Biomedical subjects

B J Taylor

Publications and source records attributed to B J Taylor.

At least 55 records · Page 3Linked to original sources

PubMed1998

Dissatisfaction encodes a tailless-like nuclear receptor expressed in a subset of CNS neurons controlling Drosophila sexual behavior.

The dissatisfaction (dsf) gene is necessary for appropriate sexual behavior and sex-specific neural development in both sexes. dsf males are bisexual and mate poorly, while mutant females resist male courtship and fail to lay eggs. Males and females have sex-specific neural abnormalities. We have cloned dsf and rescued both behavioral and neural phenotypes. dsf encodes a nuclear receptor closely related to the vertebrate Tailless proteins and is expressed in both sexes in an extremely limited set of neurons in regions of the brain potentially involved in sexual behavior. Expression of a female transformer cDNA under the control of a dsf enhancer in males leads to dsf-like bisexual behavior.

Amino Acid Sequence↗

PubMed1998

Residential mobility and sudden infant death syndrome.

OBJECTIVE: To examine whether permanent domicile change of the mother, thence the infant, or temporary relocation of the infant away from his or her usual place of residence affects the risk of sudden infant death syndrome (SIDS). DESIGN: A case-control nation-wide epidemiological study. SETTING: New Zealand between the years 1987-90. PARTICIPANTS: From the 485 SIDS diagnoses over this time, parents of 393 (81%) SIDS infants consented to participate and these comprise the cases. Controls were selected by randomly sampling 1800 infants from all babies born over 78% of the country. Parents of 1592 (88%) control infants participated. RESULTS: Infants away from their usual address were 1.70 (95% CI: 1.09, 2.66) times more likely to die from SIDS than infants sleeping at home, after controlling for likely confounding factors. A partial explanation for this finding was that SIDS infants were less likely to have been mainly breast fed in the last two days and were less likely to have shared a room with at least one adult at the nominated sleep/death. Infants of mothers who shifted house after their birth, infants having mothers who shifted house within a year prior to the study interview date, and infants who slept at numerous different houses were associated with an increased relative risk for SIDS at the univariate level, but not after adjustment. CONCLUSIONS: Infants are less likely to die in their accustomed residential environment. This finding needs confirmation by other studies.

Adult↗

PubMed1998

Heavy caffeine intake in pregnancy and sudden infant death syndrome. New Zealand Cot Death Study Group.

AIMS: To examine the association between maternal caffeine consumption during pregnancy and the risk of sudden infant death syndrome (SIDS). METHODS: A nationwide case-control study surveying parents of 393 SIDS victims and parents of 1592 control infants. Caffeine consumption in each of the first and third trimesters was estimated by questionnaire. Heavy caffeine intake was defined as 400 mg/day or more (equivalent to four or more cups of coffee per day). RESULTS: Infants whose mothers had heavy caffeine consumption throughout their pregnancy had a significantly increased risk for SIDS (odds ratio 1.65; 95% confidence interval 1.15 to 2.35) after adjusting for likely confounding factors. CONCLUSION: Caffeine intake has been associated with fetal harm and now SIDS. Reducing heavy caffeine intake during pregnancy could be another way to lessen the risk of SIDS. This needs confirmation by others.

Caffeine↗

PubMed1998

Sleep position, autonomic function, and arousal.

AIMS: To investigate and compare heart rate variability (HRV) and responses of heart rate and arousal to head-up tilting in infants sleeping prone and supine. METHODS: Thirty seven healthy infants aged 2-4 months were studied. HRV was measured for 500 beats while they were in a horizontal position. Subjects were then tilted 60 degrees head-up, and heart rate recorded over 1 minute and arousal responses observed. Data were collected during both quiet and active sleep for both prone and supine sleep positions. RESULTS: HRV, as assessed by the point dispersion of Poincaré plots, was significantly reduced in the prone position for both sleep states. Sleep position did not influence the changes in heart rate seen during a head-up tilt. Full awakening to the tilt was common in active sleep but significantly less so in the prone position (15% of prone tests vs 54% supine). Full awakening to the tilt rarely occurred during quiet sleep in either sleep position. CONCLUSION: This study provides some evidence that blunted arousal responses and/or altered autonomic function are a feature of the prone sleeping position. Decreased HRV may be a sign of autonomic impairment. It is seen in many disease states and in infants who later die of sudden infant death syndrome (SIDS).

Arousal↗

PubMed1998

Pharmacokinetics and pharmacodynamics of famotidine in infants.

The pharmacokinetics and pharmacodynamics of intravenous famotidine were evaluated in 10 infants ranging from 5 to 19 days of age who had a therapeutic indication for the prophylactic treatment of stress ulceration. After a 0.5-mg/kg infusion of famotidine, timed serum (n = 6), urine (24-hour collection), and repeated measurements of gastric pH were obtained. The mean +/- standard deviation maximum plasma concentration (Cmax) was 640.66 +/- 250.66 ng/mL, the elimination half-life (t1/2 beta) was 10.51 +/- 5.43 hours, and the apparent volume of distribution at steady state (Vdss) was 0.82 +/- 0.29 L/kg. Plasma clearance (Cl) and renal clearance (ClR) were 0.132 +/- 0.061 L/hr/kg and 0.093 +/- 0.056 L/hr/kg, respectively. No significant correlations were found between t1/2 beta, Vdss, Cl, and ClR and age. Six of the nine infants who had intragastric pH monitoring maintained a gastric pH > 4 until the final 24-hour sampling point. In this study, the t1/2 beta of famotidine was prolonged and the Vdss, Cl, ClR were reduced compared with corresponding parameters in previously reported studies of children older than one year of age and adults.

Famotidine↗

PubMed1997

Housing and sudden infant death syndrome. The New Zealand Cot Death Study Group.

AIMS: This paper examined factors relating to the infants' place of domicile to see whether they increased the risk of sudden infant death syndrome (SIDS) beyond social and environmental effects previously published. METHODS: A case control study was undertaken in New Zealand between the years 1987-90. From all sudden infant death syndrome diagnoses over this time, parents of 393 (81%) sudden infant death syndrome infants consented to participate and these derive the cases. Controls were ascertained by randomly sampling 1800 infants from all babies born over 78% of the country. Parents of 1592 (88%) control infants consented to participate in the study. RESULTS: The relative risk of sudden infant death for infants usually residing in houses rented from the government (State houses) was 1.73 (95% CI: 1.13, 2.66) times that of infants with parents owning their house, after adjusting for likely social, economic and environmental confounding factors. However, the type of housing, construction of housing, heating and age of housing was not associated with sudden infant death syndrome. Although house size, measured in terms of bedroom numbers, was similar for sudden infant death syndrome and control infants (chi 2 = 0.40, df = 2, p = 0.82), the number of people normally residing within these houses was different. Sudden infant death syndrome infants' houses were less likely to have two adults and more likely to have more children normally resident. Density calculations (derived by calculating the children and/or adult numbers divided by bedroom numbers) revealed a non significant increase in relative risk, suggesting that housing overcrowding was not associated with sudden infant death syndrome in New Zealand. CONCLUSIONS: Infants domiciled in State houses are more likely to experience sudden infant death syndrome. However, this increased relative risk for sudden infant death syndrome appears to have little to do with the house per se and, perhaps, more to do with socioeconomic characteristics.

Adult↗

PubMed1997

dissatisfaction, a gene involved in sex-specific behavior and neural development of Drosophila melanogaster.

Few mutations link well defined behaviors with individual neurons and the activity of specific genes. In Drosophila, recent evidence indicates the presence of a doublesex-independent pathway controlling sexual behavior and neuronal differentiation. We have identified a gene, dissatisfaction (dsf), that affects sex-specific courtship behaviors and neural differentiation in both sexes without an associated general behavioral debilitation. Male and female mutant animals exhibit abnormalities in courtship behaviors, suggesting a requirement for dsf in the brain. Virgin dsf females resist males during courtship and copulation and fail to lay mature eggs. dsf males actively court and attempt copulation with both mature males and females but are slow to copulate because of maladroit abdominal curling. Structural abnormalities in specific neurons indicate a role for dsf in the differentiation of sex-specific abdominal neurons. The egg-laying defect in females correlates with the absence of motor neuronal innervation on uterine muscles, and the reduced abdominal curling in males correlates with alteration in motor neuronal innervation of male ventral abdominal muscles. Epistasis experiments show that dsf acts in a tra-dependent and dsx-independent manner, placing dsf in the dsx-independent portion of the sex determination cascade.

Abdomen↗

PubMed1997

Comparison of two methods of determining asphyxial potential of infant bedding.

OBJECTIVE: To establish, with the use of live sedated piglets on a range of bedding surfaces, the possibility of asphyxia when an infant is breathing face down into infant bedding surfaces, and to compare the results with those obtained with a mechanical model. METHODS: Piglets underwent tracheotomy and were attached to a silicon rubber model head of a 3-month-old infant. This was placed face down on bedding surfaces, and respiratory and blood gas data were collected for a 60-minute period. RESULTS: All bedding surfaces but one showed some rebreathing. This was to lower levels than with the mechanical model, but the ranking of the surfaces by level of rebreathing was similar. Two piglets died within the 1-hour experimental time. CONCLUSION: It is confirmed that the data from a mechanical model of rebreathing on different bedding surfaces are matched by those derived from a piglet model that responds normally to asphyxia.

Animals↗

PubMed1997

SIDS, illness, and acute medical care. New Zealand Cot Death Study Group.

One component of the Back to Sleep campaign to reduce the risk of sudden infant death syndrome (SIDS) is the recommendation that parents seek medical attention if their infant is unwell. The aim of this study was to investigate of SIDS could in part be explained by sick infants not getting appropriate medical care. Data on symptoms of illness and on acute medical contacts made for infants dying from SIDS (n = 390) within two weeks of their death were compared with those from a randomly selected group of control infants (n = 1592). SIDS cases had more severe illness than controls (odds ratio (OR) = 3.43; 95% confidence interval (CI) = 1.69 to 5.38), and were more likely to have seen a general practitioner (OR = 1.37; 95% CI = 1.09 to 1.73) or attended hospital (OR = 3.43, 95% CI = 1.09 to 1.73). Only 1.3% of all SIDS cases had symptoms suggesting severe illness and had not seen a general practitioner. A lack of medical contacts in the two weeks before death does not contribute to the risk of SIDS.

Acute Disease↗

PubMed1997

Risk factors for sudden infant death syndrome following the prevention campaign in New Zealand: a prospective study.

OBJECTIVES: To identify the risk factors for sudden infant death syndrome (SIDS) following a national campaign to prevent SIDS. METHODS: For 2 years (October 1, 1991 through September 30, 1993) data were collected by community child health nurses on all infants born in New Zealand at initial contact and at 2 months. RESULTS: There were 232 SIDS cases in the postneonatal age group (2.0/1000 live births) and these were compared with 1200 randomly selected control subjects. Information was available for 127 cases (54.7%) and 922 (76.8%) of controls. The previously identified modifiable risk factors were examined. The prevalence of prone sleeping position of the infant was very low (0.7% at initial contact and 3. 0% at 2 months), but was still associated with an increased risk of SIDS. In addition, the side sleeping position was also found to have an increased risk of SIDS compared with the supine sleeping position (at 2 months: adjusted odds ratio (OR) = 6.57; 95% confidence interval (CI) = 1.71, 25.23). Maternal smoking was found to be the major risk factor for SIDS. Bed sharing was also associated with an increased risk of SIDS. There was an interaction between maternal smoking and bed sharing on the risk of SIDS. Compared with infants not exposed to either bed sharing or maternal smoking, the adjusted OR for infants of mothers who smoked was 5.01 (95% CI = 2.01, 12.46) for bed sharing at the initial contact and 5.02 (95% CI = 1.05, 24. 05) for bed sharing at 2 months. In this study breastfeeding was not associated with a statistically significant reduction in the risk of SIDS. The other risk factors for SIDS identified were: unmarried mother, leaving school at a younger age, young mother, greater number of previous pregnancies, late attendance for antenatal care, smoking in pregnancy, male infant, Maori ethnicity, low birth weight, and shorter gestation. CONCLUSIONS: After adjustment for potential confounders, prone and side sleeping positions, maternal smoking, and the joint exposure to bed sharing and maternal smoking were associated with statistically significant increased risk of SIDS. A change from the side to the supine sleeping position could result in a substantial reduction in SIDS. Maternal smoking is common in New Zealand and with the reduction in the prevalence of prone sleeping position is now the major risk factor in this country. However, smoking behavior has been difficult to change. Bed sharing is also a major factor but appears only to be a risk to infants of mothers who smoke. Addressing bed sharing among mothers who smoke could reduce SIDS by at least one third. Breastfeeding did not appear to offer a statistically significant reduction in SIDS risk after adjustment of potential confounders, but as breastfeeding rates are comparatively good in New Zealand, this result should be interpreted with caution as the power of this study to detect a benefit is small.

Beds↗

PubMed1996

Control of male sexual behavior and sexual orientation in Drosophila by the fruitless gene.

Sexual orientation and courtship behavior in Drosophila are regulated by fruitless (fru), the first gene in a branch of the sex-determination hierarchy functioning specifically in the central nervous system (CNS). The phenotypes of new fru mutants encompass nearly all aspects of male sexual behavior. Alternative splicing of fru transcripts produces sex-specific proteins belonging to the BTB-ZF family of transcriptional regulators. The sex-specific fru products are produced in only about 500 of the 10(5) neurons that comprise the CNS. The properties of neurons expressing these fru products suggest that fru specifies the fates or activities of neurons that carry out higher order control functions to elicit and coordinate the activities comprising male courtship behavior.

Age Factors↗

PubMed1996

Coexpression of GD3 ganglioside with CD45RO in resting and activated human T lymphocytes.

The ganglioside GD3 is preferentially expressed on the surface of malignant T cell lymphoblasts and on resting T cells which express the memory cell phenotype, CD45RA-CD29+. However, GD3 expression in activated T cells and its potential function in proliferating normal and malignant T cells are unclear. Utilizing three-color immunostaining and flow cytometry, we examined changes in the expression of GD3 in conjunction with the RA and RO isoforms of CD45 during in vitro T cell activation. GD3 was equally expressed in resting CD4 and CD8 cells and was specifically found in the CD45RO+RA population. Activation of T cells with PHA resulted in an increased percentage of GD3+ cells. This increase was evident by the first day and was observed in the CD45RO (naive cell) population; by 2 days, GD3 was expressed heterogeneously in a large population of CD45RO+RA+ cells. Further activation of T cells with PHA or anti-CD3 monoclonal antibody (OKT3) resulted in a further increase in GD3-expressing cells, and the increase in GD3 density correlated with increased CD45RO and loss of CD45RA. In contrast, increases in GD3 and interleukin-2 receptor (CD25) expression in response to PHA or OKT3 occurred independently, indicating that the GD3/ CD45RO coexpression observed was not a general consequence of cell activation. The results provide evidence for specific comodulation of GD3 and CD45RO during T cell mitogenesis, and thus suggest that these molecules may colocalize on the T cell surface.

Adult↗

PubMed1996

Receptor specificity of clinical Plasmodium falciparum isolates: nonadherence to cell-bound E-selectin and vascular cell adhesion molecule-1.

The pathogenicity of Plasmodium falciparum is due largely to the parasite's unique ability to adhere to capillary and postcapillary venular endothelium during the second-half of the 48-hour life cycle. The resulting sequestration of infected erythrocytes (IRBC) in deep vascular beds leads to tissue hypoxia, metabolic disturbances, and organ dysfunction which characterize severe falciparum malaria. Several endothelial receptors of cytoadherence have been identified, but their clinical relevance remains controversial. In the present report, the receptor specificity of 60 clinical P falciparum isolates was determined using transfectants each expressing one of CD36, intercellular adhesion molecule-1 (ICAM-1), E-selectin, and vascular cell adhesion molecule-1 (VCAM-1). All isolates tested adhered to CD36 and ICAM-1, but the adherence to CD36 was at least 10-fold higher. Seven isolates adhered to E-selectin whereas none of 19 isolates adhered to VCAM-1. From a population standpoint, about 30% of IRBC in each isolate adhered to CD36, and 2% to 3% adhered to ICAM-1. The percentage adherent to E-selectin and VCAM-1 was negligible. IRBC selected on CD36 adhered almost exclusively to CD36 whereas 80% to 90% of IRBC selected on ICAM-1 could also adhere to CD36. Selected IRBC did not adhere to E-selectin or VCAM-1. These findings indicate that cytoadherence to multiple endothelial receptors is a rare occurrence with natural P falciparum isolates, but do not exclude a role for the adhesion molecules in promoting other IRBC-endothelial interactions such as rolling under flow conditions. Receptor specificity in vivo may be dictated by the ligand-receptor combination which provides the best survival potential for the parasite.

Animals↗

PubMed1996

Correlation of P-glycoprotein expression and function in childhood acute leukemia: a children's cancer group study.

Clinical drug resistance may be attributed to the simultaneous selection and expression of genes modulating the uptake and metabolism of chemotherapeutic agents. P-glycoprotein (P-gp) functions as a membrane-associated drug efflux pump whose increased expression results in resistance to anthracyclines, epipodophyllotoxins, vinca alkaloids, and some alkylating agents. This type of resistance occurs as both de novo and acquired resistance to therapy for leukemia. We have studied P-gp expression and function in childhood acute leukemias by developing a series of doxorubicin- and vincristine-selected CEM, T-cell lymphoblastoid cell lines that recapitulate the low levels of expression and resistance seen clinically. These cell lines have been used to develop flow cytometric assays for the semiquantitative measurements of P-gp expression with the MRK16 monoclonal antibody and P-gp function using the enhanced retention of rhodamine 123 in the presence of verapamil, a resistance modulator. Kolmogorov-Smirnov statistics, represented by the D measurement, are used to determine the difference in level of P-gp expression by comparing MRK16 staining to an IgG2a isotype control. When D is > 0.09, there is an excellent correlation (R = 0.82) between P-gp expression and function. The evaluation of 107 bone marrow specimens from 84 children with lymphoblastic or myelogenous leukemia showed a statistically significant (P = .004) increase in P-gp function at relapse. P-gp expression at relapse, however, approached but did not reach a significant level (P = .097). Using this methodology, we can identify patients with levels of P-gp expression and function that we can define clinically, as well as children with discordant multidrug resistance phenotypes. This study supports the role of P-gp-mediated drug resistance in childhood leukemia and confirms that P-gp expression and function are measurable in their leukemic blasts. These assays provide the means for the in vitro testing of resistance modulators and the monitoring of in vivo response to treatment with these agents.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed1996

Infant room-sharing and prone sleep position in sudden infant death syndrome. New Zealand Cot Death Study Group.

BACKGROUND: There is evidence that the risk of sudden infant death syndrome is lower among ethnic groups in which parents generally share a room with the infant for sleeping. We investigated whether the presence of other family members in the infant's sleeping room affects the risk of the sudden infant death syndrome. METHODS: The case-control study covered a region with 78% of all births in New Zealand during 1987-90. Home interviews were completed with parents of 393 (81.0% of total) babies who died from the sudden infant death syndrome aged 28 days to 1 year and 1592 (88.4% of total) controls, selected from all hospital births in the study region. FINDINGS: The relative risk of sudden infant death for sharing the room with one or more adults compared with not sharing was 0.19 (95% CI 0.08-0.45) for sharing at night during the last 2 weeks and 0.27 (0.17-0.41) for sharing in the last sleep, after control for other confounders. Sharing the room with one or more children did not affect the relative risk (1.25 [0.86-1.82] for sharing during last 2 weeks; 1.29 [0.85-1.94] for sharing in last sleep). There was a significant interaction (p = 0.033) between not sharing the room with an adult and prone sleep position in the last sleep. Compared with infants sharing the room with an adult and not prone, the multivariate relative risk was 16.99 (10.43-27.69) for infants not sharing with an adult and prone, 3.28 (2.06-5.23) for infants sharing the room and prone, and 2.60 (1.58-4.30) for infants not sharing the room and not prone. The interaction between adult room-sharing and prone sleep position suggests that both exposures may affect the risk of sudden infant death syndrome through a common mechanism. INTERPRETATION: We recommend that infants sleep in the same bedroom as their parents at night to reduce the risk of sudden infant death syndrome.

Adult↗

PubMed1996

A population of cells isolated from rat heart capable of differentiating into several mesodermal phenotypes.

A population of stem cells has been isolated from embryonic avian and neonatal rat skeletal muscle. These cells differentiate into several mesodermal phenotypes in culture upon treatment with dexamethasone. This study reports the isolation of a similar population of stem cells from another mesodermal tissue, the heart. Hearts were excised from 3- to 5-day- old rats, minced, and treated with a collagenase-dispase solution. Single cells were collected by centrifugation, washed, and plated in dishes. The cells were grown to confluence, trypsinized, and frozen at -80 degrees C in 7.5% dimethylsulfoxide. After at least 24 hr, the cells were thawed and plated in 24-well plates and treated with media containing dexamethasone at concentrations of 10(-6)-10(-10) M for 4 weeks. Control cultures contained mononucleated cells with a stellate morphology. Treatment with dexamethasone resulted in the appearance of several mesodermal phenotypes. Bone and cartilage nodules were identified with von Kossa and Alcian blue staining respectively. Adipocytes were identified using Sudan black B stain. Smooth muscle cells were identified by an anti-smooth muscle alpha-actin antibody, and skeletal myotubes were stained with anti-myosin antibody. Large binuclear cells with obvious fibers were noted and stained with anti-desmin. These binuclear cells appeared in both the control and the dexamethasone-treated cultures and were tentatively identified as cardiomyocytes. These data strongly suggest the existence of a population of mesenchymal stem cells in neonatal rat heart.

Animals↗

PubMed1996

Arousal responses of the newborn piglet to airways obstruction and rebreathing during normothermia and hyperthermia.

Most experimental studies of arousal to respiratory stressors have been performed under neutral thermal conditions. The present study focussed on arousal responses with the added challenge of heat stress. The subjects were two groups of 10 sedated piglets aged 4-6 days and 2-6 days respectively. Respiratory stimuli (partial and total airways obstruction (AO) or rebreathing (RB) expired gases) were applied during non-rapid-eye-movement (NREM) sleep. Measurements of heart rate, SaO2, intra-pleural pressure or inspired CO2 and O2 were recorded during tests in normothermia and hyperthermia. Hyperthermia significantly shortened the time to arousal. Thus, arousal times from partial and total AO and from RB were: in normothermia, 40.3 +/- 5.8, 9.2 +/- 0.7 and 94.9 +/- 14.7 s respectively; in hyperthermia, 17.8 +/- 3.7, 7.6 +/- 0.9 and 68.5 +/- 9.1 s respectively. Cardio-respiratory variables at arousal were similar in both thermal states. Seven non-sedated piglets were challenged with RB stimuli during normothermia only to determine the influence of sleep state on arousal. Arousal in REM sleep was delayed approximately 2-3-fold (NREM, 41.2 +/- 8.2 s; REM, 88.5 +/- 18.1 s), occurring at a lower SaO2 and higher inspired CO2. It is concluded that arousal from NREM sleep under adverse conditions of hyperthermia shortens the arousal time from asphyxial stimuli induced by AO and RB with no change in the arousal threshold.

Airway Obstruction↗

PubMed1996

Sudden infant death syndrome: insulation from bedding and clothing and its effect modifiers. The National Cot Death Study Group.

BACKGROUND: Thermal stress related to excessive insulation from bedding and clothing has been postulated to be associated with sudden infant death syndrome (SIDS). METHODS: The parents of 393 (81%) of the infants who died of SIDS in the post neonatal period were interviewed at home. Interviews were also completed with the parents of 1592 (88.4% of total) controls, a representative sample of all hospital births. The study was conducted in regions of the North and South Island of New Zealand in which 78% of all New Zealand births occurred in 1987-1990. Temperatures for the infant's bedroom estimated from the outside temperature and a model were used to predict the appropriate insulation for lower critical temperature (temperature below which the metabolic rate is likely to increase). RESULTS: Sudden infant death syndrome was associated with extra thermal insulation of > 2 tog above the lower critical value, the odds ratio (OR) was 1.70 (95% confidence interval [Cl] : 1.3-2.20) after adjusting for season. After adjusting for a number of confounding factors the CR was reduced to 1.35 (95% Cl: 0.97-1.87). Also associated with SIDS was too little thermal insulation OR = 1.67(95% Cl: 1.13-2.48; and 2.63 (95% Cl: 1.61-4.30) when adjustments were made for the confounding factors. The interaction effect between infants sleeping prone and >2 tog extra thermal insulation was significant (OR = 6.07, 95% Cl: 3.83-9.60). Infants with too little thermal insulation were at increased risk if they were not tightly wrapped (OR = 3.81, 95% Cl: 2.04-7.09). There were also small additive interaction effects if the mother smoked and the infants had > 2 tog extra thermal insulation, or they were ill and had > 4 tog extra insulation. Interaction effects between thermal insulation and other factors were not significant. CONCLUSION: More thermal insulation than was necessary to maintain the lower critical temperature increased the risk of SIDS primarily among infants in the prone sleep position, and to a lesser degree in infants whose mothers smoked and in infants who were unwell.

Bedding and Linens↗