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M Guillaud

Publications and source records attributed to M Guillaud.

At least 19 recordsLinked to original sources
PubMed2005

A Java application for tissue section image analysis.

The medical industry has taken advantage of Java and Java technologies over the past few years, in large part due to the language's platform-independence and object-oriented structure. As such, Java provides powerful and effective tools for developing tissue section analysis software. The background and execution of this development are discussed in this publication. Object-oriented structure allows for the creation of "Slide", "Unit", and "Cell" objects to simulate the corresponding real-world objects. Different functions may then be created to perform various tasks on these objects, thus facilitating the development of the software package as a whole. At the current time, substantial parts of the initially planned functionality have been implemented. Getafics 1.0 is fully operational and currently supports a variety of research projects; however, there are certain features of the software that currently introduce unnecessary complexity and inefficiency. In the future, we hope to include features that obviate these problems.

Cytological Techniques↗
PubMed2005

[Prevention of infective endocarditis: are recommendations about oral health procedures for high or moderate risk patients respected?].

BACKGROUND: Infective endocarditis (IE) is a rare but particularly serious disease. It frequently requires surgical treatment with cardiac valve replacement. In-hospital mortality is very high. The guidelines of the Society of Infectious Pathology of French Language (SPILF) for the prevention of infective endocarditis of at-risk patients were updated in 2002. They recommended a bi-annual oral health follow-up and antibiotic prophylaxis for invasive sequences of care for high-risk patients. The objective of the study was to assess the application of the guidelines. METHODS: Using databases and medical files of self-employed persons insured by compulsory national health insurance in the Alps, we studied from January 2001 to December 2002 the oral ambulatory follow-up of patients with permanent health insurance for valvular heart disease or congenital heart disease. RESULTS: Among the 260 patients with valvular heart disease or congenital heart disease, 125 (48.1%) presented medical claims for at least one dental treatment. Antibiotic prophylaxis was found in 15.8% of the invasive sequences of care for high-risk patients. The prescribed antibiotic was amoxicillin in 90% of the cases. CONCLUSION: Guidelines are seldom applied. Public and practitioner awareness should be improved to promote oral health: patients should regularly consult their dentist, and practitioners should follow the guidelines for the prevention of infective endocarditis.

Aged↗
PubMed2004

[Oral health screening: evaluation of implementation of a national programme].

BACKGROUND: The first national French oral health screening was implemented in 1998 toward young people aged from 15 to 18 Years. These adolescents were invited every year to a free dental check up performed by their dentist. The aim of this study, carried out for self-employed persons insured by compulsory national health insurance, was to measure the rate of dental checks during years 1998-1999-2000, to estimate the oral health status, to assess the factors related to the dental care consumption in 1998, and the predictive factors for a successive dental check. METHODS: We included seventy four French counties. Every teenager born in 1983 (23.874) was invited. We collected data from both the health insurance databases and the form filled in by the consulted dental surgeons. We selected four variables: gender, residence place, social, and occupational group to study the consumption in 1998. RESULTS: In 1998, 10% (2462) of teenagers have got a dental check up (EXP1). Only 0,7% participated in the three screenings (1998-1999-2000). We noted a higher female consumption and disparities between the main categories of self-employed persons. Participation by boys was higher than girls. The lowest participation rates concerned the Ile of France area and adolescents living with single parents. In 1998 (EXP1), 57% of teenagers had at least one decayed tooth. Only 69% of them received appropriate curative dental treatments in the following six-Months period. However, among teenagers followed during the three years, higher rates of care reaching 90% were observed on the second and third EXP. CONCLUSION: This small participation rate may be related to the recent implementation of screening. It should lead to optimize screening and to associate other partners in particular the state education system. It should also be helpful in focusing the oral health prevention policy toward the population with a high risk of decay.

Adolescent↗
PubMed2003

Risk biomarker assessment for breast cancer progression: replication precision of nuclear morphometry.

Nuclear morphometry is a method for quantitative measurement of histopathologic changes in the appearance of stained cell nuclei. Numerous studies have indicated that these assessments may provide clinically relevant information related to the degree of progression and malignant potential of breast neoplasia. Nuclear features are derived from computerized analysis of digitized microscope images, and a quantitative Feulgen stain for DNA was used. Features analyzed included: (1) DNA content; (2) nuclear size and shape; and (3) texture features, describing spatial features of chromatin distribution. In this study replicated measurements are described on a series of 54 breast carcinoma specimens of differing pathologic grades. Duplicate measurements were performed using two serial sections, which were processed and analyzed separately. The value of a single feature measurement, the nuclear area profile, was shown to be the strongest indicator of progression. A quantitative nuclear grade was derived and shown to be strongly correlated with not only the pathologic nuclear grade, but also with tubule formation, mitotic grade, and with the overall histopathologic grade. Analysis of replication precision showed that the standard methods of the histopathology laboratory, if practiced in a uniform manner, are sufficient to ensure reproducibility of these assessments. We argue that nuclear morphometry provides a standardized and reproducible framework for quantitative pathologic assessments.

Algorithms↗
PubMed1997

Woodchuck hepatitis virus-induced carcinoma as a relevant natural model for therapy of human hepatoma.

BACKGROUND: Eastern American woodchuck (Marmota monax), naturally infected with woodchuck hepatitis virus, a virus similar to human hepatitis B virus, develops liver cancer with a high prevalence. AIMS: The aim of this work was to assess Marmota monax as a model of human hepatocellular carcinoma, especially to assess new potential adjuvant therapies after surgical resection. METHODS: Forty-four woodchuck hepatitis virus-infected animals were regularly screened by ultrasound examination from the age of 18 months and for a 30-month period. One or more liver tumors were diagnosed in 31 animals (70%). Five of them with multifocal tumor or poor general status were considered unsuitable for surgery. The other 26 were operated on. At laparotomy no tumor was found in three. RESULTS: The 18 liver tumors studied were hepatocellular carcinomas, grossly and microscopically similar to human hepatocellular carcinoma. Peritumoral parenchyma studied in 13 specimens was always non-cirrhotic but adequate staining demonstrated patterns of fibrosis in four cases. Clear evidence of chronic active hepatitis, periportal hepatitis and steatosis were demonstrated in five, seven and one of the 13 specimens, respectively. Tumors were treated by tumorectomy in eight animals, by alcoholization in seven and by laser photocoagulation in one. A simple tumor biopsy was performed in the other seven. Ten animals died postoperatively. All the survivors in the tumorectomy group died from tumor recurrence within 10-18 months after surgery. CONCLUSIONS: It is concluded that woodchuck hepatitis virus-induced liver carcinoma is a natural model of human hepatocellular carcinoma with similar pathology and natural history, including early ultrasonic detection and tumor recurrence after resection. Tumor excision is feasible in this animal model, which now provides the basis for assessment of new potential adjuvant therapies for human hepatocellular carcinoma in an attempt to reduce the high recurrence rate after surgical resection in humans.

Animals↗
PubMed1997

A novel image cytometric method for quantitation of immunohistochemical staining of cytoplasmic antigens.

Evaluation of molecular markers by immunohistochemical labelling of tissue sections has traditionally been performed by qualitative assessment by trained pathologists. For those markers with a staining component present outside of the nucleus, there has been no image histometric method available to reliably and consistently define cell interfaces within the tissue. We present a new method of approximating cellular boundaries to define cellular regions within which quantitative measurements of staining intensity may be made. The method is based upon Voronoi tessellation of a defined region of interest (ROI), and requires only the position of the nuclear centroids within the ROI. Here we describe the VORSTAIN software which has been developed based on the Oncometrics CytoSavant Automated Image Cytometry System. To demonstrate this technique, human breast cancer sections immunohistochemically stained for bcl-2 protein and counter-stained with nuclear methyl green stain were evaluated. Intra-observer variation in the measured values was between 1.5-2.6% and inter-observer variation was between 1.8-4.4%. The primary source of variability was due to difficulties in interpreting the exact position of the nuclear centroids. Analysis of mean staining densities for each slide correlated well with subjective scoring performed by two independent pathologists. Using VORSTAIN, significant variation of staining intensities between regions within the same slide was measured for some sections, indicating a large degree of heterogeneity within the tumours. The ability to accurately quantitate the degree of heterogeneity of molecular marker expression within tumours may be a valuable tool in prognostication.

Biomarkers, Tumor↗
PubMed1995

Histometric texture analysis of DNA in thin sections from breast biopsies. Application to the detection of malignancy-associated changes in carcinoma in situ.

OBJECTIVE: To evaluate histometric measurement of nuclear texture in breast biopsy sections in order to detect malignancy-associated changes in apparently normal tissue in the vicinity of carcinoma in situ. STUDY DESIGN: We previously showed that image cytometry measurements of nuclear features--foremost, texture features, describing the organization of Feulgenstained DNA in the cell--can be used to distinguish normal-appearing, diploid epithelial cells from patients with invasive carcinoma of the breast from those with benign biopsies. In that study, referred to as the "single cell analysis," images of at least 200 epithelial cells were acquired for each slide, and substantial user interaction was required to segment cells from each field. Location of isolated cells and interactive segmentation are both time-consuming procedures, particularly in breast tissue, where nuclei can be tightly clustered within a duct. With histometric texture analysis on the same specimens, segmentation of individual cells was ignored, and texture measurements were performed over the entire cluster of relevant cells. With this approach, ploidy information is not available, and touching and overlapping nuclei are included in the measurements. Measurement of histometric texture properties requires substantially less time (at least an order of magnitude) than individual cell measurement and, if ploidy information is not significant, may therefore provide a more practical means of analysis for tissue sections. RESULTS: Seventeen cases of invasive carcinoma and 17 cases of nonproliferative breast disease were examined. Using stepwise discriminant function analysis, slides were classified into one of the two groups with an accuracy of 88.6% in the case of single cell analysis and with an accuracy of 88.2% using histometric analysis. CONCLUSION: The existence of malignancy-associated changes in the breast was confirmed by an independent analysis of the same specimens. Although the two methods are not directly comparable, we found that histometric texture analysis performs at least as well as single-cell analysis for the detection of malignancy-associated changes in breast carcinoma.

Biopsy↗
PubMed1995

Malignancy associated changes in cervical smears: systematic changes in cytometric features with the grade of dysplasia.

For almost ten years. Malignancy Associated Changes have been consistently found by means of high resolution image analysis of apparently normal uterine cervix cells. The study was performed on normal intermediate cells randomly selected from 1850 cervical smear slides classified as negative, mild dysplasia, moderate dysplasia and severe dysplasia. Size and texture features, performed by the Cyto-Savant software, have shown significant monotonic changes with the grade of dysplasia. These findings indicate that the intensity of Malignancy Associated Changes are directly related to the severity of the adjacent lesions.

Cell Transformation, Neoplastic↗
PubMed1994

Interactive computer-assisted analysis of chromosome 1 colocalization with nucleoli.

The applications of DNA cloning and fluorescent in situ hybridization (FISH) techniques have strengthened the hypothesis of an ordered chromatin structure in interphase nuclei, strongly suspected to vary with functional state. The nonrandom distribution of the centromeres and their dynamic rearrangement during the cell cycle have been well documented. A close proximity of specific centromeres to nucleoli has also been reported, but the functional meaning of this association is still unknown. In order to investigate whether the chromosome 1 centromere region to nucleolus association depends on the cell cycle and chromosome status, we combined FISH of probes specific for the 1q12 region with Ki-67 nucleolar antigen fluorescent immunocytochemical (FICC) detection on the MCF-7 human breast cancer cell line and on the MRC-5 normal fibroblastic cell line. Both FISH and FICC signals were interactively localized in a one-step fluorescent microscopic observation and further analyzed using the Highly Optimized Microscope Environment (HOME) graphics microscope workstation, which provided computerized interactive marking of 1q12 to nucleolus associations (1q12-nu) at the individual nucleus and nucleolus levels. This study confirms that centromeric regions, other than those adjacent to the major ribosomal cistrons, contribute to the perinucleolar chromatin and demonstrate that, during the cell cycle, the heterochromatic band 1q12 is dynamically rearranged with regard to both the nuclear volume and the nucleoli. A relationship between the association of the chromosome 1 pericentromeric region with nucleoli and the nucleolar transcriptional activity is also strongly suggested.

Biomarkers↗
PubMed1994

Human hepatocellular carcinoma transplanted in nude mice: a relevant experimental model to assess tumoral destruction by alcoholization.

Intratumor ethanol injection was studied in the treatment of small hepatocellular carcinoma (HCC). One of the major drawbacks of this technique remains the lack of objective information about its efficiency and the practical conditions of injection. To ensure accurate evaluation of alcoholization, we developed a model based on the tumor obtained after subcutaneous injection of human hepatoma cell lines into nude mice. Each of three cell lines (Hep G2, Hep 3B, PLC/PRF/5) was tested on 24 mice. A total of 0.1 ml of a solution containing 5 x 10(6) cells was injected under the abdominal skin of a male nude mouse weighing 30 g. The Hep G2 cell line appeared to be the most suitable for the model. It enabled us to obtain tumors of 20 mm in diameter within a mean delay (m +/- SD) of 45 +/- 16 days (range: 29-60) with only a 25% failure rate. No visceral spreading of the carcinoma was noticed and the tumors obtained, similar to human HCC, were convenient to be measured, monitored, and treated by alcoholization. To validate this model for alcoholization, 38 tumors ranging in diameter from 10 to 20 mm were treated using either a unique centrotumoral injection (n = 27) or five cross-shaped injections (n = 11). Intratumor absolute ethanol injection resulted in tumoral necrosis which was easily quantified as a percentage of the tumor volume, using a semiquantitative method. It is concluded that the Hep G2 cell line transplanted in nude mice resulted in a relevant model to assess tumoral destruction by alcoholization.

Animals↗
PubMed1993

Studies of monoclonal antibody BL2-10D1 as a marker for the detection of the urothelial origin of tumors.

BACKGROUND: In previous studies, the authors demonstrated the value of the monoclonal antibody (MoAb) BL2-10D1 in identifying malignant transitional cells. In this study, the authors evaluate the possible diagnostic value of a murine MoAb, BL2-10D1, raised against human bladder cancer in the determination of the urothelial origin of metastases in a series of 29 patients with metastatic bladder or prostatic carcinoma. METHODS: Using an immunoperoxidase method, BL2-10D1 and anti-prostate-specific antigen (anti-PSA) reactivity were studied, using histologic sections from 18 pelvic lymph nodes and 4 other anatomic sites invaded by transitional cell cancer, and from 7 pelvic lymph nodes containing prostatic cancer. RESULTS: All lymph nodes containing metastases of transitional cell carcinoma were positive with BL2-10D1, whereas all metastases of prostatic cancer were negative; the four instances of distant urothelial metastases were positive with BL2-10D1 MoAb. Conversely, anti-PSA reacted only with prostatic metastases. CONCLUSION: Thus, MoAb BL2-10D1 and anti-PSA complement each other in the separation of cancers of prostatic and urothelial origin, and the BL2-10D1 MoAb has potential usefulness in differentiating between urothelial carcinoma and prostate adenocarcinoma. In patients with bladder tumors of uncertain origin, BL2-10D1 may be helpful in confirming that a tumor is a transitional cell carcinoma.

Aged↗
PubMed1993

Histopathological assessment of tumoral destruction by alcoholization in an experimental model of human hepato-cellular carcinoma transplanted in nude mice.

This study aims to assess the efficacy of intra-tumoral alcoholization as a potential therapy against small hepatocellular carcinoma (HCC). The experimental model consisted of 20-mm diameter tumors resulting from subcutaneous abdominal injection of Hep G2 human hepatoma cell lines into nude mice (nu/nu). Alcoholization was performed using either a single centro-tumoral injection or multiple cross-shaped injections (tangential and oblique), during one sequence with a total dose of 0.1, 0.2 or 0.3 ml of 95% ethanol. Efficacy was assessed by the percentage of tumoral necrosis using a semi-quantitative method. Fifty-four tumors were alcoholized. Forty-eight hours following alcoholization, the tumor was regularly replaced by a necrotic ulcer. A single centro-tumoral injection always resulted in the persistence of a small peripheral edge of tumor cells even with the highest dose used (no dose-related effect). By contrast, the use of multiple injections restored a dose-related effect. Oblique cross-shaped injections of 0.3 ml of ethanol resulted in the highest mean tumoral necrosis rate (m +/- SD = 99 +/- 1%; range = 97-100). This study confirms that alcoholization is an efficient way to destroy hepatocarcinoma tissue and suggests that ethanol diffusion in HCC is less than 20 mm. In addition it demonstrates that increasing number and location of injections restores a dose-related effect, while efficacy is improved using oblique injections.

Animals↗
PubMed1992

[Mammary microcalcifications: is there a consensus on interpretation and management?].

Twenty two view mammograms without magnification, with microcalcifications corresponding to non palpable breast lesions, were submitted to 23 experienced observers, either gynaecologists or radiologists. These mammograms consisted of 10 malignant lesions and 10 benign lesions; all of them underwent surgical procedures. The microcalcifications were graded and categorized into one of the four groups: malignant; suspect; slightly suspect; benign. One of the four options was proposed: biopsy; mammogram within 3 months; mammogram within 6 months; mammogram within a year. Twelve observers out of 23 have referred to a classification. The mammograms were assessed according to a consensus. The validity of that diagnostic test was studied in various clinical situations and the lack of homogeneity of the responses was quantified. In the trade-off situation between sensitivity and specificity (suspect or malignant considered as positive), sensitivity is 50% and specificity is 70%. Moreover, the responses are not homogeneous at all and this lack of homogeneity is found to be statistically significant, greater than by chance alone. The diagnosis of cancer is more frequently put forward by the radiologists. This study explains the low predictive value of non palpable microcalcifications undergoing surgical procedures: from 11.5 to 44% in the literature. Similarly, there is no agreement on the frequency of the follow-up for these microcalcifications when they do not lead to surgical procedures.

Breast Diseases↗
PubMed1991

[The value of immunohistochemistry in the analysis of axillary node dissection].

Immuno-histochemistry (IHC) was used and compared with Hemalum-Eosin-Safran (HES) in the analysis of the products of axillary lymphatic clearance in 42 women had breast cancer. In 32 patients who were negative by the HES test there was no lymph metastasis found by the IHC test in the 365 lymph nodes which were examined. In 3 out of 10 patients who were positive which the HES test 2 extra lymph node invasions were found, and one breach in the lymph node capsule that had not been diagnosed through HES testing were found. A review of the literature shows that the IHC test has never been show to be inferior to the HES test. The number of additional nodes that have been invaded varies between 0.9-11% in infiltrating canalicular carcinomas. The changes of the IHC test is greater in infiltrating lobular carcinomas. It varies between seven and 33%. Although the technique for using IHC is longer, it is easier to read the result and this method should be set up in current practice.

Breast Neoplasms↗
PubMed1990

Distribution of Crimean-Congo hemorrhagic fever viral antibody in Senegal: environmental and vectorial correlates.

The spatial pattern in Senegal of Crimean-Congo hemorrhagic fever (CCHF) virus IgG antibody prevalence in human and sheep was determined as was the relative abundance of potential tick vectors. A systematic, country-wide serological survey of sheep demonstrated that 10.4% of sheep exhibited IgG to CCHF virus. Sexes were infected equally. Antibody prevalence increased with age from 2.1% during the first year to 18.2% among sheep greater than or equal to 3 years of age. IgG prevalence was highest in the northern, arid Sahelian zone, averaging 75.7% seropositivity, and decreased to zero in the southern, moister Sudano-Guinean and Guinean zones. Human IgG prevalence ranged from 21% to less than 1% among the 8 sites that were sampled throughout the country, being greatest in the arid north and least in the south. Hyalomma ssp. ticks predominated in those biotopes where antibody prevalence was highest. The abundance of Hyalomma ticks may be the proximal determinant of endemic transmission.

Adult↗