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Biomedical subjects

F Collin

Publications and source records attributed to F Collin.

At least 37 records · Page 2Linked to original sources
PubMed2001

[Standards, options and recommendations: practice guidelines for difficult diagnosis in surgical pathology or cytopathology in cancer patients].

CONTEXT: The "Standards, Options and Recommendations" (SOR) project, started in 1993 is a collaboration between the Federation of the French Cancer Centres (FNCLCC), the 20 French Cancer Centres and specialists from French Public Universities, General Hospitals and Private Clinics. The main objective is the development of clinical practice guidelines to improve the quality of health care and outcome for cancer patients. The methodology is based on literature review and critical appraisal by a multidisciplinary group of experts, with feedback from specialists in cancer care delivery. OBJECTIVES: To develop clinical practice guidelines according to the definitions of the Standards, Options and Recommendations project for difficult diagnoses in surgical pathology or cytopathology in cancer patients. METHODS: Data were identified by searching Medline and using the personal reference lists of members of the expert groups. Once the guidelines were defined, the document was submitted for review to 71 independent reviewers. RESULTS: The main recommendations to prevent and reduce the number of difficult diagnoses in surgical pathology or cytopathology are: 1) The development of quality insurance programs with use of written procedures in each pathology laboratory (standard). 2) The knowledge of clinical data in order to explain surgical pathology or cytopathology results (standard). 3) The availability of complementary patient informations (radiologic data . . .) can be useful to explain surgical pathology or cytopathology results (option). The main recommendations to detect lesions associated with difficult diagnosis in surgical pathology or cytopathology are: 1) Tumor types known as potential difficult diagnosis in surgical pathology or cytopathology should be reviewed by a second pathologist. 2) The systematic second reviewing for every case is expensive but has to be done when the difficulty is know (sarcoma, lymphoma . . .) by experienced pathologists. The main recommendations to solve difficult diagnosis in surgical pathology or cytopathology are: 1) Block recuts, use of special techniques (immunocytohistochemistry and molecular biology), additional data from clinicians, second opinion by a local pathologist, or new specimen can be required for establishing the diagnosis (options). 2) Outside second opinion by expert pathologist has to be considered once the other steps did not allow to establish surgical or cytopathology diagnosis (recommendations, expert agreement).

Humans↗
PubMed2000

The cost of health conditions in a health maintenance organization.

In this retrospective cohort analysis of all adults who were members of Kaiser Permanente, Northern California, between July 1995 and June 1996 (N = 2,076,303), the authors estimated the prevalence, average annual costs per person, and percentage of total direct medical expenditures attributable to each of 25 chronic and acute conditions. Ordinary least squares regression was used to adjust for age, gender, and comorbidities. The costs attributable to the 25 conditions accounted for 78 percent of the health maintenance organization's total direct medical expense for this age-group. Injury accounted for a higher proportion (11.5 percent) of expenditures than any other single condition. Three cardiovascular conditions--ischemic heart disease, hypertension, and congestive heart failure--together accounted for 17 percent of direct medical expense and separately accounted for 6.8 percent, 5.7 percent, and 4.0 percent, respectively. Renal failure ($22,636), colorectal cancer ($10,506), pneumonia ($9,499), and lung cancer ($8,612) were the most expensive conditions per person per year.

Acute Disease↗
PubMed2000

[Sclerosing epithelioid fibrosarcoma: a fibrosarcoma with a very long course].

Sclerosing epithelioid fibrosarcoma is a rare and slowly growing variant of fibrosarcoma occurring in adults. Its carcinomatous and/or hemangiopericytomatous patterns may mislead to many different tumors. These differential diagnoses are generally ruled out by the clinical data, the morphology and the immunohistochemical study. We report two typical cases of this fibrosarcoma and we highlight the different criterias which are indispensable to make the diagnosis. The very slow course of this disease goes along with a very low proliferative rate, but an accumulation of p53 by immunohistochemistry is paradoxically always founds, even though this accumulation is more often found in highly aggressive sarcomas.

Adult↗
PubMed1999

Smoking-attributable medical care costs in the USA.

Medical care costs attributable to cigarette smoking are estimated using an econometric model of annual individual expenditures for four types of medical services: ambulatory, hospital, prescription drug, and other (which includes home health and durable medical equipment and excludes dental and mental health). The model follows the two-part specification of Duan et al. (1983). Estimation is carried out using the 1987 National Medical Expenditure Survey. Fitted values are used to calculate smoking-attributable fractions (SAFs) of expense by type of service and by age and gender category. The overall weighted average SAF is 6.54%. SAFs are generally largest for ambulatory and smallest for hospital expenses. They are larger for males and for the older age categories. The model is analyzed for heteroscedasticity and goodness of fit. Additional analysis using the National Health Interview Survey is conducted to test for the possible effect of not being able to include alcohol consumption in the primary model. A balanced repeated replication analysis is conducted to evaluate the variance of the SAFs. Variances are found to be acceptably small. An extension of the model to support evaluation of smoking-attributable costs for special populations such as individual states, and special insurance pools such as Medicaid recipients, is described. Results for the fifty states are presented. Conclusions and subjects for further research are discussed.

Adult↗
PubMed1999

[Changes in homeostasis during surgical liver resection].

OBJECTIVES: To assess changes in haemostasis during liver resection and to discuss the indications for antifibrinolytic therapy. STUDY DESIGN: Open prospective study. PATIENTS: The study included 39 consecutive non-cirrhotic patients presenting for liver resection under portal triad clamping. METHOD: General anaesthesia was obtained with thiopentone, fentanyl, vecuronium and isoflurane. Transfusion scheme was standardized. Aprotinin (5,000 kIU.kg-1 BW) was administered in case of unexplained bleeding in the operative field. Coagulation pattern was assessed by routine tests and thrombelastrography before surgery, before portal triad clamping, 5 min after reperfusion and at completion of surgery. Patients requiring aprotinin intraoperatively were compared to others. RESULTS: In 32 patients no significant bleeding occurred. Their coagulation pattern was moderately changed and remained within the normal range. In seven patients severe bleeding occurred which was treated with aprotinin. Their coagulation tests were significantly modified, especially after reperfusion, associating an increase in aPTT, TT, FDP, DDim, r + k and a decreased platelet count. CONCLUSION: These changes were more in favour of a dilution coagulopathy or a DIC than hyperfibrinolysis. Therefore substitutive therapy with coagulation factors should be preferred to an antifibrinolytic agent. A systematic administration of the latter for liver resection in non-cirrhotic patients is debatable, considering the allergic risk (reoperation for cancer recurrence), thrombosis facilitation (pedicle clamping) and high cost.

Aged↗
PubMed1999

Structure of the supernumerary ring and giant rod chromosomes in adipose tissue tumors.

Supernumerary ring or giant rod marker chromosomes are a characteristic of well-differentiated liposarcomas (WDLPS) and atypical lipomas (ALP) and are often observed as the sole cytogenetic abnormality, but are rare in lipomas. Using a combination of different methods, we extensively investigated the structure and composition of rings and giant rods in a series of 17 WDLPS-ALP samples and three intra- or intermuscular lipomas (IMLP), revealing a unique combination of particular features strikingly related to these tumors. Although the rings and rods displayed in vitro and in vivo stability, the presence of alpha-satellites could not be detected on these supernumerary structures. Comparative genomic hybridization analysis, in combination with fluorescence in situ hybridization, identified the chromosomal regions contributing to the formation of these chromosomes: in WDLPS-ALP, all carried amplifications of 12q 14-15 and the MDM2 gene, with variable other noncontiguous regions. In the three IMLP, the rings consistently carried amplifications of 12q15-21 and 1q21, but increased copies of MDM2 were found in only one case. Other genes located more proximal in 12q14-15 were amplified in several WDLPS-ALP, but showed a normal copy number in IMLP. Furthermore, the immunohistochemical expression of the MDM2 protein was detected in most (12/14) WDLPS-ALP, in 1-30% of the cells, but never in IMLP. These supernumerary chromosomes represent a peculiar kind of amplification structure, midway between double minute chromosomes and homogeneously staining regions, but the mechanisms underlying the formation of these structures remain obscure.

Aged↗
PubMed1998

Preoperative radiotherapy and surgery for endometrial carcinoma: prognostic significance of the sterilization of the specimen.

INTRODUCTION: We report a retrospective study on the analysis of the operative specimen after preoperative radiotherapy for FIGO (1971) stage I or II endometrial carcinoma. METHODS AND MATERIALS: From 1976 to 1996, 221 patients were treated with external radiotherapy (XRT) and/or low-dose-rate brachytherapy (BT) followed by surgery (S). Patients with cervical involvement (89 patients) or with high-grade tumors (49 patients) received XRT and BT. Patients stage FIGO Ia (89 patients) or with low-grade tumors (57 patients) received BT alone. Surgery was performed 5 to 6 weeks after irradiation. RESULTS: The mean follow-up is 78 months (12-216). The 5-year survival was 90% for FIGO Ia, 80% for FIGO Ib, and 84% for FIGO II (p = 0.51). According to the differentiation, 5-year survival was 87% for grade 1, 84% for grade 2, 84% for grade 3 (p = 0.10). Grade 3 complications were registered in 2% (no grade 4). The tumors were sterilized in 37 patients (17%), sterilized but with dystrophic glands in 34 patients (16%), only modified and altered in 21 patients (9.5%), with viable cells in 56 patients (26%). After preoperative radiotherapy, 37/148 specimens were sterilized (25%), 14/74 after brachytherapy and surgery (19%), 23/74 after external radiotherapy-brachytherapy and surgery (31%). According to the response of the specimen, 5-year survival was 87% when the tumor was sterilized, 96% when altered glands were present, 85% when modified, and 76% if residual tumor with viable cells was identified (p = 0.043). CONCLUSION: Preoperative radiotherapy followed by surgery is a safe and effective treatment of FIGO stage I or II endometrial carcinomas. BT with two uterine tubes seems to be of interest in the contribution of the treatment of the uterus to sterilize the specimen. The analysis of this new prognostic factor remains important to select a population with worst prognosis.

Adult↗
PubMed1998

Topographical distribution of [125I]-glial cell line-derived neurotrophic factor in unlesioned and MPTP-lesioned rhesus monkey brain following a bolus intraventricular injection.

The present study determined the topographical distribution profile for [125I]-glial cell line-derived neurotrophic factor in unlesioned and MPTP-lesioned (unilateral intracarotid injection) rhesus monkeys following an intraventricular injection. Autoradiographic analysis showed that following a bolus intraventricular injection, there was widespread distribution of [125I]-glial cell line-derived neurotrophic factor throughout the ventricular system (walls of lateral, third, and fourth ventricles and aqueduct), with some accumulation at the lateral ventricle injection site, possibly associated with the ependymal cell layer. In both unlesioned and MPTP-lesioned monkeys, there was labelling of the cerebral cortex, substantia nigra/ventral tegmental area and sequestration of [125I]-glial cell line-derived neurotrophic factor adjacent to the hippocampal formation, globus pallidus, ventral to and in the substantia nigra. However, [125I]-glial cell line-derived neurotrophic factor did not appear to diffuse readily or accumulate in the caudate-putamen even though there was some penetration away from the ventricular walls. Throughout the brain, there was also substantial non-parenchymal labelling of [125I]-glial cell line-derived neurotrophic factor, possibly associated with extracellular matrix components, meninges and vasculature due to the heparin binding properties of glial cell line-derived neurotrophic factor. In addition to the extensive loss of tyrosine hydroxylase immunoreactivity within the substantia nigra, there was also decreased accumulation of [125I]-glial cell line-derived neurotrophic factor and reduced glial cell line-derived neurotrophic factor immunoreactivity ipsilateral to the lesion. Microscopic analysis showed that glial cell line-derived neurotrophic factor immunoreactivity was associated with upper cortical layers including a high density of immunoreactivity at the surface of the cortex (meningeal, pial layer, vasculature) and around the ventricular walls (with some cellular labelling and labelling of vasculature). Moderate staining was observed in nigral cells contralateral to the MPTP-lesion, whereas only minimal levels of that glial cell line-derived neurotrophic factor immunoreactivity were detected ipsilateral to the lesion. This study shows that intraventricularly injected glial cell line-derived neurotrophic factor accumulates not only around the ventricular walls, but also in specific brain regions in which sub-populations of cells are more readily accessible than others. The presence of cells labelled with [125I] and immunopositive for glial cell line-derived neurotrophic factor in the substantia nigra indicates that these cells are a target for the trophic factor following intraventricular administration. Thus, the behavioral improvement observed in MPTP-lesioned monkeys following an intraventricular injection of glial cell line-derived neurotrophic factor is likely the result of activation of nigral cells.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗
PubMed1998

Does N-acetylcysteine improve hemodynamics and graft function in liver transplantation?

The release of toxic oxidative free radicals induced by ischemia and reperfusion may jeopardize liver graft function. N-acetylcysteine (NAC) has shown protective effects on hypothermic and warm ischemia reperfusion liver injury in animals. NAC improves hemodynamics and survival rates in patients with fulminant hepatic failure. The aim of this study was to investigate whether intraoperative treatment with NAC would improve hemodynamics and postoperative graft function in liver transplantation. Sixty patients with chronic end-stage liver disease were included in a prospective randomized placebo-controlled study. NAC or the same volume of 5% glucose was started during the anhepatic phase. Hemodynamic data and calculated tissue oxygenation parameters were compared throughout the procedure. Postoperative graft function was assessed by measurements of aminotransferases, prothrombin time, and monoethylglycinexylidide test over the 3 first postoperative days. Patient demographics were similar before the infusion of NAC or glucose. Hemodynamic parameters, oxygen consumption, oxygen delivery, oxygen extraction ratio, and lactates were not different throughout the procedure. One hour after the revascularization of the hepatic artery, the oxygen extraction ratio by the liver was similar (17% +/- 7.6% v 17% +/- 6.2%) in both groups. Postoperative graft function was comparable within the 3 first postoperative days. This study failed to show any beneficial effect of the intraoperative administration of NAC on hemodynamics and graft function in liver transplantation in patients with chronic liver disease.

Acetylcysteine↗
PubMed1998

Characterization and localization of two forms of gonadotropin-releasing hormone (GnRH) in the spinal cord of the frog Rana ridibunda.

Two molecular variants of gonadotropin-releasing hormone (GnRH) have been previously characterized in the brain of amphibians, i.e., mammalian GnRH (mGnRH) and chicken GnRH-II (cGnRH-II). The aim of the present study was to identify the molecular forms of gonadotropin-releasing hormone and to localize gonadotropin-releasing hormone-containing elements in the spinal cord of the frog Rana ridibunda using highly specific antisera against mGnRH and cGnRH-II. High-performance liquid chromatography (HPLC) analysis combined with radioimmunoassay (RIA) detection revealed that frog spinal cord extracts contained both mGnRH and cGnRH-II. Immunohistochemical labeling revealed that the frog spinal cord was devoid of GnRH-containing cell bodies. In contrast, numerous GnRH-immunoreactive fibers were observed throughout the entire length of the cord. mGnRH immunoreactivity was only detected in the rostral region of the cord and consisted of varicose processes located in the vicinity of the central canal. cGnRH-II-positive fibers were found throughout the spinal cord, the density of immunoreactive processes decreasing gradually toward the caudal region. Two main cGnRH-II-positive fiber tracts with a rostrocaudal orientation were observed: a relatively dense fiber bundle surrounding the central canal, and a more diffuse plexus in the white matter. In addition, short, varicose cGnRH-II-positive processes with a radial orientation were present throughout the gray matter. These fibers were particularly abundant ventromedially and formed a diffuse network that ramified laterally to end in the vicinity of motoneurons. Taken together, these data indicate that the frog spinal cord, like the frog brain, contains two forms of GnRH. The presence of numerous cGnRH-II-immunoreactive fibers in the ventral horn suggests that cGnRH-II may influence the activity of a subpopulation of motoneurons.

Animals↗
PubMed1998

Comparative analysis of prognostic indicators for sarcomas of the soft parts and the viscerae.

Purpose of this study was to determine which parameters may be best applied to determine the prognosis of soft tissue and visceral sarcomas, the two groups being regarded as biologically different. In a cohort of 184 soft tissue tumors (STT) and 53 gastrointestinal stromal tumors (GIST), the following factors were examined for their diagnostic and prognostic relevance: patient age, sex, tumor location, histological type, tumor size, tumor grade, DNA ploidy status, mitotic count, and immunohistochemical proliferation index. Tumors were graded according to the FNCLCC system, and antibody Ki-S11 (Ki-67) served as a proliferation marker. Median clinical follow-up time was 48 months. In STT, morphological criteria allowed a ready discrimination between benign and malignant lesions, which was only warranted by histopathological grading in GIST. 178 of all 236 tumors were thus classified as malignant. Whilst most parameters yielded significant results in the univariate analysis, age, sex, and histological type were irrelevant. A proliferation index > 20% predicted a poor outcome in soft tissue sarcomas, in contrast to a threshold of 10% for GIST. In both groups, the Cox multivariate analysis selected the proliferation index as the sole independent predictor of overall survival, whereas it was superseded by the tumor grade with respect to metastatic spread. In conclusion, soft tissue and visceral sarcomas appear to behave basically in a similar manner. Both tumor grade and immunohistochemical proliferation index are of major prognostic value. Concerning the growth fraction, however, different cut-off points should be selected for sarcomas of the soft tissues and those of the digestive tract.

DNA, Neoplasm↗
PubMed1998

[Strategy for identification of new neuropeptides].

Neuropeptides play a crucial role in cell communication as neurotransmitters, neuromodulators or neurohormones, and are involved in a number of biological activities including neuroendocrine regulations, control of neurovegetative functions, trophic effects and modulation of the immune response. The number of neuropeptides that have been fully characterized so far is rather limited, as compared to the number of precursor proteins that are actually expressed in nerve cells. Owing to the development of powerful analytical and structural identification methods, and the rapid advance in molecular biology techniques, a number of novel neuropeptides have been characterized during the last decade, in both vertebrates and invertebrates. The aim of the present review is to provide a comprehensive coverage of the different approaches which are currently used to identify novel neuropeptides.

Amino Acid Sequence↗
PubMed1997

Flow cytometric DNA content analysis of 185 soft tissue neoplasms indicates that S-phase fraction is a prognostic factor for sarcomas. French Federation of Cancer Centers (FNCLCC) Sarcoma Group.

BACKGROUND: The authors determined the flow cytometric (FCM) DNA characteristics of 53 benign tumors and 132 malignant (71 primary, 61 recurrent) soft tissue sarcomas to investigate their heterogeneity and to evaluate the prognostic values of DNA ploidy status and S-phase fraction (SPF). METHODS: One to 11 frozen samples were collected from 185 tumors at 10 participating centers of the French Federation of Cancer Centers (FNCLCC). All FCM analyses were performed in the same laboratory. Histologic diagnoses were collegially reviewed, and grade was assessed by the pathologists of the FNCLCC Sarcoma Group. Relationships between FCM, clinical, and pathologic data were investigated using univariate and multivariate analyses for risks of mortality and metastasis. RESULTS: All except 2 of the 53 benign lesions were DNA diploid. One schwannoma and one desmoid tumor exhibited small abnormal DNA peaks. SPF was low in all benign lesions. One-third of the sarcomas were DNA diploid, whereas two-thirds were DNA aneuploid. Relationships were found between aneuploidy and mitotic count, grade, and histologic subtype of malignant fibrous histiocytoma. DNA ploidy status did not influence the clinical outcome. Multiple sampling performed in 32 sarcomas showed both diploid and aneuploid samples in 6 tumors. Heterogeneity was related to tumor size. SPF evaluated in 85 sarcomas was related to DNA ploidy status, mitotic count, and grade. SPF > or = 4% was significantly associated with a low overall survival rate. In a multivariate analysis performed for the whole group of 132 patients, the single factors with independent prognostic value for patient mortality were disease free status after the treatment course (P < 0.0001) and SPF (P = 0.03). In the subgroup of patients who were initially free of metastases and free of tumor after the treatment course, SPF remained the only factor that significantly influenced the overall survival rate (P = 0.021). CONCLUSIONS: Despite its high failure rate, SPF is an independent factor in the prognosis of soft tissue sarcoma and should be considered when patients with a high mortality risk need to be selected for adjuvant chemotherapy.

Adolescent↗
PubMed1997

Predictive factors for complete removal in soft tissue sarcomas: a retrospective analysis in a series of 592 cases.

BACKGROUND AND OBJECTIVES: In order to specify the indications for conservative surgery and preoperative therapeutic approaches of soft tissues sarcomas (STS), we looked for the clinico-pathological parameters associated with the failure to obtain a complete removal (CRm) of the tumor. METHODS: We retrospectively analyzed a series of 592 cases of primary non-metastatic STS. Surgery was performed in 495 cases as a primary treatment and in 88 cases after chemo- or radiotherapy. Nine patients were treated by chemotherapy-radiotherapy. In a univariate analysis, 20 parameters were tested for their association with CRm. A multivariate analysis was then used to define the independent parameters linked to the achievement of a CRm. RESULTS: In the univariate analysis, 15 parameters were found to be linked to the achievement of a CRm. Three of them proved to be independent in the multivariate analysis: T in the TNM classification, tumor location, and tumor necrosis. By the combination of these risk factors, four groups of patients were defined, with respective rates of CRm of 97% (no factor), 95% (one factor), 70% (two factors), and 48% (three factors). CONCLUSIONS: The achievement of a CRm after surgery of STS depends not only on the accessibility of the lesion, but also on tumor aggressiveness, a reflection of which is necrosis. The detection of necrosis by imaging procedures may thus help predicting the resectability of tumors and defining the indications for neoadjuvant therapies, likely to broaden the use of conservative surgery.

Adolescent↗
PubMed1997

Hepatoid adenocarcinoma of the lung: report of a case of an unusual alpha-fetoprotein-producing lung tumor.

We report on a rare tumor of the lung characterized by its morphologic hepatoid features and alpha-fetoprotein production. This unusual neoplasm arose in the left lung of a 36-year-old man in whom clinical and radiologic examinations did not reveal any other tumor. The serum level of alpha-fetoprotein was measured at 6,090 ng/mL and was parallel to the evolution of the tumor. Despite treatment, the patient died 7 months after the diagnosis. The microscopic appearance of the tumor was the same as observed in hepatocarcinoma and hepatoid adenocarcinoma of the ovary or the stomach, with a tubular, papillary, or trabecular pattern. Periodic acid-Schiff-positive hyaline globules were numerous, and tumor cells showed immunohistologic positivity for alpha-fetoprotein and carcinoembryonic antigen. This lung adenocarcinoma was first described by Ishikura et al. in 1990 and was named hepatoid lung adenocarcinoma. Like the rare hepatoid carcinoma of the gallbladder, the pancreas, the ampulla of Vater, the renal pelvis, and the bladder, the exact histogenesis and the prognosis of this type of lung tumor are not yet known.

Adenocarcinoma↗