies; all these cells showed a unimodal DNA profile. Grade III tumor cells were labelled with antibodies G4 and E7; most of these cells showed a bimodal DNA profile. The percentage of HLe1-positive cells decreased with the pathological grade and stage of tumor. The composition of infiltrating leukocytes was different in unimodal and bimodal tumors. In conclusion, cells of low-grade tumors can be identified with 10D1 and 6D1 antibodies, and antigens recognized by G4 and E7 antibodies are mostly expressed by aneuploid cells. HLe1 antibody demonstrates the importance of the inflammatory reaction in bladder tumors. Moreover, in flow cytometry, leukocytes within a tumor could be used as internal reference for precise measurement of the DNA content of tumor cells.

Antibodies, Monoclonal↗

Focused extracorporeal pyrotherapy.

A system generating focused elastic ultrashort waves has been developed with the aim to destroy tumors by an extracorporeal way. Experimental studies on different targets (plastic phantoms, organ samples and normal live tissues in pigs) have been done showing the good focusing of the device and the possibility of getting a focal tissular coagulative necrosis. Studies on cultured tumor cells and implanted tumors in rats have shown a local effect on cells or tumor growth with the absence of metastatic risks. First human trials are summarized. This technique we call focused extracorporeal pyrotherapy could be useful for the treatment of cancers.

Animals↗

Detection of the apoptosis-suppressing oncoprotein bc1-2 in hormone-refractory human prostate cancers.

The oncoprotein encoded by bc1-2 is unique because of its intracellular location (a mitochondrial membrane protein) and apparent mode of action (suppression of apoptosis). To date, this oncogene has been associated only with the development of certain forms of human B-cell lymphoma. In this report, we describe our experience with a monoclonal antibody made against a synthetic peptide for bc1-2 that can recognize the bc1-2 protein and identify cells in human prostate glands expressing this proto-oncogene with in situ immunohistochemical procedures. These procedures were utilized to survey a series of 62 human tissues to evaluate whether bc1-2 might have a role in the developing prostate gland or in prostate oncogenesis. While all primordial epithelial cells in a fetal prostate gland immunostain for bc1-2, normal and hypertrophic prostate glands of the adult show bc1-2 expression restricted to the basal cells. All epithelial cells in areas of prostatic intraepithelial neoplasia were stained by this antibody, as were most (62%) localized invasive prostatic carcinomas. In contrast, all primary prostatic carcinomas and metastases obtained from metastatic prostate cancer patients after hormone treatment (hormone-refractory tumors) stained positive for bc1-2. This study demonstrates that the oncoprotein encoded by bc1-2 can be detected at sequential stages in the natural history of human prostate cancer. Since the bc1-2 oncoprotein is known to suppress the cellular response to apoptotic stimuli, it will be important to determine whether bc1-2 expression is a factor in the development of prostate cancers and in the survival of hormone-refractory prostate cancer cells.

Antibodies, Monoclonal↗

[Research analysis of local immune response after intravesicular treatment with BCG: a review].

Initial reports focused on purified protein derivative skin test reactivity and granuloma formation in patients treated with intravesical bacillus Calmette-Guérin. Then some investigators using immunohistochemical methods showed that some lymphocyte phenotypes where predominant in such infiltrates and that HLA DR antigens where strongly expressed following BCG therapy. Similar results where obtained in urine using flow cytometric analysis. Additionally some cytokines where found at significant levels in urine after BCG instillations. In this paper we reviewed these studies, we discussed the meaning of these results and the potential value for treatment monitoring.

Administration, Intravesical↗

[Surgical cure of anomalies of the pyelo-ureteral junction with posterior vertical lumbar excision: report of 25 cases].

Posterior vertical lumbar (PVL) incision does not involve any muscle or nerve section. It is minimally painful, does not give rise to incisional hernias and reduces the hospital stay. Pyeloplasty for cure of the ureteropelvic junction (UPJ) is a good indication, as this incision provides access to the renal pelvis without renal mobilisation and without interference by the vascular pedicle and allows a more superficial operative field. This retrospective study is based on 25 PVL incisions performed between 1979 and 1992 in 24 patients (15 females and 6 males with a mean age of 31.8 years) on the left kidney in 11 cases, right kidney in 12 cases and bilaterally in 1 case. No intraoperative complications were observed. The anastomosis was stented with a Gil-Vernet ureteronephrostomy tube for an average of eight days in every case. Early complications (< or = 1 month) consisted of six cases of fever, one wound abscess and one urinary fistula. Normal feeding was always rapidly restored. Long-term follow-up did not reveal any incisional hernias, but two cases of recurrence (8%), two cases of stones and one case (4%) of refractory neuralgia (> or = 6 months) in the territory of the ilioinguinal nerve. In this indication, there is no gain in terms of hospital stay due to the need to maintain the ureteronephrostomy tube for at least five days.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Focussed extracorporeal pyrotherapy: experimental results.

A new device made of piezoelectric ceramic placed in a semispherical dish and focussed at 320 mm was developed in order to generate heat and cavitation responsible for coagulative necrosis of deep tissues. The target to be treated is located with a central ultrasound probe of 3.5 MHz. In vitro studies with polyurethane phantoms showed that the ultrasound melted a surface of 2 x 12 mm within 1 s. The temperature recorded at the focus was 270 degrees C. In tissue samples (prostate cancer and benign prostate hyperplasia), the temperature rose to 85 degrees C in vitro and a hyperechoic zone appeared at the focus during shots. In vivo 8-mm plastic spheres, introduced surgically into the bladder of pigs, were melted by repeat shots without burning of crossed tissues. These studies were performed in the kidney and the liver. Autopsy performed on day 0 showed congestion, autopsy performed between day 6 and day 11 showed necrosis, whereas at 3 months the focussed area was fibrosed. This technique, which we called 'focussed extracorporeal pyrotherapy', combines phenomena of cavitation and high heat at the focus. Prostate tumors, bladder tumors, kidney tumors and liver metastases are potential indications for pyrotherapy.

Animals↗

[Focused extracorporeal pyrotherapy. Initial experimental results].

The objective of this study was to develop an apparatus allowing the generation of a high temperature (exceeding 80 degrees C) in a precise focus (20 mm x 2 mm) by means of extracorporeal elastic waves. The treatment time at high temperatures is brief and administered in sequences of 4 to 7 seconds. In vitro studies on blocks of polyurethane demonstrated melting of the plastic at the focal point. Studies on plastic spheres introduced into the bladder of the pig demonstrated melting of the sphere without any alteration in the tissues in the wave path. Studies of cellular viability of bladder carcinoma cultures demonstrated a significant difference after 48 hours between the non-treated control group and the group of cells submitted to high temperatures. This technique, called Pyrotherapy, should be promising if the preliminary results are confirmed.

Animals↗

[Results of treatment of superficial vesical tumors by transurethral resection alone and transurethral resection followed by an intravesical instillation of Calmette-Guerin bacillus].

Superficial bladder tumors treated at the Henri Mondor Hospital from 1984 through 1988 were analyzed for recurrence and progression using the following prognostic parameters: stage (TNM classification, 1978), grade (G1, G2, G3), size, number of tumors, and tumor malignancy index as defined by the Besançon group. Forty-five patients were treated with transurethral resection alone (TUR group) whereas 30 had TUR followed by the prophylactic instillation of fresh Calmette-Guérin bacillus in the bladder (BCG group). In TUR patients, parameters predictive of progression included grade G3, multiple tumors, stage T1, recurrence within 6 months of TUR, and a tumor malignancy index above 455. None of these criteria were predictive of a response to BCG. Results obtained in the BCG group were comparable to those reported in the literature and confirmed the efficacy of BCG instillations to prevent recurrence and progression of superficial carcinomas of the bladder.

Administration, Intravesical↗