Infection control and management of MRSA: assessing the knowledge of staff in an acute hospital setting.

Much of the recent work in tackling meticillin-resistant Staphylococcus aureus (MRSA) has focused on hygiene in hospitals, but it is unclear how much hospital staff know about the treatment and management of patients who are colonized or infected with MRSA. The aim of this study was to assess the knowledge and perceived practice of staff regarding MRSA and its management in an acute hospital setting. A further aim was to determine what staff felt was needed in terms of information or education on the risks, management and treatment of MRSA. A questionnaire survey was carried out through group administration during a study day and by face-to-face interviews. Subjects included in the questionnaire were infection and colonization, treatment, and the availability of local support and advice. There were 174 responses, divided equally between doctors and nurses. Knowledge on many aspects of MRSA and its management was deficient, although the majority of participants who felt that they required additional information about MRSA acknowledged this. The survey confirmed that assumptions should not be made about adequate knowledge and expertise of staff in relation to MRSA. Gaps in awareness of aspects of care and management were highlighted and information and educational needs identified.

Inferring Plio-Pleistocene southern African biochronology from facial affinities in Parapapio and other fossil papionins.

Buried in the same South African cave deposits as Australopithecus, fossil papionins have been referred to Parapapio (Pp. whitei, Pp. broomi, Pp. jonesi, Pp. antiquus), Papio (P. izodi, P. angusticeps, P. h. robinsoni), Theropithecus (e.g., T. darti), Gorgopithecus, or Dinopithecus on the basis of postcanine tooth size and descriptive morphology of the muzzle. The morphological patterns of variation that these papionins demonstrate can help to place the Australopithecus fossils into a biochronological context and provide valuable information for reconstructing regional Plio-Pleistocene turnover. To document these patterns of variation across fossil-bearing sites, we explore morphometric affinities within Parapapio, and between Parapapio and other Plio-Pleistocene taxa (Dinopithecus ingens, Papio angusticeps, Papio izodi, and Theropithecus darti) by analyzing a sample of interlandmark distances derived from 3-D coordinate data of the most complete fossil papionin specimens available. Bivariate and multivariate analyses show that Pp. whitei exhibits as much variation between sites and between individuals as Pp. broomi and Pp. whitei combined. Diversity in Parapapio at Makapansgat and Sterkfontein may suggest substantial time depth to the caves. Theropithecus darti, Dinopithecus ingens, Papio angusticeps, Pp. whitei from Bolt's Farm (BF 43), and Pp. jonesi from Sterkfontein (STS 565) differ considerably from one another. Other Parapapio specimens across sites form a separate cluster with P. izodi from Taung, suggesting a Pliocene age for this site.

Coupling fields and underlying space curvature: an augmented Lagrangian approach.

We demonstrate a systematic implementation of coupling between a scalar field and the geometry of the space which carries the field. This naturally gives rise to a feedback mechanism between the field and the geometry. We develop a systematic model for the feedback in a general form, inspired by a specific implementation in the context of molecular dynamics (the so-called Rahman-Parrinello molecular dynamics, or RP-MD). We use a generalized Lagrangian that allows for the coupling of the space's metric tensor to the scalar field, and add terms motivated by RP-MD. We present two implementations of the scheme: one in which the metric is only time-dependent (which gives rise to an ordinary differential equation for its temporal evolution), and the other with spatiotemporal dependence (wherein the metric's evolution is governed by a partial differential equation). Numerical results are reported for the (1+1)-dimensional model with a nonlinearity of the sine-Gordon type.

Iodine deficiency associated with parenteral nutrition in extreme preterm infants.

Infants are in negative iodine balance on current standard regimens of total parenteral nutrition, with a mean iodine intake of 3 micro g/kg/day (150 ml/kg/day). The recommended enteral intake of iodine for preterm infants is 30 micro g/kg/day. Gastrointestinal absorption of iodine is high, suggesting that parenteral intakes should approach enteral recommendations.

An evaluation of the USDA standards for feeder cattle frame size and muscle thickness.

This study was conducted to determine the live weights at which large-, medium-, and small-framed feeder steers and heifers attain a degree of finish associated with a carcass quality grade of low Choice and to examine the relationship of feeder cattle muscle thickness to carcass yield grade traits. Feeder steers (n = 401) and heifers (n = 463) representing three age classes (calf, yearling, long yearling) were selected randomly at a commercial feedlot to exhibit wide ranges in frame size and muscularity. Individual weights were recorded and a panel of five experienced evaluators scored each animal for frame size, muscle thickness, and flesh condition. The cattle were finished on a high-concentrate finishing diet and harvested at an estimated carcass fat thickness of 10 mm. Final weights and USDA carcass grade data were collected for all cattle. Frame size scores effectively predicted finished weight at a marbling end point of Small(00) for both heifers (r2 = 0.89, SE = 16 kg) and steers (r2 = 0.94, SE = 13 kg). For heifers, the Small/Medium and Medium/ Large frame score intersects corresponded to live weights of 460 kg and 520 kg, respectively. For steers, the Small/Medium and Medium/Large frame score lines corresponded to live weights of 504 kg and 577 kg, respectively. These weights were greater than weights specified in the 1979 USDA grade standards. Evaluations of feeder cattle muscling, based on 1979 USDA Standards, were associated (P < 0.05) with differences in longissimus muscle area but were not related (P = 0.08) to differences in numerical carcass yield grades. An alternative muscle thickness classification scheme, involving the use of four thickness classes, was effective for stratifying feeder cattle according to eventual differences (P = 0.004) in carcass yield grade. Our findings suggest that USDA feeder cattle grade standards developed in 1979 are no longer adequate for describing today's population of feeder cattle.

Identifying populations at risk from environmental contamination from point sources.

OBJECTIVES: To compare methods for defining the population at risk from a point source of air pollution. A major challenge for environmental epidemiology lies in correctly identifying populations at risk from exposure to environmental pollutants. The complexity of today's environment makes it essential that the methods chosen are accurate and sensitive. METHODS: Environmental and mathematical methods were used to identify the population potentially exposed to a point source of airborne pollution emanating from a waste incinerator. Soil sampling was undertaken at 83 sites throughout the city and environs. The concentrations of arsenic and copper were measured at each site. Computer software produced smoothed contour plots of the distribution of arsenic and copper in the soil based on the information derived from the sampling sites. The population at risk was also identified using concentric rings of varying radii, with the source of pollution at the centre. Lastly, we used the sites that had previously been selected and measured the frequency of wind direction, speed and distance from the source of pollution at each site. Theoretical contour plots were constructed using the distance from the source of pollution at each site, with and without incorporating wind frequency as a function of direction. RESULTS: Each method identified different populations at risk from airborne pollution. The use of circles was a very imprecise way of identifying exposed populations. Mathematical modelling that incorporated wind direction was better. Soil sampling at many sites was accurate, as the method is direct; but it is very costly and the close proximity of high and low concentrations hindered interpretation. The smoothed contour plots derived from the soil sampling sites identified an exposed population that was similar to that derived from the spot sampling. CONCLUSIONS: Using circles as the only means of identifying the exposed population leads to dilution of the potential health effect. The best approach is to use local knowledge about wind direction and speed to estimate the population likely to be at risk; to back up this estimate by judicious use of soil sampling; to use contour mapping to guide the final selection of exposed and non-exposed populations; and finally, to interpret the populations identified as being at risk by incorporating information about other potential sources of pollution (past and present) in the area.

Rattling the plate--reasons and rationales for early weaning.

To identify a range of attitudes and beliefs which influence the timing of introduction to solid food, five focus group discussions were undertaken within a maternity hospital setting. These sessions explored early feeding behaviour, stimuli to changing feeding habits and subsequent responses in 22 primiparous and seven multiparous mothers (mean age 27.0+/-4.8 years) with babies aged 8-18 weeks (mean age 13.0+/-4.2 weeks). One-third of the participants had introduced solid food to their infants (mean age of introduction 11.6 weeks, range 2-16 weeks). Mothers believed that the introduction of solids was baby led and initiated by some physical characteristic or behavioural action of the infant. All mothers were aware of current recommendations to avoid the introduction of solid food until 4 months. Few knew why this should be and concepts of long-term ill health were difficult to conceptualize. The conflict between rigid feeding guidelines and flexible advice from supportive health professionals created confusion over the importance of good weaning practices. The current findings highlight issues relevant to the introduction of solid food, and provide a foundation for further research which can identify the relative importance of these factors and provide a rationale for the design of contemporary intervention strategies.

Sudden unexpected infant deaths in Dundee, 1882-1891: overlying or SIDS?

Using a cohort study of all deaths in infants under 12 months in Dundee born between 1882-91 we set out to compare the aetiology of sudden unexpected infant deaths in Dundee at the end of the 19th Century with the aetiology of present day Sudden Infant Death Syndrome (SIDS). During 1882-1891, 361 infants died suddenly and unexpectedly and without obvious cause while in bed with their parents. The sex ratio of deaths was even (0.51 male) whereas the typical male fraction of SIDS today is 0.61. The mean age at death was almost two and one-half weeks younger in the Dundee cohort than for SIDS in modern Scotland. The infants in the Dundee cohort were discovered more frequently early in the morning than is typical. Their social class distribution was different in that no overlying cases were found in the higher classes whereas SIDS affects all classes. The overlying rate for illegitimate infants was lower than that reported for SIDS today. The epidemiological characteristics of the Dundee cohort and of those dying from present day SIDS differ considerably. The Dundee cohort apparently died from overlying rather than from SIDS as it is classified today. Present day advice that co-sleeping is safe should be given more cautiously until the safety of co-sleeping is resolved. It might be prudent to inform parents that co-sleeping is a risk factor for SIDS and that it should therefore be avoided.

Spatial competing risk models in disease mapping.

Often it is required that the 'health status' of an area must be assessed and this involves the analysis of a range of different diseases within one study window. This often arises, for example, when disease cluster alarms are sounded and there is a need to provide a general overview of health in the vicinity of he cluster area. Our approach leads to the consideration of the joint spatial distribution of a 'basket' of diseases. We examine the use of weighting schemes within our general formulation, and extensions to count data and spatio-temporal modelling.

Using live estimates and ultrasound measurements to predict beef carcass cutability.

Commercial slaughter steers (n = 329) and heifers (n = 335) were selected to vary in frame size, muscle score, and carcass fat thickness to study the effectiveness of live evaluation and ultrasound as predictors of carcass composition. Three trained personnel evaluated cattle for frame size, muscle score, fat thickness, longissimus muscle area, and USDA quality and yield grade. Live and carcass real-time ultrasound measures for 12th-rib fat thickness and longissimus muscle area were taken on a subset of the cattle. At the time of slaughter, carcass ultrasound measures were taken at "chain speed." After USDA grade data were collected, one side of each carcass was fabricated into boneless primals/subprimals and trimmed to .64 cm of external fat. Simple correlation coefficients showed a moderately high positive relationship between 12th rib fat thickness and fat thickness measures obtained from live estimates (r = .70), live ultrasound (r = .81), and carcass ultrasound (r = .73). The association between estimates of longissimus muscle area and carcass longissimus muscle area were significant (P < .001) and were higher for live evaluation (r = .71) than for the ultrasonic measures (live ultrasound, r = .61; carcass ultrasound, r = .55). Three-variable regression equations, developed from the live ultrasound measures, explained 57% of the variation in percentage yield of boneless subprimals, followed by live estimates (R2 = .49) and carcass ultrasound (R2 = .31). Four-variable equations using frame size, muscle score, and selected fat thickness and weight measures explained from 43% to 66% of the variation for the percentage yield of boneless subprimals trimmed to .64 cm. Live ultrasound and(or) live estimates are viable options for assessing carcass composition before slaughter.

Feasibility of an outpatient and home parenteral antibiotic therapy (OHPAT) programme in Tayside, Scotland.

Outpatient and home parenteral antibiotic therapy (OHPAT) is under-utilized in the U.K. We performed a feasibility study over a 5-month period in a regional U.K. infection unit. After exclusions, 183 antibiotic treated patients were evaluated. Ninety-five received intravenous (i.v.) therapy, of whom 32 received at least 4 days. Prolonged i.v. therapy was most frequent in soft tissue infections. In these patients, length of stay and duration of i.v. treatment were correlated (r = 0.74, 0.51-0.87). Eighty-three (86%) of patients who received IV therapy judged OHPAT to be an acceptable alternative to hospitalization. Those who did not were older (mean age 64 vs. 46 years, P<0.001) and were less likely to have a carer willing to administer the antibiotic at home (8/28 vs. 117/151, P<0.001). Twenty-five of 32 (79%) patients treated with prolonged parenteral therapy and 27/95 (28%) treated with any length of parenteral therapy met criteria for OHPAT. Thirteen of these were safely and successfully managed as outpatients by ward staff, OHPAT is an acceptable alternative to inpatient therapy in Tayside and may reduce the duration of hospitalization or prevent admission in certain patients.

Confounded by confounding: separating association from causation.

Health-care professionals need to be able to distinguish causal relationships from simple associations in two main areas: when unravelling the aetiology of diseases, and when assessing the effects of therapies. In each of these the presence of confounding can seriously mislead. This short report explains the nature of confounding and outlines criteria that can be applied to help distinguish causality from mere statistical associations.

Screening practices for gestational diabetes mellitus in UK obstetric units.

AIM: To identify current screening practices for gestational diabetes mellitus (GDM) in all maternity units. METHODS: A questionnaire was sent to the senior obstetrician of all obstetric units known to the UK Royal College of Obstetricians and Gynaecologists. RESULTS: A response rate of 84% was achieved. 89% of units reported that they screened for GDM with a wide variation in the screening methods used, both between and within units. The most commonly employed procedure (81% of units) was screening based on the presence of maternal risk factors. The 75 g oral glucose tolerance test (OGTT) was the commonest diagnostic test (79% of units). Sixty-six per cent of units operate a combined diabetic antenatal clinic and 58% of units have written guidelines for screening. Seventy-six per cent of units would welcome national guidelines. CONCLUSION: The majority of obstetric units in the UK screen for GDM but with little consensus on the appropriate screening methods. National guidelines would probably be welcomed.

Assessment of uterine arterial notching as a screening test for adverse pregnancy outcome.

OBJECTIVE: The objective of the study was to evaluate the screening potential of routine uterine arterial Doppler ultrasonography as a predictor of adverse pregnancy outcome. STUDY DESIGN: All women (n = 6579) with singleton pregnancies undergoing a fetal anomaly scan at 18 to 20 weeks' gestation between January 1, 1994, and December 31, 1995, at Ninewells Hospital and Medical School were screened for the presence of uterine arterial notching. Women who had evidence of bilateral notching were rescanned at 22 to 24 weeks' gestation. Outcome measures included proteinuric hypertension, premature separation of the placenta, and birth weight z score. RESULTS: The sensitivity and positive predictive value of uterine arterial notching as a predictor of adverse pregnancy outcomes was low. For all types of notching and disease, outcome sensitivity was never higher than 44% and positive predictive value was never higher than 27%. In contrast, the relative risk of adverse pregnancy outcome in the presence of uterine arterial notching was uniformly high for all disease outcomes (range of relative risk 3.5-30.7). Significant obstetric morbidity was seen in 57% of women with bilateral notches at 18 to 20 weeks' gestation and 72% of women with persistent bilateral notches. CONCLUSIONS: As a screening test for adverse pregnancy outcomes, detection of uterine arterial notching is poor. Nevertheless, the presence of bilateral uterine arterial notching is associated with a significantly increased risk of adverse pregnancy outcome. In units performing routine anomaly screening, the addition of maternal uterine arterial Doppler ultrasonography may help to discriminate this small group of women at high risk.

An evaluation of current and alternative systems for quality grading carcasses of mature slaughter cows.

Strip loins from 354 female bovine carcasses, selected to represent 30 skeletal maturity (A, B, C, D, and E) x marbling score (SA/MA/AB, MD, MT, SM, SL, and TR/PD) subclasses, were used to evaluate current and alternative systems for classifying cow carcasses into expected-palatability groups. Strip loins were vacuum-packaged, stored for 14 d postmortem at 2 degrees C, and frozen (-27 degrees C). Five steaks from each strip loin, each cooked to a different internal temperature (60, 66, 71, 77, or 82 degrees C), were used for shear force determinations. Two steaks from each strip loin, one cooked to 66 degrees C and the other to 77 degrees C, were used for sensory evaluation. Increased carcass maturity was associated with decreased tenderness and juiciness, increased flavor intensity, and a higher incidence of flavors described as "painty," "fishy," and "grassy." Position of a carcass within a maturity group had a negligible effect on palatability. Increased marbling was associated with greater tenderness and juiciness, a lower incidence of steaks with a "grassy" flavor, and a higher incidence of steaks with a flavor described as "fatty." Relationships between marbling and beef palatability traits were consistent across all maturity groups. Carcasses of maturities A through E were most effectively stratified according to differences in palatability when marbling scores were grouped as follows: 1) MD and higher; 2) SL, SM, MT; and 3) TR/PD. Among mature (C, D, and E maturity) carcasses, yellow-colored fat was associated with greater beef toughness and higher detection rates for "grassy" and "fishy" flavors. Higher end-point temperatures were associated with higher shear force values and lower ratings for muscle fiber tenderness, connective tissue amount, overall tenderness, and juiciness. Two alternative grading approaches (one involving current quality grading factors and the other involving the use of fat color as an additional grade factor) were developed for possible use in classification of cow carcasses into expected-palatability groups. Both alternative systems provided a more effective stratification of cow carcasses according to palatability differences than did the current USDA quality grading system.

Prediction of slaughter cow composition using live animal and carcass traits.

Slaughter cows (n = 120), representing four genotypes (British, continental, Bos indicus, and dairy) and three body condition classes (thin, moderate, and fat), n = 10 per subclass, were used to identify practical and accurate prediction equations for the yield of boneless manufacturing beef of specific fat percentages. Cows and their carcasses were weighed and evaluated for USDA yield and quality grade factors and for physical muscle and fat indicators. Carcass sides were fabricated; total fat percentage (TFP) was calculated as total fat (trimmed and chemical) divided by side weight, and tissue lean percentage (TLP) was calculated as boneless fat-free lean divided by soft tissue weight. Data were analyzed using maximum R2 multiple regression. The best live trait prediction model for TFP included live preliminary yield grade (LPYG), body condition score (LCOND), visual live muscle score (LMUSC), and live weight (LWT), R2 = .83. The best carcass trait TFP prediction model included adjusted preliminary yield grade (CPYGA); kidney, pelvic, and heart fat adjustment (CKPHADJ); marbling score (CMARB); and hot carcass weight (HCW), R2 = .92. The best live trait TLP prediction model included LPYG, LCOND, LMUSC, and LWT, R2 = .82. The best carcass trait TLP prediction model included CPYGA, CKPHADJ, CMARB, and lean maturity, R2 = .91. These data indicate that TFP and TLP of slaughter cows can be accurately and practically predicted using live animal and carcass traits.

Relationship of visual assessments of feeder lamb muscularity to differences in carcass yield traits.

We examined the relationship between visual differences in muscle thickness among feeder lambs and subsequent differences in carcass composition. Medium-framed, crossbred feeder lambs (n = 120) were selected at two commercial feedlots to exhibit distinct phenotypic differences in muscularity. The lambs were assigned scores (ranging from 1 to 9; 1 = extremely thin, 5 = average, 9 = extremely thick) for muscle thickness and were sampled serially on d 0, 14, 28, and 42 of the trial. After recording yield grades, one side of each carcass was deboned, and the soft tissues from the entire side were ground, sampled, and analyzed for lipid and moisture content. The opposite side was fabricated into boneless, closely trimmed (.25 cm maximum fat depth) subprimal cuts. When lambs of the same frame size were compared at the same live weight, greater muscle thickness was associated with greater (P < .05) fat-free muscle mass. Correspondingly, thickly muscled lambs produced carcasses of a given weight that had a higher (P < .05) composite yield of lean meat and a lower (P < .05) proportion of trimmable fat compared with carcasses of thinly muscled lambs. When comparisons were made at the same percentage of extractable fat in the carcass, greater muscle thickness was associated with heavier (P < .05) live and carcass weights, increased (P < .05) fat-free muscle mass, and increased (P < .05) weights of trimmed, boneless subprimal cuts. Results suggest that visual assessments of muscle thickness in feeder lambs, as applied in this study, are indicative of commercially important differences in carcass yields of lean meat.

Relationship of feeder lamb frame size to feedlot gain and carcass yield and quality grades.

Small-(S), medium-(M), and large-(L) framed feeder lambs (n = 243 S, 247 M, and 245 L) were finished on five diets differing in amount of concentrate (C) and crude protein (CP): 1) 30% C, 12.5% CP; 2) 55% C, 12.5% CP; 3) 55% C, 14.5% CP; 4) 80% C, 12.5% CP; and 5) 80% C, 14.5% CP. Lambs were sampled over a wide weight range to establish relationships of frame size to daily gain and live weight at specific carcass grade end points. Increased frame size (F) was associated with more rapid gains during finishing, although differences in daily gain among L, M, and S lambs were not expressed consistently across all dietary treatments (D), as reflected by a significant F x D interaction for ADG. The rate at which external fat thickness increased as the lambs became heavier was not affected by frame size, sex, or diet. However, increased frame size was associated with lower (P < .05) values for fat thickness (FT), body wall thickness (BWT), yield grade (YG), and quality grade (QG) when comparisons were made at a constant slaughter weight. Similarly, later-maturing wether lambs were leaner and had lower YG and QG than ewes of the same weight. Dietary treatment had no effect on FT, BWT, and YG when treatment groups were compared at a constant live weight. Subclass regressions of YG on live weight were used to project the weights at which lambs of various frame sizes would be expected to produce YG-2 carcasses. Projected final weights for wethers were less than 50 kg for S, 50 to 55 kg for M, and greater than 55 kg for L. Projected final weights for ewe lambs were approximately 2.5 kg lower. Dietary treatment did not affect relationships among frame size, live weight, and YG. A grading/classification system for feeder lambs based on frame size could be developed to predict carcass grade end point.

Episiotomy and perineal tears in low-risk UK primigravidae.

BACKGROUND: The aim of the study was to determine the rates and to describe the risk factors for episiotomy and perineal tears in low-risk primigravidae. METHOD: A cross-sectional survey of 101 randomly selected NHS hospitals in the UK was carried out between February 1993 and January 1994. Subjects were 40 consecutive low-risk primigravidae in each hospital. The main outcome measures were number and reasons for episiotomy, and number and degree of perineal tears. RESULTS: A large proportion of women (83 per cent) experienced some form of perineal trauma. Forty per cent of the women had an episiotomy only, 6 per cent an episiotomy and perineal tear, and 37 per cent perineal or other tears without episiotomy. The main reasons for performing an episiotomy were foetal distress (27 per cent), impending tear (25 per cent) and delay of the second stage of labour (21 per cent). Fifty-nine per cent of women with a delayed second stage had a spontaneous vaginal delivery and 41 per cent required instrumental assistance. The likelihood of having an episiotomy increased with the duration of the second stage of labour, irrespective of type of delivery. Episiotomy rates varied appreciably throughout regions and hospitals in the United Kingdom, ranging from 26 to 67 per cent. There was also a large regional variation in the rates of perineal trauma; generally, high rates of one outcome were associated with low rates of the other. Compared with white women, women from the Indian sub-continent were almost twice as likely and those from the Orient almost five times as likely to have an episiotomy. CONCLUSIONS: The magnitude of the geographical variation suggests a lack of uniformity in indications for performing episiotomies and that guidelines for performing episiotomies may need to be reviewed. The rates of episiotomy in women from the Indian sub-continent and Orient were very high compared with those for white women, and this requires clarification and explanation, as they are contrary to rates experienced in these ethnic groups in other countries.