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CatSper is a voltage dependent calcium ion channel present in the principal piece of sperm tail. It plays a crucial role in sperm hyperactivated motility and so in fertilization. Extracellular loops of mouse sperm CatSper were used to develop a vaccine to achieve protection from pregnancy. These loops were inserted at one of the three hypervariable regions of Human Papilloma Virus (HPV) capsid protein (L1). Recombinant vaccines were expressed in E.coli as inclusion body (IB), purified, refolded and assembled into virus-like particles (VLP) in vitro, and adsorbed on alum. Four vaccine candidates were tested in Balb/C mice. All the constructs proved immunogenic, one showed contraceptive efficacy. This recombinant contraceptive vaccine is a non-hormonal intervention and is expected to give long-acting protection from undesired pregnancies.
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BACKGROUND: Spinal anaesthesia, the most common form of anaesthesia for caesarean section, leads to sympathetic blockade and profound maternal hypotension resulting in adverse maternal and neonatal outcomes. Hypotension, nausea and vomiting remain common but until the publication of the National Institute of Health and Care Excellence (NICE) 2021 guidance, no national guideline existed on how best to manage maternal hypotension following spinal anaesthesia for caesarean section. A 2017 international consensus statement recommended prophylactic vasopressor administration to maintain a systolic blood pressure of >90% of an accurate pre-spinal value, and to avoid a drop to <80% of this value. This survey aimed to assess regional adherence to these recommendations, the presence of local guidelines for management of hypotension during caesarean section under spinal anaesthesia, and the individual clinician's treatment thresholds for maternal hypotension and tachycardia. METHODS: The West Midlands Trainee-led Research in Anaesthesia and Intensive Care Network co-ordinated surveys of obstetric anaesthetic departments and consultant obstetric anaesthetists across 11 National Health Service Trusts in the Midlands, England. RESULTS: One-hundred-and-two consultant obstetric anaesthetists returned the survey and 73% of sites had a policy for vasopressor use; 91% used phenylephrine as the first-line drug but a wide range of recommended delivery methods was noted and target blood pressure was only listed in 50% of policies. Significant variation existed in both vasopressor delivery methods and target blood pressures. CONCLUSIONS: Although NICE has since recommended prophylactic phenylephrine infusion and a target blood pressure, the previous international consensus statement was not adhered to routinely.
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Anestesia Obstétrica , Anestesia Raquidea , Cesárea , Hipotensión , Vasoconstrictores , Humanos , Femenino , Embarazo , Adulto , Hipotensión/etiología , Anestesia Raquidea/efectos adversos , Anestesia Obstétrica/efectos adversos , Reino Unido , Encuestas y Cuestionarios , Vasoconstrictores/administración & dosificación , Vasoconstrictores/efectos adversosRESUMEN
In 2022, nursing faculty reflect on the transition without global or national benchmarks or blueprints of a South African Nursing Education Institution to online education during the Covid-19 pandemic. Objective: To provide policy makers a resource in preparation for future crises in education. A theoretical-reflective study supported by a SWOT analysis aimed to understand the transition to online teaching and learning and assessments for the Nursing Discipline (nursing faculty n = 22; undergraduate students n = 291) of a select South African university. It revealed four key lessons learned. Firstly, whether change is planned or unplanned, policy frameworks should guide it. Secondly, resources exist within faculty, and at times, change agents might not be necessary as strengths can be drawn from within. Thirdly, through managing a crisis, faculty-service partnership can be strengthened. Lastly, a need exists for continual surveillance as the inequality gap in Higher Education students has become increasingly visible and amplified further marginalisation. Our reflections have highlighted that opportunities and strengths abound as the pandemic has fast-tracked nursing education institutions to embrace technology for teaching and learning and assessments. Three of the key lessons learned emphasise what is known about the successful outcome of working together.
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The American Neurogastroenterology and Motility Society (ANMS) proposed quality measures (QMs) for performance and interpretation of esophageal manometry (EM). We implemented a quality improvement (QI) study at a large community hospital to assess and improve procedural adherence and interpretation of EM studies based on the ANMS QMs using the Chicago Classification 3.0 (CC) Guidelines. For pre-intervention, three motility independent reviewers reinterpreted 60 EM studies conducted by community gastroenterologists without Tier II-III motility training from October to December 2018 for compliance with pre-procedural, procedural, and data interpretation ANMS QMs. In December 2018, we developed a pre-procedural form, educated nurses on EM procedural compliance, and provided preliminary pre-intervention results to gastroenterologists along with literature utilizing the CC 3.0 Guidelines. For post-intervention, we reinterpreted 54 EM studies from January to August 2019 and investigated whether they met QMs for data interpretation with respect to the CC Guidelines and resulted in appropriate treatment. We found a statistically significant improvement in procedural compliance among nursing staff for 30 s of swallows (76% post-intervention versus 12% pre-intervention, p < 0.001) and 7 evaluable swallows (94% post-intervention versus 53% pre-intervention, p < 0.001). However, quality metrics within data interpretation by physicians post-intervention showed mixed results. An incorrect diagnosis was made in 50% (n = 27)) of studies with 72% (n = 39) having at least one missing item based on the CC. The most missed diagnosis was fragmented peristalsis (30%, n = 29). Among the 39% (n = 21) of surgery referrals, 24% (n = 5) were incorrectly referred. Our study shows poor data interpretation by community gastroenterologists without formal motility training despite adequate performance by nursing staff. This further supports the need for a national ANMS certification process for formal HRM education.
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Deglución , Trastornos de la Motilidad Esofágica , Humanos , Manometría/métodos , PeristaltismoRESUMEN
Digital technologies continue to penetrate the South African (SA) healthcare sector at an increasing rate. Clinician-to-clinician diagnostic and management assistance through mHealth is expanding rapidly, reducing professional isolation and unnecessary referrals, and promoting better patient outcomes and more equitable healthcare systems. However, the widespread uptake of mHealth use raises ethical concerns around patient autonomy and safety, and guidance for healthcare workers around the ethical use of mHealth is needed. This article presents the results of a multi-stakeholder workshop at which the 'dos and don'ts' pertaining to mHealth ethics in the SA context were formulated and aligned to seven basic recommendations derived from the literature and previous multi-stakeholder, multi-country meetings.
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Atención a la Salud/organización & administración , Personal de Salud/organización & administración , Telemedicina/organización & administración , Atención a la Salud/ética , Humanos , Autonomía Personal , Derivación y Consulta , Sudáfrica , Telemedicina/éticaRESUMEN
The continuing emergence of SARS-CoV-2 variants calls for regular assessment to identify differences in viral replication, shedding and associated disease. In this study, African green monkeys were infected intranasally with either a contemporary D614G or the UK B.1.1.7 variant. Both variants caused mild respiratory disease with no significant differences in clinical presentation. Significantly higher levels of viral RNA and infectious virus were found in upper and lower respiratory tract samples and tissues from B.1.1.7 infected animals. Interestingly, D614G infected animals showed significantly higher levels of viral RNA and infectious virus in rectal swabs and gastrointestinal tract tissues. Our results indicate that B.1.1.7 infection in African green monkeys is associated with increased respiratory replication and shedding but no disease enhancement similar to human B.1.1.7 cases. ONE-SENTENCE SUMMARY: UK B.1.1.7 infection of African green monkeys exhibits increased respiratory replication and shedding but no disease enhancement.
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We present the first joint analysis of cluster abundances and auto or cross-correlations of three cosmic tracer fields: galaxy density, weak gravitational lensing shear, and cluster density split by optical richness. From a joint analysis (4×2pt+N) of cluster abundances, three cluster cross-correlations, and the auto correlations of the galaxy density measured from the first year data of the Dark Energy Survey, we obtain Ω_{m}=0.305_{-0.038}^{+0.055} and σ_{8}=0.783_{-0.054}^{+0.064}. This result is consistent with constraints from the DES-Y1 galaxy clustering and weak lensing two-point correlation functions for the flat νΛCDM model. Consequently, we combine cluster abundances and all two-point correlations from across all three cosmic tracer fields (6×2pt+N) and find improved constraints on cosmological parameters as well as on the cluster observable-mass scaling relation. This analysis is an important advance in both optical cluster cosmology and multiprobe analyses of upcoming wide imaging surveys.
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In recent years, many γ-ray sources have been identified, yet the unresolved component hosts valuable information on the faintest emission. In order to extract it, a cross-correlation with gravitational tracers of matter in the Universe has been shown to be a promising tool. We report here the first identification of a cross-correlation signal between γ rays and the distribution of mass in the Universe probed by weak gravitational lensing. We use data from the Dark Energy Survey Y1 weak lensing data and the Fermi Large Area Telescope 9-yr γ-ray data, obtaining a signal-to-noise ratio of 5.3. The signal is mostly localized at small angular scales and high γ-ray energies, with a hint of correlation at extended separation. Blazar emission is likely the origin of the small-scale effect. We investigate implications of the large-scale component in terms of astrophysical sources and particle dark matter emission.
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Although whole-fruit consumption is regarded as protective against type 2 diabetes (T2DM), conventionally prepared fruit juice is associated with increased T2DM risk, and current public health advice recommends its restriction. 'Nutrient extractor' style blenders are increasing in popularity worldwide as an alternative means of juicing fruit, but little is known about their effect on postprandial glucose levels. The current study investigated the effect of nutrient extraction on postprandial blood glucose response and glycemic index (GI) compared with a glucose control for both mixed fruit and a high GI fruit (mango). Remarkably, consumption of nutrient-extracted mixed fruit resulted in a significant lowering of the GI (32.7±8.5) compared with whole mixed fruit (66.2±8.2, P<0.05). For the high GI mango, there were no differences between nutrient-extracted and whole fruit, indicating that even for a high GI fruit the effect of nutrient extraction does not increase GI compared with the whole fruit. These findings suggest that, in contrast to conventionally prepared fruit juice, fruit juice prepared by nutrient extraction in some cases elicits a more favorable postprandial glycemic response than whole fruit and even for high GI fruits do not worsen the response. The mechanism responsible for this effect is currently unclear. However, these results suggest that fruit homogenized by nutrient extraction should be considered as a potential dietetic strategy for glycemic control.
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Glucemia/análisis , Manipulación de Alimentos/métodos , Jugos de Frutas y Vegetales/análisis , Periodo Posprandial , Adulto , Estudios Cruzados , Diabetes Mellitus Tipo 2 , Femenino , Frutas , Índice Glucémico , Humanos , Cinética , Masculino , Mangifera , Factores de RiesgoRESUMEN
Doctors sometimes tell patients with rare but highly treatable cancers that they have 'good' cancer which some patients have found unhelpful, but this has been little explored. The aim of this study was to explore how patients reacted to being told they had a 'good' cancer. Qualitative interviews were carried out with 25 people with rare but prognostically favourable cancers who had received treatment at two hospitals within a cancer network. Results showed that despite good treatment outcomes, patients are still very shocked to hear the word cancer and react in similar ways to those with other forms of cancer. The potential effects of treatment should be recognised as having a detrimental effect on patient well-being whatever the prognosis. We should therefore avoid using 'good' and 'cancer' in the same sentence. In addition, the impact on all family members should not be underestimated. The data can be used to improve clinical practice and improve support for people affected by cancer.
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Neoplasias/psicología , Enfermedades Raras/psicología , Adolescente , Adulto , Anciano , Actitud Frente a la Salud , Imagen Corporal , Relaciones Familiares , Femenino , Humanos , Masculino , Persona de Mediana Edad , Neoplasias/terapia , Relaciones Profesional-Paciente , Enfermedades Raras/terapia , Apoyo Social , Revelación de la Verdad , Adulto JovenRESUMEN
BACKGROUND: The receptor for advanced glycation end products (RAGE) is a multi-ligand receptor in the immunoglobulin superfamily. RAGE is localized throughout ascending sensory pathways (skin, peripheral nerve, dorsal root ganglion, spinal cord), and in cell types interacting with sensory neurons (endothelial cells, smooth muscle cells, monocytes and macrophages). Neuronal RAGE expression increases in pathological pain states in humans and rodents, and soluble RAGE attenuates thermal hypoalgesia in diabetic mice. The objective of the present study was to investigate whether pharmacological modulation of RAGE could attenuate mechanical allodynia in rodent pain models. METHODS: We developed an anti-RAGE monoclonal antibody (11E6) that binds to the C2 immunoglobulin domain of human RAGE, binds to mouse RAGE, and presumably to the same domain in mouse RAGE. The antinociceptive activity of 11E6 was investigated in mouse models of inflammatory (complete Freund's adjuvant) and neuropathic (chronic constriction injury of the sciatic nerve) pain. Mice were dosed intraperitoneally with 11E6 or IgG (negative control). RESULTS: Increased mechanical thresholds were observed following a single dose of 11E6 in both inflammatory and neuropathic pain models. Similar treatment with IgG did not alter nociceptive sensitivity. Repeated dosing with 11E6 significantly attenuated established mechanical hypersensitivity in a neuropathic pain model in a dose-related fashion. CONCLUSIONS: These data demonstrate that specific modulation of RAGE effectively attenuates nociceptive sensitivity associated with chronic inflammatory and neuropathic pain states.
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Anticuerpos Monoclonales/uso terapéutico , Hiperalgesia/tratamiento farmacológico , Hiperalgesia/etiología , Factores Inmunológicos/uso terapéutico , Neuralgia/tratamiento farmacológico , Receptor para Productos Finales de Glicación Avanzada/antagonistas & inhibidores , Animales , Diabetes Mellitus Experimental/complicaciones , Diabetes Mellitus Experimental/metabolismo , Modelos Animales de Enfermedad , Femenino , Adyuvante de Freund , Ganglios Espinales/metabolismo , Humanos , Hiperalgesia/fisiopatología , Masculino , Ratones , Ratones Endogámicos C57BL , Neuralgia/etiología , Neuronas Aferentes/metabolismo , Receptor para Productos Finales de Glicación Avanzada/inmunología , Nervio Ciático/metabolismo , Médula Espinal/metabolismoRESUMEN
We present a mass map reconstructed from weak gravitational lensing shear measurements over 139 deg2 from the Dark Energy Survey science verification data. The mass map probes both luminous and dark matter, thus providing a tool for studying cosmology. We find good agreement between the mass map and the distribution of massive galaxy clusters identified using a red-sequence cluster finder. Potential candidates for superclusters and voids are identified using these maps. We measure the cross-correlation between the mass map and a magnitude-limited foreground galaxy sample and find a detection at the 6.8σ level with 20 arc min smoothing. These measurements are consistent with simulated galaxy catalogs based on N-body simulations from a cold dark matter model with a cosmological constant. This suggests low systematics uncertainties in the map. We summarize our key findings in this Letter; the detailed methodology and tests for systematics are presented in a companion paper.
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OBJECTIVES: The recent growth in the market for electronic cigarettes (e-cigarettes) has led to concerns over their use by young people. It is therefore important to examine trends in the perception and use of e-cigarettes and conventional cigarettes in this group. STUDY DESIGN: Two-wave cross-sectional survey design. METHODS: Young people aged 11-18 in Great Britain were surveyed online by YouGov in 2013 and 2014. Use of e-cigarettes, together with perceived health harms and intention to use were assessed and compared in relation to cigarette smoking history, age and gender. RESULTS: Ever-use of e-cigarettes increased significantly from 4.6% (95% CI 3.8-5.7) in 2013 to 8.2% (95% CI 7.0-9.6) in 2014. Monthly or more use of e-cigarettes increased from 0.9% (95% CI 0.5-1.5) to 1.7 (1.2-2.4), but remained rare in never-smokers at under 0.2%. The proportion of young people who perceived e-cigarettes to be less harmful to users than cigarettes fell from 73.4% (95% CI 71.0-75.8) to 66.9% (95% CI 64.5-69.2), while the proportion who considered e-cigarettes to cause similar levels of harm increased from 11.8% (95% CI 10.0-13.5) to 18.2% (95% CI 16.3-20.1). Of the 8.2% of e-cigarette ever-users in 2014, 69.8% (95% CI 62.2%-77.3%) had smoked a cigarette prior to using an e-cigarette, while 8.2% (95% CI 4.1%-12.2%) first smoked a cigarette after e-cigarette use. CONCLUSIONS: A growing proportion of young people in Great Britain believe e-cigarettes are as harmful as smoking tobacco. Use of e-cigarettes by young people is increasing, but is largely confined to those who smoke.
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Sistemas Electrónicos de Liberación de Nicotina/estadística & datos numéricos , Adolescente , Actitud Frente a la Salud , Niño , Estudios Transversales , Femenino , Humanos , Intención , Masculino , Fumar/epidemiología , Fumar/psicología , Encuestas y Cuestionarios , Reino Unido/epidemiologíaRESUMEN
BACKGROUND: The noradrenergic system contributes to pain modulation, but the roles of its specific adrenoceptors are still being defined. We have identified a novel, potent (rat EC50 = 4.3 nM) and selective α2B receptor agonist, A-1262543, to further explore this adrenoceptor subtype's contribution to pathological nociception. METHODS: Systemic administration of A-1262543 (1-10 mg/kg, intraperitoneal) dose-dependently attenuated mechanical allodynia in animals with a spinal nerve ligation injury. To further explore its mechanism of action, the activity of nociceptive neurones in the spinal cord and medial prefrontal cortex (mPFC) were examined after injection of 3 mg/kg of A-1262543 (intravenous, i.v.). These effects were compared with duloxetine (3 mg/kg, i.v.), a dual noradrenaline (NA) and serotonin (5-HT) reuptake inhibitor. RESULTS: Systemic administration of A-1262543 or duloxetine did not alter the spontaneous or evoked firing of spinal wide dynamic range and nociceptive-specific neurones in the neuropathic rats, indicating that neither compound engaged spinal, peripheral or descending pathways. In contrast to the lack of effect on spinal neurones, both A-1262543 and duloxetine reduced the evoked and spontaneous firing of 'pain-responsive' (PR) neurones in the mPFC. Duloxetine, but not A-1262543, also inhibited the firing of pain non-responsive (nPR) neurones in the mPFC probably reflecting duloxetine's contribution to modulating non-pain endpoints. CONCLUSIONS: These data highlight that activation of the α2B adrenoceptor as well as inhibiting NA and 5-HT reuptake can result in modulating the ascending nociceptive system, and in particular, dampening the firing of PR neurones in the mPFC.
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Inhibidores de Captación Adrenérgica/uso terapéutico , Agonistas alfa-Adrenérgicos/uso terapéutico , Compuestos de Anilina/uso terapéutico , Clorhidrato de Duloxetina/uso terapéutico , Imidazolinas/uso terapéutico , Neuralgia/tratamiento farmacológico , Neuronas/efectos de los fármacos , Nociceptores/efectos de los fármacos , Corteza Prefrontal/efectos de los fármacos , Receptores Adrenérgicos alfa 2/efectos de los fármacos , Médula Espinal/efectos de los fármacos , Animales , Conducta Animal/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Fenómenos Electrofisiológicos/efectos de los fármacos , Células HEK293 , Humanos , Masculino , Ratas , Ratas Sprague-Dawley , Receptores Adrenérgicos alfa 2/genética , Nervios Espinales/lesionesRESUMEN
This study aims to assess the performance of an in-house sickle cell solubility test (SCT) and compare it against data published on other in-house and commercial methods. Also assessed are the effects of possible interference due to haemoglobin (Hb) level, Hb F and Hb S levels, as well as lipaemia, icterus and haemolysis index. A total of 1030 patient samples were tested by the SCT and subsequently confirmed by high-performance liquid chromatography (HPLC). Seventy-five (7.3%) samples revealed a positive SCT whereas 955 (92.7%) were negative. The sensitivity and specificity of the method was 100% and it was shown to detect low levels of Hb S (12.1%). These data show that the authors' in-house SCT method has an excellent performance against other documented methods (including some commercial kits), which is probably explained by its robustness against low levels of Hb S and interfering substances such as lipaemia. The authors believe this shows that in-house tests are able to produce highly reliable results comparable to, if not better than, certain commercially available CE-marked kits.
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Anemia de Células Falciformes/diagnóstico , Pruebas Hematológicas/métodos , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Anemia de Células Falciformes/sangre , Niño , Preescolar , Femenino , Hemoglobinas/análisis , Humanos , Lactante , Masculino , Persona de Mediana Edad , Sensibilidad y Especificidad , Solubilidad , Adulto JovenRESUMEN
Galaxies are believed to evolve through merging, which should lead to some hosting multiple supermassive black holes. There are four known triple black hole systems, with the closest black hole pair being 2.4 kiloparsecs apart (the third component in this system is at 3 kiloparsecs), which is far from the gravitational sphere of influence (about 100 parsecs for a black hole with mass one billion times that of the Sun). Previous searches for compact black hole systems concluded that they were rare, with the tightest binary system having a separation of 7 parsecs (ref. 10). Here we report observations of a triple black hole system at redshift z = 0.39, with the closest pair separated by about 140 parsecs and significantly more distant from Earth than any other known binary of comparable orbital separation. The effect of the tight pair is to introduce a rotationally symmetric helical modulation on the structure of the large-scale radio jets, which provides a useful way to search for other tight pairs without needing extremely high resolution observations. As we found this tight pair after searching only six galaxies, we conclude that tight pairs are more common than hitherto believed, which is an important observational constraint for low-frequency gravitational wave experiments.
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BACKGROUND: Microglia serve as macrophage-like cells in the central nervous system, and activation of microglial cells in the spinal cord may contribute to ongoing pain following peripheral trauma or nerve injury. Following pronociceptive stimulation, activated microglia exhibit increased expression of the peripheral benzodiazepine receptor (PBR)/translocator protein 18 kDa (TSPO). METHODS: Using radioligand binding autoradiography and filtration assays, we examined the specific binding of the PBR/TSPO ligand [(3)H]PK11195 in spinal cords from the following rat experimental pain models: neuropathic pain induced by spinal nerve ligation (SNL), osteoarthritic pain induced by intraarticular injection of monosodium iodoacetate in the knee joint (MIA-OA), and subchronic inflammatory pain induced by intraplantar injection of complete Freund's adjuvant (CFA). RESULTS: Specific [(3)H]PK11195 binding in dorsal and ventral regions of lumbar spinal cord was increased by ≥70% ipsilateral to SNL. Also, specific [(3)H]PK11195 binding in the ipsilateral (injured) lumbar spinal cord was increased by approximately 25% in MIA-OA. In contrast to the data obtained in these chronic neuropathic and nociceptive pain models, specific [(3)H]PK11195 binding in the ipsilateral (injured) dorsal horn was elevated in only one of six CFA rats. Consistent with increased PBR/TSPO binding measured for SNL and MIA-OA rats, increased anti-OX-42 immunostaining of the cell surface microglial marker CD11b was observed in the ipsilateral spinal cord from these models. CONCLUSIONS: These studies demonstrate that [(3)H]PK11195 binding assays may serve as a marker of spinal microglial activation in experimental models of chronic neuropathic or osteoarthritic pain, which may be translatable to clinical research through novel applications of PBR/TSPO imaging agents.
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Isoquinolinas/farmacología , Microglía/metabolismo , Neuralgia/metabolismo , Osteoartritis/metabolismo , Dolor/metabolismo , Médula Espinal/metabolismo , Animales , Autorradiografía , Modelos Animales de Enfermedad , Masculino , Microglía/efectos de los fármacos , Dimensión del Dolor , Ratas , Ratas Sprague-DawleyRESUMEN
Gravitational lensing is a powerful astrophysical and cosmological probe and is particularly valuable at submillimeter wavelengths for the study of the statistical and individual properties of dusty star-forming galaxies. However, the identification of gravitational lenses is often time-intensive, involving the sifting of large volumes of imaging or spectroscopic data to find few candidates. We used early data from the Herschel Astrophysical Terahertz Large Area Survey to demonstrate that wide-area submillimeter surveys can simply and easily detect strong gravitational lensing events, with close to 100% efficiency.
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OBJECTIVE: To examine the prevalence of smoke-free homes in England between 1996 and 2007 and their impact on children's exposure to second-hand smoke via a series of annual cross-sectional surveys: the Health Survey for England. These comprised nationally representative samples of non-smoking children aged 4-15 (n = 13 365) and their parents interviewed in the home. Main outcome measures were cotinine measured in saliva, smoke-free homes defined by "no" response to "Does anyone smoke inside this house/flat on most days?", self-reported smoking status of parents and self-reported and cotinine validated smoking status in children. RESULTS: The proportion of homes where one parent was a smoker that were smoke free increased from 21% in 1996 to 37% in 2007, and where both parents were smokers from 6% to 21%. The overwhelming majority of homes with non-smoking parents were smoke free (95% in 1996; 99% in 2007). For children with non-smoking parents and living in a smoke-free home the geometric mean cotinine across all years was 0.22 ng/ml. For children with one smoking parent geometric mean cotinine levels were 0.37 ng/ml when the home was smoke free and 1.67 ng/ml when there was smoking in the home; and for those with two smoking parents, 0.71 ng/ml and 2.46 ng/ml. There were strong trends across years for declines in cotinine concentrations in children in smoke-free homes for the children of smokers and non-smokers. CONCLUSIONS: There has been a marked secular trend towards smoke-free homes, even when parents themselves are smokers. Living in a smoke-free home offers children a considerable, but not complete, degree of protection against exposure to parental smoking.