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Biomedical subjects

C McKenzie

Publications and source records attributed to C McKenzie.

At least 37 records · Page 2Linked to original sources
PubMed2000

Prevalence of malnutrition on admission to four hospitals in England. The Malnutrition Prevalence Group.

AIMS: The primary objective was to estimate prevalence of malnutrition on admission to four hospitals. Secondary objectives included assessing the relationship between nutritional status and length of hospital stay, numbers of new prescriptions, new infections and disease severity. METHODS: We entered eligible patients according to predefined quotas for elective and emergency admissions to 23 specialties. We measured height, weight, Body Mass Index and anthropometrics, and recorded history of unintentional weight loss. Patients who had lost > or = 10% of their body weight, had a Body Mass Index <20, or had a Body Mass Index <20 with one anthropometric measurement <15th centile were considered malnourished. RESULTS: Of 1611 eligible patients, 761 did not participate; 269 were too ill; 256 could not be weighed; and 236 refused consent. Eight hundred and fifty were subsequently evaluated. Prevalence of malnutrition on admission was 20%. Length of stay, new prescriptions and infections and disease severity were significantly higher in the malnourished. CONCLUSIONS: One patient in every five admitted to hospital is malnourished. Although this figure is unacceptably high, it may underestimate true prevalence. Malnutrition was associated with increased length of stay, new prescriptions and infections. Malnutrition may also have contributed to disease severity.

Adolescent↗
PubMed2000

Ecological effects of triclosan and triclosan monophosphate on defined mixed cultures of oral species grown in continuous culture.

The effects of triclosan and its phosphorylated derivative, triclosan monophosphate were studied using a continuous culture microcosm model. Two conditions were simulated, a caries-like state (pH 5.5 with artificial saliva plus glucose as growth medium) and a periodontal disease-like state (pH 7.5 with BHI plus yeast extract, haemin and cysteine as growth medium). Both cultures were maintained anaerobically at 37 degrees C at a growth rate of 0.1/h. Steady-state chemostats were pulsed with triclosan or triclosan monophosphate (initial concentrations between 20 and 40 mg/L) and changes in the ecological composition noted after 6 h. The caries-like microcosm steady state was dominated by streptococci, Lactobacillus and Veillonella sp. with low but detectable levels of Neisseria, Actinomyces and Fusobacterium sp. No significant ecological shifts occurred following pulses of either antimicrobial agent; all species were affected to approximately the same degree. The periodontal disease-like microcosm steady state was dominated by streptococci, Fusobacterium, Veillonella, Actinomyces, Prevotella and Porphyromonas sp. with low numbers of Neisseria and Lactobacillus sp. Significant ecological shifts were apparent following pulses of triclosan. The streptococci became the dominant group followed by Fusobacterium sp. For triclosan monophosphate, the streptococci again became dominant although Lactobacillus and Actinomyces were now the main sub-dominant species and Gram-negative anaerobes including Fusobacterium sp. were markedly inhibited. It is concluded that in the periodontal disease state, both triclosan and triclosan monophosphate affected the Gram-negative anaerobes to a greater extent than the Gram-positive groups and that this effect was more marked for triclosan monophosphate.

Anti-Infective Agents, Local↗
PubMed1998

T1 fast acquisition relaxation mapping (T1-FARM): an optimized reconstruction.

Maps of spin lattice relaxation time (T1) can be reconstructed directly from magnetic resonance imaging (MRI) k-space data measured with very short data acquisition times, e.g., a data set for a 128 x 128 T1 map can be acquired in less than 3 s using gradients with 10-T/m/s slew rate. In principle, this approach could be extended to quantitate other MRI parameters but current use is limited by the lack of precise, accurate and fast reconstruction. Using theoretical calculations, computer simulations, and experiments we have optimized a parametric reconstruction method using a Leverberg-Marquardt (L-M) algorithm and compared it to the quasi-Newton method originally used. We have found significant improvement using the L-M method provided T1 is solved for directly without linearization. Reconstruction time was reduced by a factor of 60. Computer simulations show that the method has acceptable accuracy even in signals with 5% noise. Optimization included the investigation of the signal-to-noise (S/N) of each k-space data point and its impact on relative error of the reconstruction. This result indicates that rectangular k-space data could be collected for further reduction of data acquisition times. Determination of T1 maps by direct parametric reconstruction of k-space data appears feasible and may stimulate further application of quantitative MRI.

Algorithms↗
PubMed1998

Quality of midwifery led care: assessing the effects of different models of continuity for women's satisfaction.

BACKGROUND: Changing Childbirth (1993), a report on the future of maternity services in the United Kingdom, endorsed the development of a primarily community based midwifery led service for normal pregnancy, with priority given to the provision of "woman centred care". This has led to the development of local schemes emphasising continuity of midwifery care and increased choice and control for women. AIMS: To compare two models of midwifery group practices (shared caseload and personal caseload) in terms of: (a) the extent to which women see the same midwife antenatally and know the delivery midwife, and (b) women's preference for continuity and satisfaction with their care. METHODS: A review of maternity case notes and survey of a cohort of women at 36 weeks of gestation and 2 weeks postpartum who attended the two midwifery group practices. Questionnaires were completed by 247 women antenatally (72% response) and 222 (68%) postnatally. Outcome measures were the level of continuity experienced during antenatal, intrapartum, and postnatal care, women's preferences for continuity of carer, and ratings of satisfaction with care. RESULTS: The higher level of antenatal continuity of carer with personal caseload midwifery was associated with a lower percentage having previously met their main delivery midwife (60% v 74%). Women's preferences for antenatal continuity were significantly associated with their experiences. Postnatal rating of knowing the delivery midwife as "very important indeed" was associated with both previous antenatal ratings of its importance, and women's actual experiences. Personal continuity of carer was not a clear predictor of women's satisfaction with care. Of greater importance were women's expectations, their relations with midwives, communication, and involvement in decision making. CONCLUSIONS: Midwifery led schemes based on both shared and personal caseloads are acceptable to women. More important determinants of quality and women's satisfaction are the ethos of care consistency of care, good communication, and participation in decisions.

Cohort Studies↗
PubMed1998

Dumping syndrome in a young Jamaican child.

The dumping syndrome in childhood is an uncommon complication of gastro-oesophageal surgery, principally Nissen fundoplication. A Jamaican child developed the syndrome after fundoplication and pyloroplasty to relieve gastro-oesophageal reflux complicating the repair of a congenital tracheo-oesophageal fistula. He developed marasmus and failed to gain weight on the standard remedial milk-based high-energy diet. An oral glucose tolerance test confirmed the diagnosis of dumping syndrome. A low sugar low milk diet based on adult type meals with continuous nibbling of fried dumplings relieved his diarrhoea and hypoglycaemia and he gained weight. This is a cheaper and more practical dietary therapy than the regimens described previously.

Dumping Syndrome↗
PubMed1998

General practitioners' attitudes to the development of midwifery group practices.

BACKGROUND: The report Changing childbirth (1993) has led to the development of midwifery-led schemes that aim to increase the continuity of maternity care. AIM: To determine the impact of midwifery group practices on the work of general practitioners (GPs) and their perceptions of midwifery group practice care. METHOD: Postal questionnaires were sent to 58 GPs referring women to the care of midwifery group practices (group-practice GPs), and a shorter questionnaire was sent to the remaining 67 GPs (non-group-practice GPs) within the same postcode area as a comparison group. In-depth interviews were conducted with 12 GPs. RESULTS: Questionnaires were returned by 71% of group-practice GPs and 81% of non-group practice GPs. One third of the group practice GPs felt that they were seeing group practice women too few times, and 50% thought midwives discouraged women from visiting their GP for antenatal checks. Over 80% of group practice GPs believed that midwives had the skills to detect deviation from the normal, and 66% would confidently refer women to their care. However, only 14% of group practice GPs believed that their own role was clear, while 64% agreed that communication with group practice midwives was poor, and concerns were expressed about the level of consultation before establishing schemes. Of the non-group practice GPs, 87% said they would consider referring women to the care of a midwifery group practice in the future. CONCLUSIONS: General practitioners were generally positive about the quality of care provided by midwifery group practices but identified issues that require addressing in developing this model of care.

Attitude of Health Personnel↗
PubMed1997

Concentrations and patterns of organic contaminants in Atlantic white-sided dolphins (Lagenorhynchus acutus) from Irish and Scottish coastal waters.

Chlorobiphenyls (CBs) and organochlorine pesticides (OCPs) have been determined in the blubber of 17 Atlantic white-sided dolphins stranded at Killala Bay, Co Mayo, Ireland and five from the Scottish coast. The concentrations of the contaminants measured range from 773 to 63,400 microg kg(-1) for sigmaCB and from 160 to 54,600 microg kg(-1) for sigmaDDT. The concentrations of the CBs and OCPs is highly dependent on the age, sex, reproductive state and nutritional condition of the animals in addition to the intake via the food web. Principal Components Analysis (PCA) has been used to study the variation of chemical patterns (data ratioed to CB 153). Immature animals (< 6 years), mature males and primogravid females, and lactating females could be distinguished on the basis of their contaminant patterns. This paper describes the different processes of bioaccumulation and metabolism of organochlorine contaminants (OCs) in this species.

Journal Article↗
PubMed1997

Effects of triclosan and triclosan monophosphate on maximum specific growth rates, biomass and hydrolytic enzyme production of Streptococcus sanguis and Capnocytophaga gingivalis in continuous culture.

Dental plaque species, Streptococcus sanguis and Capnocytophaga gingivalis, were grown in continuous culture with progressively increasing concentrations of triclosan or its phosphorylated derivative, triclosan monophosphate (TMP). For both organisms, the maximum specific growth rates decreased with increasing concentrations of triclosan or TMP until complete inhibition of growth occurred, which for S. sanguis was at 20 mg/L and 50 mg/L, and for C. gingivalis was at 10 mg/L and 5 mg/L for triclosan and TMP respectively. For both species, biomass levels remained approximately constant or, in some cases, increased slightly at low levels of triclosan or TMP. However, biomass levels then decreased significantly as the triclosan or TMP concentrations approached lethal levels. For S. sanguis, levels of hydrolytic enzymes (acid phosphatase, leucine aminopeptidase and esterase) generally remained approximately constant or increased with increasing concentrations of triclosan or TMP until close to inhibitory levels where enzyme levels were reduced. The ratio of extracellular soluble enzymes to cell-bound enzymes remained constant or increased slightly with increasing levels of triclosan or TMP. For C. gingivalis, production of hydrolytic enzymes (neutral phosphatase, leucine aminopeptidase and trypsin-like protease) remained constant or were reduced when grown with low levels of triclosan and TMP but in some cases increased with higher levels of agents. The proportion of extracellular soluble activity increased significantly when concentrations of agent neared inhibitory levels. The results taken together show that the physiology of cells is significantly altered and that hydrolytic enzymes are released from the cells when these are grown in the presence of increasing concentrations of triclosan or TMP. Enzyme release is more pronounced in the Gram-negative C. gingivalis and indicates that triclosan or TMP can cause membrane perturbation with subsequent release of membrane-located (S. sanguis) or periplasmic (C. gingivalis) hydrolytic enzymes. S. sanguis was more sensitive to triclosan than TMP while C. gingivalis was more sensitive to TMP. This suggests that, in C. gingivalis, TMP may diffuse into the cell wall more easily than triclosan and then be converted to triclosan by phosphatase activity within the cell wall complex, where it may give rise to high localized concentrations and subsequent cell damage.

Acid Phosphatase↗
PubMed1997

Deprivation of form vision suppresses diurnal cycling of retinal levels of leu-enkephalin.

Deprivation of form vision by the fitting of translucent occluders suppressed the diurnal cycling of enkephalinergic amacrine cells (the ENSLI amacrine cells), in the chicken. Daily periods of normal vision or enforcing temporal contrast using strobe lighting appeared to restore normal functioning of the ENSLI cells. These results suggest that the ENSLI cells are involved in retinal circuits that assess the quality of the visual image and control eye growth.

Adaptation, Ocular↗
PubMed1997

Pancreatic spasmolytic polypeptide protects the gastric mucosa but does not inhibit acid secretion or motility.

The objectives of these studies were to examine whether the trefoil peptide porcine pancreatic spasmolytic polypeptide (PSP) had gastric mucosal protectant properties similar to its human equivalent human spasmolytic polypeptide (hSP) and to confirm the antisecretory and antimotility action of the peptide. PSP and recombinant hSP reduced gastric mucosal damage caused by a combination of subcutaneous indomethacin and restraint stress in the conscious rat. At a dose of 500 micrograms/kg bolus plus 500 micrograms.kg-1.h-1 sc, PSP significantly reduced the total area of damage by 58%. PSP at a dose of 150 micrograms/kg iv had no inhibitory effect on pentagastrin-stimulated gastric acid secretion in the perfused stomachs of anesthetized rats. This lack of antisecretory activity was confirmed in vitro using an isolated stomach preparation from the immature rat. PSP and hSP at concentrations up to 800 nM did not inhibit electrically or chemically evoked contractions of the guinea pig ileum and duodenum in vitro. Thus antisecretory and antimotility actions do not underlie the mucosal protectant properties of PSP. PSP did, however, stimulate cell migration, and this may, at least in part, account for its protectant properties.

Animals↗
PubMed1996

Second licensure for advanced practice: current status.

This article provides a through update of second licensure for advanced practice nurses. The National Council of State Boards of Nursing (NCSBN) has proposed new requirements for legislation and licensure for advanced practice nurses. This proposal could have major repercussions for all advanced practice nurses, depending on whether the state boards of nursing adopt the council's recommendation. A review of the historical aspect and the development of nursing licensure is reported. Both the 1992 and 1995 second licensure proposals are analyzed. Support for and dissent against the proposals by nursing organizations and individuals in the nursing community are included. The current status of the proposal for second licensure by the National Council of State Boards of Nursing is high-lighted.

Humans↗
PubMed1994

Developing and implementing a user-driven departmental database system--implications for the Royal College of Radiologists' COIN proposal.

With the increasing availability of computers, more departments are using word processors in place of typewriters. In the course of typing patient discharge summaries and letters, a large amount of information of potential use for audit or research purposes is entered into the computer but in a form inaccessible for analysis. We have developed a data-base system, based on information entered by departmental staff in the course of their work, rather than by designated data managers. The aim of the system is to replace word-processed clinical summaries. We describe the design, implementation and possible advantages and disadvantages of such a system and implications for the COIN proposal of the Royal College of Radiologists.

Computer Communication Networks↗