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Biomedical subjects

B J Taylor

Publications and source records attributed to B J Taylor.

At least 145 records · Page 8Linked to original sources
PubMed1989

Should intramuscular vitamin K prophylaxis for haemorrhagic disease of the newborn be continued? A decision analysis.

Haemorrhagic disease of the newborn is now a rare life threatening disease due to the widespread use of effective prophylaxis with vitamin K at birth. In recent years the continued need for routine prophylaxis has been questioned and alternative strategies proposed. We have reviewed the literature and using techniques of decision analysis, we reaffirm the need for continued prophylaxis. The cost for each life saved by an oral programme is $4500 and $11,000 for intramuscular prophylaxis. The cost to the state of no prophylactic programme is $6.40 per child born and $0.81 for an oral prophylactic programme. It is recommended that the oral route of vitamin K prophylaxis be adopted as it is equally efficacious with the intramuscular route, but cheaper, more consumer acceptable, and has a lower risk of iatrogenic disease.

Administration, Oral↗
PubMed1989

Infant clothing, bedding and room heating in an area of high postneonatal mortality.

Documentation of infant care practices (clothing, bedding and room heating) was undertaken in an area where the postneonatal mortality rate is 9.3 per 1000 live births. Three hundred and eleven infants (mean age 5 weeks) were studied in their own home during winter and spring. Low room temperatures were associated with low socioeconomic status, but not consistently with clothing or bedding thicknesses. The estimated thickness of bedding covering infants was less if their mothers were less well educated. Infants at high risk for possibly preventable postneonatal mortality, based on a locally developed scoring system, had less bedding and colder rooms. Ideas of illness management were often inappropriate, in that a large number of mothers would further wrap up their infants if they had a cold (58%), were febrile (8%) or had a convulsion (21%). The clothing and bedding appropriate for different environmental conditions in health and illness needs physiological evaluation. Meanwhile parents should be reminded of the risk of both hypothermia and hyperthermia.

Bedding and Linens↗
PubMed1989

Postneonatal mortality in south New Zealand: necropsy data review.

Three southern New Zealand health districts had a postneonatal mortality rate of 8.1 per 1000 livebirths and a postneonatal sudden infant death syndrome (SIDS) mortality rate of 6.3 per 1000 livebirths for the period 1979-1984. This is one of the highest reported rates of SIDS. The 429 postneonatal deaths occurring during the period were assigned to one of four groups: unpreventable (n = 52), possibly preventable non-SIDS (n = 45), SIDS with minor abnormalities at necropsy or premorbid symptoms (n = 167), and SIDS with no abnormalities at necropsy or documented premorbid symptoms (n = 165). These groups were related to obstetric and perinatal data. For those infants classified as SIDS, the winter peak of deaths was particularly marked if death occurred after 3 months of age. These older SIDS deaths had more minor abnormalities at necropsy, a longer interval between time last seen or heard alive and found dead and more thymic petechiae.

Cause of Death↗
PubMed1989

Child care practices and the sudden infant death syndrome.

Southern New Zealand has one of the highest reported rates of the sudden infant death syndrome (SIDS) in the world. Data were collected on 49 infants who died from SIDS in the Dunedin and Invercargill Health Districts of southern New Zealand. Forty-two of the families were interviewed at home following the loss of their infant. In the week prior to death, 17 infants (40%) had an upper respiratory tract infection, although in 11 of these infants their infection had apparently resolved at least 24 h prior to death. Thirty infants (71%) had their faces down into the bedding or their heads covered with bedding. Thirty-four infants (81%) were found dead in the prone position, whereas 49% of New Zealand infants aged 3 months would be expected to sleep prone. Sleep position and the terminal position of the head in relation to SIDS requires further study.

Humans↗
PubMed1989

Neurobehavioural effects of short duration exposures to acetone and methyl ethyl ketone.

A total of 137 volunteers were recruited and tested for neurobehavioural performance before, during, and after a short duration (4 h) exposure to acetone at 250 ppm, methyl ethyl ketone (MEK) at 200 ppm, acetone at 125 ppm with MEK at 100 ppm, or a placebo. Ethanol (95%-0.84 ml/kg) was used as a positive control. Performance testing was computer controlled and took place in an environmental chamber with four test stations. The total test regimen before, during, and after exposure covered 10 hours and 32 measures were collected. The measurements were extracted from two biochemical (venous blood and alveolar breath) tests, four psychomotor (choice reaction time, visual vigilance, dual task (auditory tone discrimination and tracking), memory scanning) tests, one sensorimotor (postural sway) test, and one psychological (profile of mood states (POMS] test. The exposure to 250 ppm acetone produced small but statistically significant changes in performance from controls in two measures of the auditory tone discrimination task and on the anger hostility scale (men only) of the POMS test. Neither MEK nor the combined acetone/MEK exposures produced statistically significant interpretable results. The combination exposure provides some indication that there was no potentiation of the acetone effects with the coexposure to MEK or vice versa. More pronounced performance decrements occurred with ethanol at 0.07-0.08% BAC. Significant (less than 0.05) differences were evident on both the auditory tone and tracking tests in the dual task and there was partial significance on the visual vigilance test (0.05-0.06) and some postural sway measures (less than 0.09). These findings agree with an earlier Japanese study in showing some mild decrements on behavioural performance tests with exposures to acetone at 250 ppm.

Acetone↗
PubMed1989

Duplex pulsed Doppler US versus intracranial pressure in the neonate: clinical and experimental studies.

This study was conducted to determine if the resistive index (RI) could be used for the examination and follow-up of neonates with increased intracranial pressure. First, in a laboratory model with four mongrel dogs, RI was found to correlate linearly with cerebral perfusion pressure. Second, RI was studied in 57 healthy neonates and 285 neonates with abnormal clinical or head ultrasound findings. Average RI for healthy newborns was 75 +/- 10 and was inversely related to gestational age. RI in newborns with abnormal findings was uniformly elevated, but these values varied considerably and were not statistically different from normal values. Third, the RI was found to decrease significantly after patent ductus arteriosus ligation, tapping of subdural effusions, ventricular tapping (later cerebrospinal fluid shunting led to a further drop in RI), and ventriculoperitoneal shunting. Elevated RI indicates possible intra- or extracranial abnormality affecting cerebral blood flow. Doppler RI is valuable in following up neonates with abnormal or unstable conditions and in assessing the effectiveness of therapies to improve cerebral perfusion.

Animals↗
PubMed1989

Sexually dimorphic neurons in the terminalia of Drosophila melanogaster: I. Development of sensory neurons in the genital disc during metamorphosis.

The adult terminalia of Drosophila melanogaster males and females are sexually dimorphic. The sensory neurons that innervate the sex-specific bristles of the analia and genitalia arise within the genital disc during metamorphosis. Using antibodies that recognize peripheral neurons, I have followed the development of neurons in the female genital, the male genital and the shared anal primordium. Neurons form only in the expressed genital and anal primordium at the onset of the white prepupal stage. Two basic types of neurons differentiate in the genital disc; exteroreceptors that innervate the external bristles and enteroreceptors that innervate the internal reproductive organs. Within the genital disc, each structure has a sex-specific time during pupation when its neurons differentiate even when neurons are derived from homologous primordia. The data suggest that the sexually dimorphic arrangement of sensory neurons is a product of sex-specific neurogenesis.

Animals↗
PubMed1989

Sexually dimorphic neurons of the terminalia of Drosophila melanogaster: II. Sex-specific axonal arborizations in the central nervous system.

In order to understand how the peripheral nervous system in male and female flies differ, I have determined the projection pattern of sensory neurons that innervate the sex-specific adult terminalia, the genitalia and analia, of Drosophila melanogaster. In the adult male and female fly, mechanosensory bristles arranged on the external terminalia are innervated by sensory neurons that arborize in the abdominal ganglion. The distribution of axonal arbors differs between males and females. In males, sensory neurons terminate in a greater variety of patterns over a larger area of neuropil than those in females. Mutations in a sex-determining gene (transformer-2, tra-2,) which regulates the development of secondary sexual characteristics in somatic tissues, cause female flies to be transformed into phenotypic males. The sensory neurons of the terminalia are also transformed leading them to arborize appropriately for male neurons.

Animals↗
PubMed1989

Cardiovascular response to histamine during normoxaemia and hypoxaemia in piglets.

The cardiovascular effects of exogenously administered histamine were investigated in conscious newborn piglets aged 10-11 days during normoxia (21% (v/v) O2) and during isocapneic alveolar hypoxia (10% O2, 3% CO2, 87% N2) to determine its influence on preexisting vascular tone. In the first set of experiments (n = 6), four histamine doses (1,10,50,100 micrograms/kg) were tested in sequence during normoxia. Histamine was injected intravenously and cardiovascular variables were recorded. Heart rate increased at all doses studied. Pulmonary and systemic arterial pressures, cardiac output and stroke volume were unchanged at the low histamine doses (1 and 10 micrograms), but all decreased at the high doses (50 and 100 micrograms). Pulmonary and systemic vascular resistances were unchanged at each dose. In the second set of experiments (n = 7), two histamine doses (1 and 5 micrograms/kg) were administered during alveolar hypoxia. Hypoxia caused increases in heart rate and pulmonary arterial pressure and resistance. After injection of each dose of histamine, pulmonary pressure and resistance decreased but remained higher than baseline. No other measured cardiovascular variables were altered. Thus, during normoxia histamine did not alter vascular tone, but high doses did adversely affect myocardial function. During alveolar hypoxia histamine caused weak pulmonary vasodilation at doses that did not alter systemic vascular tone. Histamine is not a potent modifier of the circulation in the newborn piglet during conditions of normoxaemia or hypoxaemia.

Animals↗
PubMed1988

Climatic and social associations with postneonatal mortality rates within New Zealand.

There is considerable regional variation in postneonatal mortality rates within New Zealand. The majority of postneonatal deaths are recorded as sudden infant death syndrome, and the regional rates of these deaths show a significant negative correlation with the mean daily temperature and mean 0900 hr vapour pressure (p less than 0.001). Postneonatal mortality rates, excluding sudden infant death syndrome mortality, show significant positive correlation with the regional percentage of the population of Maori descent (p less than 0.001). Further investigation of environmental temperature or factors closely related to it may shed light on the aetiology of the sudden infant death syndrome.

Climate↗
PubMed1988

Haemorrhagic shock encephalopathy syndrome.

Haemorrhagic shock encephalopathy syndrome is a recently described condition which appears to be an important cause of infant mortality and morbidity. Six infants, with some features of this condition, admitted to Dunedin Hospital during the last three years, are presented and their diagnoses reviewed. Diagnostic overlap may occur between haemorrhagic shock encephalopathy syndrome, hypoxic-ischaemic encephalopathy and near miss sudden infant death syndrome. An investigative approach to the infant with shock and acute encephalopathy is outlined.

Brain Diseases↗
PubMed1988

Effects of short duration exposures to acetone and methyl ethyl ketone.

Workers are commonly exposed to mixtures or combinations of chemical agents, and these mixtures often consist of solvents. One group of solvents that has been extensively studied for its neurotoxic properties has been the ketones. However, previous research has focused on neuropathies produced by extended exposures and not on the simple pharmacokinetics or the reversible central nervous system (CNS) effects from short-duration exposures. In this research, 137 volunteers were recruited and tested for neurobehavioral performance changes and biochemical indicators during and after a short-duration (4-h) exposure to either acetone at 250 ppm, methyl ethyl ketone (MEK) at 200 ppm, acetone at 125 ppm with MEK at 100 ppm, or a chemical-placebo. Ethanol (95%, 0.84 ml/kg) was used as a positive control. Testing took place in an environmental chamber with four test stations. The computer-controlled test regimen took 10 h, and several measures were collected: (1) biochemical measurements of venous blood and alveolar breath; (2) psychomotor tests of choice reaction time, visual vigilance, dual task (auditory tone discrimination and tracking), and memory scanning; (3) one sensorimotor (postural sway) test; and (4) one psychological (Profile of Mood States [POMS]) test. Blood and breath concentrations during and after exposure did not demonstrate any interaction between the two solvents, nor were statistically significant sex differences present during uptake or elimination. The 250-ppm acetone exposure produced small but statistically significant differences from controls in two measures of the auditory tone discrimination task, and on the anger-hostility scale (males only) of the POMS test. The other chemical exposure conditions, MEK at 200 ppm and combination MEK with acetone, produced no consistent statistically significant results, which suggests there was no potentiation of the acetone effects with the co-exposure to MEK or vice versa under these test conditions. Ethanol at 0.07-0.08% blood alcohol concentration (BAC) caused significant decrements on both the auditory tone and tracking tests in the dual task.

Acetone↗
PubMed1988

Recurrent pseudo-scarlatina and allergy to pseudoephedrine hydrochloride.

A case of recurrent pseudo-scarlatina is described. Challenge with pseudoephedrine hydrochloride reproduced a typical attack but pseudoephedrine ingestion could not be related definitely to all episodes. Allergy to pseudoephedrine or codeine should be considered as a cause for recurrent scarlet fever-like eruptions.

Adult↗
PubMed1988

Influence of repeated upper airway obstruction on the arousal and cardiopulmonary response to upper airway obstruction in lambs.

Experiments were done on five lambs to determine if repeated obstruction of the upper airway influences the arousal and cardiopulmonary response to upper airway obstruction. Each lamb was anesthetized and instrumented for recordings of electrocorticogram, electrooculogram, nuchal and diaphragm electromyograms, and measurements of arterial blood pressure and arterial hemoglobin oxygen saturation. A tracheostomy was done and a fenestrated tracheostomy tube placed in the trachea. The animals were studied after a 3-day recovery period. During a study, a 5F balloon-tipped catheter was inserted into the tracheostomy tube so that air flow could be obstructed by inflating the balloon. The balloon was inflated each time the animal went to sleep for approximately 100 consecutive epochs (17 to 30 h) and the time to arousal and the arterial hemoglobin oxygen saturation at arousal were recorded. Upper airway obstruction was terminated by deflating the balloon once the animal aroused from sleep. Arousal occurred from both sleep states during upper airway obstruction but was delayed in active sleep compared to quiet sleep. The time to arousal and the decrease in arterial hemoglobin oxygen saturation were significantly increased with repeated upper airway obstruction only during active sleep. Inasmuch as it is possible that alterations in the arousal response to respiratory stimuli play a role in sudden infant death, studies to investigate the mechanisms of the state-specific changes in the arousal response to upper airway obstruction are warranted.

Airway Obstruction↗
PubMed1988

Pulmonary vascular response to aerosolized cromolyn sodium and repeated epochs of isocapneic alveolar hypoxia in lambs.

We investigated the effect of aerosolized cromolyn sodium (CS) on the pulmonary vascular response to isocapneic alveolar hypoxia in chronically instrumented lambs aged 11-12 days. Each lamb underwent two operations: chest instrumentation for measurements of pulmonary arterial, systemic arterial, and left atrial pressures, and pulmonary blood flow; and a tracheotomy for drug administration. The animals were recovered 3 days before study. Each lamb received an aerosol of normal saline (placebo) and CS in paired experiments 24 h apart. In the first set of experiments (n = 8), placebo or CS (30 mg) was given, followed by four 15-min epochs of alveolar hypoxia (8% O2, 5% CO2, 87% N2) each separated by 30 min of alveolar normoxia (21% O2). During hypoxia after both placebo and CS, pulmonary arterial pressure and resistance increased. This response was unchanged with repeated epochs. In the second set of experiments (n = 8), normal saline or CS (30 mg) was administered three times over a 90-min period, followed by one 15-min epoch of hypoxia. Pulmonary arterial pressure and resistance increased during hypoxia after placebo, but did not change after CS. Thus, the single dose of aerosolized CS did not alter the pulmonary vascular response to alveolar hypoxia, whereas the triple dose of CS attenuated the response. Additionally, the pulmonary vascular response to hypoxia alone was not altered by repeated exposures to hypoxia. We conclude that CS interferes with the mechanism(s) responsible for hypoxic pulmonary vasoconstriction in newborn lambs.

Administration, Intranasal↗
PubMed1987

Pseudoporphyria from nonsteroidal antiinflammatory drugs.

Pseudoporphyria is a condition in which skin fragility and blistering typical of cutaneous porphyria are associated with normal porphyrin metabolism. Naproxen has recently been described as a cause for drug-induced pseudoporphyria and eight examples of this are reported. We also report instances from ketoprofen and diflunisal.

Adult↗
PubMed1987

Sonographic detection of neonatal umbilical-artery thrombosis: clinical correlation.

Eighty-one neonates were prospectively studied by sonography of the abdomen to determine the frequency, risk factors, clinical symptoms, complications, and natural history of aortic thrombosis seen in conjunction with the use of umbilical-artery catheters. Twenty-six percent of neonates developed sonographically detectable thrombosis. Twenty-nine percent of the neonates with thrombosis were asymptomatic, and an additional 24% had hematuria (diagnosed by dipstick) as their only clinical finding. Significant risk factors associated with aortic thrombosis were calcium in the umbilical-artery-catheter infusate, placement of the catheter for any length of time above the renal arteries, and low birth weight. Physical examination did not reliably predict aortic thrombosis, and asymptomatic thrombosis was more frequent than previously recognized.

Aorta, Abdominal↗