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Biomedical subjects

B J Taylor

Publications and source records attributed to B J Taylor.

At least 109 records · Page 6Linked to original sources
PubMed1993

Dummies and the sudden infant death syndrome.

The association between dummy use and sudden infant death syndrome (SIDS) was investigated in 485 deaths due to SIDS in the postneonatal age group and compared with 1800 control infants. Parental interviews were completed in 87% of subjects. The prevalence of dummy use in New Zealand is low and varies within New Zealand. Dummy use in the two week period before death was less in cases of SIDS than in the last two weeks for controls (odds ratio (OR) 0.76, 95% confidence interval (CI) 0.57 to 1.02). Use of a dummy in the last sleep for cases of SIDS or in the nominated sleep for controls was significantly less in cases than controls (OR 0.44, 95% CI 0.26 to 0.73). The OR changed very little after controlling for a wide range of potential confounders. It is concluded that dummy use may protect against SIDS, but this observation needs to be repeated before dummies can be recommended for this purpose. If dummy sucking is protective then it is one of several factors that may explain the higher mortality from SIDS in New Zealand than in other countries, and may also explain in part the regional variation within New Zealand.

Case-Control Studies↗
PubMed1993

Rebreathing expired gases from bedding: a cause of cot death?

The reported association of cot death and sleeping prone could be due to rebreathing of expired gases. A mechanical model simulating the respiratory system of an infant, exhaling warm humidified air with an end tidal carbon dioxide of 5%, has been used to investigate this. Some commonly used bedding materials caused an accumulation of carbon dioxide of 7% to over 10% with the model lying face down. This phenomenon persisted even with the head inclined at 45 degrees, but only on very soft materials, and could be a cause of cot death in a baby unresponsive to asphyxial blood gas changes. A coir fibre mattress allowed complete dispersal of exhalate as did a rubber sheet between any mattress and the covering sheet.

Asphyxia↗
PubMed1993

Apnea and rapid eye movement sleep excess in the piglet during recovery from hyperthermia.

This investigation tested the hypothesis that artificially induced mild hyperthermia and recovery from hyperthermia in the developing newborn piglet (2-10 d of age) alter sleep state patterns and respiratory control. Continuous measurements of sleep state, respiratory pattern, carbon dioxide production and oxygen consumption were made before, during, and after a 3-h period of sustained hyperthermia. During hyperthermia, rectal temperatures were raised a mild 1-1.5 degree C above normal, well below the levels likely to cause severe physiologic distress in this species. This resulted in a disruption of the sleep state pattern characterized by a decrease in duration of rapid eye movement (REM) episodes, whereas immediately afterwards, during recovery, the amount of REM sleep increased. In some cases the amount of REM sleep in recovery more than doubled the basal level. Apneas were rarely observed during hyperthermia, but in recovery there was an increase in the total amount of time spent in apnea in both REM and non-rapid eye movement sleep states with a predominance in the REM state. Arousal responses to chemostimulation were not affected at this time. We conclude that the sleeping newborn piglet does indeed show marked changes in sleep state pattern (particularly REM sleep) and in the amount of apnea recorded during and immediately after only a mild increase in core temperature.

Aging↗
PubMed1993

Smoking and the sudden infant death syndrome.

OBJECTIVE: Maternal smoking has been shown to be a risk factor for sudden infant death syndrome (SIDS). The effect of smoking by the father and other household members has not previously been examined. METHODS: A large nationwide case-control study. Four hundred eighty-five SIDS deaths in the postneonatal age group were compared with 1800 control infants. RESULTS: Infants of mothers who smoked during pregnancy had a 4.09 (95% confidence interval [CI] = 3.28, 5.11) greater risk of death than infants of mothers who did not smoke. Infants of mothers who smoked postnatally also had an increased risk of SIDS compared with infants of nonsmokers and, furthermore, the risk increased with increasing levels of maternal smoking. Smoking by the father and other household members increased the risk (odds ratio [OR] = 2.41, 95% CI = 1.92, 3.02 and OR = 1.54, 95% CI = 1.20, 1.99, respectively). Smoking by the father increased the risk of SIDS if the mother smoked, but had no effect if she did not smoke. In analyses controlled for a wide range of potential confounders, smoking by the mother and father was still significantly associated with an increased risk of SIDS. CONCLUSION: Passive tobacco smoking is causally related to SIDS.

Case-Control Studies↗
PubMed1992

Pharmacokinetics and pharmacodynamics of bumetanide in neonates treated with extracorporeal membrane oxygenation.

Eleven term neonates treated with extracorporeal membrane oxygenation received bumetanide to treat volume overload. All patients had stable renal function, no history of prior diuretic therapy, and no overt evidence of hepatobiliary disease or hypoalbuminemia. Pretreatment creatinine clearance was 35.2 +/- 4.5 ml/min per 1.73 m2 (range, 20.3 to 57.5). Bumetanide, 0.095 +/- 0.003 mg/kg, was administered for 2 minutes into the postmembrane side of the extracorporeal membrane oxygenation circuit. Serial plasma and urine samples were collected for measurement of bumetanide and electrolyte concentrations. Total plasma and renal clearances for bumetanide were 0.63 +/- 0.11 and 0.16 +/- 0.04 ml/min per kilogram, respectively. The steady-state volume of distribution (0.44 +/- 0.03 L/kg) and the elimination half-life (13.2 +/- 3.8 hours) were greater than similar values reported in previous studies of bumetanide disposition in premature and term neonates who were not treated with extracorporeal membrane oxygenation. At observed rates of bumetanide excretion, the diuretic, natriuretic, and kaliuretic responses were linear. Significant diuresis, natriuresis, and kaliuresis were observed, although the duration of these effects was less than expected given the prolonged renal elimination of bumetanide. Nonrenal elimination of bumetanide was variable (47.2% to 96.9%) but higher than expected; this may explain the relatively brief diuretic and kaliuretic response.

Analysis of Variance↗
PubMed1992

Differentiation of a male-specific muscle in Drosophila melanogaster does not require the sex-determining genes doublesex or intersex.

A pair of muscles span the fifth abdominal segment of male but not female Drosophila melanogaster adults. To establish whether genes involved in the development of other sexually dimorphic tissues controlled the differentiation of sex-specific muscles, flies mutant for five known sex-determining genes were examined for the occurrence of male-specific abdominal muscles. Female flies mutant for alleles of Sex-lethal, defective in sex determination, or null alleles of transformer or transformer-2 are converted into phenotypic males that formed male-specific abdominal muscles. Both male and female flies, when mutant for null alleles of doublesex, develop as nearly identical intersexes in other somatic characteristics. Male doublesex flies produced the male-specific muscles, whereas female doublesex flies lacked them. Female flies, even when they inappropriately expressed the male-specific form of doublesex mRNA, failed to produce the male-specific muscles. Therefore, the wild-type products of the genes Sex-lethal, transformer and transformer-2 act to prevent the differentiation of male-specific muscles in female flies. However, there is no role for the genes doublesex or intersex in either the generation of the male-specific muscles in males or their suppression in females.

Animals↗
PubMed1992

Relieving pain through ordinariness in nursing: a phenomenologic account of a comforting nurse--patient encounter.

This article describes a nursing encounter between Sue, a nurse, and Becky, a patient. Sue and Becky related to one another through a sense of shared humanity that not only relieved some of Becky's pain, but also created some possibilities for changing patterns in her life that had been built up over a long period. The article suggests that nurses and patients relate to one another through their affinity as humans. Within the context of caring, nurses such as Sue are ordinary people perceived as being extraordinarily effective by the very ways in which their humanness shines through their knowledge and skills to make their whole being with patients something more than just professional helping. An implication for nursing knowledge arising from Sue's and Becky's interaction, and from the study generally, is the need to reconceptualize the nurse as person, so that nurses are described not only in terms of their professional roles and functions but also as people who share the everyday human qualities of their patients.

Aged↗
PubMed1992

From helper to human: a reconceptualization of the nurse as person.

This paper explores the nature of the nurse as person, as represented by nursing literature and in the author's own research, by considering the tendency nurses have to perceive as different the characteristics of nurses and patients as human beings. Nursing scholars have tended to categorize nurses and patients into discrete 'compartments' that are convenient for descriptive purposes, but nevertheless have had a tendency to limit people's essential humanness. The metaparadigm concept of person in nursing can take on a different meaning if people are regarded in terms of their oneness, rather than by their separateness. A brief introduction will be given to some meanings generated in some nursing research, which described the effects of ordinariness as they were manifested by nurses and patients in everyday nursing unit life. The possibility is raised that a reconceptualization of the nurse could describe the nurse, not only as a professional helper, but also as a human, whose effectiveness is enhanced through a sense of shared humanity with patients.

Helping Behavior↗
PubMed1992

Postnatal depression and SIDS: a prospective study.

This study was carried out in response to reports from nurses to a post-neonatal mortality review committee that a number of mothers of infants dying from sudden infant death syndrome (SIDS) appeared to be depressed before the child's death. The New Zealand Cot Death Study was a 3 year multicentre case-control study for SIDS. There were 485 SIDS cases in the post-neonatal age group in the study regions, and these were compared with 1800 control infants. Infants of mothers with either a self-reported use of medication for psychiatric disorders, a history of hospitalization for psychiatric illness or a family history of postnatal depression had a significantly increased risk of SIDS compared with infants of mothers who were either not using medication (odds ratio (OR) = 1.45; 95% confidence interval (CI) = 1.03, 2.04) or were without a history of hospitalization for psychiatric illness (OR = 1.80; 95% CI = 1.03, 3.11) or a family history of postnatal depression (OR = 1.61; 95% CI = 1.06, 2.43). All mothers of infants born in the study areas over a 1 year period were eligible to complete a questionnaire measuring maternal depression when the infant was 4 weeks of age. Thirty-three infants subsequently died from SIDS, and they were compared with 174 controls. Fifteen (45.5%) of the mothers of cases were depressed, compared with 28 (16.1%) of the mothers of controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Case-Control Studies↗
PubMed1992

Four modifiable and other major risk factors for cot death: the New Zealand study.

New Zealand's high mortality rate from sudden infant death syndrome (SIDS) prompted the development of the New Zealand Cot Death Study. A report of the analysis of the data from the first year has been published. This report now gives the major identified risk factors from the full 3 year data set. In this case-control study there were 485 infants who died from SIDS in the post-neonatal age group, and 1800 control infants, who were a representative sample of all hospital births in the study region. Obstetric records were examined and parental interviews were completed in 97.5% and 86.9% of subjects, respectively. As expected many risk factors for SIDS were confirmed including: lower socio-economic status, unmarried mother, young mother, younger school-leaving age of mother, younger age of mother at first pregnancy, late attendance at antenatal clinic, non-attendance at antenatal classes, Maori, greater number of previous pregnancies, the further south the domicile, winter, low birthweight, short gestation, male infant and admission to a special care baby unit. In addition, however, we identified four risk factors that are potentially amenable to modification.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗
PubMed1992

Oxygen consumption in the newborn piglet during combined cold face/hot body exposure.

There is increasing evidence that hyperthermia can occur in cool climates because of overwrapping and that this practice precedes many deaths labelled as SIDS. We have attempted to test the hypothesis that the interaction of a cold face and a hot body might lead to further hyperthermia in a piglet model. Twelve non-sedated newborn piglets were studied over the first 10 days of development. Oxygen consumption was measured continuously during sleep. Animals were exposed to cold face conditions initially while the animal's body was kept warm and then while the body was hyperthermic. The results show that stimulation of the face with cool ambient air during conditions of raised metabolic activity (hot body) causes a fall in oxygen consumption towards basal levels. These studies do not, therefore, support the hypothesis that a further increase in metabolic rate occurs during combined cold face and hot body exposure in the piglet model.

Animals↗
PubMed1992

Further evidence supporting a causal relationship between prone sleeping position and SIDS.

A 3 year case-control study identifying the risk factors for SIDS was undertaken. Preliminary analysis of the data from the first year suggested that SIDS mortality could fall by 50% if the prevalence of the prone sleeping position changed from 40 to 0%. During the 3 year study the prevalence of the prone sleeping position among infants has fallen from 43% in the first year to 20% in the third year. SIDS mortality has fallen to 3.1/1000 live births, which is very close to that predicted. When considered with other available evidence this strongly supports a causal relationship between the prone sleeping position and SIDS.

Case-Control Studies↗
PubMed1992

Commitment of abdominal neuroblasts in Drosophila to a male or female fate is dependent on genes of the sex-determining hierarchy.

Adult specific neurons in the central nervous system of holometabolous insects are generated by the postembryonic divisions of neuronal stem cells (neuroblasts). In the ventral nervous system of Drosophila melanogaster, sex-specific divisions by a set of abdominal neuroblasts occur during larval and early pupal stages. Animals mutant for several sex-determining genes were analyzed to determine the genetic regulation of neuroblast commitment to the male or female pattern of division and the time during development when these decisions are made. We have found that the choice of the sexual pathway taken by sex-specific neuroblasts depends on the expression of one of these genes, doublesex (dsx). In the absence of any functional dxs+ products, the sex-specific neuroblasts fail to undergo any postembryonic divisions in male or female larval nervous systems. From the analysis of intersexes generated by dominant alleles of dsx, it has been concluded that the same neuroblasts provide the sex-specific neuroblasts in both male and female central nervous systems. The time when neuroblasts become committed to generate their sex-specific divisions were identified by shifting tra-2ts flies between the male- and female-specifying temperatures at various times during larval development. Neuroblasts become determined to adopt a male or female state at the end of the first larval instar, a time when abdominal neuroblasts enter their first postembryonic S-phase.

Abdomen↗
PubMed1992

Effects of alveolar hypoxia on the pulmonary circulation and lung mechanics after cromolyn sodium and U-60,257 in lambs.

Because alveolar hypoxia (HYP) triggers pulmonary mast cell degranulation with elaboration of vasoactive mediators such as leukotrienes, we investigated the effects of aerosolized cromolyn sodium (CS), a mast cell stabilizing agent, and U-60,257(U) (a leukotriene blocker) on the circulation, lung mechanics and thromboxane (TXB2) levels in 11 lambs during acute exposure to HYP. Studies were performed in awake, chronically instrumented animals, once after placebo (saline) and again after CS (100 mg; n = 5) or U (90 mg; n = 6). Pulmonary arterial pressure increased 42% during HYP after saline, and 32% and 19% after CS and U, respectively. Pulmonary vascular resistance did not change during HYP after CS or U. Systemic arterial pressure was unchanged after saline and CS but decreased after U; systemic vascular resistance dropped after both CS and U. No changes were seen in tidal volume, lung compliance or airway resistance during HYP after saline or either drug, but minute ventilation increased during HYP in all studies. TXB2 increased during HYP after saline in both studies and was not altered by CS. In contrast, after U, TXB2 decreased. Thus, U more effectively blunted the pulmonary vascular response to HYP than CS and resulted in mild systemic hypotension. The drop in TXB2 after U suggests leukotriene-induced thromboxane synthesis contributes to regulation of pulmonary, and possibly, systemic vasoactivity.

Animals↗
PubMed1992

Evaluation of the reconstructed carotid artery following extracorporeal membrane oxygenation.

Over a 12-month period, 28 neonatal patients in respiratory failure were supported with extracorporeal membrane oxygenation (ECMO), and 11 of these underwent successful repair of the right carotid artery post-ECMO. Nine of 11 were studied with duplex color-flow Doppler imaging between 14 and 109 days of age and again at 1 year of age. A velocity ratio (A/B) of the peak systolic velocity above the level of the anastomosis to the peak systolic velocity below the anastomosis was measured to assess the degree of stenosis, if any, at the repair site. Antegrade flow through the carotid was detected post-ECMO in 8 of 9 infants, and antegrade and retrograde flow was documented in 1 infant. A/B ratios ranged from 1.00 to 8.60 (A/B ratio of 1 is normal; 2.0 indicates at least a 50% obstruction to flow). Four of 9 patients had ratios greater than 2.0, and 8 of 9 exhibited some evidence of obstruction. Follow-up scans were performed on 8 of 9 infants between 12 and 18 months of age. All infants examined showed marked improvement in A/B ratio and patency of the vessel, documenting that initial narrowing of the vessel is reversible. No infant had evidence of embolic phenomena to the right side of the brain by magnetic resonance imaging. Repair of the common carotid artery post-ECMO is technically feasible without increasing the risk of brain injury.

Blood Flow Velocity↗
PubMed1992

The New Zealand Cot Death Study: some legal and ethical issues.

The New Zealand Cot Death Study is a 3 year multicentre case-control study aimed at identifying the risk factors for sudden infant death syndrome (SIDS). The paper describes some of the legal and ethical issues which arose in the planning, implementation and analysis of the study.

Case-Control Studies↗