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Biomedical subjects

J Baird

Publications and source records attributed to J Baird.

At least 19 recordsLinked to original sources

A systematic review of lay views about infant size and growth.

OBJECTIVES: To understand lay views on infant size and growth and their implications for a British population. METHODS: A systematic review of parental and other lay views about the meanings and importance of infant size and growth using Medline, PsycInfo, CINAHL, Sociological Abstracts, IBSS, ASSIA, British Nursing Index ChildData, Caredata, SIGLE, Dissertation Abstracts (US), Index to Theses. 19 studies, most of which reported the views of mothers, from the US, Canada, the UK and Finland were reviewed. RESULTS: Notions of healthy size and growth were dominated by the concept of normality. Participants created norms by assessing and comparing size and growth against several reference points. When size or growth differed from these norms, explanations were sought for factors that would account for this difference. When no plausible explanation could be found, growth or size became a worry for parents. CONCLUSIONS: Parents consider the importance of contextual factors when judging what is appropriate or healthy growth. For public health advice to be effective, lay, as well as scientific, findings and values need to be considered.

Anthropometry↗

Immune interactions between mosquitoes and their hosts.

The intimate contact between mosquitoes and the immune system of their hosts is generally not considered important because of the transient nature of mosquito feeding. However, when hosts are exposed to many feeding mosquitoes, they develop immune responses against a range of salivary antigens. Understanding the importance of these responses will provide new tools for monitoring vector populations and identifying individuals at risk of mosquito-borne diseases, and allow the development of novel methods for monitoring control and mosquito-release programmes. Antibodies targeting the mosquito midgut are also important in the development of mosquito vaccines. The feasibility of this approach has been demonstrated and future research opportunities are considered in this review. The potential impact of mosquito vaccines is also discussed. Our understanding of the interplay between mosquitoes and the immune system of their hosts is still in its infancy, but it is clear that there is great potential for exploiting this interplay in the control of mosquito-borne diseases.

Animals↗

Implementation of universal antenatal screening for HIV and hepatitis B--lessons for future work.

This paper describes the successful implementation of universal antenatal screening for HIV and hepatitis B in Southampton and South West Hampshire Health Authority. This was achieved through formation of a multi-disciplinary planning group of clinicians and managers from local trusts. The approach taken in implementing screening is described, key elements of this being the appointment of screening co-ordinators and consultation with local midwives to ensure their training needs were addressed. Lessons for future work are discussed.

England↗

A survey of the delivery and uptake of influenza vaccine among health care workers.

During the 1990s, policies for immunizing fit health care workers against influenza varied between National Health Service (NHS) employers and the uptake of influenza vaccine by NHS staff was poor. In light of recent Department of Health recommendations to immunize key health care staff against influenza, we explored the possible reasons for poor uptake and assessed the impact of an intensive promotion campaign on vaccine acceptance. Among 290 doctors and nurses, the main perceived barriers to influenza immunization were difficulty with practical access to vaccine and lack of time to attend. Following intensive promotion and improved local access to influenza vaccine, the uptake among health care workers was approximately doubled. However, the overall proportion of staff immunized was low (5%) and the immunization rate among medical staff was particularly poor (2%). The practical implications for influenza immunization campaigns aimed at health care workers are discussed.

Attitude of Health Personnel↗

Testing the fetal origins hypothesis in twins: the Birmingham twin study.

AIMS/HYPOTHESIS: To test whether the link between birthsize and raised blood pressure or glucose tolerance is due to genetic or intrauterine factors, we studied whether differences in birthweight between pairs of monozygous and dizygous twins are associated with adult differences in blood pressure and glucose tolerance. METHODS: A sample of 58 monozygous and 140 dizygous twins were identified from a register of births in Birmingham, United Kingdom, between 1950 and 1954. The twins had their blood pressure measured and underwent an oral glucose tolerance test. RESULTS: There were no statistically significant associations between birthweight, length or ponderal index, and either blood pressure or glucose tolerance in the twins. Although there were substantial within-pair differences in birthweight between monozygous and dizygous twin pairs, these differences did not correlate with the adult outcomes. Monozygous correlations, however, for both blood pressure and glucose tolerance were statistically significantly higher than dizygous correlations and a quantitative genetic model suggested statistically significant heritability for these traits. In contrast correlations of birthsize were similar in monozygous and dizygous pairs suggesting only a small genetic component in determining fetal size. CONCLUSION/INTERPRETATION: Our results show that birthsize in twins does not predict adult blood pressure or glucose tolerance. We also suggest that shared genetic determinants for fetal growth and adult outcomes are not likely to be prevalent or powerful.

Adult↗

The evolution of ADHD: a disorder of communication?

Attention deficit hyperactivity disorder (ADHD) is the most commonly diagnosed psychiatric condition. Many believe that the central disability is impaired inhibition, which leads to reduced abilities in social skills, self-control, organization and time management. The behaviors identified by clinicians as problematic--inattention, hyperactivity and impulsivity--have been incorporated into several evolutionary models as selectively adaptive cognitive skills for surviving the challenges of a variable Pleistocene environment. We propose that the "disabilities" exhibited by individuals with ADHD are maladaptive, and we concur with Barkley that there is a central impairment in the behavioral inhibition system. The underlying neural anatomy and physiology support the possibility that neurotransmitter pathology may have an impact on other interlinked systems (including language), and may also account for the frequent comorbidity of aggression, anxiety, depression, and learning disabilities (many of which are language-related). Language skills compete with other cognitive activities for the attentional system, and thus the evolution of language could not in fact be independent of the evolution of attention. If language represents the ultimate expression of the attentional system, and some individuals with ADHD are seriously impaired in the coordination of interlinked neural systems (including language), then ADHD fits Jerome Wakefield's definition of "harmful dysfunction," and communication impairments should be investigated more thoroughly by clinicians.

Adaptation, Physiological↗

Increased stroop facilitation effects in schizophrenia are not due to increased automatic spreading activation.

Studies using the single trial Stroop task consistently reveal increased reaction time (RT) facilitation effects among schizophrenia patients. One possible mechanism underlying this effect is increased automatic spreading activation in semantic networks. The current study was designed to test this hypothesis. We administered the Stroop task and two semantic priming tasks to the same subjects. Patients showed greater Stroop RT facilitation than controls, no evidence of increased semantic priming at short stimulus onset asynchronies (SOAs), and reduced semantic priming at long SOAs. In addition, abnormal Stroop performance was related to the severity of Disorganization symptoms. These results are inconsistent with the spreading activation hypothesis. Alternative hypotheses regarding the source of Stroop task performance deficits in schizophrenia are discussed.

Adult↗

Mortality from birth to adult life: a longitudinal study of twins.

We have examined mortality from birth through adult life in a cohort of 2562 twins born in Birmingham, UK, between 1950 and 1954. Their birthweights and obstetric details had been recorded as part of a longitudinal study of births in Birmingham. There were a total of 151 perinatal deaths (perinatal mortality rate = 116 per 1000 births) and 227 infant deaths (infant mortality rate = 94 per 1000 live births). 70 deaths occurred after the age of one year. In comparison with national mortality rates in the UK, overall mortality in the twins was high (standard mortality rate, SMR = 259, 95% CI 221-300). Mortality was highest in the first year of life and, although it then declined progressively, it remained significantly higher that that of the general population until age 5 years. The excess mortality was largely due to conditions originating in the perinatal period but there were excess rates of congenital abnormalities, diseases of the respiratory system, digestive system and nervous and sensory organs. A Cox proportional Hazards analysis showed that the risk of death was related to low birthweight, prematurity and male sex. Death of the co-twin was highly predictive of mortality throughout the period of follow up. These studies not only underline the excess mortality associated with twin birth but show for the first time that this excess mortality extends into childhood.

Adolescent↗

Characteristics of infants receiving prompt first diphtheria-tetanus-pertussis immunisation in an infant cohort.

The Centers for Disease Control in the United States have stated that studies to determine factors associated with failure to receive the first recommended dose of diphtheria-tetanus-pertussis are required. We examined an infant cohort to identify family and infant characteristics predictive of prompt first immunisation, to document changes in prompt first immunisation rates over time and to identify reasons for immunisation delay. The study sample consisted of one-fifth of live births in Tasmania at risk of sudden infant death syndrome. From 1 January 1988 to 31 December 1994, families of 8011 infants (83 per cent of eligible infants) participated in a telephone interview when the infants were a median postnatal age of 11 weeks and 3 days. Prompt immunisation was defined as the report by parents of diphtheria-tetanus-pertussis vaccination before a postnatal age of 10 weeks. The proportion of cohort infants promptly immunised increased (P < 0.0001) over time from 1988 to 1994. Prompt immunisation was associated with various characteristics of the infant and family. The proportion of infants promptly immunised decreased as birth order increased and as the interpregnancy interval between the index child and his or her immediately elder sibling decreased. After exclusion of infants not promptly immunised because of illness, birth order and interbirth interval remained significant predictors of prompt immunisation, suggesting that these factors are acting to increase immunisation delay through pathways unrelated to their potential effect on infant illness rates.

Appointments and Schedules↗

The association of an HPV16 oncogene variant with HLA-B7 has implications for vaccine design in cervical cancer.

HLA-restricted cytotoxic T-lymphocyte (CTL) recognition of human papillomavirus (HPV) oncogene products may be important in the control of the HPV infections associated with the development of cervical cancer. We have identified, in HLA-B7 individuals, a consistent variation in the HPV16 E6 oncoprotein sequence, which alters an HLA-B7 peptide binding epitope in a way likely to influence immune recognition by CTLs. These results illustrate a biologically relevant mechanism for escape from immune surveillance of HPV16 in HLA-B7 individuals. Thus, both HLA type and HPV16 strain variation need to be considered in the screening of at-risk individuals and for the rational design of anti-HPV vaccines.

Amino Acid Sequence↗

The prevalence of akathisia in patients receiving stable doses of clozapine.

BACKGROUND: Akathisia is a common side effect of traditional neuroleptic drugs and is associated with medication refusal and impulsive behavior. While our previous experience indicates that clozapine is effective in treating persistent akathisia, two controlled studies indicate vastly different prevalence rates of akathisia (7% vs. 40%) in patients receiving clozapine. METHOD: We used the Barnes Rating Scale for Drug-Induced Akathisia to estimate the prevalence of akathisia in patients receiving stable doses of clozapine alone (N = 29) in a state hospital. Measurements were also made of manifest psychopathology (Brief Psychiatric Rating Scale) and tardive dyskinesia (Abnormal Involuntary Movement Scale). RESULTS: Two patients (6.8%) receiving clozapine were rated as having akathisia. Only 4 (28.6%) of the 14 subjects with a history of moderate-to-severe tardive dyskinesia on traditional neuroleptic drugs continued to show current evidence of tardive dyskinesia, and in 10 patients (71.4%) there was no evidence of the syndrome (p < .002). In the 4 subjects with tardive dyskinesia there was amelioration to a milder form of the syndrome. There were no new cases of tardive dyskinesia among clozapine-treated subjects. CONCLUSION: These data support the low prevalence of akathisia in patients receiving stable doses of clozapine monotherapy. There is further support that clozapine has an ameliorating effect on tardive dyskinesia associated with traditional neuroleptic drugs. These and other data indicate the need for a controlled trial of clozapine in patients experiencing persistent and disabling akathisia on traditional neuroleptic drugs.

Adult↗

Histone H4 acetylation and transcription in amphibian chromatin.

Lampbrush chromosomes from oocytes of the amphibian Triturus cristatus have been used to examine the role of histone acetylation in transcription by indirect immunofluorescence with antisera to H4 acetylated at specific lysine residues. Electrophoresis on acid-urea-Triton gels and Western blotting have confirmed the specificity of these antisera and defined the order in which particular lysine residues are acetylated in amphibian cells. As in mammals, lysine 16 is acetylated first, followed by 8 and/or 12 and then 5. With lampbrush chromosomes from immature (previtellogenic) oocytes, antisera to H4 acetylated at lysines 8, 12, and 16 labeled fluorescent foci at the bases of transcription loops. Antisera to H4 acetylated at lysine 5 labeled weakly (i.e., the tri- and tetraacetylated isoforms must be rare). Loops showed weak labeling of the chromatin axis but intense fluorescence at particular points, which probably represent incompletely decondensed chromatin. The RNP matrix of loops, including the RNP-rich sphere bodies and the dense matrix of "marker" loops, was not labeled. Treatment of immature oocytes with butyrate for 12 h to inhibit histone deacetylation did not affect immunolabeling, suggesting that turnover of H4 acetates is slow. In contrast, in chromosomes from mature oocytes, in which loops have retracted and transcription is low, butyrate caused an increase in labeling with all antisera, followed by the appearance of vestigial loops, weakly labeled, but with regions of intense fluorescence. These loops contain RNP and are presumably transcriptionally active. We conclude that H4 acetates turn over more rapidly in mature than immature oocytes and that histone hyperacetylation precedes, and possibly induces, loop formation and transcriptional activation.

Acetylation↗

Which comes first, Kt/V or PCR--chicken or egg?

We previously hypothesized that PCR is dependent on Kt/V (urea). To test the hypothesis, 30 patients from two hemodialysis (HD) units with PCR values consistently less than 1 regardless of the Kt/V (urea) without an obvious cause (such as malignancy, peptic ulceration, etc.) were identified. These patients were randomized into an experimental group where an increase in the Kt/V (urea) was made or into a control group where a Kt/V (urea) remained unchanged. In the experimental group the minimal increment in Kt/V (urea) was 0.3 plus a minimum requirement of a Kt/V (urea) greater than or equal to 1. The control group were to maintain the existing Kt/V (urea) within +/- 0.2. Urea kinetic modeling was monitored monthly and the patients followed for three months. Of 30 patients, 18 fulfilled the criteria (9 experimental; 9 controls). In the experimental group, the initial Kt/V (urea) was 0.82 +/- 0.19 (means +/- SD); the final Kt/V (urea) was 1.32 +/- 0.21 (P = 0.000). These patients had an initial PCR of 0.81 +/- 0.08. This increased to 1.02 +/- 0.15 (P = 0.005). The control group had an initial Kt/V (urea) of 0.82 +/- 0.16. The final Kt/V (urea) was 0.87 +/- 0.15. Their initial PCR was 0.87 +/- 0.14 and the final PCR was 0.86 +/- 0.087 (P = NS). In the experimental group, the mean increments in Kt/V (urea) and PCR were 0.49 +/- 0.17 and 0.21 +/- 0.16 (P less than 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)

Humans↗

Linkage analysis of maturity-onset diabetes of the young (MODY): genetic heterogeneity and nonpenetrance.

We have analyzed the inheritance of maturity-onset diabetes of the young (MODY) on chromosome 20 in a large multigeneration family, the R.-W. family, and in two other MODY families. Of the four branches of the R.-W. pedigree which have been studied, two have documented early onset of non-insulin-dependent diabetes mellitus (NIDDM), while there is no evidence of early onset in the other two branches. The early-onset branches have apparently inherited the same D20S16 allele from the affected parent, while another D20S16 allele was inherited in the two branches without evidence of early onset. A test for homogeneity, the M-test, using the results of two-point linkage analysis with D20S16 indicates heterogeneity between early- and late-onset branches of the R.-W. family (P less than or equal to .014). In addition, analysis strongly suggests that MODY as expressed in the EDI and WIS families is unlinked to loci on chromosome 20 (P less than or equal to .018-.004). Comparable results are seen when the data are analyzed by the HOMOG program. Three polymorphic loci-D20S16, D20S17, and ADA--show no recombination with the MODY locus when two-point linkage analysis is used in the early-onset branches of the family. The multipoint lod score in the early-onset branches of the R.-W. family is 10.16, with the most likely location being between D20S4 and D20S17. Multipoint linkage analysis using the CHROMPICS option of the program CRI-MAP has been used to follow inheritance of the MODY disease locus. This analysis has identified two cases of possible nonpenetrance in the early-onset branches of the family (odds of at least 156:1), as determined by the appearance of apparent isolated double crossovers at the MODY locus in these unaffected individuals.

Adolescent↗

Characterization of pancreatic islet cell infiltrates in NOD mice: effect of cell transfer and transgene expression.

Insulin-dependent diabetes mellitus can be transferred into young irradiated non-obese diabetic (NOD) mice by spleen cells from a diabetic NOD donor. T cells (both L3T4+ and Ly-2+) enter the pancreas 2 weeks following transfer. They are present initially at peri-islet locations but progressively infiltrate the islet with accompanying beta cell destruction. The infiltrate is heterogeneous with respect to V beta usage. Inflammatory macrophages (Mac-1+, F4/80+) can be detected at peri-islet locations at 1 week after transfer and continue to be recruited during the disease process. Their presence at the initiation of disease suggests that their primary function may be autoantigen presentation. Increased expression of major histocompatibility complex (MHC) class I molecules is observed on both endocrine and exocrine tissue in areas of intra-islet infiltration. MHC class II and ICAM-1 expression was restricted to the cells constituting the inflammatory infiltrate. Expression of these molecules was not observed on beta cells implying that presentation of autoantigen by the beta cell itself does not play a role in the beta cell destruction in NOD mice.

Animals↗