Effect of bismuth subgallate (a hemostatic agent) on bone repair; a histologic, radiographic and histomorphometric study in rats.

Bismuth subgallate (BS) is a hemostatic agent used for soft tissue surgery in otorhinolaryngology and dermatology. Its effect on bone repair has not been studied. The present study undertook a quantitative and qualitative evaluation of post-extraction bone healing in the presence of BS. Under intraperitoneal anesthesia, forty male Wistar rats, 80+/-5g body weight, underwent the extraction of both lower first molars. BS was placed in the right post-extraction socket (group E) and the contralateral socket served as control (group C). The animals were killed in groups immediately, 7, 14 and 30 days post-extraction. The mandibles were resected, radiographed and processed for embedding in paraffin. The mesial socket was sectioned along the bucco-lingual axis and stained with hematoxylin-eosin. Total tissue volume and trabecular bone volume of the apical third of the sockets were determined histomorphometrically. At 14 and 30 days post-extraction, group E exhibited bone tissue that resembled that of group C. Histomorphometric analyses showed no statistically significant differences between groups C and E. Bismuth subgallate did not interfere with post-extraction bone healing. Further studies will analyze the effect of this hemostatic agent on bone repair in aniticoagulated rats.

Lime treatment of stabilized leachates.

Reverse Osmosis is the most widely used method for treating municipal solid waste landfill leachates, since it produces a permeate in compliance with reject requirements. However, the efficiency of this process at the industrial scale is limited mainly because of membrane fouling and the high osmotic pressures involved. Although lime precipitation is traditionally used to eliminate the temporary hardness of water by decarbonation, it has also been shown to be highly efficient in removing humic substances which are known to have strong fouling potential towards membranes. Our objective is to study the lime/leachate physico-chemistry, in order to determine the potential of the lime precipitation as pre-treatment for reverse osmosis. The results show that the lime treatment makes it possible (i) to act efficiently on the inorganic fraction of leachates through a decarbonation mechanism which entails massive precipitation of the carbonates under the form of CaCO(3), (ii) to eliminate by co-precipitation the high Molecular Weight (MW) organic macromolecules (>50,000 g.mol(-1)) such as humic acids, and (iii) to generate a stable residue that can be easily stored at a landfill. The reverse osmosis step will be facilitated through significant reduction of the osmotic pressures and prevention of membrane fouling.

Landfill leachate treatment: Review and opportunity.

In most countries, sanitary landfilling is nowadays the most common way to eliminate municipal solid wastes (MSW). In spite of many advantages, generation of heavily polluted leachates, presenting significant variations in both volumetric flow and chemical composition, constitutes a major drawback. Year after year, the recognition of landfill leachate impact on environment has forced authorities to fix more and more stringent requirements for pollution control. This paper is a review of landfill leachate treatments. After the state of art, a discussion put in light an opportunity and some results of the treatment process performances are given. Advantages and drawbacks of the various treatments are discussed under the items: (a) leachate transfer, (b) biodegradation, (c) chemical and physical methods and (d) membrane processes. Several tables permit to review and summarize each treatment efficiency depending on operating conditions. Finally, considering the hardening of the standards of rejection, conventional landfill leachate treatment plants appear under-dimensioned or do not allow to reach the specifications required by the legislator. So that, new technologies or conventional ones improvements have been developed and tried to be financially attractive. Today, the use of membrane technologies, more especially reverse osmosis (RO), either as a main step in a landfill leachate treatment chain or as single post-treatment step has shown to be an indispensable means of achieving purification.

[Diagnostic structured interviews in child and adolescent's psychiatry]. / Entretiens diagnostiques structurés en psychiatrie de l'enfant et de l'adolescent.

Structured diagnostic interviews, which evolved along the development of classification's systems, are now widely used in adult psychiatry, in the fields of clinical trials, epidemiological studies, academic research as well as, more recently, clinical practice. These instruments improved the reliability of the data collection and interrater reliability allowing greater homogenisation of the subjects taking part in clinical research, essential factor to ensure the reproducibility of the results. The diagnostic instruments, conversely to the clinical traditional diagnostic processes allow a systematic and exhaustive exploration of disorders, diagnostic criteria but also severity levels, and duration. The format of the data collection, including the order of exploration of the symptoms, is fixed. The formulation of the questions is tested to be univocal, in order to avoid confusions. In child and adolescent, researches in pharmacology and epidemiology increased a lot in the last decade and the standardisation of diagnostic procedures is becoming a key feature. This Article aims to make an assessment, a selection, and a description of the standardized instruments helping psychiatric diagnosis currently available in the field of child and adolescent's psychiatry. Medline and PsycINFO databases were exhaustively checked and the selection of the instruments was based on the review of four main criteria: i) compatibility with international diagnostic systems (DSM IV and/or ICD-10); ii) number of disorders explored; iii) peer reviewed Journals and iv) richness of psychometric data. After the analysis of the instruments described or mentioned in the literature, 2 structured interviews [the Diagnostic Interview Schedule for Children (DISC) and the Children's Interview for Psychiatric Syndromes (ChIPS)] and 4 diagnostic semi-structured interviews [the Schedule for Affective Disorders and Schizophrenia for School-Age Children (Kiddie-SADS), the Diagnostic Interview for Children and Adolescent (DICA), the Child and Adolescent Psychiatric Assessment (CAPA) and the Interview Schedule for Children and Adolescents ISCA)] were retained according to the 3 first criteria. All can be administered by clinicians, and x out of 6 can also be administered by lay-interviewers. All include a child/adolescent version and a parent version. Two instruments evaluate the presence of DSM IV axe II disorders: The ISCA explores the criteria of the Antisocial Personality Disorder. The CAPA evaluates Borderline, Obsessional-compulsive, Histrionic and Schizotypic Personality Disorders. Regarding the psychometric quality criterion, the selection was much more difficult because of the lack of data and the weakness of the samples studied in reliability studies. Interrater reliability appeared to be good for the 6 instruments, with kappas ranging from 0.5 to 1. This is usual in such instruments. The test-retest reliability was found to vary from bad to excellent depending on the instruments, the "informant" status (child/adolescent or parent), and the disorder explored, kappas ranging from 0.32 to 1. The worst results concerned face-to-face reliability studies which showed weak concordances for the diagnoses, whatever the procedure implemented: Diagnostic interview vs. i) Another diagnostic interview, vs. ii) An expert diagnosis or vs. iii) Scales and questionnaires. Overall, the K-SADS-PL appeared to be the instrument that has the best test-retest reliability for Anxious Disorders and Affective Disorders (the value kappa showing good to excellent reliabilities). Several important methodological observations emerged from this review. Firstly, the metrological data corresponding to the diagnoses according to DSM IV or ICD-10 criteria's were lacking. The face validity was globally satisfactory, but the data concerning their face-to-face validities and their test-retest reliability, although better than in the former versions, were limited because they were tested on small sample. In fact, it appeared that the agreements depend on the informant, the sample studied, the various diagnostic categories and the instrument used. Since the studies carried out by Cohen et al., with now obsolete versions of the DISC and K-SADS, no other study establishing a comparison between two EDS have been conducted. Consequently, the clinicians must be very careful before comparing DSM or ICD diagnoses generated by different instruments. The second point was the length of the interviews that appeared sometimes longer than instruments used in adults, considering the fact that diagnostic procedure implies two independent interviews, one with the child/adolescent and one with the adult referent. The minimum duration was found to be 1 h 30 for the Chips in clinical setting, while it could reach 4 h or more for the DISC IV or the ISCA. The interviews had to be often carried out in several sessions, so the assessment became very difficult in easily tired and/or distractible subjects. The third point referred to the necessity to consider multiple data sources in young patients during the diagnostic procedure, and the weakness of the levels of agreement generally reported between sources. Empirically, it was observed that the investigator granted more weight to the report of the children than to the parent's one, when the clinical judgement was necessary to synthesize the data. On another level, studies showed a high agreement on the factual contents or on the specific events (ex: hospitalization), like on the obvious symptoms (ex: enuresis). The parents report more problems of behaviour, school and relational difficulties, whereas the children report more fear, anxiety, obsessions and compulsions, or delusional ideas. In other words, it appeared that children were better informants in describing their mental states (internalised disorders), and that adults would bring more reliable information in describing externalised disorders. Like McClellan and Werry, we think that further researches are needed to clarify if and when this is the case. The last major point concerned the problem of language. These instruments must be used in the maternal language of the interviewees and they were developed for most of them into English only. For example, there is only one instrument available into French (the Kiddie SADS). Nowadays, it remains difficult to conduct international studies in child and adolescent psychiatry and/or to compare data is this domain. To conclude, the use of the EDS and EDSS brings many benefits, in academic researches as well as in clinical practice, but a more systematic use is limited by a certain number of parameters. The instruments currently available in child and adolescent are far from being optimal in terms of quality and quantity. It seems necessary and useful to contribute to their development and their improvement. In particular, the following points should be considered: drastic reduction of the length of the interviews; simplification in the use of these instruments, during the interviews, but also in the treatment of the data collected during the final phase of diagnosis generation, the clinician having to carry out ceaseless returns to check the presence or not of each diagnostic criterion; reduction of the duration of the highly necessary training, which can be easily solved by the global simplification of the instruments; quantitative and qualitative improvements of psychometric properties, in particular in terms of sensitivity, specificity and face-to-face validity. Finally, it is highly necessary to continue to develop structured diagnostic interviews adapted to the assessment of child and adolescent psychiatric diagnoses keeping in mind simplicity, feasibility and reliability. Developing this kind of instruments is hard, expensive, and sometimes tiresome but it remains the inescapable stage to produce high quality data in the future.

Monoarylhydrazones of alpha-lapachone: synthesis, chemical properties and antineoplastic activity.

The biological activities of the naphthoquinones lapachol, extracted from trees of the genus Tabebuia and its cyclization products alpha and beta-lapachone, have been intensively studied. Giving continuity to the research about new derivatives obtained from the reaction of these naphthoquinones with amino-containing reagents, a series of arylhydrazones of alpha-lapachone was synthesized and their antineoplastic activity was evaluated. This new structure is based on the great electrophilicity of 1,4-quinoidal carbonyl groups towards reagents containing nitrogen as nucleophilic centers, such as arylhydrazines. The products were assayed by the National Cancer Institute (NCI, USA) and their binding to DNA, redox properties and QSAR studies were also determined.

Effect of total body irradiation on peri-implant tissue reaction: an experimental study.

The aim of the present study was to evaluate the osseointegration process under total body irradiation conditions (LD 50/30). Twenty Wistar rats (mean body weight: 90 g) were used. Under ethyl urethane intraperitoneal anesthesia (1 g/kg body weight), the animals were irradiated with a single 700 cGy dose (linear accelerator 6 Mev photons). Four days post irradiation, a titanium laminar implant was placed in the left tibia of each rat. Antibiotic therapy (ceftriaxone) was administered daily post implantation, to prevent infection by radiation. Fourteen days post implantation, the animals were killed by ether overdose. The tibiae were resected, radiographed and processed for embedding in methyl methacrylate. The results showed impaired osteogenesis and absence of osseointegration in experimental tibiae. This could be due to a direct action of total body irradiation on osteogenesis precursor cells. This effect would impair bone formation involved in peri-implant osseointegration processes in this experimental model.

A histomorphometric study of tissue interface by laminar implant test in rats.

Study of the implant-tissue interface is one of the fundamental issues in implantology, both odontologic and orthopedic. The characteristics of this interface will influence the success or failure of an implant. The aim of the present study was to evaluate histomorphometrically the capacity of different metals to osseointegrate employing laminar implants of zirconium, titanium, aluminum, and zirconium coated with diamond-like carbon. The experimental model herein allowed for the quantitative evaluation of the tissue-implant interface for different metals. The implants were placed in the tibiae of Wistar rats under anesthesia and allowed to remain in situ for a 30-day period. The interfaces of the zirconium and diamond-like coated zirconium implants exhibited better responses than the interface of titanium implants. Aluminum produced a local toxic effect, evidenced by osteoid formation.

Evaluation of bone tissue on metallic implants by energy-dispersive x-ray analysis: an experimental study.

Osseointegration capacity of the different metallic implants depends on several variables. Osseointegration can be evaluated by using different methodologies, such as light microscopy and scanning or transmission electron microscopy. The aim of this study was to develop a qualitative and quantitative method to evaluate the presence of bone tissue on large metallic surfaces. A laminar implant was placed in each tibia of 10 Wistar rats. The animals were killed 30 days after surgery. Tibiae were resected, one for embedding in methyl methacrylate and the other for evaluation by energy-dispersive x-ray analysis. Light microscopy revealed osseointegration. Observation of the implant surface by scanning electron microscopy revealed the presence of a coating on the metallic surface that was rough in some areas and smooth in others. Analysis of the coating by energy-dispersive x-ray analysis showed the presence of Ca and P. Eighty percent (+/- 10%) of the metallic implant surface exhibited bone tissue. After confirmation of the occurrence of osseointegration capacity using light microscopy, the method described here allows qualitative and quantitative evaluation of the bone tissue found on large metallic surfaces.

Estudio experimental de la interfase oseointegrada

El estudio del material del implante en relación con el tejido vivo (hueso y/o médula) es de especial importancia. En esta presentación deseamos resumir una serie de datos experimentales obtenidos del estudio de diferentes materiales y condiciones que han posibilitado disponer de una metodología que puede ser aplicada sobre un número significativo de muestras, obteniéndose medidas y datos a nivel microscópico y con valor estadístico

Estudio experimental de la interfase oseointegrada

El estudio del material del implante en relación con el tejido vivo (hueso y/o médula) es de especial importancia. En esta presentación deseamos resumir una serie de datos experimentales obtenidos del estudio de diferentes materiales y condiciones que han posibilitado disponer de una metodología que puede ser aplicada sobre un número significativo de muestras, obteniéndose medidas y datos a nivel microscópico y con valor estadístico