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S Livingstone

Publications and source records attributed to S Livingstone.

15 recordsLinked to original sources
PubMed2006

Anthropometry profiles of elite rugby players: quantifying changes in lean mass.

OBJECTIVE: To demonstrate the utility of a practical measure of lean mass for monitoring changes in the body composition of athletes. METHODS: Between 1999 and 2003 body mass and sum of seven skinfolds were recorded for 40 forwards and 32 backs from one Super 12 rugby union franchise. Players were assessed on 13 (7) occasions (mean (SD)) over 1.9 (1.3) years. Mixed modelling of log transformed variables provided a lean mass index (LMI) of the form mass/skinfolds(x), for monitoring changes in mass controlled for changes in skinfold thickness. Mean effects of phase of season and time in programme were modelled as percentage changes. Effects were standardised for interpretation of magnitudes. RESULTS: The exponent x was 0.13 for forwards and 0.14 for backs (90% confidence limits +/-0.03). The forwards had a small decrease in skinfolds (5.3%, 90% confidence limits +/-2.2%) between preseason and competition phases, and a small increase (7.8%, 90% confidence limits +/-3.1%) during the club season. A small decrease in LMI (approximately 1.5%) occurred after one year in the programme for forwards and backs, whereas increases in skinfolds for forwards became substantial (4.3%, 90% confidence limits +/-2.2%) after three years. Individual variation in body composition was small within a season (within subject SD: body mass, 1.6%; skinfolds, 6.8%; LMI, 1.1%) and somewhat greater for body mass (2.1%) and LMI (1.7%) between seasons. CONCLUSIONS: Despite a lack of substantial mean changes, there was substantial individual variation in lean mass within and between seasons. An index of lean mass based on body mass and skinfolds is a potentially useful tool for assessing body composition of athletes.

Adult↗
PubMed2004

Study of agreement between LDL size as measured by nuclear magnetic resonance and gradient gel electrophoresis.

LDL particle size can be measured by gradient gel electrophoresis (GGE) and NMR. The agreement between the two methods has not been extensively evaluated. Therefore, we measured LDL size by NMR and GGE in 324 individuals (152 with type 1 diabetes and 172 controls). The Spearman correlation between both methods was 0.39 [95% confidence interval (CI) = 0.29, 0.48]. The average difference was 5.38 nm (NMR being smaller), but it increased with increasing LDL size. Less than 50% of people classified as pattern B on GGE were classified as pattern B on NMR (kappa = 0.31; 95% CI = 0.17, 0.45). Agreement was lower for diabetic subjects compared with controls, for women compared with men, and for subjects with triglycerides less than 1.30 mmol/l compared with subjects with triglycerides greater than 1.30 mmol/l. External validation showed that cholesteryl ester transfer rate was related to LDL size on GGE in all subgroups and to LDL size on NMR only in men and nondiabetic subjects. Our findings show that agreement between NMR- and GGE-based LDL size is far from perfect and is not consistent across subgroups of patients. In particular, the two methods should not be assumed to be interchangeable in women and diabetic subjects. Whether NMR or GGE predicts cardiovascular disease risk better has not yet been evaluated.

Adult↗
PubMed2001

Assessing the impact of national anti-HIV sexual health campaigns: trends in the transmission of HIV and other sexually transmitted infections in England.

OBJECTIVE: To assess the impact of the sexual component of AIDS and HIV campaigns on transmission of HIV and other sexually transmitted infections (STIs). DESIGN: Comparison of time series data. SETTING: England, 1971-1999. OUTCOME MEASURES: HIV transmission and diagnoses among men who have sex with men (MSMs), rates of attendances and specific STI diagnoses (per 100 000 total population) at genitourinary medicine (GUM) clinics. RESULTS: Awareness of AIDS and campaigns in 1983-4 among homosexual men coincided with substantial declines in transmission of HIV and diagnoses of syphilis among MSMs. During general population campaigns in 1986-7 new GUM clinic attendances requiring treatment fell by 117/10(5) in men and 42/10(5) in women. Rates for gonorrhoea fell by 81/10(5) and 43/10(5) and genital herpes by 6/10(5) and 4/10(5), respectively. Previous rises in genital wart rates were interrupted, while rates of attendances not requiring treatment (the "worried well") increased by 47/10(5) and 58/10(5) for men and women, respectively. Since 1987 diagnoses of HIV among MSMs have not declined, averaging 1300-1400 annually. Following a period of unchanging rates there have been substantial increases in GUM attendances requiring treatment, notably for gonorrhoea, syphilis, and viral STIs since 1995. CONCLUSIONS: Self help initiatives and awareness among homosexual men in 1983-4 contributed significantly to a fall in HIV transmission among MSMs, and the general campaigns of 1986-7 were associated with similar effects on all STI transmission. Both effects seem to have occurred through changing sexual behaviour, and probably contributed to the UK's low national HIV prevalence. Bacterial STI incidence has increased significantly since 1995 and there is no evidence that recent prevention initiatives have reduced HIV transmission among MSMs, hence sexual health initiatives need to be comprehensively reinvigorated in England.

Condylomata Acuminata↗
PubMed2001

Characterization of female preference functions for Drosophila montana courtship song and a test of the temperature coupling hypothesis.

Female mate preferences are a major cause of diversity and elaboration in male sexual traits. Here we characterize the shape of female preference functions for pulse length and carrier frequency of the courtship song of Drosophila montana by fitting both parametric and nonparametric functions to the incidence of female receptive gestures to synthetic song. Preference functions for both traits are strongly directional. That for pulse length is linear and favors short pulses, whereas that for carrier frequency is stabilizing in shape, but would exert directional preferences favoring males with high carrier frequency. The preference for carrier frequency has probably evolved under sexual selection, but reasons for the preference for short pulses are less apparent. We also examine the effect of ambient temperature on the carrier frequency of male song and on the preference function for carrier frequency. For many similar acoustic communication systems, temperature coupling, a compensatory effect of temperature on preference functions, is thought to maintain coordination between preferences and signals. However, although the carrier frequency of D. montana song is highly dependent on environmental temperature, there is no temperature coupling of the female preference function. We suggest that temperature coupling may often arise due to a common effect of temperature on song and preference, rather than be an advantageous characteristic whose function is to maintain coordination in temperature-affected communication systems.

Animals↗
PubMed1995

Reproducibility of body temperature response to standardized test conditions when assessing clothing.

The traditional use of core temperature to assess the thermal effects of clothing has recently been questioned. The purpose of this study was to assess the reproducibility of body temperature in five subjects (mean age, 22.6 +/- 1.5 years) wearing either athletic clothing or a chemical protective overgarment while exercising at 20 degrees C and at 40 degrees C. The exercise was preceded by a 1 h adaptation period in a controlled environmental chamber. Results indicated that mean group change in rectal temperature (delta Tr) appeared to be reproducible for both garment ensembles at 20 degrees C but not at 40 degrees C. For mean change in oesophageal temperature (delta T(oes)) at 20 degrees C, reproducibility was obtained for the overgarment but not for the athletic garment; at 40 degrees C, mean delta T(oes) appeared to be reproducible with both garments. However, when individual responses were examined, there was little reproducibility for either delta Tr or delta T(oes). In addition, these measurements failed to show differences in the types of clothing worn. It was concluded that the use of core temperature to assess heat stress imposed by wearing clothing during exercise may lead to erroneous conclusions.

Adult↗
PubMed1994

Disturbance of thermal homeostasis during post-exercise hyperthermia.

The response of core temperature to exercise was investigated during recovery in order to avoid the antagonistic competition between exercise and thermal reflexes for the same effector systems which control skin blood flow. Five healthy, non-training males [mean (SD) age, 23.8 (2.04) years] were habituated to 29 degrees C at relative 50% humidity for more than 2 h and then exercised by treadmill running at about 75% maximum oxygen uptake for 18 min. They then remained at 29 degrees C for up to 65 min of recovery. Oesophageal (T(es)), rectal (Tre) and skin temperatures (Tsk) were recorded at 5-s intervals throughout. The abrupt fall of temperature gradient from the forearm to finger was used to identify the T(es) for skin vessel dilatation (Tdil) during exercise. Mean (SE) Tes rose from a resting value of 36.67 (0.15) degrees C to 38.22 (0.24) degrees C, mean Tre rose from 37.09 (0.25) degrees C to 38.23 (0.15) degrees C, and Tdil occurred at 37.39 (0.32) degrees C. Within 10 min of recovery mean T(es) fell to 37.31 (0.24) degrees C, where it remained a significant 0.64 degrees C above its pre-exercise (PrEx) level (P < or = 0.018) but insignificantly different from Tdil for the remaining 55 min of recovery. Meanwhile, Tre fell gradually throughout recovery to 37.64 (0.18) degrees C. The Tsk at all non-acral sites except the thigh had recovered to PrEx levels by 20-30 min post-exercise (PoEx).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Effect of inspiratory resistance to prolonged exercise in a hot environment wearing protective clothing.

The effects of inspiratory resistance on prolonged work in a hot environment wearing a nuclear, bacteriological and chemical warfare (NBCW) mask and overgarment were assessed in 10 males. Subjects walked on a treadmill at 5 km/hr, 2% gradient, until their core temperature reached 39 degrees C or for a duration of 90 min. Rectal temperature, heart rate, ventilation, oxygen consumption and rate of perceived breathing were measured. There were no differences between break-point time without the canister (62.2 +/- 21 min) and with the canister (58.9 +/- 17 min). Regression analysis indicated that the mean core temperature increased by 0.02 degrees C for every minute of work performed and heart rate by 6 beats/min for every increase of 0.2 degrees C in core temperature. Reduction in heat transfer brought about by wearing the protective overgarment and mask with or without the canister will significantly increase core temperature and limit the performance of moderate work to approximately 1 h in a moderately fit individual.

Adult↗
PubMed1992

The United Kingdom Heart Valve Registry.

The United Kingdom Heart Valve Registry project began in 1986 following discussions between the Department of Health (DOH) and the Society of Cardiothoracic Surgeons of the United Kingdom and Ireland. The intention was to establish a computerized database for valve replacement operations carried out in the UK Health Service cardiac units. This paper describes the experience gained over the first five years of this project. Around 30,000 patients were entered in the registry between 1986 and 1990. All Uk Health Service cardiac surgical units contribute their data, which is processed by the central Registry Office. The accuracy of the mortality data is ensured by tracking the registered patients through the Office of Population Census and Surveys (OPCS). The pattern of valve replacement surgery over the period 1986-90 revealed several interesting trends. Although the number of procedures remained static at around 5,000 valve transplants per year, the number of aortic replacements increased and the number of mitrals decreased. The use of prosthetic valves increased from 54% in 1986 to over 70% in 1990. The mean age of the patients increased from 58.31 years in 1986 to 60.97 years in 1990, with over 22% of the valve replacement operations in 1990 being performed on patients over 70 years of age. The five year survival rate for patients over 70 years at the time of the valve implant is significantly lower than for patients under 70 years (p < 0.005).

Aged↗
PubMed1992

Influence of a new vapor protective clothing layer on physical work tolerance times at 40 degrees C.

The purpose of the present study was to examine the influence of a new vapor protective clothing on physical work performance in a hot environment (40 degrees C and 25% relative humidity). Eleven unacclimatized males (28 +/- 6 years, 79 +/- 8 kg, 1.76 +/- 0.06 m) were assigned to exercise at either a light intermittent (L) (N = 6), or heavy continuous (H) (N = 5) metabolic rate. Group L alternated between 15 min of walking on a treadmill at 1.11 m.s-1 with a 0% grade and 15 min of rest. Group H walked continuously at 1.33 m.s-1 with a 3% grade. Subjects were tested wearing three clothing configurations: full nuclear, biological and chemical (NBC) protection (TOPP High) with the combat clothing worn under the NBC garment (TH + CC); full NBC protection without combat clothing (TH - CC); the new vapor protective clothing together with the NBC gloves, boots, and respirator (NPC). WTT was the time-period until rectal temperature (Tre) reached 39.3 degrees C, heart rate reached 95% maximum, dizziness or nausea precluded further exercise, or 3 h had elapsed. For group L, WTT was similar for TH + CC (113 +/- 12 min) and TH - CC (139 +/- 18 min). WTT was significantly increased for NPC where all subjects completed the 3 h in the climatic chamber. The rate of increase for Tre was significantly reduced for NPC (0.3 +/- 0.1 degree C.h-1) compared with both TH + CC (0.9 +/- 0.1 degree C.h-1) and TH - CC (0.8 +/- 0.2 degree C.h-1).(ABSTRACT TRUNCATED AT 250 WORDS)

Body Temperature↗
PubMed1990

Physiological effects of inspiratory resistance on progressive aerobic work.

The purpose of this study was to determine the potential effects on progressive aerobic work while breathing through a new military type chemical and biological (CB) respirator loaded with three different types of purifying canisters. Twelve healthy well-motivated male subjects (mean age 23 +/- 3 years) participated in the study. Results indicated that mean maximal oxygen uptake (VO2max), time to exhaustion, respiratory exchange ratio, rate of perceived exertion, respiratory rate and tidal volume at exhaustion, maximal lactate and the 2-min post-exercise lactate were not significantly influenced when breathing with the respirator and the canisters in comparison to a laboratory valve. Mean pulmonary ventilation, however, was reduced by 21% while oxygen and carbon dioxide ventilatory equivalents were significantly lower by 9% and 8% respectively. Review of the stage-by-stage responses to the treadmill test between the laboratory valve and respirator/canister conditions indicated no significant differences (NS) in oxygen uptake but slightly lower heart rates (NS). Ventilation was not influenced by the canisters until 80% of VO2max at which time the mean oxygen ventilatory equivalent became significantly lower. Blood lactate was significantly depressed between 60% and 90% VO2max under the respirator/canister conditions. It was concluded that, although physiological adaptation occurred, breathing with the new CB respirator and each of the three purifying canisters had no detrimental effect on progressive aerobic work to exhaustion. However, prolonged work at intensities greater than 80-85% of VO2max would in all probability be impaired when breathing with the CB mask and the canisters.

Adult↗
PubMed1989

A classification of prescription errors.

Three independent methods of study of prescription errors led to the development of a classification of errors based on the potential effects and inconvenience to patients, pharmacists and doctors. Four types of error are described: type A (potentially serious to patient); type B (major nuisance - pharmacist/doctor contact required); type C (minor nuisance - pharmacist must use professional judgement); and type D (trivial). The types of frequency of errors are detailed for a group of eight principals from one health centre. There were a total of 504 errors from 15,916 prescription items (3.17%) during a three month observation period. A close correspondence was found between individual doctor's types of error rates, suggesting that doctors who make type C and D errors are also likely to make type B (major nuisance) errors. A system of feedback of errors from each doctor was devised. No significant reduction was seen in error rates, possibly because the group of self selected doctors taking part had low error rates initially. It is suggested that pharmacists and doctors should work closely together to prevent the potentially harmful consequences of prescription errors.

Drug Prescriptions↗
PubMed1988

Verification of the fetal valproate syndrome phenotype.

We have evaluated 19 children who were exposed to valproic acid (VPA) in utero to look for manifestations of a fetal valproate syndrome (FVS), as proposed by Di Liberti et al. [1984]. We found no consistent alterations of pre- or postnatal growth with exposure to VPA monotherapy. Postnatal growth deficiency and microcephaly were present however, in two thirds of children exposed to VPA in combination with other anticonvulsants. Developmental delay or neurologic abnormality was found in 71% of those exposed to VPA monotherapy, and in 90% of those exposed to VPA and other anticonvulsants. Craniofacial anomalies, which can be seen with other anticonvulsant exposures, including midface hypoplasia, short nose with a broad and/or flat bridge, epicanthal folds, minor abnormalities of the ear, philtrum or lip, and micrognathia were also found in infants whose mothers used VPA. Prominent metopic ridge and outer orbital ridge deficiency or bifrontal narrowing and certain major anomalies such as tracheomalacia, talipes equinovarus (with intact spine) and lumbosacral meningomyelocele seem to be peculiar to infants with VPA exposure. Other defects such as urogenital anomalies, inguinal or umbilical hernias, and minor digital anomalies that are common to other prenatal anticonvulsant exposures are also occasionally found in those exposed to VPA. Heart defects have been found in infants exposed to nearly every class of anticonvulsant although the types of defects associated with maternal VPA use may be clarified when classified by pathogenetic mechanism. Our findings overall are in agreement with the report of Di Liberti et al. [1984].

Abnormalities, Drug-Induced↗
PubMed1980

Body cooling after death.

In the analyses of cases of death in cold air environments, it is often of interest to determine the time required for the body of the individual to cool to ambient temperature. Usually such determinations have been based on Newton's law of cooling. This paper describes a case history in which this technique was experimentally tested and consequently abandoned in favour of a more complex biophysical model which more accurately described the thermo-physical events inherent in body cooling. This model is recommended for determination of the times required for various body parts to cool to ambient environmental temperatures.

Animals↗
PubMedDate not supplied

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Communication↗