Search PubMed⌕ Search

Biomedical subjects

G Sayers

Publications and source records attributed to G Sayers.

At least 19 recordsLinked to original sources
PubMed1999

Determinants of folic acid knowledge and use among antenatal women.

BACKGROUND: Although recommendations on folic acid use were issued by health authorities in a number of countries in the early 1990s, uptake of peri-conceptional folic acid is still disappointingly low. Regardless of food fortification policies, folic acid promotion will probably be required in most countries to optimize folate levels among women of child-bearing age. The aim of this study was to examine folic acid knowledge and use, and their determinants among antenatal women in the east of Ireland in 1997. METHODS: Three hundred antenatal women attending their initial booking appointment in three Dublin maternity hospitals were surveyed. An interviewer-administered questionnaire was used with questions on folic acid knowledge and use, and demographic and obstetric questions. A univariate analysis of data was undertaken followed by a multivariate analysis using logistic regression to determine factors predicting knowledge and use of folic acid. RESULTS: Seventy-six per cent of respondents had heard of folic acid, 16 per cent had taken it before pregnancy and 51 per cent during pregnancy. Women who had planned their pregnancy, were married and were relatively affluent were significantly more likely to have heard of folic acid, to know that it could prevent neural tube defects and to have taken it peri-conceptionally. Less affluent women tended to use their general practitioner (GP) more as a source of information and advice than those who were better off. In multivariate analysis, marriage and planned pregnancy were important predictors of folic acid knowledge whereas planned pregnancy advice given before pregnancy and relative affluence were predictive of peri-conceptional use. CONCLUSIONS: Many women know of folic acid but do not take it peri-conceptionally. Women may associate folic acid with pregnancy and less with pre-pregnancy. Greater emphasis on peri-conceptional use should improve folic acid uptake. Focusing on less affluent women for folic acid promotion by GPs and other primary care professionals is also important.

Adult↗
PubMed1999

Folic acid knowledge and use among expectant mothers in 1997: a comparison with 1996.

This study examined changes in folic acid knowledge and use among antenatal women in Dublin maternity hospitals between 1996 and 1997, following a campaign to improve the very low uptake of peri-conceptional folic acid. The results showed significant improvements between the two years. Almost 76% of respondents had heard of folic acid in 1997 compared with 54% in 1996 (p < 0.01), with a shift in the proportion of people hearing of folic acid from hospital doctors to general practitioners (GP). Almost 43% of respondents in 1997 knew that folic acid can prevent spina bifida compared with 21% in 1996 (p < 0.01). A higher proportion was taking folic acid prior to conception in 1997 (16% vs 6%, p < 0.01). We conclude that the improvements may have been in part due to the promotional campaign among health professionals, women's groups and the media. However, less than a fifth of women were taking folic acid peri-conceptionally in 1997 and there is still scope for much improvement.

Adult↗
PubMed1997

National survey of MRSA: Ireland, 1995.

The objective of this survey was to obtain an indication of the size of the methicillin-resistant Staphylococcus aureus (MRSA) problem in Ireland prior to introducing national MRSA control guidelines. A survey of all microbiology laboratories in Ireland was carried out over two weeks in Spring 1995. For patients from whom MRSA was isolated during the study period standard demographic and clinical data were requested and period prevalence/1000 discharges was calculated. All 45 microbiology laboratories surveyed responded. MRSA was isolated from 448 patients during the two-week period. The period prevalence of MRSA was 16.5/1000 discharges. Males aged > or = 65 had the highest rate (50/1000 discharges). Half of all isolates were from patients in surgical or medical wards, but 4% were from community-based sources such as GPs, nursing homes and hospices. Thirty-two percent of MRSA patients were infected rather than colonized. MRSA is clearly a significant problem in Ireland. While it is largely a hospital problem at present, the increasing trend towards day procedures and shorter hospital stay means that infection will increase in the community.

Adolescent↗
PubMed1997

Knowledge and use of peri-conceptional folic acid among antenatal patients.

Peri-conceptional folic acid can prevent more than half of all neural tube defects (NTDs). A cross-sectional interviewer administered study was undertaken among 300 women attending their first antenatal appointment in the three major Dublin maternity hospitals. The aim of the study was to monitor knowledge and behaviour with respect to peri-conceptional folic acid among antenatal patients. There was a 98% (295/300) response rate. 53.6% (158/295) had heard of folic acid. Such knowledge was significantly associated with age over 30 years (p < 0.001), a planned pregnancy (p < 0.001) and being married (p < 0.001). The majority (58.2%) found out about folic acid from lay sources such as friends or the media. One eighth (12.9%, 38/295) had been advised to take folic acid before pregnancy, the majority (58.3%, 21/38) having been advised by doctors. 21% (62/295) knew that it prevented spina bifida. 5.8% (17/295) had taken it before becoming pregnant. Taking folic acid before pregnancy was significantly associated with having a planned pregnancy (p < 0.005) and being married (p < 0.005). This study highlights the poor impact of health promotion campaigns to date and provides a challenge to health professionals.

Adolescent↗
PubMed1992

Plasmacyte-reticulum cell satellitism in multiple myeloma associated with amyloidosis.

A novel morphological feature is described in a patient with myeloma and associated amyloidosis: characteristic clustering (satellitism) of neoplastic plasma cells around macrophages in bone marrow aspirates. Although described in myeloma cell culture, as far as is known, this is the first description of this phenomenon in a patient. This unique association may partly explain the origin of amyloid deposition in tissues and organs.

Aged↗
PubMed1989

Identification, synthesis and immunogenicity of cuticular collagens from the filarial nematodes Brugia malayi and Brugia pahangi.

The major structural proteins of the cuticle of the filarial nematode parasites Brugia malayi and Brugia pahangi were identified by extrinsic iodination and sensitivity to clostridial collagenase. At least 16 acidic components were identified in adult worms by 2-dimensional electrophoresis, with molecular weights ranging from 35,000 to 160,000. These proteins appear to be cross-linked by disulphide bonds, and localised in the basal and inner cortical layers of the cuticle. The outer cortex, containing the epicuticle, is insoluble in 1% sodium dodecyl sulphate and 5% 2-mercaptoethanol, and can be isolated free of cellular material. Despite their inaccessibility to the immune system in intact worms, antibodies to the cuticular collagens are provoked in humans infected with a variety of filarial parasites. Immunological cross-reactivity was demonstrated between a 35 kDa component and human type IV (basement membrane) collagen. Autoantibodies to type IV collagen were detected in a number of individuals with lymphatic filariasis, although no correlation could be drawn with observed pathology. Synthesis of cuticular collagens is discontinuous, occurs at negligible levels in mature adult male worms, and does not appear to involve the production of small molecular weight precursors, in contrast to Caenorhabditis elegans. Hybridisation with a heterologous cDNA probe coding for the alpha 2 chain of chicken type 1 collagen suggests that they are encoded by a multigene family.

Animals↗
PubMed1987

Leishmania donovani metacyclic promastigotes: transformation in vitro, lectin agglutination, complement resistance, and infectivity.

Freshly transformed Leishmania donovani amastigotes from hamster spleen were used to establish axenic cultures at high density in a modified Grace's medium, which was only partly replenished when cultures were fed. Small, free-swimming, highly active stationary phase promastigotes with a short cell body and long flagellum were induced in this medium. The freshly transformed stationary phase promastigotes so induced were less able to bind peanut agglutinin, had more than 40-fold increased resistance to killing by normal human serum, and 15-fold increased infectivity both in vivo and in vitro when compared to freshly transformed logarithmic phase or long term culture promastigotes. These short form promastigotes may correspond to the metacyclic promastigote forms in the sand fly vector.

Agglutination↗
PubMed1986

Macrophage type 3 complement receptors mediate serum-independent binding of Leishmania donovani. Detection of macrophage-derived complement on the parasite surface by immunoelectron microscopy.

In this study, direct visual evidence for local opsonization of L. donovani by macrophage (M phi)-derived complement components was obtained using immunoelectron microscopy. C3 deposition was detected on the surface of both promastigotes and amastigotes after 20 min serum-free incubation with murine resident peritoneal M phi (RPM), followed by fixation and incubation first with specific antibody directed against C3 and then with gold-labelled protein A. Gold deposition was not observed around either form of the parasite if the anti-C3 antibody was omitted. For promastigotes, the degree of C3 deposition under serum-free conditions was comparable with that observed in the presence of an exogenous (serum) source of C3, but did not result in the same severe damage to the parasite as did the latter. Addition of sodium salicyl hydroxamate, which prevents covalent binding of C3 to activator surfaces, abrogated promastigote binding. Hence, although the anti-C3 antibody did not distinguish between native C3 and its breakdown product iC3b, these data support our earlier conclusion that promastigote binding to the CR3 of murine RPM is complement dependent. For amastigotes, gold deposition and binding to murine RPM were not eliminated by sodium salicyl hydroxamate. The presence of normal mouse serum resulted in increased gold deposition, but did not mediate either enhanced binding to M phi or damage to the amastigote. These data suggest that a proportion of C3 binding to the amastigote surface may be via noncovalent linkages, and that the C3 bound may not be in the correct form to mediate binding to CR3.

Animals↗
PubMed1985

Oxygen radical release by adherent cell populations during the initial stages of a lethal rodent malarial infection.

A series of experiments was carried out to assess the levels of reactive oxygen intermediates (ROI) released by macrophages and monocytes during an acute malarial infection, and to consider the importance of oxidant-induced parasite killing in host protection. Adherent cell populations were removed from the peritoneum and spleen of BALB/c and B10/D2/n mice between Days 0-5 of a Plasmodium yoelii nigeriensis infection. These cell populations were quantified, characterized and their ROI-releasing capacity was measured by following ferricytochrome c reduction upon stimulation with phorbol myristate acetate (PMA). Both strains of mice displayed higher numbers of macrophages and macrophage precursors as the infection progressed; this rise was more marked and accompanied by splenomegaly in BALB/c mice. A concurrent decrease in peritoneal cell numbers was observed. Splenic adherent cell populations released much lower levels of ROI than peritoneal macrophages upon triggering. The levels of ROI released from BALB/c splenic adherent cells rose gradually until Day 3, when the parasitaemia was slightly decreased. In contrast, splenic populations from B10 mice had a decreased capacity to release ROI, particularly after Day 3, when the parasitaemia rose sharply. In further studies, electron microscopy was used to detect H2O2 release during the in vitro interaction of peritoneal macrophages and parasitized erythrocytes. Cerium chloride staining techniques demonstrated that H2O production was not dependent on phagocytosis or the presence of immune serum, although levels were increased by the presence of the latter.

Animals↗
PubMed1984

Biochemical surface components of Brugia pahangi microfilariae.

The sheath and cuticle of microfilariae of Brugia pahangi were examined by electron microscopy and the presence of various proteins, carbohydrate and enzymes sought. The epicuticle of microfilariae consists of a pentalaminate structure (24.0 +/- 1.4 nm), a cortex (13.7 +/- 3.6 nm) and a basal zone (27.8 +/- 4.8 nm) which is often banded in appearance. The pentalaminate layers are not continuous at the base of the interannular grooves. The sheath and the epicuticle of B. pahangi stained positively with concanavalin A and saccharated iron oxide. The sheath of approximately 50% of microfilariae showed activity for acid phosphatase, 5' nucleotidase and peroxidase, but not for ATPases, alkaline phosphatase or esterase. No enzymes were detected in the epicuticle although the cortex and basal layers of the cuticle did show enzymic activity. Structures beneath the cuticle in the main body of the worms contained considerable enzymic activity. Microfilariae directly isolated from the blood of infected cats were found by immunochemical means to carry serum proteins on their sheaths but not on their cuticles. These studies extend the definition of the outer structures of microfilariae and confirm that they significantly differ in morphology and enzyme content from typical mammalian cell membranes.

Acid Phosphatase↗