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Biomedical subjects

H Francois

Publications and source records attributed to H Francois.

8 recordsLinked to original sources
PubMed1996

Percentage of free serum prostate-specific antigen: a new tool in the early diagnosis of prostatic cancer.

Prostate-specific antigen (PSA) is a protease able to bind to serum antiproteases as alpha 1 antichymotrypsin (ACT). Free PSA (FPSA) corresponds to the fraction of total PSA (TPSA) which is unbound to ACT. Specific detection of the FPSA seems to be a valuable tool in the distinction between prostatic cancer (PCa) and benign prostatic hyperplasia (BPH). Our aim was to evaluate retrospectively the FPSA/TPSA ratio in comparison to TPSA or FPSA determination, using two new immunoradiometric assays (PSA-RIACT and FPSA-RIACT, CIS bio international, Gif Sur Yvette, France) in the early diagnosis of PCa. 256 men, with TPSA levels between 0.7 and 44.7 ng/ml (median age = 69 years), including 164 sera obtained from patients with BPH and 92 sera from patients with untreated PCa were assayed. All diagnoses were histologically confirmed and patients tested before any adjuvant treatment. The evaluation of the median FPSA/TPSA ratio in the two groups showed significantly different values (BPH group: 24.2%, PCa group: 12.1%, P < 0.0001). By R.O.C. (Receiver-Operating-Characteristics) analysis, we show that the FPSA/TPSA ratio is the method of choice for discriminating BPH and PCa, since the area under curve is the greatest for the FPSA/TPSA ratio curve, as compared to the TPSA or FPSA curves (P < 0.0001). The best accuracy (number of true positive + true negative/total = 82.4%) was obtained with a FPSA/TPSA ratio < or = 15% with high odds ratio (20.5; confidence interval (CI): 11.2; 37.7). Of interest, similar results were also confirmed even in the subpopulation with serum TPSA levels between 2.5 and 10 ng/ml (161 patients including 99 BPH and 62 PCa). We thus confirm that combined serum measurement of FPSA and TPSA is of particular interest in the early diagnosis of PCa for patients with non-suspicious digital rectal examination and a TPSA value between 2.5 and 10 ng/ml. In those patients, biopsy should be reserved to the cases with FPSA/TPSA below 15%, which allows significant odds ratio (12.8; CI: 5.2; 31.4). Otherwise, to avoid the risk of missing any PCa, usual follow-up with combined TPSA and FPSA determination would be required with the same criteria of biopsy (i.e. FPSA/TPSA ratio < or = 15% when TPSA value is between 2.5 and 10 ng/ml; or TPSA > 10 ng/ml).

Adult↗
PubMed1993

The treatment of 783 keloid scars by iridium 192 interstitial irradiation after surgical excision.

PURPOSE: the aim of this study is to confirm the effectiveness of irradiation associated with surgery in the treatment of keloids, to precise the factors favoring the recurrence of these keloids, and to evaluate the risk of recurrence, according to their initial distinctive features. METHODS AND MATERIALS: between 1977 and 1988, 544 patients, with a total of 855 keloids, were treated by interstitial radiotherapy immediately following total excision. RESULTS: recurrence rate is 21%, as against 50 to 80% for surgery alone, according to most authors. This recurrence rate is about the same as for external radiotherapy, but we prefer our method for practical reasons (cost, equipment, radiobiology, technique). Ninety percent of recurrences occurred in the year following therapy, which proves that a follow-up time of at least 12 months is needed for a study of keloids. In our experience, the keloids that are the most likely to recur are the largest and those giving rise to most symptoms. Bruising and loosened stitches, but in particular infection during therapy, largely favor a recurrence. In our series, the symptoms disappeared or were much improved in 80% of cases, and the cosmetic result was judged good by 75% of the patients. CONCLUSION: the results of this study proves the effectiveness of the method linking surgical excision and Iridium 192 interstitial irradiation and shows the importance of the sterile conditions of the treatment.

Adolescent↗
PubMed1984

Advanced biostack: experiment 1 ES 027 on Spacelab-1.

The radiobiological properties of the heavy ions of cosmic radiation were investigated on Spacelab 1 by use of biostacks, monolayers of biological test organisms sandwiched between thin foils of different types of nuclear track detectors. Biostacks were exposed to cosmic radiation at several locations with different shielding environments in the module and on the pallet. Evaluations of the physical and biological components of the experiment to date indicate that in general they survived the spaceflight in good condition. Dosimetric data are presented for the different shielding environments.

Animals↗
PubMed1973

The Biostack experiment on Apollo 16.

The object of the Biostack experiment is to study the biological effects of high ZE particles of cosmic radiation in order to obtain information on the mechanism of these particles in biological matter. For this purpose individual local evaluation methods have been developed which allow one to identify each biologically effective particle and to correlate the individual hitting particle with the biological effect produced. The Biostack experimental package contains a series of monolayers of selected biological objects (Bacillus subtilis spores, Arabidopsis thaliana seeds, Vicia faba radiculae, Artemia salina eggs) with each layer sandwiched between several different cosmic ion track detectors (nuclear emulsions, cellulose nitrate, polycarbonate). By this arrangement a variety of biological effects due to a single penetrating particle can be analysed. Influence on cellular and tissue development, nuclear damages, and mutation induction are the main investigated effects. These space flight findings will be completed by results of balloon flight and accelerator experiments.

Animals↗