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Biomedical subjects

M Douglas

Publications and source records attributed to M Douglas.

At least 55 records · Page 3Linked to original sources
PubMed1996

The resolution of the neutral N-linked oligosaccharides of IgG by high pH anion-exchange chromatography.

The introduction of high pH anion-exchange chromatography (HPAEC) has represented a major development in the qualitative analysis of glycoprotein derived oligosaccharides. When coupled with pulsed amperometric detection, the technique permits the detection of picomole quantities of heterogeneous mixtures of oligosaccharide without the need for derivatisation. The applications of HPAEC have generally been limited to the analysis of sialylated oligosaccharides, however, it is now possible to analyse heterogenous mixtures of neutral oligosaccharides with the latest systems. We have used such a system to separate completely a panel of seven commercially available neutral N-linked oligosaccharides and found the influence of monosaccharide substitution on elution position to be identical to that for sialylated structures. A standard monosialylated N-linked oligosaccharide was modified by sequential digestion with specific exoglycosidases to produce a monogalactosylated, diantennary oligosaccharide which is commercially unavailable. This standard's elution position was confirmed by HPAEC. The technique was applied to the identification of neutral N-linked oligosaccharides released from human immunoglobulin G using the enzyme peptide-N-glycosidase F.

Carbohydrate Conformation↗
PubMed1996

Recruitment experience in the African American Study of Kidney Disease and Hypertension (AASK) Pilot Study.

Several approaches for recruitment of African American adults with renal insufficiency due to hypertension (glomerular filtration rate between 25 and 70 ml/min/1.73 m2) were explored in the Pilot Study for the African American Study of Kidney Disease and Hypertension (AASK). Over a period of 42 weeks, prescreening information was obtained on 2880 individuals, of whom 498 (17%) were evaluated at a screening visit. Two hundred and twenty-five (8%) had an 125I-iothalamate assessment of glomerular filtration rate. Ninety-four of 97 participants who met all the study eligibility criteria were enrolled in the trial. The most common reasons for ineligibility during screening were absence of renal insufficiency or hypertension, presence of diabetes mellitus, and a body mass index above the acceptable level. Overall, an average of 31 prescreen contacts and 8 screening visits were conducted for every randomization (3.3% yield from prescreening to randomization). Screening in clinical practice was the most efficient method for recruitment (12.6% yield from prescreen contact to randomization compared to 1.1% from mass mailing campaigns, 1.3% from mass media campaigns, and 1.7% from referrals by patients with end-stage renal disease). Randomization yields increased with progressively higher age ranges (2.4%, 3.3%, and 6.0% prescreen to randomization yields for those aged < or = 50, 51-60, and 61-70, respectively). A slight majority (51%) of the prescreen contacts were women, but 75% of the randomized participants were men. Our results suggest that clinic-based screening is an effective approach for recruitment of African Americans with hypertension and renal insufficiency into clinical trials. They also suggest that enrollment of African American women in such studies is a special challenge.

Adult↗
PubMed1996

Appointment attendance, pill counts, and achievement of goal blood pressure in the African American Study of Kidney Disease and Hypertension Pilot Study.

The African American Study of Kidney Disease and Hypertension (AASK) Pilot Study evaluated the feasibility of conducting a 7-year clinical trial to assess the effect of two levels of blood pressure control based on mean arterial pressure (MAP) (low goal < or = 92 mm Hg or usual goal of 102-107 mm Hg) and three antihypertensive drug regimens (atenolol, amlodipine, or enalapril) as initial therapy in slowing the decline of renal function in African Americans with clinically diagnosed hypertensive nephrosclerosis. Ninety-four African American men and women between 18 and 70 years of age were randomized and followed for an average of 4.6 months. On average participants attended 87.5% of the scheduled monthly follow-up visits and achieved an acceptable level of medication adherence (80%-100% of prescribed doses by pill count) at 65.4% of those visits Blood pressure levels within goal were observed in 17.5% and 25.6% of the participants in the low- and usual MAP goal groups, respectively. Neither attendance nor medication adherence by pill count was associated with attainment of goal blood pressure. Although AASK Pilot Study participants maintained excellent attendance, their pill counts were lower than previously reported among clinical trial participants and goal blood pressure levels were difficult to achieve during the short period of follow-up.

Adult↗
PubMed1996

Necrotizing fasciitis: a nursing perspective.

Necrotizing fasciitis (NF) has been around for many years but recent media attention has brought attention to this potentially fatal disease. This paper examines the most recent descriptions of NF, and describes initial as well as advanced stages of the infection. Treatment of NF is widely agreed upon by physicians in that broad spectrum antibiotics and immediate debridement are crucial to patient outcome. Recent thoughts as to immune system response are briefly explored. The client presented is an extremely unusual case where spontaneous remission occurred after 4 days, and so gives rise to the potential immune system theory.

Anti-Bacterial Agents↗
PubMed1995

Characterization of a recombinant pneumolysin and its use as a protein carrier for pneumococcal type 18C conjugate vaccines.

Pneumolysin from Streptococcus pneumoniae was expressed in Escherichia coli as a glutathione S-transferase fusion protein and purified by affinity and hydroxylapatite chromatography. The purified recombinant pneumolysin (rPL), with a molecular mass of 53 kDa, had a specific activity of 3 x 10(5) hemolytic units per mg of protein on rabbit erythrocytes and reacted identically in immunodiffusion with the antisera against native pneumolysin. The rPL was used as a protein carrier to prepare conjugate vaccine with pneumococcal type 18C polysaccharide (PS18C). The PS18C was directly coupled to rPL by reductive animation or was indirectly coupled to rPL via a spacer molecule, adipic acid dihydrazide. The conjugates were nontoxic for mice and guinea pigs at 100 micrograms per dose. The immunogenicity and protective efficacy of both conjugates were tested in mice. A single dose of either of the vaccines elicited a rise in immunoglobulin G antibody production; after two booster injections of the vaccines, statistically significant booster responses (P < 0.001) to both rPL and PS18C were produced. The sera containing the antibodies to rPL were capable of neutralizing the hemolytic activity of rPL to rabbit erythrocytes and the cytotoxicity of rPL to bovine pulmonary endothelial cells. Immunization with the conjugate vaccines conferred statistically significant protection in mice against lethal challenge with type 18C pneumococci.

Animals↗
PubMed1995

The clinical value of three-dimensional intravascular ultrasound imaging.

Two-dimensional (2D) intravascular ultrasound (IVUS) imaging can now be reconstructed into three dimensions from serial 2D images captured following a "pullback" of the IVUS catheter through the target site. Three-dimensional (3D) reconstructions provide "longitudinal" and "volume" images. The former is similar to an angiogram and can be examined in three dimensions by rotating the image around its longitudinal axis, providing clinically useful information during endovascular procedures. The volume view takes longer to create and is not an exact reconstruction, but it provides images that can be rotated into any spatial position. It visualizes the luminal aspect of the vessel particularly well. The clinical value of 3D IVUS is in the diagnosis of vascular disease and the assessment of endovascular interventions. Three-dimensional IVUS, which provides better, more informative images than 2D IVUS, can be particularly useful intraprocedurally in detecting inaccurate deployment of intravascular stents and endoluminal grafts.

Arteries↗
PubMed1992

Improving the diet of under fives in a deprived inner city practice.

This paper reports the introduction of a programme of dietary education to a selected group of young mothers living in a deprived inner city area. The programme was devised by a general practitioner and practice health visitors in collaboration with two hospital dietitians. A diary was used to provide data on diet, food choice, shopping habits, eating together, and planning and frequency of meals. These were included in a list of twelve 'desirable' food groups and three organisational skills, thus providing an individual syllabus for teaching, and a means of assessing the intervention. At the start of the study milk, fruit, vegetables and protein containing iron were common dietary omissions. However, the results show that these foods were an established part of the children's diets following the intervention. The dietary diaries provided a successful means of analysis, and the teaching programme is continuing in this practice. The limitations of such a small study are acknowledged, and a long-term controlled study is suggested.

Adult↗
PubMed1991

Chicken bone lodged in the upper esophagus: CT findings.

The authors report a case of a chicken bone lodged in the esophagus at the cervicothoracic junction. Both the radiographic and endoscopic examinations of the esophagus had failed to detect the ingested bone, but computed tomography (CT) demonstrated it as an opaque fragment penetrating the esophageal wall.

Bone and Bones↗
PubMed1991

Supervision of rural health centres in Papua New Guinea: consolidation of the delivery of health services.

Aid posts and health centres remain the health facilities in most direct contact with the community in Papua New Guinea. The planners of health services have well accepted the difficulties of adverse geography and sectoral differences, and adapted a method of delivery which is efficient and appropriate for all levels of health personnel. Those peripheral staff, however, have been left to their own devices. It should be considered that the continued success and achievement of the milestones of health care in Papua New Guinea require close surveillance and support at the basic level. Intensive supervision is essential to the consolidation and progress of existing health services.

Allied Health Personnel↗
PubMed1991

2'-O-alkyloligoribonucleotides, synthesis and applications in molecular biology.

Oligo(2'-O-alkylribonucleotides) have been synthesized in which alkyl is methyl, allyl and butyl. The various phosphoramidite monomers of 2'-O-alkyl uridine, cytidine, adenosine, guanosine, inosine and 2,6-diaminopurine riboside have been synthesized from a minimum of key intermediates. Extra protection of the lactam function in uracil and hypoxanthine proves useful. The high stability of the oligomers combined with incorporation of non-radioactive reporter groups such as fluorophores, biotin and 2,4-dinitrophenylamino (DNP) moities renders them as excellent antisense tools for studying RNA processing, for locating and visualising RNA and RNP complexes in cells, for examining splicing complexes by electron microscopy and for the affinity chromatography of RNA or RNP complexes.

Antisense Elements (Genetics)↗