Epilepsy and brain abnormalities in mice lacking the Otx1 gene.

The morphogenesis of the brain and the differentiation of the neural structures are highly complex processes. A series of temporally and spatially regulated morphogenetic events gives rise to smaller areas that are phylogenetically, functionally and often morphogenetically different. Candidate genes for positional information and differentiation during morphogenesis have been isolated. Both in vivo inactivation in mice and impairment in human diseases revealed, that they are required in regional specification and/or correct cell-type induction. We have previously cloned and characterized the murine Otx1 gene, which is related to orthodenticle (otd), a homeobox-containing gene required for Drosophila head development. Expression data during murine embryogenesis and postnatal brain development support the idea that Otx1 could be required for correct brain and sense organs development. To decipher its role in vivo we produced null mice by replacing Otx1 with the lacZ gene. Otx1-/- mice showed spontaneous epileptic behaviour and multiple abnormalities affecting mainly the telencephalic temporal and perirhinal areas, the hippocampus, the mesencephalon and the cerebellum, as well as the acoustic and visual sense organs. Our findings indicate that the Otx1 gene product is required for proper brain functions.

[Malnutrition in pediatric oncology: prevalence and screening]. / Dénutrition en cancérologie pédiatrique: prévalence et dépistage.

UNLABELLED: Algorithms for nutritional pediatric support have been proposed in a French national nutritional framework program. However, they are not specific for oncology. With the pediatric nutritional risk score (PNRS) all children with cancer have a high risk of malnutrition, but a systematic nutritional support is not possible for all of them. AIM: Estimation of malnutrition prevalence and identification of predictive factors of major weight loss during treatment defined by a weight loss more than 5% within 1 month, 7.5% within 3 months, 10% within 6 months. POPULATION AND METHODS: This historical study included children registered with a solid tumor in 2002 in an oncology pediatric unit. Data collected at diagnosis were weight, height, PNRS, the Lansky functional score, tumor type. Furthermore weight, height, and major weight loss were collected at each cure of chemotherapy and during evolution. Malnutrition at diagnosis was defined using the weight for height ratio. Relations between major weight loss and risks factors were estimated using logistic regression. RESULTS: Seventy children were included, 16 (22.9%) were malnourished at admission. During chemotherapy, 29 (41.4%) children experienced a major weight loss. Odds ratio of those who were malnourished at diagnosis was not significantly higher in comparison to well-nourished children. Children with a high risk of malnutrition are those affected by Ewing tumor, B lymphom, head and neck localisations, osteosarcomas, metastatic cancers, or cancers treated by high dose chemotherapy with stem cell rescue. For these 29 (41.4%) children the major weight loss odds ratio was 5.9 [IC95% 2.0-16.7]. CONCLUSION: Taking into account others factors with items of PNRS allows to screen children with an higher risk of a major weight loss during treatment and to enhance nutritional care plan for them.

Msx1-deficient mice fail to form prosomere 1 derivatives, subcommissural organ, and posterior commissure and develop hydrocephalus.

Msx1 is a regulatory gene involved in epithelio-mesenchymal interactions in limb formation and organogenesis. In the embryonic CNS, the Msx1 gene is expressed along the dorsal midline. Msx1 mutant mice have been obtained by insertion of the nlacZ gene in the Msx1 homeodomain. The most important features of homozygous mutants that we observed were the absence or malformation of the posterior commissure (PC) and of the subcommissural organ (SCO), the collapse of the cerebral aqueduct, and the development of hydrocephalus. Heterozygous mutants developed abnormal PC and reduced SCO, as revealed by specific antibodies against SCO secretory glycoproteins. About one third of the heterozygous mutants also showed hydrocephalus. Other defects displayed by homozygous mutants were ependymal denudation, subventricular cavitations and edema, and underdevelopment of the pineal gland and subfornical organ. Some homozygous mutants developed both SCO and PC, probably as a consequence of genetic redundancy with Msx2. However, these mutants did not show SCO-immunoreactive glycoproteins and displayed obstructive hydrocephalus. This suggests that Msx1 is necessary for the synthesis of SCO glycoproteins, which would then be required for the maintenance of an open aqueduct.

Energy expenditure during allogeneic and autologous bone marrow transplantation.

Resting energy expenditure (REE) was measured by indirect calorimetry during allogeneic and autologous bone marrow transplantation in order to evaluate the evolution in allogeneic and autologous recipient patients. REE values obtained with indirect calorimetry and compared with values using the Harris-Benedict formula were different. Evolution of REE during aplasia were significantly different in autologous and allogeneic recipients with an increase 11.5 ' 10.8 cent for autologous and a decrease of - 7.3 ' 8.9 cent in allogeneic bone marrow transplantation (BMT) patients. There were no differences in nutritional status and REE before BMT, at discharge and 1 month after discharge between the two groups but all patients had inflicted damage on their nutritional status at discharge from hospital after BMT. However, these patients differed because of the decrease in oral nutritional intake and an increase in the length of aplasia and hospital stay in allogeneic patients. Currently, there is no proof that recommendations for nutritional interventions or results of nutritional investigations in allogeneic BMT can be extrapolated in autologous patients. Harris-Benedict formula does not estimate the energy expenditure of patients submitted to massive chemotherapy and BMT with enough precision because of the great differences in individuals.

[Good clinical practice in nutritional management in cancer patients: malnutrition and nutritional assessment]. / Bonnes pratiques diététiques en cancérologie: dénutrition et évaluation nutritionnelle. Groupe de travail SOR.

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 the nutritional evaluation of cancer patients. METHODS: Data were identified by searching Medline and personal reference lists of members of the expert groups. Once the guidelines were defined, the document was submitted for review to 83 independent reviewers, and to the medical committees of the 20 French Cancer Centres. RESULTS: The main recommendations for the nutritional evaluation of cancer patients are: 1) Clinical and anthropometric evaluation should measure height, current weight, ideal weight, weight lost and rate of loss, and Body Mass Index. Social and economic data, details of previous history, current treatment and clinical examination results should also be collected. Gastrointestinal disorders and energetic needs should be assessed. 2) Nutritional intervention is recommended for all patients with a weight loss of 10% or more. 3) A multidimensional assessment can be performed using three validated nutritional and clinical scales: the Subjective Global Assessment, the Scored PG-SGA and the Mini Nutritional assessment. 4) The predictive value of biological factors (albumin) is not sufficient individually, risk scales combining several factors should be used: the Prognostic Inflammatory and Nutritional Index (PINI), the Nutritional Risk Index (NRI), the Prognostic Nutritional Index (Mullen) or the Sadan. 5) Minimal nutritional assessment should include clinical data, patient interview, height, current weight, ideal weight and weight change. 6) The efficacy of the nutrional management should be followed by assessing weight, and the presence of oedema and ascitis. The ratio of calorie to nitrogen intake should be calculated regularly.

[Good clinical practice in nutritional management of head and neck cancer patients]. / Bonnes pratiques pour la prise en charge diététique des patients atteints de cancer des voies aérodigestives supérieures. Groupe de travail SOR.

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. OBJECTIVE: To develop clinical practice guidelines according to the definitions of Standards, Options and Recommandations for the nutritional management of the head and neck cancer patients. METHODS: Data have been identified by literature search using Medline and the expert groups personal reference lists. Once the guidelines were defined, the document was submitted for review to 121 independent reviewers, and to the medical committees of the 20 French Cancer Centres. RESULTS: The main recommendations for the nutritional management of head and neck cancer patients are that: 1) Nutritional management prevents undernutrition, improves quality of life, reduces adverse effects of the treatment and prevents treatment delay; 2) The nutritional management of the head and neck cancer patient must be done before, during and after cancer treatment; 3) Before treatment, the weight of the patient must be assessed: 10% of weight loss in 6 months requires to an urgent nutritional intervention; 4) During radiation therapy, feeding should be adapted to various characteristics such as swallowing mechanism, side effects of the treatment, age; 5) During chemotherapy, nutrition must be checked and assessed at each cycle; 6) During surgery, enteral feeding must be stopped and nasogastric feeding progressively introduced starting on day 1 post-operatively. The quality of feed must be adequate during all the healing period. Close surveillance of fever and regurgitation allows regular review of the amount and nature of enteral feed to be given; 7) The patients are given individualised and written advice at the end of treatment and the nutritional follow-up must be planned.

[Good clinical practice in the dietetic management of cancer patients]. / Bonnes pratiques pour la prise en charge diététique en cancérologie: la consultation.

CONTEXT: The "Standards, Options and Recommendations" (SOR) project, started in 1993, is a collaboration between the Federation of the French Cancer Centres (FNCL CC), 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 feed-back from specialists in cancer care delivery. OBJECTIVES: To develop clinical practice guidelines according to the definitions of Standards, Options and Recommendations for the dietetic consultation for cancer patient. METHODS: Data have been identified by literature search wing Medline and the expert groups personal reference lists. Once the guidelines were defined, the document was submitted for review to 74 independent reviewers, and to the medical committees of the 20 French Cancer Centres. RESULTS: The main recommendations for the referral of cancer patients for dietary advice are: I) in oncology, there are 3 types of dietetic consultation: diagnostic, preventive and therapeutic; 2) the following cancer patients must have a dietetic consultation: i) those with, or at risk of malnutrition, ii) those without malnutrition but in need of counseling and iii) those at risk of treatment-related nutritional side effects; 3) a nutritional assessment is standard at the time of the first dietetic consultation. Patients must be given individualized and written advice; 4) the dietetic opinion and advice should be brought to the attention of medical staff to facilitate a multidisciplinary approach to cancer treatment; 5) patient's relatives should be involved in the dietetic management; 6) the efficacy of dietetic advice can be assessed by monitoring weight, gastrointestinal signs and patient satisfaction.

[Standards, options and recommendations: Good clinical practice in the dietetic management of cancer patients: hospital catering]. / Standards, options et recommandations: Bonnes practiques de diététique en cancérologie: la prestation alimentaire.

CONTEXT: The "Standards, Options and Recommendations" (SOR) project, started in 1993, involves a collaboration between the Federation of the French Cancer Centres (FNCLCC), the 20 French Regional Cancer Centres, some French public university and general hospitals and private Clinics and medical scientific societies. Its 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 a literature review followed by a critical appraisal by a multidisciplinary group of experts to produce the draft guidelines which are then validated by specialists in cancer care delivery. OBJECTIVES: To develop clinical practice guidelines for hospital catering for cancer patient using the methodology developed by the Standards, Options and Recommendations project. METHODS: Data were identified by a literature search of Medline and the reference lists of experts in the groups. After the guidelines were drafted, they were validated by independent reviewers. RESULTS: The main recommendations are: 1) While taking into consideration the specific needs of cancer patients, the dietician is responsible for the hygiene, the sanitary quality of alimentation, the equilibrium and nutritional quality of the hospital catering. 2) Ordering and distribution of meals, and clearing up afterwards contribute to the quality of hospital catering and the personnel who do this should have time and be willing to listen to the patients. 3) The ordering of meals should be adapted to individual patient's requirements and must take into account the patient's medication. 4) The method of transporting the food chosen by the institution (cold or warm method) should be respected. The personnel responsible should receive regular and specific training to use the method correctly. 5) The intake of patients with nutritional follow-up should be reliably and reproducibly evaluated by the personnel after every meal. 6) Patient satisfaction should be assessed once a year and the results of this assessment used to improve the quality of hospital catering. 7) The dietician is the interface between the accounts department, the medical wards, the hospital catering department and the patients.

An in situ assessment of the routes and extents of colonisation of the mouse embryo by embryonic stem cells and their descendants.

An embryonic stem (ES) cell line stably expressing lacZ under the control of an endogenous promoter has been isolated and used as a marker to follow the fate of ES cells injected into blastocysts and morulae, before midgestation. The results show a multisite pattern of blastocyst colonization by ES cells deposited into the blastocoel cavity and a low degree of mingling between ES cells and ICM cells. Furthermore, analysis of dispersal of ES cell descendants in postimplantation chimaeric embryos showed that colonization can be highly variable from one region of the embryo to another. In contrast, a high and reproducible degree of chimaerism was obtained when the ES cells were injected at the morula stage prior to ICM formation.

Targeted replacement of the homeobox gene Hox-3.1 by the Escherichia coli lacZ in mouse chimeric embryos.

Through gene targeting based upon homologous recombination in embryonic stem cells, a chosen gene can be inactivated and eventually a strain of mutant mice created. We have devised a procedure to specifically replace a targeted gene by another gene. A murine homeobox gene was disrupted at high frequency in embryonic stem cells by its replacement with Escherichia coli lacZ. Injection of such stem cells into blastocysts yielded chimeric embryos in which beta-galactosidase activity was driven by the Hox-3.1 promoter. This technique will allow the visual assessment at the cellular level of gene inactivation effects in transgenic mice.

Homeosis in the mouse induced by a null mutation in the Hox-3.1 gene.

We have replaced the Hox-3.1 coding sequence with the E. coli lacZ gene by means of homologous recombination in embryonic stem cells and thus produced null mutant mice. Homozygous mice were born alive, but most of them died within a few days. In the trunk region of homozygotes, several skeletal segments were transformed into the likeness of more anterior ones, as observed in Drosophila with loss-of-function homeotic mutations. The most obvious transformations were the attachment of the 8th pair of ribs to the sternum and the appearance of a 14th pair of ribs on the 1st lumbar vertebra. The pattern of beta-galactosidase activity was identical in heterozygotes and homozygotes and reflected faithfully the Hox-3.1 expression pattern. Thus, the mutation modified the identity, rather than the position, of embryonic cells that would normally express Hox-3.1.

Maternally expressed PGK-Cre transgene as a tool for early and uniform activation of the Cre site-specific recombinase.

A transgenic mouse strain with early and uniform expression of the Cre site-specific recombinase is described. In this strain, PGK-Crem, Cre is driven by the early acting PGK-1 promoter, but, probably due to cis effects at the integration site, the recombinase is under dominant maternal control. When Cre is transmitted by PGK-Crem females mated to males that carry a reporter transgene flanked by loxP sites, even offspring that do not inherit PGK-Cre delete the target gene. It follows that in the PGK-Crem female Cre activity commences in the diploid phase of oogenesis. In PGK-Crem crosses complete recombination was observed in all organs, including testis and ovary. We prepared a mouse stock that is homozygous for PGK-Crem and at the albino (c) locus. This strain will be useful for the early and uniform induction of ectopic and dominant negative mutations, for the in vivo removal of selective elements from targeted mutations and in connection with the manipulation of targeted loci in 'knock in' and related technologies.

Altering the spatial determinations in the mouse embryos by manipulating the Hox genes.

Developmental genetics in Drosophila led to the isolation of the homeotic genes which are involved in the cellular positional information. In vertebrates, homologous genes have been characterized and play similar roles in the spatial determination. However, the subtle mechanisms by which positional identity is specified by the Hox genes co-expression are little known. The Hoxc-8 null mutation can induce homeosis at the anterior margin of Hoxc-8 expression, where the mosaicism observed suggests that, at least in the segmented paraxial mesoderm, the number of cells expressing a Hox gene is a determinant parameter. A combinatorial model is also suggested by several genetic experiments where the level of Hox genes expression is modified. Expression of some related Hox genes in Hoxc-8 homozygous mutants is not altered, suggesting the absence of genetic interregulations between these genes.

Function and regulation of heat shock factor 2 during mouse embryogenesis.

The spontaneous expression of heat shock genes during development is well documented in many animal species, but the mechanisms responsible for this developmental regulation are only poorly understood. In vertebrates, additional heat shock transcription factors, distinct from the heat shock factor 1 (HSF1) involved in the stress response, were suggested to be involved in this developmental control. In particular, the mouse HSF2 has been found to be active in testis and during preimplantation development. However, the role of HSF2 and its mechanism of activation have remained elusive due to the paucity of data on its expression during development. In this study, we have examined HSF2 expression during the postimplantation phase of mouse development. Our data show a developmental regulation of HSF2, which is expressed at least until 15.5 days of embryogenesis. It becomes restricted to the central nervous system during the second half of gestation. It is expressed in the ventricular layer of the neural tube which contains mitotically active cells but not in postmitotic neurons. Parallel results were obtained for mRNA, protein, and activity levels, demonstrating that the main level of control was transcriptional. The detailed analysis of the activity of a luciferase reporter gene under the control of the hsp70.1 promoter, as well as the description of the protein expression patterns of the major heat shock proteins in the central nervous system, show that HSF2 and heat shock protein expression domains do not coincide. This result suggests that HFS2 might be involved in other regulatory developmental pathways and paves the way to new functional approaches.

Forebrain and midbrain regions are deleted in Otx2-/- mutants due to a defective anterior neuroectoderm specification during gastrulation.

We have replaced part of the mouse homeogene Otx2 coding region with the E. coli lacZ coding sequence, thus creating a null allele of Otx2. By 9.5 dpc, homozygous mutant embryos are characterized by the absence of forebrain and midbrain regions. From the early to midstreak stages, endomesodermal cells expressing lacZ fail to be properly localized anteriorly. In the ectodermal layer, lacZ transcription is progressively extinguished, being barely detectable by the late streak stage. These data suggest that Otx2 expression in endomesoderm and ectoderm is required for anterior neuroectoderm specification. In gastrulating heterozygous embryos, a post-transcriptional repression acts on lacZ transcripts in the ectoderm, but not in the external layer, suggesting that different post-transcriptional mechanisms control Otx2 expression in both layers.

Abnormal avoidance learning in mice lacking functional high-affinity nicotine receptor in the brain.

Nicotine affects many aspects of behaviour including learning and memory through its interaction with neuronal nicotinic acetylcholine receptors (nAChR). Functional nAChRs are pentameric proteins containing at least one type of alpha-subunit and one type of beta-subunit. The involvement of a particular neuronal nicotinic subunit in pharmacology and behaviour was examined using gene targeting to mutate beta 2, the most widely expressed nAChR subunit in the central nervous system. We report here that high-affinity binding sites for nicotine are absent from the brains of mice homozygous for the beta 2-subunit mutation. Further, electrophysiological recording from brain slices reveals that thalamic neurons from these mice do not respond to nicotine application. Finally, behavioural tests demonstrate that nicotine no longer augments the performance of beta 2-1- mice on passive avoidance, a test of associative memory. Paradoxically, mutant mice are able to perform better than their non-mutant siblings on this task.