PubMed Health⌕ Search

Biomedical subjects

P Lucas

Publications and source records attributed to P Lucas.

At least 19 recordsLinked to original sources
PubMed2006

A systematic review of lay views about infant size and growth.

OBJECTIVES: To understand lay views on infant size and growth and their implications for a British population. METHODS: A systematic review of parental and other lay views about the meanings and importance of infant size and growth using Medline, PsycInfo, CINAHL, Sociological Abstracts, IBSS, ASSIA, British Nursing Index ChildData, Caredata, SIGLE, Dissertation Abstracts (US), Index to Theses. 19 studies, most of which reported the views of mothers, from the US, Canada, the UK and Finland were reviewed. RESULTS: Notions of healthy size and growth were dominated by the concept of normality. Participants created norms by assessing and comparing size and growth against several reference points. When size or growth differed from these norms, explanations were sought for factors that would account for this difference. When no plausible explanation could be found, growth or size became a worry for parents. CONCLUSIONS: Parents consider the importance of contextual factors when judging what is appropriate or healthy growth. For public health advice to be effective, lay, as well as scientific, findings and values need to be considered.

Anthropometry↗
PubMed2004

[Certificates for insurances: common law, industrial accidents, personal insurances].

The certificates for the insurances are medical testimonies based on this principle: the truth, all the truth, nothing but the truth. They must give to the insurance the informations which are essential for building the patient's file, but they must respect the rules of ethics and the laws concerning the protection of privacy and the patient's rights. The certificate giving the description of the traumatic lesions is essential in all the procedures but the physician must know what to write and to whom this document must be delivered. In common law, where the victim must prove the lesions and their traumatic origin, the certificate is due to the patient himself. In industrial accidents, the specific law of 10 April 1971 dictates the contents of the several certificates: report of the lesions, recovery, review. In personal insurance, the law concerning the patient's rights teaches the limits of the information and to whom it must be given. The certificate is a service and a right of the victim; it must be quite relevant.

Accidents, Occupational↗
PubMed2003

[Human African trypanosomiasis in an urban area: an emerging problem?].

The human African trypanosomiasis is essentially a rural disease. The notification of cases in urban area has always been incidental; either a diagnosis made in town revealed a disease contracted in rural environment or it meant the preservation of a complete epidemiological cycle in a remaining urban micro-focus. In Kinshasa, in Democratic Republic of Congo, about forty cases have been notified each year. All of them came from the nearby foci of Bandundu, Lower Congo and Kasaï. In 1996 the number of cases reached suddenly 254 and today the average annual number comes up to 500 in spite of all the efforts undertaken to fight the disease. A study of cases in 1998 and 1999 shows that patients are essentially distributed in suburbs and that the most affected by the disease are the 15-49 year old ones whose job is related with agricultural or fishing activities. Two phenomena seem to explain this sudden increase: the massive inflow of refugees in outskirts of town coming from provinces where trypanosomiasis is endemic and a major economic crisis throwing out urban population in suburbs living on a subsistence micro-agriculture. These concomitant factors have contributed to the setting up of a trypanosomiasis belt around the capital. Today a strategy has to be reconsidered in order to fight against the disease in the capital itself and to make the medical staff aware of the diagnosis of a disease still unknown in their sanitary district.

Adolescent↗
PubMed2002

[Sleeping sickness: one hundred years of control strategy evolution].

Sleeping sickness has been known since the fifteenth century but the real progress in the knowledge of the disease occurred in the nineteenth century with the development of microscopy. From 1841 to 1901 the parasites and their vectors have been identified, the symptomatology and the epidemiology have been described. However, due to absence of any effective cure, the campaign against the disease was still based on the isolation of the patients and the transfer of exposed populations. The discovery of atoxyl in 1905 provided doctors with their first therapeutic weapon and, in 1910, the first action of vector control was undertaken with success in the Island of Principe. Between the two world conflicts, Jamot published the rules to fight against major outbreaks. Their application in Oubangui-Chari, in Cameroon and in French Occidental Africa brought tremendous results and signed the triumph of the mobile unit concept. Success which will not be denied until the sixties when the disease was believed to be eradicated. From the sixties to the nineties, the concept of the integration of prevention and care added to the exclusion of any vertical system will result in a progressive reniewed outbreak of the sleeping sickness in the known foci. As a paradox, it is a time rich in discovery as regards diagnosis, treatment and entomology. In 1994, the World Health Organisation got concerned with the situation of the disease in Central Africa where the outbreak of the disease reinforced. A second paradox appeared; it is the next to total disinterest from the politics and fund raisers which will save the disease. Today, sleeping sickness is the typical example of the orphan disease, a show case brandished by all the good souls. In 2001, an agreement between the WHO and the pharmaceutical industry brings back the financial funds required to fight the disease. Basically, it is a matter of resuming the action by using what is still existing and by creating new strategies considering the extreme lack of human and logistical resources. The objective is to eradicate the sleeping sickness as a public health problem. The challenge is huge, but is on the way to success.

Africa↗
PubMed2001

Rapid evolution of the DNA-binding site in LAGLIDADG homing endonucleases.

Sequence analysis of chloroplast and mitochondrial large subunit rRNA genes from over 75 green algae disclosed 28 new group I intron-encoded proteins carrying a single LAGLIDADG motif. These putative homing endonucleases form four subfamilies of homologous enzymes, with the members of each subfamily being encoded by introns sharing the same insertion site. We showed that four divergent endonucleases from the I-CreI subfamily cleave the same DNA substrates. Mapping of the 66 amino acids that are conserved among the members of this subfamily on the 3-dimensional structure of I-CreI bound to its recognition sequence revealed that these residues participate in protein folding, homodimerization, DNA recognition and catalysis. Surprisingly, only seven of the 21 I-CreI amino acids interacting with DNA are conserved, suggesting that I-CreI and its homologs use different subsets of residues to recognize the same DNA sequence. Our sequence comparison of all 45 single-LAGLIDADG proteins identified so far suggests that these proteins share related structures and that there is a weak pressure in each subfamily to maintain identical protein-DNA contacts. The high sequence variability we observed in the DNA-binding site of homologous LAGLIDADG endonucleases provides insight into how these proteins evolve new DNA specificity.

Amino Acid Motifs↗
PubMed2001

Sleeping sickness surveillance: an essential step towards elimination.

In the last decades, with little or no surveillance sleeping sickness has returned to alarming levels comparable to the early twentieth century. Sixty million people are considered at risk but only 3-4 million are under surveillance, yielding some 45 000 new cases annually. It is estimated that at least 300 000-500 000 people are presently infected. Despite the almost universal presence of the vector in sub-Saharan Africa and the existence of an animal parasite reservoir, it is technically feasible to control and eliminate the disease as a public health problem. The authors describe, step-by-step, a surveillance method based on the epidemiological status of the village and using several approaches ranging from passive to active surveillance. Co-ordinated by the WHO, such surveillance has been incepted in several countries. Epidemiological data is spatially linked to the village, whose geographical co-ordinates are collected using a Global Positioning Systems (GPS). Information is transmitted to WHO through internet. Data analysis and mapping is carried out using Geographical Information System (GIS) software and thematic maps are generated to illustrate epidemiological status. Examples from Central African Republic (CAR), Cameroon and Gabon illustrate the process and mapping.

Cameroon↗
PubMed2001

Randomized study comparing the efficacy of a novel manual breast pump with a mini-electric breast pump in mothers of term infants.

The objective of this study was to compare the efficacy of a mini-electric pump (MEP) and a novel manual breast pump (MP) designed to operate more physiologically. Sixty term breastfeeding mothers used the MP and MEP in randomized order 8 weeks postpartum, expressing for 10 minutes from each breast. Milk volume, fat content, and pattern of milk flow were measured. Mothers rated pump characteristics by questionnaire. There was no significant difference in the milk volume or fat content when mothers used the pumps in randomized order. The MP was rated significantly better overall and more comfortable and pleasant to use. Significantly more mothers kept the MP than the MEP. Despite the greater complexity and expense of the MEP, the pumps showed similar efficacy. The MP was preferred by mothers. The novel, more physiological operation of the MP represents an advance in milk expression technology.

Adult↗
PubMed2001

Randomized trial comparing the efficacy of a novel manual breast pump with a standard electric breast pump in mothers who delivered preterm infants.

OBJECTIVE: The benefits of human milk for preterm infants are widely recognized, yet technological advances in milk expression have been slow. We compared the efficacy of a standard electric pump (EP; Egnell) used in 94% of United Kingdom neonatal units with a novel manual pump (MP; Avent ISIS) designed to operate more physiologically by simulating the infant's compressive action on the areola during breastfeeding. METHODS: We randomized 145 women who delivered infants of <35 weeks' gestation to use the MP or the EP and measured total milk volume expressed while using the randomized pump during the infant's hospital stay, pattern of milk output and creamatocrit of milk expressed during a test period in the second week, and pump characteristics by maternal questionnaire. RESULTS: Mothers who used the EP, who frequently double pumped, showed shorter expression times but produced no more milk than mothers who used the MP. When both pumped sequentially, however, mothers who used the MP showed significantly greater milk flow and total volume over 20 minutes. Creamatocrit was unaffected by pump type. The MP was rated significantly higher than the EP on 5 major characteristics. CONCLUSIONS: When compared on equal terms (sequential pumping), mothers who used the MP showed greater milk flow, perhaps reflecting more physiologic pump design. Even with double pumping, mothers who used the EP did not advantage their infants with greater milk production. We believe that this novel, effective MP, preferred by mothers and costing a fraction of the EP price, reflects a significant advance in milk expression for high-risk infants.breast pumps, randomized trial, preterm infants.

Breast↗
PubMed2001

[Monitoring human African trypanosomiasis in Central Africa in 2001 and cartography: results and perspectives].

Cases of human African trypanosomiasis are distributed in changing geographical "outbreak areas" that can be visualized over time and space. Because of these variations in distribution, cartography and spatial analysis provide powerful tools for planning surveillance and control strategies. In 1996, the WHO in collaboration with the 15 most endemic countries in Central Africa undertook a program to develop a standardized inter-regional map of trypanosomiasis. This article provides a brief overview of the value of geomatic tools in public health followed by a description of the WHO program and its preliminary results. Also presented in this article is the Trypinfo site being development on the internet to increase the surveillance response-time and improve the feedback system.

Africa, Central↗
PubMed2001

[Control of human African trypanosomiasis: back to square one].

The natural history of sleeping sickness is cyclic. The first epidemic outbreak in the 19th century devastated the population and resolved spontaneously for lack of victims. Intensive development during the colonial period and the movement of population that it spawned led to another epidemic in the early 1920s that reached such severe proportions that drastic steps had to be taken. At that time, Jamot was given complete political, administrative, and financial freedom to combat the disease. This program led to the development of the mobile team concept and so-called vertically structured vector control strategy and was so successful that sleeping sickness ceased to be considered as a major public health problem at the beginning of the 1960s. In the ensuing years sleeping sickness was largely neglected. Monitoring the disease required specialized teams that were no longer considered as cost-effective. One by one the measures that had been implemented to control the disease disappeared, thus setting the scene for a new outbreak grew. In 1995, the incidence of sleeping sickness reached the same levels as in the 1920s. The current situation is a classic example of a neglected disease with a paucity of competent specialists, diagnostic tests, effective drugs, and operational facilities. It was not until 2001 that new hope appeared thanks to a combined public- and private-sector initiative allowing restructuring of treatment teams, renovation of facilities, free distribution of drugs, and research to develop new therapeutic agents. Also thanks to the PATTEC initiative, the governments of the African affected nations are showing new in interest in sleeping sickness. However the battle is far from won and much effort will be required. Time is running out and the stakes are high.

Africa↗
PubMed2001

[Human African trypanosomiasis in the urban milieu: the example of Kinshasa, Democratic Republic if the Congo, in 1998 and 1999].

Human African trypanosomiasis is an essentially rural disease. Occurrence in urban areas is uncommon except in cities that reproduce rural conditions conducive to the survival of glossinidae, i.e., forest and water. This is the case in neighborhoods near the zoo in Brazzaville, People's Republic of the Congo and in the residual mangrove forest in Conakry, Guinea. In Kinshasa, Democratic Republic of the Congo, an average of 39 cases were reported annually from 1970 to 1995. This figure increased to 254 in 1996 and 226 in 1997. This sharp rise led authorities to organize screening operations in some neighborhoods of the capital city. Results documented 433 cases in 1998 and 912 cases in 1999. The highest prevalence was found in outlying areas. This finding was probably related to focus of screening in these locations and to the practice of market gardening on plots surrounding the city. Placement of 276 insect traps along the Ndjili River led to the capture of 42,231 glossinidae over a 4 month period. Taken together, these findings indicate that the conditions necessary for active disease transmission are now reunited and that priority should be given to intensifying screening operations and information campaigns to health care providers working in the city.

Adolescent↗
PubMed2000

Biochemical characterization of I-CmoeI reveals that this H-N-H homing endonuclease shares functional similarities with H-N-H colicins.

Endonuclease assays of the H-N-H proteins encoded by two group I introns in the Chlamydomonas moewusii chloroplast psbA gene revealed that the CmpsbA.1 intron specifies a site-specific DNA endonuclease, designated I-CMOE:I. Like most previously reported intron-encoded endonucleases, I-CMOE:I generates a double-strand break near the insertion site of its encoding intron, leaving 3' extensions of 4 nt. This enzyme was purified from Escherichia coli as a fusion protein with a His tag at its N-terminus. The recombinant protein (rI-CMOE:I) requires a divalent alkaline earth cation for DNA cleavage (Mg(2+) > Ca(2+) > Sr(2+) > Ba(2+)). It also requires a metal cofactor for DNA binding, a property shared with H-N-H colicins but not with the homing endonucleases characterized to date. rI-CMOE:I binds its recognition sequence as a monomer, as revealed by gel retardation assays. K:(m) and k(cat) values of 100 +/- 40 pM and 0.26 +/- 0.04 min(-1), respectively, were determined. Replacement of the first histidine of the H-N-H motif by an alanine residue abolishes both rI-CMOE:I activity and binding to its substrate. We propose that this conserved histidine residue plays a role in binding the metal cofactor and that such binding induces a structural modification of the enzyme which is required for DNA recognition.

Algal Proteins↗
PubMed2000

HIV-1 infection through the CCR5 receptor is blocked by receptor dimerization.

The identification of the chemokine receptors as receptors for HIV-1 has boosted interest in these molecules, raising expectations for the development of new strategies to prevent HIV-1 infection. The discovery that chemokines block HIV-1 replication has focused attention on identifying their mechanism of action. Previous studies concluded that this inhibitory effect may be mediated by steric hindrance or by receptor down-regulation. We have identified a CCR5 receptor-specific mAb that neither competes with the chemokine for binding nor triggers signaling, as measured by Ca(2+) influx or chemotaxis. The antibody neither triggers receptor down-regulation nor interferes with the R5 JRFL viral strain gp120 binding to CCR5, but blocks HIV-1 replication in both in vitro assays using peripheral blood mononuclear cells as HIV-1 targets, as well as in vivo using human peripheral blood mononuclear cell-reconstituted SCID (severe combined immunodeficient) mice. Our evidence shows that the anti-CCR5 mAb efficiently prevents HIV-1 infection by inducing receptor dimerization. Chemokine receptor dimerization also is induced by chemokines and is required for their anti-HIV-1 activity. In addition to providing a molecular mechanism through which chemokines block HIV-1 infection, these results illustrate the prospects for developing new tools that possess HIV-1 suppressor activity, but lack the undesired inflammatory side effects of the chemokines.

Animals↗