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Biomedical subjects

C Foa

Publications and source records attributed to C Foa.

At least 19 recordsLinked to original sources
PubMed2004

[Image processing and radiotherapy].

Medical images are of great importance in radiotherapy, which became a privileged application field for image processing techniques. Moreover, because of the progression of the computers' performances, these techniques are also in full expansion. Today, the recent developments of the radiotherapy (3DCR, IMRT) offer a huge place to them. Effectively, they can potentially answer to the precision requirements of the modern radiotherapy, and may then contribute to improve the delivered treatments. The purpose of this article is to present the different image processing techniques that are currently used in radiotherapy (including image matching and segmentation) as they are described in the literature.

Algorithms↗
PubMed2004

A weekly schedule of docetaxel for metastatic hormone-refractory prostate cancer.

RATIONALE: Docetaxel has proven its efficacy in the management of hormone-refractory prostate cancer (HRPC). Schedules of docetaxel administration differ. This prospective phase II study was designed to reevaluate the activity and toxicity of docetaxel administered weekly at an optimal dose to a large cohort of HRPC patients. PATIENTS AND METHODS: Sixty-four patients were treated with docetaxel 40 mg/m(2) i.v., administered weekly for 6 consecutive weeks followed by a 2-week recovery period. Three treatment cycles were planned in the absence of progression or toxicity. The principal end point was the biochemical response based on the prostate-specific antigen (PSA) level (a decline of more than 50% for at least 4 weeks). Secondary end points were objective response to measurable disease, survival and toxicity. RESULTS: Toxicity was assessed in 64 patients. Toxicity was acceptable, with no toxicity-related deaths. Twenty-one percent of the patients developed grade 3-4 hematological toxicity. Sixty-four patients were evaluable for the PSA response. Forty-one patients (64%) achieved a decrease in PSA of >50%, 13 of whom had a PSA <4 ng/ml. Two out of 12 patients with measurable disease exhibited an objective response. With respect to PSA, the median progression-free survival was 29 weeks (95% confidence interval: 18-46 weeks). The global 1-year survival rate was 58%. CONCLUSION: Weekly docetaxel at a dosage of 40 mg/m(2) is a well-tolerated treatment, which has very promising activity on the reduction of PSA in metastatic HRPC. A large phase III study is underway.

Aged↗
PubMed2003

[Treatment of brain metastasis from ovarian cancer].

Systemic metastases from ovarian carcinoma are frequent, but they seldom affect the central nervous system. We present here the case of a patient treated for an ovarian cancer by surgery and chemotherapy. Three months after the end of chemotherapy, the patient developed cerebral metastases from ovarian carcinoma (CMOC) treated by iterative surgery and and whole brain irradiation. As the frequency of solitary cerebral metastasis of ovarian cancer is higher than with other cancers, it is likely that they behave slightly differently. Literature analysis reveals an increase in the incidence of CMOC since the middle of the nineties. CMOC can occur during or after adjuvant chemotherapy and the best management strategies to better define determinants of survival for patients are not well known. It appears that a better outcome of CMOC may be obtained by an aggressive treatment, if possible, including surgery, radiotherapy, and chemotherapy. Taking into account the increase in the incidence of the CMOC and their early occurrence, some authors have proposed a prophylactic brain radiotherapy in patients who receive adjuvant chemotherapy.

Antineoplastic Agents, Phytogenic↗
PubMed2001

Comparison between nasogastric tube feeding and percutaneous fluoroscopic gastrostomy in advanced head and neck cancer patients.

Wasting is a major complication of advanced head and neck cancer and the aim of this study was to compare nasogastric tube feeding (NG) and percutaneous fluoroscopic gastrostomy (PFG) in these patients. The goal of these two methods of nutritional support was to improve or maintain the initial nutritional status during treatment. A total of 90 patients, all stage IV oropharynx or hypopharynx tumor, were reviewed from a prospective databank. All these patients were treated by concomitant chemotherapy and twice-daily continuous radiotherapy with no acceleration. Fifty patients were managed by PFG, and the rest by NG. Mechanical failure, duration of feeding, complications, nutritional evaluation and quality of life were analysed. Mechanical failure occurred in 32 of the 40 NG patients and in seven of the gastrostomy group. In the PFG group, 80% of patients conserved their nutritional support after the end of the radiotherapy, none patient in the NG group. In the PFG group, two presented a wound infection and six had aspiration pneumonia while in the NG group, 21 had aspiration pneumonia probably due to the NG tube (gastroesophageal reflux). The feeding methods were found to be equally effective at maintaining body weight and body mass index at time 1 (3 weeks) and at time 2 (6 weeks). Advantages were associated with PFG cosmesis, mobility and quality of life. PFG is a safe and effective method of providing enteral nutrition during treatment to patients with advanced head and neck cancer and offers important advantages over NG.

Administration, Cutaneous↗
PubMed2001

[Testicular seminoma and multifocal aseptic osteonecrosis following chemotherapy].

INTRODUCTION: Multifocal osteonecrosis has a wide variety of etiologies, but in the cancer patient several risk factors could have a synergic effect (chemotherapy, radiotherapy, corticosteroid, metabolism disorder). EXEGESIS: A patient with testicular seminoma receiving cisplatin-based chemotherapy and short-term corticosteroid developed multifocal osteonecrosis. Early diagnosis of osteonecrosis is important to prevent orthopedic complications. CONCLUSION: Cisplatin could represent one of the possible etiologies of multifocal osteonecrosis. Magnetic resonance imaging has a high sensitivity and specificity in the diagnosis of osteonecrosis and should be used when this condition is suspected.

Adult↗
PubMed2001

Clinical prognostic factors for patients with recurrent head and neck cancer: implications for randomized trials.

The purpose of our study was to determine the clinical prognostic factors for the duration of the overall survival from recurrence (OSR) in patients with recurrent head and neck squamous-cell carcinoma. We performed a retrospective analysis on 496 patients treated between 1982 and 1993 at the Antoine Lacassagne Center. The significant favorable prognostic factors for the OSR were: initial T(1-2) (p = 0.008), no initial nodal involvement (p = 0.002), no initial chemotherapy exposure (p = 0.002), induction chemotherapy response (p = 0.001), duration of disease-free interval (DFI; p = 0.0001), performance status (PS) 0-1 (p = 0.004) and local-regional recurrence (p = 0.001). In the multivariate analysis, the apparent nonsignificance of all factors apart from the DFI suggested that relevant prognostic factors could be embedded in the DFI. Multivariate analysis was performed after excluding the DFI. The results indicated that local-regional recurrence, PS 0-1 and no initial chemotherapy exposure remained significant favorable prognostic factors for the OSR. The advantages of taking into account such prognostic factors are to eliminate the patient selection bias and to ensure a fairer comparative evaluation of new or already existing agents in recurrent head and neck cancer.

Adult↗
PubMed2000

Sonographic discovery of a pharyngocele.

Cervical sonography was performed in a 25-year-old man who was referred to our department because of the recent appearance of a left anterolateral cervical mass. This mass had the sonographic properties of air; it communicated with and extended the piriform sinus as well as deformed the left lamina of the thyroid cartilage. A preliminary diagnosis of left pharyngocele was confirmed by CT. To our knowledge, this is the first sonographic description of such an abnormality.

Adult↗
PubMed2000

An analysis of potential factors allowing an individual prediction of cisplatin-induced anaemia.

Severe cisplatin (CP)-induced anaemia significantly impairs the patient's quality of life. Prevention based on erythropoietin (EPO) administration would be cost-effective providing that individual predictive factors of anaemia are identified. The aim of the present study was to identify parameters able to predict the occurrence of CP-related anaemia. This prospective study was conducted on 40 head and neck cancer patients receiving a CP (100 mg/m(2), intravenous (i. v.) on day 1) - 5-fluorouracil (5-FU, 1 g/m(2)/dx5 days by continuous infusion) induction chemotherapy. Three cycles were given at 3-weekly intervals. Platinum pharmacokinetics (total and ultrafilterable plasma platinum concentration measured 16 h after CP administration) and 5-FU pharmacokinetics (full-cycle plasma area under the curve, (AUC(0-105h)30 g/l) occurred in 15 patients (38%) and 3 of them also received a blood transfusion. Patient age, 5-FU AUC(0-105h) and total platinum concentration were unrelated to Hb loss. In contrast, ultrafilterable (UF) platinum concentration was significantly correlated to Hb loss: the higher the UF platinum concentration, the greater the Hb loss (P=0.015). A discriminant analysis allowed a cut-off value for UF platinum to be proposed to identify patients developing significant loss of Hb: 91% of patients exhibiting a UF platinum concentration above 50 ng/ml developed significant loss of Hb in contrast to 18% in the group of patients with a UF platinum concentration below 50 ng/ml (odds ratio (95% confidence interval, CI) of 46 (4.7-446)). In conclusion, the present platinum pharmacokinetic survey may be proposed as a valuable approach to identify patients at risk for developing severe anaemia.

Adult↗
PubMed2000

Comparative CD43 behavior on monocytes and lymphocytes in kidney transplants.

In human cultured monocytic cells stimulated by cytokines, CD43 was demonstrated to exhibit a modification of sialylated epitopes (dys-sialylation) [Soler et al: Leukoc Biol 1997;61:609-618]. Therefore, we chose to investigate CD43 behavior on patients who present pathological status implicating monocytes after renal graft (KTR). We performed flow cytometry after immune staining using monoclonal antibodies to CD43 sialic acid-dependent (L60) and -independent (L10) epitopes. Compared to normal controls, mean fluorescence intensity was never altered on lymphocytes. Conversely, on monocytes, we found different profiles with L60: 26% of patients having normal CD43 expression, 54% displayed decreased values and 20% had a double population of monocytes, the major one being normal and the minor one with a very low staining. Decreased values were more frequent among KTR during the first 3 months following transplantation. L10 immunostaining was not altered on monocytes in patients with low values of CD43 staining by L60, confirming that the mechanism involved was a CD43 dys-sialylation. We investigated a possible role of cyclosporin (CsA) on human monocytic (THP-1) and lymphoid (Jurkat) cell lines. CsA decreases CD43 expression in monocytic and not in lymphoid cell lines and could be responsible for the specific dys-sialylation of KTR monocytes. Whatever, CD43 dys-sialylation might lead to functional abnormalities of monocytes in KTR, possibly involving the adhesion process.

Adolescent↗
PubMed2000

Glycocalyx modulation is a physiological means of regulating cell adhesion.

Here we present experimental evidence that phagocytic cells use modulation of specific components of their glycocalyx to regulate their binding capacity. Particles coated with antibodies specific for the CD32 medium affinity IgG receptor were driven along human monocytic THP-1 cells (expressing CD32) in a flow chamber operated at low shear rate. Surprisingly, only minimal adhesion was observed. However, when cells were activated by exposure to fibronectin-coated surfaces and/or soluble &ggr; interferon, adhesion efficiency was dramatically increased, whereas the apparent glycocalyx thickness displayed 20% decrease, and the surface density of CD43/leukosialin carbohydrate epitopes displayed 30-40% decrease on activated cells. The existence of a causal link between adhesion increase and glycocalyx alteration was strongly supported by the finding that (i) both phenomena displayed similar kinetics, (ii) an inverse relationship between THP-1 cell binding capacity and glycocalyx density was demonstrated at the individual cell level, and (iii) adhesion enhancement could not be ascribed to an increased binding site density or improved functional capacity of activated cells. Additional experiments revealed that cell-to-particle adhesion resulted in delayed (i.e. more than a few minutes) egress of CD43/leukosialin from contact areas. Since the time scale of particle attachment was less than a second, surface mobility should not affect the potential of CD43 to impair the initial step of adhesion. Finally, studies performed with fluorescent lectins suggested that THP-1 cell activation and increased adhesive potential were related to a decrease of O-glysosylation rather than N-glycosylation of surface glycoproteins.

Cell Adhesion↗
PubMed1998

Adhesion-related glycocalyx study: quantitative approach with imaging-spectrum in the energy filtering transmission electron microscope (EFTEM).

Large polysaccharide molecules composing the glycocalyx have been shown to prevent cell adhesion. However, this process was not observed microscopically. Terbium labeling, combined with a new quantitative imaging method based on electron energy loss spectroscopy, allowed specific glycocalyx staining with excellent contrast. Image analysis enabled us to compare glycocalyx structure in free membrane areas and contacts between monocytic cells and bound erythrocytes. Apparent glycocalyx thickness, in contact areas, was half of the sum of glycocalyx thicknesses in free areas without label density increase. Ultrastructural immunogold localization of CD43 molecules, a major component of glycocalyx, was also demonstrated to be excluded from contact areas during adhesion. Thus, both approaches strongly suggest that some glycocalyx elements must exit from contact to allow binding of adhesion molecules.

Antigens, CD↗