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Biomedical subjects

M B Walker

Publications and source records attributed to M B Walker.

At least 37 records · Page 2Linked to original sources
PubMed1996

Height and weight measurements of Ibadan school children.

Height and weight measurements were carried out on three groups of Nigerian primary school children aged 6-12 years, in and around Ibadan. A total of 1,192 children was examined from three social classes as follows: (1) the educated elite group (n = 444); (2) the urban low socio-economic group (n = 366), and (3) the rural village group (n = 382). The school children from the educated elite group had the highest mean height and weight values while the school children from the rural group had the lowest values and the urban low socio-economic came in between the two. In the children of the educated elite class, mean heights and weights were higher than those of the international reference population (though not significantly so) only at ages 6-9 years. Malnutrition as indicated by wasting and stunting was prevalent among both rural and urban low socio-economic school children. The prevalence of wasting was 75.9% among the rural school children, while it was 62.5% among the urban low socio-economic children. The prevalence of stunting was 79.1% among the rural school children, while it was 62.9% among the urban low socio-economic school children. Neither stunting nor wasting was observed among the children of the elite educated group. This study has demonstrated that there has been no change with time in the pattern of differences of height and weight with respect to school children of various social classes.

Age Distribution↗
PubMed1995

The marriage tax and the rate and timing of marriage.

"The effect of the differential tax treatment of married and unmarried couples, the so-called marriage tax, on the rate and timing of [U.S.] marriages is analyzed. Using time-series data, we study the effect of the marriage tax on the fraction of unmarried women over the age of 15 years who marry in each year. We find no effect. We also investigate whether couples shift the timing of their marriage from the end of one year to the beginning of the next year in response to an increase in the marriage tax. We find empirical support for this behavior."

Americas↗
PubMed1994

A chicken achaete-scute homolog (CASH-1) is expressed in a temporally and spatially discrete manner in the developing nervous system.

We have identified a basic helix-loop-helix encoding cDNA from embryonic chicken retina which shares sequence similarity with the achaete-scute family of genes of Drosophila. The deduced amino acid sequence of this chicken achaete-scute homolog (CASH-1) is identical, over the region encoding the basic helix-loop-helix domain, to the recently identified mammalian achaete-scute homolog (MASH-1) and to the Xenopus homolog (XASH1), and 70% identical, over the same region, to Drosophila achaete-scute complex members. The expression of CASH-1 is restricted to subsets of neuronal progenitor cells in the developing chicken nervous system, similar in distribution to that reported for MASH-1 and XASH1. In addition, in situ localization in the retina reveals a dynamic character of expression of the gene in a particular region of the CNS, and suggests that the expression of CASH-1 may be important in defining a particular stage in the progenitor cell necessary for the differentiation of particular neuronal phenotypes.

Amino Acid Sequence↗
PubMed1994

The use of pulmonary artery catheters in intensive care: time for reappraisal?

The precise role of the pulmonary artery catheter (PAC) in reducing the morbidity and mortality of intensive care patients remains uncertain. Future studies of the different patient groups who possibly benefit from their use may well require multicentre trials in order to include sufficient numbers and produce significant conclusions. This would suggest a need for a consensus opinion on how PACs are actually used to obtain the different physiological variables which can influence patient management. A questionnaire was designed to assess the degree of conformity of PAC use in intensive care; the questions were derived from a Medline search and considered by the authors to represent a cross-section of the different aspects and potential errors of PAC use. A postal questionnaire was sent from a District General Hospital to 42 adult Intensive Care Units (ICUs) requesting information on the use of PACs in each ICU. The reply rate was 93%, with all but one of the respondents using PACs. The questionnaire obtained information in different areas of PAC use: 1. General usage of PACs. 2. Measurement of patient height and weight. 3. Confirmation of position of PAC tip. 4. Measurement of pulmonary artery wedge pressure (PAWP). 5. Measurement of cardiac output (CO). 6. Derived values. 7. Monitoring for PAC-related sepsis. The results of the questionnaire demonstrated a considerable lack of standardisation in the use of PACs in the United Kingdom.(ABSTRACT TRUNCATED AT 250 WORDS)

Catheterization, Swan-Ganz↗
PubMed1993

Associative priming in perceptual identification: effects of prime-processing requirements.

Three experiments assessed the effects of prime-processing instructions on associative priming in word identification and episodic memory for primes. In Experiment 1, groups instructed to read the prime silently or generate silently an associate of the prime showed a larger accuracy benefit for related over unrelated targets than did a group that decided whether an asterisk was to the right or left of the prime. The asterisk-search group showed a weaker repetition effect on a subsequent identification test of primes, indicating that the weaker priming in this group was a result of poorer perceptual processing. On a cued-recall test for primes, the generate group was superior to the other groups. In Experiment 2, we found that with weak prime-target associations, priming was comparable for read and generate groups and stronger than estimated for a guessing strategy, on the basis of single predictions made from each prime by an additional group. In Experiment 3, we demonstrated that the read and generate instructions produced similar mispriming and inhibitory effects. The results suggest that the depths of prime-processing manipulations do not have parallel effects on priming and episodic memory, and that associative priming in word identification, as in other tasks, may involve an expectancy process.

Adult↗
PubMed1992

Comparison of the endotracheal tube and laryngeal mask in airway management by paramedical personnel.

An evaluation of the laryngeal mask airway (LMA) as a means of airway support when used by paramedical personnel was performed. Forty medical and paramedical students attempted to intubate the tracheas of 40 healthy anesthetized adults with the LMA and a cuffed endotracheal tube (ETT). The number of attempts to achieve correct placement and the time taken to adequately ventilate the lungs were recorded for both devices. End-tidal carbon dioxide was detected significantly sooner after commencement of the intubation attempt using the LMA (mean 38.6 s) compared with the ETT (mean 88.3 s, P less than 0.0001). Ninety-four percent of the students successfully ventilated the lungs on their first attempt with the LMA, whereas only 69% intubated the trachea on their first attempt with the ETT (P less than 0.01). Five students were unable to intubate the trachea after three attempts with the ETT, but all positioned the LMA satisfactorily on their first try in a mean time of 40 s. We conclude that unskilled operators with minimal training can safely and successfully ventilate unconscious patients more rapidly using the LMA than the ETT. These results suggest the LMA should be available in all areas where resuscitation is performed.

Adolescent↗
PubMed1989

Structural changes vary along individual arterioles in deoxycorticosterone acetate hypertensive rats.

The variability of structural changes along individual arterioles in deoxycorticosterone acetate (DOCA) hypertensive rats was measured by coefficients of variation of: (a) serial lumen diameters along microfil casts of individual mesenteric arterioles; and (b) wall and lumen indices in serial histological cross-sections along individual renal arterioles. The mean lumen diameter of third-order mesenteric arterioles decreased with increasing duration of hypertension. There was increased variability of lumen diameter along lengths of DOCA arterioles, the coefficient of variation at 10 weeks DOCA treatment being 20.2 +/- 0.6% compared to 9.2 +/- 0.2% in controls (P less than 0.001). Medial area to internal elastic lamina (IEL) radius ratio of renal arterioles was increased in DOCA rats compared with control rats (P less than 0.025) and its variability along individual arterioles expressed as the coefficient of variation was 31.70 +/- 3.87% in DOCA rats compared with 15.29 +/- 1.72% in controls (P less than 0.005). The observed increase in variability of lumen diameter and medial area along short lengths of individual arterioles in DOCA hypertensive rats indicates that hypertensive structural changes are probably not directly related to local blood pressure. We suggest that irregular functional vasoconstriction in hypertensive rats could account for this distribution of structural changes.

Animals↗
PubMed1978

Interpersonal distance as a function of situationally induced anxiety.

Two experiments were conducted to investigate the effects of situationally induced anxiety on interpersonal distance in a two-person conversation. In the anxiety-arousing situation subjects were asked to discuss an interesting incident while their social competence was assessed from behind a one-way screen. The briefing and debriefing periods were used for control purposes. Analysis of speech disturbance rates showed that the anxiety manipulation was successful. A significant increase in interpersonal distance was found in the anxiety-inducing situation relative to the low stress situation. The implications for the controversy concerning the effect of anxiety on the need for affliation are discussed.

Anxiety↗
PubMed1977

Plasma prostaglandin E concentrations from birth through childhood.

The prostaglandins are synthesized in a variety of tissues and participate in an extensive number of physiologic processes. As prostaglandin concentrations have not been reported in infants and children, we measured PGE levels from birth through childhood. PGE levels in cord blood were significantly higher than those in adults. By 48 to 72 hours of age, however, they had fallen to levels that were significantly lower than those in adults. Although PGE concentrations increased with age, they remained significantly lower than did adult levels. These low levels may be related to some of the functional pecularities of the immature kidney.

Adolescent↗