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Biomedical subjects

A McLeod

Publications and source records attributed to A McLeod.

At least 19 recordsLinked to original sources
PubMed2006

Social, economic and policy issues in the long-term control of HPAI.

Prevention and control of HPAI in Asia is a long term problem with important economic and policy consequences. The macro level impact of a single national outbreak is greatest for an exporting country, ranging in 2003-5 from dollars 65 million to over dollars 400 million. No estimates are available for the impact of market disruption if endemic disease changes the pattern of regional and international trade. In countries with minimal exports, the total financial impact may be much smaller, but there can be serious losses to vulnerable sectors of society at several stages of the market chain. The economies of the region are growing and some countries could finance recurrent costs of AI control, but substantial investment in veterinary services is required. National and regional financing structures need to be reviewed. AI control strategies should include a broad financial support system that addresses education, credit, compensation and social relief programmes. Some strategies may result in restructuring of the industry, or affect the wider development of rural areas and local food security.

Animal Husbandry↗
PubMed2005

The incidence of calf morbidity and mortality due to vector-borne infections in smallholder dairy farms in Kwale District, Kenya.

An observational longitudinal study was carried out on 92 randomly selected smallholder farms in two coastal lowland zones of Kwale District in Kenya between December 1997 and November 1999. The objective was to estimate the incidence of the main vector-transmitted diseases in pre-weaned calves. From an initial 41 pure or cross-bred Bos taurus calves which were less than 2 months and whose birth and disease histories were known, study calves were recruited progressively and monitored until they were weaned at around 146 days. Overall, 130 calves in 67 farms were monitored and these contributed a total risk period of 30,062 days. Disease parameters were analysed and compared as true annual and age-specific incidence rates. The incidences of East Coast fever (ECF) (23.1%) and trypanosomosis (29.1%) were the highest among the vector-borne diseases. The corresponding mortality incidence rates of ECF and trypanosomosis were 10.9 and 3.6%, respectively. The annual incidence rates of anaplasmosis and babesiosis were 10.9 and 1.2%, respectively. There was no mortality arising specifically from anaplasmosis or babesiosis. Analysis of survival times to natural infection indicated that the field challenge resulting to cases of trypanosomosis was much higher compared to the risk of either ECF or anaplasmosis. It was concluded that these vector-borne diseases constrain production of replacement stock in this coastal lowlands region of Kenya.

Aging↗
PubMed2005

Strategies, effectiveness and rationale of vector-borne disease control in the pastoralist system of south-western Uganda.

In Uganda, control of vector-borne diseases is mainly in form of vector control, and chemotherapy. There have been reports that acaricides are being misused in the pastoralist systems in Uganda. This is because of the belief by scientists that intensive application of acaricide is uneconomical and unsustainable particularly in the indigenous cattle. The objective of this study was to investigate the strategies, rationale and effectiveness of vector-borne disease control by pastoralists. To systematically carry out these investigations, a combination of qualitative and quantitative research methods was used, in both the collection and the analysis of data. Cattle keepers were found to control tick-borne diseases (TBDs) mainly through spraying, in contrast with the control of trypanosomosis for which the main method of control was by chemotherapy. The majority of herders applied acaricides weekly and used an acaricide of lower strength than recommended by the manufacturers. They used very little acaricide wash, and spraying was preferred to dipping. Furthermore, pastoralists either treated sick animals themselves or did nothing at all, rather than using veterinary personnel. Oxytetracycline (OTC) was the drug commonly used in the treatment of TBDs. Nevertheless, although pastoralists may not have been following recommended practices in their control of ticks and tick-borne diseases, they were neither wasteful nor uneconomical and their methods appeared to be effective. Trypanosomosis was not a problem either in Sembabule or Mbarara district. Those who used trypanocides were found to use more drugs than were necessary.

Animal Husbandry↗
PubMed2004

Estimation of milk production from smallholder dairy cattle in the coastal lowlands of Kenya.

A study was carried out on 92 smallholder farms in Kwale district in Coast Province of Kenya to estimate the milk yield. The effect of concentrate feed supplementation on milk yield was also evaluated. Data were collected during a one-year observational longitudinal study. Analysis was done for 371 observations following 63 calving events. The mean annual milk offtake was estimated at 2021 kg/cow. Forty-nine (77.8%) of the lactating cows were supplemented with concentrate feeds at varying rates of 0.5-3.0 kg/cow per day. Supplementary feeding of lactating cows led to a significantly higher mean daily milk yield compared to non-supplemented cows throughout the year (p < 0.05). The mean annual milk offtake from supplemented cows (2195 kg/cow) was 18.6% more than offtake from non-supplemented cows, a difference that was statistically significant (p < 0.05). Therefore, supplementary feeding of commercial feed concentrates was a rational management practice. It was also concluded that milk production from smallholder dairy cows in the coastal lowlands of Kenya was comparable to that from similar production systems but lower than national targets.

Animal Feed↗
PubMed2004

Employment retention after moderate-severe traumatic brain injury (TBI) in the British Army 1989-98.

AIMS: To examine retention in employment of subjects with moderate-severe traumatic brain injury (TBI) in the British Army. METHODS: Comparative groups study of retention in Army employment after TBI using 564 TBI, 368 lower limb fracture, and 25 575 healthy subjects. Kaplan-Meier survival analysis was used to examine, stratifying for age, continuation in Army employment for six years after TBI. RESULTS: Subjects in the younger groups (mean ages 23 years and 27 years respectively) with either TBI or lower limb fracture remained in employment longer than healthy peers (median time for TBI, 3.91 years, lower limb fracture, 4.39 years, and healthy, 1.74 years). This trend changed through age stratification and for older subjects the reverse pattern was seen. In group 4 (mean age 41 years), median retention time for TBI was 3.33 years, for lower limb fracture, 3.75 years, healthy 5.55 years. Older subjects also showed a marked drop out rate at one year after injury; 32.7% of those with TBI in group 3 (mean age 31 years) had left Army employment at the end of year one compared with 19% in age group 1 (mean age 23 years). CONCLUSIONS: Younger soldiers with either TBI or lower limb fracture are retained in Army employment longer than their healthy peers. This may be due to sheltered employment, the availability of ongoing support, or transience of the healthy population. Since these results were drawn from incidence data on moderate and severe TBI it may be that those who serve on after TBI will do so with some degree of disability which affects occupational performance. There may be a significant unmet rehabilitation need for this group which is the focus of ongoing research.

Adolescent↗
PubMed2003

Evaluation of mattresses using interface pressure mapping.

OBJECTIVE: To compare the ranking of mattresses using several different performance indices, calculated from interface pressure-mapping data. METHOD: Five mattresses were compared using interface pressure-mapping on 10 healthy volunteers. Mattresses were ranked in order, on the basis of several different specified performance indices. RESULTS: Different performance indices ranked the mattresses in different orders. CONCLUSION: Elaborate performance indices should be used with care, since it is possible to construct a 'tailor-made' performance index to make any chosen mattress rank as the best. Care should be taken to ensure that a performance index is validated, preferably by some demonstrated link to clinical outcomes.

Aged↗
PubMed2003

Use of rapid rural appraisal and cross-sectional studies in the assessment of constraints in smallholder cattle production systems in the western Kenya highlands.

Assessment of livestock production constraints in the smallholder dairy systems in the western Kenya highlands was carried out using both qualitative and quantitative epidemiological methods. Rapid rural appraisals (qualitative) were conducted in rural and peri-urban areas. A cross-sectional survey (quantitative) was then conducted on a random sample of farms in the study area. Diseases, poor communication, lack of marketing of livestock produce, lack of artificial insemination services, and feed and water shortages during the dry season were identified as the major constraints to cattle production in both areas. Tick borne diseases (especially East Coast fever) were identified as the major constraint to cattle production. Qualitative methods were found to be more flexible and cheaper than the quantitative methods by a ratio of between 2.19-2.0. The two methods were found to complement each other. Qualitative studies could be applied in preliminary studies before initiating more specific follow up quantitative studies.

Animal Feed↗
PubMed2001

Induction of hypoxia-inducible factor-1alpha and activation of caspase-3 in hypoxia-reoxygenated bone marrow stroma is negatively regulated by the delayed production of substance P.

The bone marrow (BM), which is the major site of immune cell development in the adult, responds to different stimuli such as inflammation and hemorrhagic shock. Substance P (SP) is the major peptide encoded by the immune/hemopoietic modulator gene, preprotachykinin-1 (PPT-I). Differential gene expression using a microarray showed that SP reduced hypoxia-inducible factor-1alpha (HIF-1alpha) mRNA levels in BM stroma. Because long-term hypoxia induced the expression of PPT-I in BM mononuclear cells, we used timeline studies to determine whether PPT-I is central to the biologic responses of BM stroma subjected to 30-min hypoxia (pO(2) = 35 mm Hg) followed by reoxygenation. HIF-1alpha mRNA and protein levels were increased up to 12 h. At this time, beta-PPT-I mRNA was detected with the release of SP at 16 h. SP release correlated with down-regulation of HIF-1alpha to baseline. A direct role for SP in HIF-1alpha expression was demonstrated as follows: 1) transient knockout of beta-PPT-I showed an increase in HIF-1alpha expression up to 48 h of reoxygenation; and 2) HIF-1alpha expression remained baseline during reoxygenation when stroma was subjected to hypoxia in the presence of SP. Reoxygenation activated the PPT-I promoter with concomitant nuclear translocation of HIF-1alpha that can bind to the respective consensus sequences within the PPT-I promoter. SP reversed active caspase-3, an indicator of apoptosis and erythropoiesis, to homeostasis level after reoxygenation of hypoxic stroma. The results show that during reoxgenation the PPT-I gene acts as a negative regulator on the expression of HIF-1alpha and active caspase-3 in BM stroma subjected to reoxygenation.

5' Untranslated Regions↗
PubMed2001

Changing patterns of teenage pregnancy: population based study of small areas.

OBJECTIVES: To measure the impact of socioeconomic deprivation on rates of teenage pregnancy and the extent of local variation in pregnancy rates in Scotland, and to examine how both have changed over time. DESIGN: Population study using routine data from hospital records, aggregated for small areas. SUBJECTS: Female teenagers resident in Scotland who were treated for pregnancy in an NHS hospital in either 1981-5 (62 338 teenagers) or 1991-5 (48 514) and who were aged 13-19 at the time of conception. MAIN OUTCOME MEASURES: Pregnancy rates per 1000 in age group and the proportions of pregnancies resulting in a maternity (live birth or stillbirth) in teenagers aged 13-15, 16-17, and 18-19. RESULTS: From the 1980s to the 1990s pregnancy rates increased differentially according to levels of local deprivation, as measured by the Carstairs index. Among teenagers aged less than 18 the annual pregnancy rate increased in the most deprived areas (from 7.0 to 12.5 pregnancies per 1000 13-15 year olds and from 67.6 to 84.6 per 1000 16-17 year olds), but there was no change, on average, among teenagers in the most affluent areas (3.8 per 1000 13-15 year olds and 28.9 per 1000 16-17 year olds). Among 18-19 year olds the pregnancy rate decreased in the most affluent areas (from 60.0 to 46.3 per 1000) and increased in the most deprived areas (from 112.4 to 116.0 per 1000). The amount of local variation explained by deprivation more than doubled from the 1980s to the 1990s. The proportion of pregnancies resulting in a maternity was positively associated with level of deprivation, but the effect remained similar over time. CONCLUSION: From the 1980s to the 1990s the difference in rates of teenage pregnancy between more affluent and more deprived areas widened. This has implications for allocating resources to achieve government targets and points to important social processes behind the general increase in the number of teenage pregnancies in Scotland.

Adolescent↗
PubMed1999

Variation in the provision of chemotherapy for colorectal cancer.

OBJECTIVE: To quantify the impact of patient, area and hospital characteristics on variations in the provision of chemotherapy for colorectal cancer. SUBJECTS: Incident cases of colorectal cancer (ICD 153-154), aged under 75 years and resident in Scotland, derived from linked hospital discharge records and death records for the period January 1990 to June 1994. The final analysis was carried out on 7852 patients resident in 823 areas and first admitted to one of 59 hospitals. MAIN OUTCOME MEASURE: Whether a patient received chemotherapy (OPCS4 procedure code X35.2) during any hospital episode in the six months after their first admission. METHODS: Multilevel logistic regression to separate effects of patients, areas and hospitals. RESULTS: During the study period, 8% (n = 626) of the study population received chemotherapy within six months of their first admission. Adjusting for comorbidities and emergency admissions, both age and deprivation were significantly associated with the treatment. The odds ratios (OR) of chemotherapy relative to patients aged 65-74 were 2.13 and 4.50 for patients aged 55-64 and under 55 respectively. Relative to patients resident in the most affluent areas, the OR of chemotherapy for patients resident in the most deprived areas was 0.73. Area level availability of the treatment was not significantly associated with a patient's odds of receiving the treatment while on site provision of chemotherapy at the hospital of first admission was (OR = 4.32). There was significant unexplained variation between hospitals of first admission but not between areas of residence; between hospital variation decreased by 22% during the study period. CONCLUSION: Differences according to age may reflect both clinical and patient decisions regarding the benefits of the treatment relative to its toxicity. Lower treatment rates in deprived areas may indicate inequitable access to services. Hospital differences may reflect consultant effects and it would be expected that these should decrease now that the efficacy of the treatment has been recognised and guidelines have been issued.

Adolescent↗
PubMed1997

Transient seizure: a subtle clue to diagnosis of subarachnoid haemorrhage.

A case is described of a 25-year-old primigravida who sustained a transient seizure following the administration of an epidural bolus of local anaesthetic. She had previously complained of a headache, and 3 days after caesarean section, died from subarachnoid haemorrhage. This case report highlights the difficulty in diagnosing subarachnoid haemorrhage in pregnancy and discusses the anaesthetic complications that may arise in the presence of an undiagnosed aneurysmal rupture. In this case the diagnosis was delayed due to absence of neurological signs, but the transient seizure may have been a clue to an earlier diagnosis.

Journal Article↗
PubMed1997

Prevalence of Helicobacter pylori antibodies in children in Bloemfontein, South Africa.

BACKGROUND: An association of H. pylori infection with chronic gastritis, peptic ulceration and gastric cancer is known. METHODS: Prevalence of IgG antibodies to Helicobacter pylori in children in the Bloemfontein, South Africa area was studied. Children attending the general pediatric outpatient department at Pelonomi Hospital in Bloemfontein were grouped according to age. A minimum of 100 children was investigated in each age group. Baseline demographic and socioeconomic data were collected. RESULTS: The study showed a high prevalence of H. pylori antibodies. Prevalence increased with age: 13.5% in children 3 months-2 years, 48.5% at 2-5 years, 67.3% at 5-10 years and 84.2% at 10-15 years. Investigation of the socioeconomic data in relation to the prevalence of H. pylori was inconclusive. CONCLUSIONS: This high prevalence needs further study.

Adolescent↗
PubMed1996

Respiratory health in a total very low birthweight cohort and their classroom controls.

AIMS: To compare the respiratory health and function at 8 to 9 years of age of a total population based cohort of 300 very low birthweight (VLBW) children with that of two classroom controls (n = 590) matched for age and sex. STUDY DESIGN: Cohort study with controls. SETTING: Schools throughout Scotland. RESULTS: The VLBW children were more likely than their peers to use an inhaler, to be absent from school, and to be admitted to hospital because of respiratory illness. They were significantly shorter than their classroom controls, but even after adjusting for differences in height, the VLBW children had reduced forced vital capacity (FVC); this was associated with a history of prolonged ventilation (> 28 days) and pneumothorax in the neonatal period. There were no significant differences between the groups in forced expiratory volume in one second (FEV1)/FVC but twice as many (7.9% v 3.7%) of the VLBW children had ratios < 70%, denoting obstructive airways disease. Poor expiratory function was associated with neonatal respiratory distress syndrome, prolonged ventilation, and the need for > 40% oxygen. Exercise induced airway narrowing was increased in VLBW children (odds ratio = 2.0; 95% confidence interval 1.2 to 3.4) and was very little changed by adjustment for inhaler use and exposure to cigarette smoke. CONCLUSIONS: As in other low birthweight cohorts, respiratory morbidity was increased. Unlike previous studies, FVC was more affected than expiratory function in this VLBW population. Our findings support the hypothesis that poorer lung function is associated with very low birth weight, but not with intrauterine growth retardation.

Asthma, Exercise-Induced↗
PubMed1995

Patterns of care in advanced HIV disease in a tertiary treatment centre.

A retrospective chart review of all in-patient deaths in 1992 was undertaken to examine patterns of care in advanced HIV disease at St Paul's Hospital, Vancouver, Canada. St Paul's Hospital cares for approximately 75% of the Province of British Columbia's AIDS caseload. This represents about 18% of Canada's caseload. Data were collected on demographic characteristics, the utilization of home care and community services, income and social support, symptom presentation at terminal admission and the utilization of acute hospital care and hospital based palliative care. A total of 126 deaths were reviewed. All but two subjects were homosexual/bisexual men. The median age at death was 39 years (range 24-67). Four patterns of care at death were identified: (1) aggressive therapy with resuscitation 24 (19%), (resuscitation was initiated in 58%); (2) aggressive therapy with a no resuscitation order 49 (39%), in which the palliative period was a median of three days; (3) death on the palliative care unit 33 (29%), with a median survival once palliative of 20 days; and (4) death on the palliative care unit following respite admissions 16 (13%), with a median survival once palliative of 64 days. Despite a well known and respected Palliative Care Unit and community palliative care programme, there is a marked trend towards death occurring during aggressive therapy with a 200% increase in the initiation of resuscitation compared to the previous three years. No-one has been discharged alive from hospital following the initiation of resuscitation since 1988. This study illustrates the need for providers and persons infected with HIV to reconsider expectations about treatment outcomes in advanced HIV disease.

Acquired Immunodeficiency Syndrome↗
PubMed1995

School attainment, cognitive ability and motor function in a total Scottish very-low-birthweight population at eight years: a controlled study.

The prevalence of learning problems and of cognitive and motor impairment in a total geographically based very-low-birthweight population (N = 324) was compared at eight years of age with that in a population comprising two classroom peers, matched for gender and age (N = 590). 15 per cent of those with birthweights less than 1000g and 6 per cent of those weighing 1000 to 1499 g attended special schools. Index children in main-stream schools performed significantly less well in tests of neuromotor function than their comparison groups. Their mean IQs were 90.4 and 93.7 for those below and above 1000 g, respectively, while their comparison groups' IQs were 102.5 and 101.2. In all cognitive subscales apart from that testing short-term auditory sequential memory, both index groups were less competent. They were also less able in Word Reading and Basic Number Skills. These children placed heavy demands on mainstream schools, with 52 per cent and 37 per cent of the index groups, respectively, requiring learning support compared with 16 per cent in both comparison groups.

Achievement↗