[Hospitalized sick or premature neonates are not exclusively breast-fed because of a too restricting circular].
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to C Laurent.
Explore the source record for details and available documents.
As the vestibular system is the only sensory organ whose primary function is self-motion detection, we examined the conditions under which the otoliths, which detect the linear acceleration of the head, could be used to estimate traveled distance. In order to isolate the contribution of the otoliths (with the somatosensory system) from contributions of the visual and motor systems subjects were transported in darkness. We initially hypothesized that self-transport with continuously varying linear velocity should facilitate distance computation by continuously stimulating the otoliths, and that active control of self-motion should also help subjects estimate the distance traveled. However, it was found that the distance covered during self-motion is actually better estimated when transport velocity is quasi-constant. Nevertheless, such estimates strongly depend upon velocity magnitude; subjects show an idiosyncratic preferred self-motion velocity for which distance measurements are most accurate. Furthermore, the active control of self-transport improves estimates of self-motion mainly because the subjects can then adopt a constant velocity, and more precisely their preferred one. It was finally found that subjects mentally count in order to assess their displacement length, and that time perception is indeed disturbed by varying self-motion velocity.
Manic-depressive (bipolar) illness is a serious psychiatric disorder with a strong genetic predisposition. The disorder is likely to be multifactorial and etiologically complex, and the causes of genetic susceptibility have been difficult to unveil. Lithium therapy is a widely used pharmacological treatment of manic-depressive illness, which both stabilizes the ongoing episodes and prevents relapses. A putative target of lithium treatment has been the inhibition of the myo-inositol monophosphatase (IMPase) enzyme, which dephosphorylates myo-inositol monophosphate in the phosphatidylinositol signaling system. Two genes encoding human IMPases have so far been isolated, namely myo-inositol monophosphatase 1 (IMPA1) on chromosome 8q21.13-21.3 and myo-inositol monophosphatase 2 (IMPA2) on chromosome 18p11.2. In the present study, we have scanned for DNA variants in the human IMPA1 and IMPA2 genes in a pilot sample of Norwegian manic-depressive patients, followed by examination of selected polymorphisms and haplotypes in a family-based bipolar sample of Palestinian Arab proband-parent trios. Intriguingly, two frequent single-nucleotide polymorphisms (-461C>T and -207T>C) in the IMPA2 promoter sequence and their corresponding haplotypes showed transmission disequilibrium in the Palestinian Arab trios. No association was found between the IMPA1 polymorphisms and bipolar disorder, neither with respect to disease susceptibility nor with variation in lithium treatment response. The association between manic-depressive illness and IMPA2 variants supports several reports on the linkage of bipolar disorder to chromosome 18p11.2, and sustains the possible role of IMPA2 as a susceptibility gene in bipolar disorder.
The hypothesis of the existence of one or more schizophrenia susceptibility loci on chromosome 22q is supported by reports of genetic linkage and association, meta-analyses of linkage, and the observation of elevated risk for psychosis in people with velocardiofacial syndrome, caused by 22q11 microdeletions. We tested this hypothesis by evaluating 10 microsatellite markers spanning 22q in a multicenter sample of 779 pedigrees. We also incorporated age at onset and sex into the analysis as covariates. No significant evidence for linkage to schizophrenia or for linkage associated with earlier age at onset, gender, or heterogeneity across sites was observed. We interpret these findings to mean that the population-wide effects of putative 22q schizophrenia susceptibility loci are too weak to detect with linkage analysis even in large samples.
BACKGROUND: A phase II randomised trial was conducted to evaluate the tolerability and activity of weekly or 3-weekly docetaxel in patients with metastatic breast cancer. PATIENTS AND METHODS: Eighty-three patients with histologically proven metastatic breast cancer were randomised to receive either docetaxel 40 mg/m2 weekly for 6 consecutive weeks followed by 2 weeks without treatment (n = 41), or docetaxel 100 mg/m2 on day 1 every 3 weeks (n = 42). RESULTS: The incidence of all grade 3-4 adverse events was higher in the 3-weekly group than in the weekly group (96 versus 44), and the number of patients with grade 3-4 adverse events was also greater in the 3-weekly group (31 versus 20). Analysis of individual adverse events tended to favour the weekly regimen. Intent-to-treat overall response rate was 34% and 33% in the weekly and 3-weekly groups, respectively. Median time to progression was 5.7 and 5.3 months after weekly and 3-weekly docetaxel, respectively, and median time to treatment failure was 4.1 and 4.9 months, respectively. CONCLUSION: Weekly docetaxel is an active regimen in metastatic breast cancer with comparable efficacy to 3 weekly docetaxel. Although both schedules were well tolerated, weekly docetaxel appears to have a more favourable toxicity profile.
This study investigated demographic variables, including affected sibling pair status, as risk factors for suicidal behavior in schizophrenia patients of African (Xhosa) descent. Xhosa subjects with schizophrenia were interviewed with the Diagnostic Interview for Genetic Studies (DIGS) and then stratified into two groups: those with ( n = 90) and those without ( n = 364) a history of previous suicide attempts. Demographic parameters (including gender, age, and social circumstances, sib ship) were then compared across these groups. Demographic predictors of suicide included sib ship status ( p = 0.038; OR = 1.7) and age of onset of illness ( p = 0.008; OR = 2.5). On further analysis of suicide in siblings, only a minority of sib pairs was found to be concordant for a lifetime history of suicide attempts (3%). These findings raise the possibility that affected sib pair status may be protective in nature. Given the counter-intuitive nature of this finding, further work is needed to replicate it, and to explore possible underlying mechanisms.
We propose a new method of biodosimetry that could be applied in cases of localized irradiation. The approach is based on excess chromosome segments determination by the PCC-FISH technique in fibroblasts isolated from skin biopsy. Typically, 0 to 10 Gy ex vivo gamma-irradiated human skin biopsies were dissociated and fibroblasts were isolated and grown for several days. Cells next underwent PCC-FISH painting of whole chromosome 4, and the number of excess chromosome segments per metaphase was determined. An ex vivo reference curve correlating the number of excess chromosome segments per metaphase to the radiation dose was established and used to assess the dose delivered to the skin of one of the victims of the radiological accident that occurred at Lia in Georgia in December 2001. Specifically, the victim suffering from moist desquamation underwent skin excision in Hospital Percy (France). Measurement of excess chromosome segments per metaphase was done in fibroblasts isolated and grown from removed wounded skin and subsequent conversion to radiation doses was performed. The radiation dose map obtained was shown to be in accordance with clinical data and physical dosimetry as well as with conventional biodosimetry. These results demonstrated that PCC-FISH painting applied to skin fibroblasts may be a suitable technique for dose estimation. To assess its worth, this approach needs to be extended to future accidents involving localized radiation exposure.
The synthesis and pharmacological evaluation of a new series of potent P2X(7) receptor antagonists is disclosed. The compounds inhibit BzATP-mediated pore formation in THP-1 cells. The distribution of the P2X(7) receptor in inflammatory cells, most notably the macrophage, mast cell and lymphocyte, suggests that P2X(7) antagonists have a significant role to play in the treatment of inflammatory disease.
A solid-liquid extraction method able to perform in situ extraction of organic compounds on Mars is proposed. The extraction efficiency of various organic solvents was tested and compared to that of water. The selected key compounds are molecules of exobiological interest: glycine, alanine, serine, glutamic acid, oxalic acid, benzoic acid, phthalic acid, isophthalic acid, terephthalic acid and 1,3,5-benzenetricarboxylic acid. Among the organic solvents, propanol gives the highest yield of extraction for all the targeted compounds except for benzoic acid. A mixture of propanol and ethyl acetate increases significantly the extraction yield of benzoic acid. The extraction time was considerably reduced (140 h to 15 min) by using sonication. The method is discussed for an easy automation with coupling to an in situ GC-MS space instrument.
BACKGROUND: Survival after resection of colorectal liver metastases may be influenced by the patient, the primary tumour and the liver metastases. Postoperative morbidity is associated with poor survival in several cancers. The aim of this retrospective study was to evaluate prognostic factors of survival after resection of colorectal liver metastases, including postoperative morbidity. METHODS: From 1985 to 2000, 311 consecutive patients with liver metastases from colorectal cancer underwent resection with curative intent. Univariate and multivariate analyses were performed to assess the influence of age, sex, site and stage of the colorectal tumour, disease-free interval, number, size and distribution of metastases, type of hepatectomy, pedicular clamping, resection margin, blood transfusion, postoperative morbidity and adjuvant chemotherapy on overall and disease-free survival. RESULTS: The postoperative mortality and morbidity rates were 3 and 30 per cent respectively. The 3- and 5-year overall survival rates were 53 and 36 per cent respectively. Both overall and disease-free survival rates were independently associated with nodal status of the colorectal tumour, number of metastases and postoperative morbidity. Patients with postoperative morbidity had an overall and disease-free 5-year survival rate half that of patients with no morbidity: 21 versus 42 per cent for overall survival (P < 0.001) and 12 versus 28 per cent for disease-free survival (P = 0.001) respectively. CONCLUSION: Long-term survival can be altered by postoperative morbidity after resection of colorectal liver metastases by increasing the risk of tumour recurrence. This justifies optimizing the surgical treatment of colorectal liver metastases to decrease postoperative morbidity and the use of efficient adjuvant treatments in patients with postoperative morbidity.
OBJECTIVE: To evaluate results of laparoscopic pancreatectomy for benign lesions of the pancreas. Peri-operative data, surgical outcomes and techniques are presented. PATIENTS AND METHODS: Eighteen women and four men underwent laparoscopic pancreatectomy and were collected retrospectively from 1999 to 2003. RESULTS: Laparoscopic pancreatectomy was attempted in 22 patients and completed successfully in 18: 10 enucleations, three distal pancreatectomies, four left pancreatectomies and one total pancreatectomy for endocrine and cystic tumors. Left and distal pancreatectomies were performed with preservation of the spleen. Four patients were converted (one enucleation, one whipple procedure and two left pancreatectomy). There was no mortality; the post-operative morbidity included two pancreatic leaks and one case of half splenic infarction. The median length of hospital stay was 12 days. CONCLUSION: Patients appear to benefit from laparoscopic pancreatectomy for pancreatic benign tumors.
Explore the source record for details and available documents.
Infections with 3 species of malaria parasites are rarely encountered and observed in less than 0.05% of cases. We came across such an infection in four year-old, monozygote twin sisters, coming from Kinshasa (Democratic Republic of Congo). In both of them, parasitemia was low or very low for P. falciparum and P. ovale and of 0.1-0.2% for P. malariae. The twin sisters presented with an iron deficiency anaemia, associated with an heterozygous sickle-cell anaemia and a moderate splenomegaly. The biological tests results were similar. They responded well to treatment. We point out the difficulty in recognizing the concomitant presence of several species of hematozoaire on blood smear.
UNLABELLED: Increased understanding of the natural history of the disease, standardization of surgery and new procedures have led to significant advances in the treatment of rectal cancer. Anatomical dissection of the mesorectum permits optimal local control and volume cases may further improve oncological RESULTS: Autonomic pelvic nerves are preserved by the technique of total mesorectal excision (TME) and adapted anterior dissection plans improve preservation of genito-urinary functions. Sphincter preservation can be achieved by a conventional anterior resection for high and mid-rectal tumours, and by the technique of intersphincteric resection for low tumours. A J-pouch or a recently-designed coloplasty pouch must be associated with coloanal anastomoses in order to improve functional results and loop ileostomy is recommended to decrease early postoperative morbidity. Local excision constitutes an alternative to major surgery in patients with a low-risk early rectal cancer. Neoadjuvant treatments have a role in local control of the disease after TME surgery and in new strategies of sphincter-saving procedures. The place of anorectal reconstruction and that of laparoscopy are also discussed.
Polychlorodibenzo-para-dioxins (PCDDs) and Polychlorodibenzofurans (PCDFs) are ubiquitous in the environment. They are mainly formed as unwanted byproducts during various chemical, industrial, and combustion processes. Thus, these pollutants can be found in the food chain. The aim of this experiment was to study the transfer of PCDD/Fs from spiked milk to arterial blood in pigs, which are considered as valid models for humans. Pigs were fed with 900 mL of milk spiked with a mixture of 17 dioxins. The levels of PCDD/Fs in the serum extracts were determined using HRGC/HRMS prior to consumption of the milk, and at 3, 5, and 7 h after milk ingestion. Concentrations of PCDD/Fs in arterial plasma increased from 3 h to 5 h and decreased at 7 h. At time point 5 h, concentrations were found between 500 and 10000 pg x g(-1) fat. The transfer ratio < > was usually found between 0.7 and 3%. Related to the different milk concentrations, results of this study indicate a similar behavior of the studied molecules.
Two different methods of derivatization were studied in order to select and optimize one for the in situ enantiomeric separation of amino acids present in Martian samples. The method, using DMF-DMA [N,N-dimethylformamide dimethyl acetal], is simple and easily automated. However, byproducts of the reaction interfere in the gas chromatograms and mass spectrometry detection is needed for in situ analysis. The chloroformate derivatization has several advantages, including the use of achiral robust capillary column, room temperature reaction, and short analysis. The choice of the definitive derivatization method will depend on the energy and time devoted to the analysis of amino acids in the next Mars exploration missions.
UNLABELLED: Underdiagnosis of asthma is frequent in children and may be improved by the development of school-based health programs. MATERIAL AND METHODS: We developed an educational program in 11-year-old schoolchildren who participated in a screening test for exercise-induced asthma (EIA). All children were given an asthma questionnaire before and after two educational sessions. RESULTS: Mean score for asthma knowledge quiz increased from 63 to 85% (p < 0.001). Thirty-six children (3.7%) were initially considered as asthmatic and showed better responses than non-asthmatic children. Peak expiratory flow (PEF) was measured before and after an outside running exercise. A fall in PEF of at least 15% was considered an abnormal result. Seventy-height children (8%) had a decrease in PEF, including 65 children initially not recognized as asthmatic. For these latter, a medical evaluation was recommended to parents. Only 28 of these children gave informations on follow-up: 19 had lung function tests, two received a treatment without preliminary function test, and seven had neither lung function test nor treatment. Among the children who realized lung function tests, five had criteria for airway obstruction at baseline, and ten had significant bronchial hyperreactivity. CONCLUSIONS: However, a new screening test revealed that only a small minority of children initially not recognized as asthmatic but having decreased their PEF, were consequently considered as asthmatic by their practitioner, even in case of positive lung function test.
Malaria is a worldwide epidemic causing high morbidity and mortality especially in children younger than 5 years. In France the incidence of pediatric malaria has constantly increased up to 1500 cases in the last two years, due to Plasmodium falciparum in more than 80% of cases. According to current recommendations, any patient with clinical suspicion or confirmed diagnosis of malaria must be hospitalized for treatment. Halofantrine is the most widely used antimalarial for treatment of uncomplicated P. falciparum malaria in children. However due to halofontrine-related cardiotoxicity some teams recommend mefloquine as the first-line drug despite disadvantages related to its poorly adapted formulation and adverse gastrointestinal effects in young children. Treatment of malaria involving other plasmodium species is still based on chloroquine. Likewise the World Health Organization continues to recommend chloroquine as the first-line agent for uncomplicated malaria in endemic zones with moderate chloroquine resistance. Amodiaquin or sulfadoxine-pyrimethamine combination may be used either in case of failure or as first-line agents in zones with high chloroquine resistance. In case of multiple resistance, quinine may be used alone or in association with an antimicrobial. Other drug therapies such as combinations using artemisinine derivatives have been shown to be highly effective for control of clinical symptoms and parasitemia. Widespread use of these therapies to prevent the appearance and extension of resistance is now undergoing evaluation.