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Biomedical subjects

A Camus

Publications and source records attributed to A Camus.

At least 19 recordsLinked to original sources
PubMed2006

[The comparison of the process of five different vitrification devices].

Over the last decade, several methods have been designed to improve the survival rate of vitrificated embryos. Although some teams have succeeded, the main remaining drawback of these methods is that they do not provide a leak proof environment for cryopreserved biological samples. To respond to that demand in respect with the European reglementation, the Cryo Bio System company (CBS) designed the HSV High Security Vitrification Kit (HSV). This system is composed of three distinct parts, a High Security thermal-autogenic sealed clear straw, a capillary with its extremity in form of a gutter, and an introducer that can be mounted on the manipulation rod before introduction into the straw. In this study, we confirmed that the CBS vitrification kit is a suitable method for vitrification in association with a small amount of cryoprotector enriched viscous media such as 25 microM Ficool 400, 750 mM Sucrose, 1% Bovine albumin, 20% Dimethyl Sulfoxide and 20% Ethylene glycol in a Phosphate buffered saline solution. We also evaluated the speed of the temperature decrease during vitrification in comparison with four other commercially available non-aseptic methods and showed the protective role of the CBS system during transfer. These physical data have now been confirmed biologically by P. Vanderzwalmen who obtained easily reproductible good results with human embryo using our method. Today, the HSV represents the unique aseptic alternative device (EC and FDA approved) for embryos, oocytes, and biological samples vitrification.

Cryopreservation↗
PubMed2006

Mutation in the Trapalpha/Ssr1 gene, encoding translocon-associated protein alpha, results in outflow tract morphogenetic defects.

Translocon-associated protein complex (TRAP) is thought to be required for efficient protein-specific translocation across the endoplasmic reticulum membrane. We created a mutation in the Trapalpha gene that leads to the synthesis of a truncated TRAPalpha protein fused to ShBle-beta-galactosidase. Analysis of Trapalpha cDNAs reveals that among three different messenger RNAs expressed in the mouse, one of them encodes a slightly larger protein that differs in its C-terminal end. This mRNA, specific for skeletal muscle and heart, is only expressed after birth. Homozygous Trapalpha mutant pups die at birth, likely as a result of severe cardiac defects. Indeed, the septation of the proximal part of the outflow tract is absent, resulting in a double-outlet right ventricle. Studies of protein secretion in transfected embryonic fibroblasts reveal that the TRAP complex does not function properly in homozygous mutant cells and confirm, in vivo, the involvement of TRAP in substrate-specific translocation. Our results provide the first in vivo demonstration that a member of the TRAP complex plays a crucial role in mammalian heart development and suggest that TRAPalpha could be involved in translocation of factors necessary for maturation of endocardial cushions.

Aging↗
PubMed2005

[The palliative care in geriatrics: a retrospective study of 40 cases].

INTRODUCTION: Owing to the very great age and the polypathology of the patients in geriatrics, we are often confronted to the palliative care decision. PURPOSE: The purposes of this retrospective study were both to define the criteria leading to palliative care and to analyse the evolution of patients. METHOD: We analysed 40 files of patients hospitalised in Geriatric internal medicine or Geriatric rehabilitation departments over 11 months. RESULTS: Mean age was 85.4 years and 62.5% of patients were females. Infections, heart failure, general weakness, orthopaedic affections, strokes and cancers were the main causes of hospitalisation. Patients had 3 medical or surgical histories of chronic or cured serious diseases and a MMSE average value of 17.7. The rate of malnutrition was 92% and 90% of patients were very dependent. Severe infections, cancers, heart failure and severe pressure ulcers were the main affections for decision of palliative care. The latter was always decided by the staff with patients or families taking part in 8 cases and being informed in other cases. The palliative care lasted 7 days on average. Morphine was used in 31 cases. No artificial nutrition was introduced. CONCLUSION: The decision of palliative care is very complex since great age, polypathology, great dependence and high prevalence of cognitive disorders are frequent in this population.

Aged↗
PubMed2004

Evaluation of the microbial safety of a new 1.5 l enteral feeding diet reservoir system.

BACKGROUND & AIMS: Microbial safety is essential during enteral nutrition (EN) as it can be the origin of gastrointestinal symptoms, but can also lead to systemic infections. The use of large-volume diet reservoirs could limit the risk of contamination and reduce nursing time, due to fewer repeated manipulations. The aim of the study was to evaluate in vivo the microbial safety of a new 1.5l enteral feeding diet reservoir system. METHODS: After validation of the study settings under standard laboratory conditions, 86 EN lines with sealed fittings were connected to 1.5l diet reservoirs under hospital/patient conditions. Microbial identification and quantification at different sampling times and points were performed. RESULTS AND CONCLUSIONS: No microbial contamination was observed in the diet reservoirs and in the nutrition lines above the drip chamber, demonstrating the microbial safety of this system. Retrograde contamination of the distal nutrition line end at completion of EN was observed and may be affected by the cumulative time of use of the tube. The contaminating microbial species were essentially bacteria of normal oral and digestive flora.

Bacteria↗
PubMed2001

Gene trap insertion reveals two open reading frames in the mouse SSeCKS gene: the form predominantly detected in the nervous system is suppressed by the insertion while the other, specific of the testis, remains expressed.

Scaffold proteins play an important role in regulating signal transduction by targeting kinases and phosphatases in close proximity to their relevant substrates. SSeCKS protein has been described as a protein kinase C and A (PKC/PKA) anchoring protein as well as a PKC substrate with a tumor suppressor activity. In this study, we report the generation, via gene trapping in embryonic stem cells of mice carrying an insertion in the mouse SSeCKS gene. Through the molecular analysis of the insertion site, we show that SSeCKS contains two alternative promoters directing the synthesis of mRNAs (P1- and P2-mRNA), encoding two different proteins, one of which would be a truncated form of the other. Interestingly, these RNAs are differentially expressed, P2 being found exclusively in the male germ line, while P1 exhibits a dynamic and wider pattern of expression during embryonic development and in the adult; its expression is predominant in the nervous system. Finally, we show that P1- but not P2-mRNA expression is abolished by the insertion and furthermore that mice homozygous for the mutation lack SSeCKS in all tissues except the male germ cells. Nevertheless and surprisingly, these mice do not exhibit any obvious phenotype. The functional implications of these observations are discussed.

A Kinase Anchor Proteins↗
PubMed2000

[Posture and aging. Current fundamental studies and management concepts].

FUNDAMENTAL IMPORTANCE OF POSTURE: In the elderly subject, preservation of posture is fundamental to maintaining functional independence. In recent years, there has been much progress in our understanding of the mechanisms underlying strategies used to control equilibrium in the upright position. Physiological aging, associated with diverse disease states, dangerously alters the postural function, particularly anticipated adjustments which allow an adaptation of posture to movement. CLINICAL ASSESSMENT OF POSTURE: Several tests have been developed to assess posture in the elderly subject, particularly the time it takes to start walking. We selected certain tests which can be used in everyday practice to predict falls: the stance test, the improved Romberg test, the "timed get up and go test", measurement of walking cadence, assessment of balance reactions, sitting-standing and standing-sitting movements and capacity to get up off the floor. PATIENT CARE: Elderly patients with equilibrium disorders can benefit from specific personalized rehabilitation protocols. Different techniques have been developed for multiple afferential stimulation, reprogramming postural strategies, and correcting for deficient motor automatisms.

Accidental Falls↗
PubMed2000

The plague

Explore the source record for details and available documents.

Journal Article↗
PubMed2000

The morphogenetic role of midline mesendoderm and ectoderm in the development of the forebrain and the midbrain of the mouse embryo.

The anterior midline tissue (AML) of the late gastrula mouse embryo comprises the axial mesendoderm and the ventral neuroectoderm of the prospective forebrain, midbrain and rostral hindbrain. In this study, we have investigated the morphogenetic role of defined segments of the AML by testing their inductive and patterning activity and by assessing the impact of their ablation on the patterning of the neural tube at the early-somite-stage. Both rostral and caudal segments of the AML were found to induce neural gene activity in the host tissue; however, the de novo gene activity did not show any regional characteristic that might be correlated with the segmental origin of the AML. Removal of the rostral AML that contains the prechordal plate resulted in a truncation of the head accompanied by the loss of several forebrain markers. However, the remaining tissues reconstituted Gsc and Shh activity and expressed the ventral forebrain marker Nkx2.1. Furthermore, analysis of Gsc-deficient embryos reveals that the morphogenetic function of the rostral AML requires Gsc activity. Removal of the caudal AML led to a complete loss of midline molecular markers anterior to the 4th somite. In addition, Nkx2.1 expression was not detected in the ventral neural tube. The maintenance and function of the rostral AML therefore require inductive signals emanating from the caudal AML. Our results point to a role for AML in the refinement of the anteroposterior patterning and morphogenesis of the brain.

Animals↗
PubMed1998

Altered control of cellular proliferation in the absence of mammalian brahma (SNF2alpha).

The mammalian SWI-SNF complex is an evolutionarily conserved, multi-subunit machine, involved in chromatin remodelling during transcriptional activation. Within this complex, the BRM (SNF2alpha) and BRG1 (SNF2beta) proteins are mutually exclusive subunits that are believed to affect nucleosomal structures using the energy of ATP hydrolysis. In order to characterize possible differences in the function of BRM and BRG1, and to gain further insights into the role of BRM-containing SWI-SNF complexes, the mouse BRM gene was inactivated by homologous recombination. BRM-/- mice develop normally, suggesting that an observed up-regulation of the BRG1 protein can functionally replace BRM in the SWI-SNF complexes of mutant cells. Nonetheless, adult mutant mice were approximately 15% heavier than control littermates. This may be caused by increased cell proliferation, as demonstrated by a higher mitotic index detected in mutant livers. This is supported further by the observation that mutant embryonic fibroblasts were significantly deficient in their ability to arrest in the G0/G1 phase of the cell cycle in response to cell confluency or DNA damage. These studies suggest that BRM participates in the regulation of cell proliferation in adult mice.

Animals↗
PubMed1998

Comparison of bacteriological qualities of various egg yolk sources and the in vitro and in vivo fertilizing potential of bovine semen frozen in egg yolk or lecithin based diluents.

The addition of components of animal origin (egg yolk, milk) to most commercial diluents used to freeze bull semen represents a potential risk of contamination of the doses with bacteria or mycoplasma. A series of quantitative and qualitative analyses were performed to detect microbiological contamination observed in Biociphos plus (a new lecithin-glycerol based freezing salt buffer), in an egg yolk diluent (Triladyl) or in an egg yolk + milk-based (Laiciphos) diluent of bull semen. The 2 diluents containing animal products showed moderate (10 to 60 CFU/mL) contamination (17/17 samples) with bacteria or mycoplasma, or both, while no contamination was observed in the 6 examined batches of Biociphos plus. Biociphos plus was also compared with another commercial diluent (Laiciphos) for use in freezing bull semen intended for in vitro and/or in vivo fertilization. No difference (P > 0.05) could be detected between the 2 diluents for in vitro fertility rates (percentage of cleaved zygotes: 85.7% and 88.0%, respectively, for Laiciphos and Biociphos plus). Similarly, 2 series of comparisons conducted in dairy cows artificially inseminated with semen frozen in either Biociphos plus or Laiciphos showed no difference in fertilizing capacity (tested at 60 to 90 d; P > 0.05) irrespective of the age of the bulls (Trial 1, bulls aged 14 to 15 m.o.; Trial 2, bulls aged 2 to 5 yr, field trials). It is concluded that, in addition to maintaining the fertilizing capacity of bull semen at levels comparable to those observed with standard freezing diluent, Biociphos plus also prevents microbiological contamination by bacteria or mycoplasma, both of which are generally present in the various commercially available sources of egg yolk.

Animals↗
PubMed1998

[Reversible bronchial spasm syndrome in the very old].

UNLABELLED: HIGH PREVALENCE: Several epidemiological studies have shown that the prevalence of bronchial asthma is high in the elderly. It is often difficult to establish the diagnosis of asthma in this population because of the scarcity of symptoms. Pulmonary function tests are widely used to confirm the diagnosis. These tests are possible in most elderly people excepting cases of severe dementia. MECHANISMS: Pathophysiology of asthma in the elderly may be characterized by superimposition of different factors: 1) the effect of age which is associated with airway adrenoreceptor dysfunction; 2) the impact of chronic pulmonary diseases which may increase airways inflammation; 3) the role of triggers such as infections or various medications. MANAGEMENT: Management of asthma consists in a specific treatment of trigger(s) associated with anti-inflammatory and bronchodilator medications. Elderly subjects may have difficulty using offinhalators and spacer devices are widely used.

Aged↗
PubMed1997

Null mutation of the prolactin receptor gene produces multiple reproductive defects in the mouse.

Mice carrying a germ-line null mutation of the prolactin receptor gene have been produced by gene targeting in embryonic stem cells. Heterozygous females showed almost complete failure of lactation attributable to greatly reduced mammary gland development after their first, but not subsequent, pregnancies. Homozygous females were sterile owing to a complete failure of embryonic implantation. Moreover, they presented multiple reproductive abnormalities, including irregular cycles, reduced fertilization rates, defective preimplantation embryonic development, and lack of pseudopregnancy. Half of the homozygous males were infertile or showed reduced fertility. This work establishes the prolactin receptor as a key regulator of mammalian reproduction, and provides the first total ablation model to further study the role of the prolactin receptor and its ligands.

Animals↗
PubMed1997

63Cu-31P coupling constants and 63Cu quadrupole couplings from 31P CP/MAS spectra of copper (I)--phosphine complexes with aryldithiocarboxylates or benzoate.

Magic-angle spinning 31P NMR spectra of solid [CuS2C-Ph(PPh3)2] 1, [{CuS2C-pT}4(PPh3)2] 2, [{CuS2C-Ph}4(PPh3)2] 3. [CuS2C-Ph(dppm)]2 4 and [CuO2C-Ph(dppm)]2 5, (T = tolyl, dppm = bis(diphenylphosphino)methane) were obtained at 109.6 MH2. They consist of distorted quartets from non-equivalent phosphorus atoms and provide approximate values of the indirect spin-spin coupling constant J[63Cu,31P], that are indicative of the covalency of the dithiocarboxylate-copper bonding. The spacing distortions are related to a number of molecular and structural parameters and thereby allow an estimation of the copper quadrupole coupling constant e2qQ/h which, as expected, is smaller for tetra-coordinated (1, 2, 3 and 4) than for tri-coordinated (5) copper sites. The spectrum of 2 has been successfully simulated (including the isotope effects from the less abundant 65Cu isotope) using the full theory for calculation of the spin eigenfunctions of the quadrupolar nucleus.

Benzoates↗
PubMed1996

Transgenic mice expressing the Sh ble bleomycin resistance gene are protected against bleomycin-induced pulmonary fibrosis.

Despite the high efficiency of bleomycin (BLM) as a chemotherapeutic agent against various carcinomas, the potentially lethal and chronic fibrotic response of the lung is a major dose-limiting side effect. Here, we explore the possibility of a direct inhibition of lung tissue injury by in vivo expression of the actinomycetes BLM resistance protein Sh ble. Transgenic mice expressing the Sh ble gene under the control of a composite viral promoter were produced after introduction of the transgene into D3 ES cells. The protein was detected at high level in lungs, spleen, and kidney. We then assessed its ability to modulate the BLM-induced fibrotic response in the transgenic mice in comparison with C57BL/6 and 129/Sv parental mice. Cumulative doses of 300, 400, or 500 mg/kg BLM were administered either by i.p. or s.c. repeated injections in the different strains. Transgenic mice were shown to be clearly less sensitive to BLM toxicity, as assessed by lung histology. The pulmonary hydroxyproline content in the treated transgenic mice was close to its baseline level, whereas it was up to 50% higher than the control level in C57BL/6 and 129/Sv parental mice. These observations are consistent with the hypothesis that a resistance gene specifically expressed in lungs may prevent the BLM-induced inflammation.

Acetyltransferases↗
PubMed1996

Unexpected behavior of a gene trap vector comprising a fusion between the Sh ble and the lacZ genes.

A new gene trap vector has been designed, comprised of a fusion between the Sh ble gene, which confers resistance to the antibiotic phleomycin, and the lacZ gene (phleal fusion gene). A synthetic splice acceptor, made of the yeast branchpoint followed by a pyrimidin-rich sequence of 27 nucleotides, is included at the 5' extremity. The linearized gene trap vector was introduced into mouse embryonic stem cells (ES cells), and 40 phleomycin resistant (phleo') cell lines possessing a single copy of the insert were selected. They were stable in expressing the lacZ gene. Reporter gene expression was studied at days 8.5 and 10.5 of embryonic development in chimeric embryos obtained after injection of phleo' ES clones into 8-cell stage embryos. Out of 20 phleal lines examined, 14 exhibited beta-galactosidase expression at day 10.5. Use of the phleal fusion gene trap vector to select genes expressed in ES cells, therefore, is compatible with the isolation of genes expressed at midgestation. However, and most intriguingly, 10 out of these 14 cell lines (71%) displayed reporter gene expression mostly in heart and liver. Two of them exhibited, in addition, expression in central nervous system (CNS) or in CNS and limb buds, respectively. Germline chimeras were subsequently obtained and 15 mouse lines have been established. Intercrosses of animals heterozygous for the insertion revealed a mutant phenotype in several lines.

Animals↗