Biomedical subjects

A Dierick

Publications and source records attributed to A Dierick.

11 recordsLinked to original sources

PubMed2003

Fast separations on monolithic silica columns: method transfer, robustness and column ageing for some case studies.

Six separation methods, developed on conventional silica high performance liquid chromatography (HPLC) columns were transferred to monolithic silica columns of 5 and 10 cm length. The transferred methods include the separation of an alkylbenzene mixture, the separations of drugs from their impurities (nimesulide, tetracycline, phenoxymethylpenicillin and erythromycin) and the separation of a green tea extract. The transfer of the first three methods was successful while for the latter three it was not. Increasing the flow rate up to 9 ml/min (where possible) inversely decreased the analysis time of the successfully transferred methods to 48 s (alkylbenzene mixture) 1.8 min (nimesulide mixture) and 3 min (tetracycline mixture) while still reasonable well separated peaks were obtained. The robustness and repeatability of the transferred and accelerated separations was found to be acceptable. Despite the use of flow rates up to 9 ml/min and frequent mobile phase changes with pH values varying from 3.5 to 7, the column performance was found to be rather constant and the column ageing to be minimal.

Chromatography, High Pressure Liquid↗

PubMed1998

Surgery of lung metastases of breast cancer: analysis of 40 cases

Between 1987 and 1995, 52 breast cancer patients had a surgical resection of lung secondaries. In 40 patients, the diagnosis of metastatic breast cancer could be confirmed following pathological examination. Five-year survival rates of these 40 patients was 54 8 % and 5-year disease free survival was 30 8%. The median survival (70 months) of these patients was better than that of 57 patients with isolated lung metastases who had been treated conservately (chemo- or/and hormonotherapy) during the same time interval. Twenty-six patients benefitted from a radical excision and had a longer disease free interval (42 versus 27 months, p = 0.03) than patients who had had a wedge resection. Overall survival was not significantly different (71 versus 41 months, p = 0.07). We feel that isolated lung nodules may best be treated by radical (segment or lobe) excision, in particular since preoperative differential diagnosis with primary lung cancer may be difficult. In the presence of multiple nodules, first line medical treatment by chemo- or hormonotherapy should be advocated, allowing to reduce the tumor load and to optimize survival in association with surgery.

Journal Article↗

PubMed1998

[Surgical excision of pulmonary metastasis of cancer of the breast: apropos of 40 patients].

Between 1987 and 1995, 52 breast cancer patients had a surgical resection of lung secondaries. In 40 patients, the diagnosis of metastatic breast cancer could be confirmed following pathological examination. Five-year survival rates of these 40 patients was 54 +/- 8% and 5-year disease free survival was 30 +/- 8%. The median survival (70 months) of these patients was better than that of 57 patients with isolated lung metastases who had been treated conservatively (chemo- or/and hormonotherapy) during the same time interval. Twenty-six patients benefitted from a radical excision and had a longer disease free interval (42 versus 27 months, p = 0.03) than patients who had had a wedge resection. Overall survival was not significantly different (71 versus 41 months, p = 0.07). We feel that isolated lung nodules may best be treated by radical (segment or lobe) excision, in particular since preoperative differential diagnosis with primary lung cancer may be difficult. In the presence of multiple nodules, first line medical treatment by chemo- or hormonotherapy should be advocated, allowing to reduce the tumor load and to optimize survival in association with surgery.

Adult↗

PubMed1997

[A combined radiochemotherapy trial for non-small cell lung cancers: initial results].

PURPOSE: Analysis of the preliminary results of a phase I study investigating the feasibility of concomitant chemotherapy with daily doses of carboplatin (20 to 25 mg/m2/d over 45 or 10 min) and accelerated chest irradiation (60 to 64 Gy over 4 weeks, 2 Gy per fraction, using the concomitant boost technique). MATERIALS AND METHODS: This combination was given alone or following three cycles of induction chemotherapy (cisplatin, 25 mg/m2 per day from d1 to d5; 5-fluorouracil, 600 mg/m2 per day from d1 to d5 and vinorelbine, 25 mg/m2 per day at d1 and d5 with a 4-week interval) in 15 patients with locally advanced unresectable non-small cell lung cancer. All patients received the planned sequence. RESULTS: The dose-limiting toxicity was esophagitis (5 out of 15 grade 4). No toxic deaths were observed. The tumor response rate was high: six out of 15 complete responses and 14 out of 15 tumor regressions greater than 50%. The median survival was not reached after a mean follow-up of 14 months (range, 6-28 months). CONCLUSION: We are now planning a multicenter phase II study using the following combination: 20 mg/m2 of daily carboplatin over 10 min and a 60-Gy irradiation dose over 4 weeks.

Adult↗

PubMed1995

Continuous infusion cisplatin and 5-fluorouracil with bolus vinorelbine in the treatment of advanced nonsmall cell carcinoma of the lung.

Thirty-three patients, with histologically proven advanced nonsmall cell lung cancer (NSCLC) were treated at Institut Curie with a three-drug combination chemotherapy. The regimen consisted of cisplatin 25 mg/m2 per day continuous infusion (CI) and 5-fluorouracil (5-FU) CI 600 mg/m2 on 5 consecutive days with 30 minutes infusion navelbine 25 mg/m2 on days 1 and 5 only. Cycles were repeated every 28 days. Response was evaluated after three cycles. One patient died of an ischemic cerebrovascular stroke after the third cycle. Thirty-two pts were evaluable. Partial response was achieved in 11/20 patients with stage III disease (55%) and in 7/12 patients with stage IV disease (58%). WHO grade 4 toxicities were leucopenia 31%, thrombocytopenia 4%, and mucositis 4%. The tolerance was acceptable. Median survival was 19 months for stage III and 9.5 months for stage IV. We conclude that the combination of 5-FU, navelbine, and cisplatin is an effective chemotherapy regimen for patients with advanced stage NSCLC.

Adult↗

PubMed1994

First-pass images of musculoskeletal lesions: a new and useful diagnostic application of dynamic contrast-enhanced MRI.

The purpose of this study was to evaluate the diagnostic value of parametric images which display the first-pass of Gd-DTPA after intravenous bolus injection. Single slice dynamic contrast-enhanced MRI (Turbo-FLASH) with a temporal resolution of 2.41 s was performed in 40 benign and malignant musculoskeletal lesions. Parametric 'first-pass' images were obtained by using a new postprocessing technique, derived from a home written computer program, which calculated the steepest slope of the time-intensity curve pixel by pixel. First-pass images provided qualitative and quantitative information, which was useful for diagnosis and therapy. Demonstration of the areas with the highest vascularization was very helpful in planning the best biopsy site in 6 patients and to delineate tumor from peritumoral muscle edema in 4 patients. In 10 patients the first-pass images provided additional information, which was not visible on the conventional spin-echo images. The most promising application was the ability to evaluate the response to preoperative chemotherapy in a patient with Ewing's sarcoma. Although a highly statistically significant difference (p < 0.001) was found between the first-pass slope values of benign and malignant lesions, the sensitivity (77%) and specificity (71%) of this method were too low to permit a definite differentiation of highly vascular benign from malignant lesions. Pathologic examination of 17 lesions, performed in the plane of the first-pass image, showed a good correlation between the first-pass slope values and the vascularization of the tissues.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1994

Benign and malignant musculoskeletal lesions: dynamic contrast-enhanced MR imaging--parametric "first-pass" images depict tissue vascularization and perfusion.

PURPOSE: To assess the diagnostic value of parametric magnetic resonance images that display the first pass (FP) of gadopentetate dimeglumine. MATERIALS AND METHODS: Dynamic, contrast material-enhanced, fast low-angle shot MR imaging was performed of 100 musculoskeletal lesions in 36 female and 64 male patients (aged 9-81 years [mean, 34 years]). The highest slope value of the time-intensity curve was calculated pixel by pixel and displayed on the FP image, with a gray-scale value equal to the slope value. Tissue vascularization and perfusion were evaluated at pathologic and angiographic examinations in 33 lesions. RESULTS: A significant difference (P < .001) was found between the FP slope values of benign (mean, 36.2% per second) and malignant (mean, 67.4% per second) lesions. FP images depicted tissue vascularization and perfusion rather than benignity or malignancy, because there is an overlap in the slope values of highly vascular benign lesions and malignant lesions. CONCLUSION: FP images provide diagnostically useful information by depicting tissue vascularization and perfusion.

Adolescent↗

PubMed1993

[Acute febrile neutrophilic dermatitis (Sweet's syndrome) during therapeutic agranulocytosis in acute myeloblastic leukemia].

INTRODUCTION: the association of acute febrile neutrophilic dermatosis (Sweet's syndrome) with malignant haemopathies is well known and characterized by an usual lack of hyperleukocytosis: indeed, moderate neutropenia is often reported. However, cases of Sweet's syndrome in the agranulocytosis stage are exceptional (7 in the literature). CASE-REPORT: We report the case of a woman with acute myeloblastic leukaemia who had presented with Sweet's syndrome in the phase of therapeutic aplasia during induction of treatment, in the absence of white blood cells transfusion or treatment with haematopoietic growth factor (GM CSF, GCSF). COMMENTS: the physiopathology of Sweet's syndrome is unknown. Various mechanisms have been suggested, including immune reaction type III, increased interleukin-1 synthesis, increased chemotaxis of neutrophils, action of haematopoietic growth factors, iatrogenic effect of some drugs (e.g. cotrimoxazole, furosemide or minocycline). Yet none of these mechanisms involving circulating polymorphonuclears or their bone marrow precursors can explain the occurrence of Sweet's syndrome in the phase of agranulocytosis. CONCLUSION: the diagnosis of Sweet's syndrome must be considered in patients with agranulocytosis in order to avoid ineffective antibiotics and to initiate a corticosteroid therapy that will accelerate the cure of this benign dermatosis.

Agranulocytosis↗

PubMed1992

Elastofibroma dorsi: CT, MR and pathologic study in a new case.

As reported before elastofibroma dorsi is a rare benign tumor of elastic connective tissue with typical clinical and suggestive radiological features. We evaluated the CT and MR characteristics of this periscapular lesion in a new case, before and after contrast enhancement, and tried to determine in how far the nature and extent of the tumor can be predicted.

Back↗

PubMed1983

Practical value of a simplified air caloric stimulation with freon.

Caloric testing is the only method to examine the vestibular function of each labyrinth separately. When a perforated drum is present, caloric stimulation has to be achieved by air injection. In this study we examine the applicability and reliability of a simplified stimulator with Fréon. This comparative study proves it to be a reliable method for daily ENT practice.

Adult↗

PubMedDate not supplied

Effects of diluent volume of a single dose of epidural bupivacaine in parturients during the first stage of labor.

BACKGROUND AND OBJECTIVES: 0.1% bupivacaine for obstetric epidural analgesia is given by infusion, using a loading dose of a higher concentration alone or in combination with opioid analgesics. A single dose of 0.1% without any additive for relief of first-stage labor pain has not yet been documented. METHODS: Fifty-eight primiparae in active labor and with less than 5 cm cervical dilatation received 20 mg epidural bupivacaine diluted in 4 mL [group 1: 0.5% (I)], 10 mL [group 2: 0.2% (II)], or 20 mL [group 3: 0.1% (III)]. Pain relief, dermatomal spread, and motor block were assessed. RESULTS: Visual analog pain scale (VAS) was significantly lower in group 2 (0.88 +/- 1.34) and group 3 (0.25 +/- 0.61) than in group 1 (4.37 +/- 2.57). Onset and time to maximum analgesia was significantly shorter in group 2 than in group 3. Mean duration of analgesia was 120 +/- 21 minutes in group 3, 100 +/- 26 in group 2, and 43 +/- 21 in group 1. The mean numbers and upper limits of dermatomes blocked did not differ between groups 2 and 3, but were higher than in group 1. Motor blocks in groups 2 and 3 were more extensive than in group 1 with no difference between groups 2 and 3. Ten mL 0.2% or 20 mL 0.1% epidural bupivacaine results in a similar degree of pain relief, superior to that following 4 mL 0.5%, while duration was longest after 20 mL 0.1%. CONCLUSIONS: Analgesia lasts significantly longer following 20 mL 0.1% bupivacaine than following 10 mL 0.2% bupivacaine when given for first-stage labor pain. Four milliliters 0.5% bupivacaine results in inadequate pain relief.

Adult↗