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1.
Ultrasound Obstet Gynecol ; 62(1): 106-114, 2023 07.
Article in English | MEDLINE | ID: mdl-36864542

ABSTRACT

OBJECTIVES: There is limited prospective evidence to guide the management of late-onset fetal growth restriction (FGR) and its differentiation from small-for-gestational age. The aim of this study was to assess prospectively a novel protocol in which ultrasound criteria were used to classify women with suspected late FGR into two groups: those at low risk, who were managed expectantly until the anticipated date of delivery, and those at high risk, who were delivered soon after 37 weeks of gestation. We also compared the outcome of this prospective cohort with that of a historical cohort of women presenting similarly with suspected late FGR, in order to evaluate the impact of the new protocol. METHODS: This was a prospective study of women with a non-anomalous singleton pregnancy at ≥ 32 weeks' gestation attending a tertiary hospital in London, UK, between February 2018 and September 2019, with estimated fetal weight (EFW) ≤ 10th centile, or EFW > 10th centile in addition to a decrease in fetal abdominal circumference of ≥ 50 centiles compared with a previous scan, umbilical artery Doppler pulsatility index > 95th centile or cerebroplacental ratio < 5th centile. Women were classified as low or high risk based on ultrasound and Doppler criteria. Women in the low-risk group were delivered by 41 weeks of gestation, unless they subsequently met high-risk criteria, whereas women in the high-risk group (EFW < 3rd centile, umbilical artery Doppler pulsatility index > 95th centile or EFW between 3rd and 10th centiles (inclusive) with abdominal circumference drop or abnormal Dopplers) were delivered at or soon after 37 weeks. The primary outcome was adverse neonatal outcome and included hypothermia, hypoglycemia, neonatal unit admission, jaundice requiring treatment, suspected infection, feeding difficulties, 1-min Apgar score < 7, hospital readmission and any severe adverse neonatal outcome (perinatal death, resuscitation using inotropes or mechanical ventilation, 5-min Apgar score < 7, metabolic acidosis, sepsis, and cerebral, cardiac or respiratory morbidity). Secondary outcomes were adverse maternal outcome (operative delivery for abnormal fetal heart rate) and severe adverse neonatal outcome. Women managed according to the new protocol were compared with a historical cohort of 323 women delivered prior to the implementation of the new protocol, for whom management was guided by individual clinician expertise. RESULTS: Over 18 months, 321 women were recruited to the prospective cohort, of whom 156 were classified as low risk and 165 were high risk. Adverse neonatal outcome was significantly less common in the low-risk compared with the high-risk group (45% vs 58%; adjusted odds ratio (aOR), 0.6 (95% CI, 0.4-0.9); P = 0.022). There was no significant difference in the rate of adverse maternal outcome (18% vs 24%; aOR, 0.7 (95% CI, 0.4-1.2); P = 0.142) or severe adverse neonatal outcome (3.8% vs 8.5%; aOR, 0.5 (95% CI, 0.2-1.3); P = 0.153) between the low- and high-risk groups. Compared with women in the historical cohort classified retrospectively as low risk, low-risk women managed under the new protocol had a lower rate of adverse neonatal outcome (45% vs 58%; aOR, 0.6 (95% CI, 0.4-0.9); P = 0.026). CONCLUSIONS: Appropriate risk stratification to guide management of late FGR was associated with a reduced rate of adverse neonatal outcome in low-risk pregnancies. In clinical practice, a policy of expectantly managing women with a low-risk late-onset FGR pregnancy at term could improve neonatal and long-term development. Randomized controlled trials are needed to assess the effect of an evidence-based conservative management protocol for late FGR on perinatal morbidity and mortality and long-term neurodevelopment. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.


Subject(s)
Fetal Growth Retardation , Ultrasonography, Prenatal , Pregnancy , Infant, Newborn , Female , Humans , Fetal Growth Retardation/diagnostic imaging , Fetal Growth Retardation/therapy , Prospective Studies , Retrospective Studies , Ultrasonography, Prenatal/methods , Infant, Small for Gestational Age , Fetal Weight/physiology , Gestational Age
2.
Science ; 376(6596): 982-987, 2022 05 27.
Article in English | MEDLINE | ID: mdl-35617409

ABSTRACT

The dynamic interactions between noble metal particles and reducible metal-oxide supports can depend on redox reactions with ambient gases. Transmission electron microscopy revealed that the strong metal-support interaction (SMSI)-induced encapsulation of platinum particles on titania observed under reducing conditions is lost once the system is exposed to a redox-reactive environment containing oxygen and hydrogen at a total pressure of ~1 bar. Destabilization of the metal-oxide interface and redox-mediated reconstructions of titania lead to particle dynamics and directed particle migration that depend on nanoparticle orientation. A static encapsulated SMSI state was reestablished when switching back to purely oxidizing conditions. This work highlights the difference between reactive and nonreactive states and demonstrates that manifestations of the metal-support interaction strongly depend on the chemical environment.

3.
Top Catal ; 61(20): 2052-2061, 2018.
Article in English | MEDLINE | ID: mdl-30930589

ABSTRACT

The selective hydrogenation of propyne over a Pd-black model catalyst was investigated under operando conditions at 1 bar making use of advanced X-ray diffraction (bulk sensitive) and photo-electron spectroscopy (surface sensitive) techniques. It was found that the population of subsurface species controls the selective catalytic semi-hydrogenation of propyne to propylene due to the formation of surface and near-surface PdCx that inhibits the participation of more reactive bulk hydrogen in the hydrogenation reaction. However, increasing the partial pressure of hydrogen reduces the population of PdCx with the concomitant formation of a ß-PdHx phase up to the surface, which is accompanied by a lattice expansion, allowing the participation of more active bulk hydrogen which is responsible for the unselective total alkyne hydrogenation. Therefore, controlling the surface and subsurface catalyst chemistry is crucial to control the selective alkyne semi-hydrogenation.

4.
Phys Chem Chem Phys ; 17(38): 25073-89, 2015 Oct 14.
Article in English | MEDLINE | ID: mdl-26345450

ABSTRACT

The oxidation of copper catalysts during ethylene epoxidation was characterized using in situ photoemission spectroscopy and electron microscopy. Gas chromatography, proton-transfer reaction mass spectrometry and electron-ionization mass spectrometry were used to characterize the catalytic properties of the oxidized copper. We find that copper corrodes during epoxidation in a 1 : 1 mixture of oxygen and ethylene. The catalyst corrosion passes through several stages, beginning with the formation of an O-terminated surface, followed by the formation of Cu2O scale and eventually a CuO scale. The oxidized catalyst exhibits measurable activity for ethylene epoxidation, but with a low selectivity of <3%. Tests on pure Cu2O and CuO powders confirm that the oxides intrinsically exhibit partial-oxidation activity. Cu2O was found to form acetaldehyde and ethylene epoxide in roughly equal amounts (1.0% and 1.2% respectively), while CuO was found to form much less ethyl aldehyde than ethylene epoxide (0.1% and 1.0%, respectively). Metallic copper catalysts were examined in extreme dilute-O2 epoxidation conditions to try and keep the catalyst from oxidizing during the reaction. It was found that in feed of 1 part O2 to 2500 parts C2H4 (PO2 = 1.2 × 10(-4) mbar) the copper surface becomes O-terminated. The O-terminated surface was found to exhibit partial-oxidation selectivity similar to that of Cu2O. With increasing O2 concentration (>8/2500) Cu2O forms and eventually covers the surface.

5.
J Nanosci Nanotechnol ; 10(4): 2422-33, 2010 Apr.
Article in English | MEDLINE | ID: mdl-20355444

ABSTRACT

We propose a novel template method for large scale synthesis of Ultra-Nanocrystalline Diamond (UNCD) fibres and helices with lengths of thousands of microns and diameters ranging from 0.5 to 5 microm: (i) Large quantities of submicrometer- or nanometer-diameter silica (a-SiO2) nanostructures, with lengths in the order of 2 to 4 mm, were synthesized by Vapor-Liquid-Solid (VLS) method; (ii) UNCD coating of as-synthesized a-SiO2 micro- or nanonanostructures by Microwave Plasma Chemical Vapour Deposition (MPCVD) technique in hydrogen-deficient condition. Electron Field Emission (EFE) of as-synthesized UNCD structures was observed with a threshold field of 3.4 V/microm. These micro- or nanostructures may find potential applications in high power electronics, vertical field-effect transistors in vacuum electronics, heat sinks in microelectronics and structural materials in Micro- and Nano-Electro-Mechanical Systems (MEMS/NEMS). The successful preparation of various types of UNCD structures suggests that this templating process can be used for a wide range of materials.

6.
Nanoscale ; 1(3): 360-5, 2009 Dec.
Article in English | MEDLINE | ID: mdl-20648274

ABSTRACT

A nonaqueous route based on the solvothermal reaction of alkaline earth precursors with aluminium isopropoxide in benzyl alcohol is introduced. This simple process leads to crystalline complex nanostructures of alkaline earth aluminates, which, up to now, could only be obtained by solid state reaction at temperatures above 1100 degrees C or by sol-gel and further calcination at temperatures only slightly lower ( approximately 800 degrees C). The approach appears to be rather general since under the same reaction conditions BaAl(2)O(4), CaAl(4)O(7), and SrAl(4)O(7) could be obtained. The as-synthesized materials were characterized by X-ray diffraction, electron microscopy techniques, solid-state NMR and FT-IR spectroscopies. The reaction mechanism, which was studied as well, indicates the in-situ formation of benzoate species. These can preferentially bind to particular crystallographic facets of the aluminates via bridging bonds, thereby stabilizing the surfaces that give rise to the peculiar complex structure of the final material. In order to supplement the synthesis approach and to investigate the formation of impurity phases, pure aluminium oxide hybrid nanostructures were synthesized under similar conditions and fully characterized.

7.
J Matern Fetal Neonatal Med ; 14(1): 39-44, 2003 Jul.
Article in English | MEDLINE | ID: mdl-14563091

ABSTRACT

OBJECTIVE: Stillbirth affects a large portion of the population and results in mortality rates comparable to those of preterm delivery and sudden infant death syndrome combined. Despite the large burden, little information is available to offer patients regarding etiology, treatment or prevention for a subsequent pregnancy. METHODS: We surveyed a sample of Fellows of the American College of Obstetricians and Gynecologists to determine the practice patterns in the management of stillbirth. RESULTS: The majority of Fellows agreed on the definition of stillbirth; however, their approach to treatment and prevention varied. A majority of Fellows believed that research on understanding stillbirth was of national importance. CONCLUSIONS: A comprehensive educational effort to include current knowledge regarding causes and management, standardized diagnostic procedures, death registration and case review is recommended to improve obstetric care of those with a stillbirth.


Subject(s)
Education, Medical, Continuing , Fetal Death/prevention & control , Obstetrics , Practice Patterns, Physicians' , Adult , Female , Humans , Male , Middle Aged , Pregnancy , Societies, Medical , Surveys and Questionnaires , United States
8.
Micron ; 34(3-5): 227-33, 2003.
Article in English | MEDLINE | ID: mdl-12895494

ABSTRACT

We present a theoretical study of the anisotropy and collection angle dependence of the oxygen K ELNES in V2O5. Ab initio band-structure calculations were performed with WIEN97, a program package based on the full potential linearised augmented plane waves (FP-LAPW) method. An analysis of the site and angular momentum projected DOS allowed the identification of differently coordinated oxygens and the separation of the oxygen K-edge into contributions from terminal (vanadyl) oxygens, bridging oxygens and chain oxygens. The major contribution to the anisotropy of the O K-edge ELNES could be assigned to transitions at the vanadyl oxygen. Theoretical calculations predict that the extent of changes in the ELNES would be large enough for detection in collection angle dependent O K-edge measurements. A variation in the fine structure of the O K-edge with decreasing collection angle was confirmed by experiments.

10.
Article in English | MEDLINE | ID: mdl-11484150

ABSTRACT

Of all Indian Health Service areas, the Aberdeen Area has consistently had the highest infant mortality rate. Among some tribes in this area the rate has exceeded 30/ 1000 live birth and half the infant deaths have been attributed to Sudden Infant Death Syndrome,a rate four to five times higher than the national average. The Indian Health Service, Centers for Disease Control and Prevention, National Institute of Child Health and Human Development, and the Aberdeen Area Tribal Chairmen's Health Board collaborated to investigate these high rates with the goals of refining the ascertainment of the causes of death, improving cause-specific infant mortality rates and identifying factors contributing to the high rates. Ten of the 19 tribes or tribal communities, representing 66%of the area population, participated in a 4-year prospective case-control study of infants who died after discharge from the hospital. Infant care practices and socio-demographic, economic, medical, health care, and environmental factors were examined. The study included parental interviews, death scene investigations, autopsies, neuropathology studies, medical chart abstractions, blood cotinine assays, and a surveillance system for infant deaths. Controls were the previous and subsequent infants born on the case mother's reservation. From December 1,1992 until November 30,1996,72 infant deaths were investigated. This report describes the study methods and the model employed for involving the community and multiple agencies to study the problem of infant mortality among Northern Plains Indians. Data gathered during the investigations are being analyzed and will be published at a later date.


Subject(s)
Indians, North American/statistics & numerical data , Infant Mortality , Case-Control Studies , Cause of Death , Data Collection/methods , Epidemiologic Research Design , Female , Humans , Incidence , Infant, Newborn , Male , Prospective Studies , Sudden Infant Death/ethnology , United States/epidemiology , United States Indian Health Service/statistics & numerical data
11.
JAMA ; 285(17): 2199-207, 2001 May 02.
Article in English | MEDLINE | ID: mdl-11325321

ABSTRACT

CONTEXT: Home monitors designed to identify cardiorespiratory events are frequently used in infants at increased risk for sudden infant death syndrome (SIDS), but the efficacy of such devices for this use is unproven. OBJECTIVE: To test the hypothesis that preterm infants, siblings of infants who died of SIDS, and infants who have experienced an idiopathic, apparent life-threatening event have a greater risk of cardiorespiratory events than healthy term infants. DESIGN: Longitudinal cohort study conducted from May 1994 through February 1998. SETTING: Five metropolitan medical centers in the United States. PARTICIPANTS: A total of 1079 infants (classified as healthy term infants and 6 groups of those at risk for SIDS) who, during the first 6 months after birth, were observed with home cardiorespiratory monitors using respiratory inductance plethysmography to detect apnea and obstructed breathing. MAIN OUTCOME MEASURES: Occurrence of cardiorespiratory events that exceeded predefined conventional and extreme thresholds as recorded by the monitors. RESULTS: During 718 358 hours of home monitoring, 6993 events exceeding conventional alarm thresholds occurred in 445 infants (41%). Of these, 653 were extreme events in 116 infants (10%), and of those events with apnea, 70% included at least 3 obstructed breaths. The frequency of at least 1 extreme event was similar in term infants in all groups, but preterm infants were at increased risk of extreme events until 43 weeks' postconceptional age. CONCLUSIONS: In this study, conventional events are quite common, even in healthy term infants. Extreme events were common only in preterm infants, and their timing suggests that they are not likely to be immediate precursors to SIDS. The high frequency of obstructed breathing in study participants would likely preclude detection of many events by conventional techniques. These data should be important for designing future monitors and determining if an infant is likely to be at risk for a cardiorespiratory event.


Subject(s)
Apnea/diagnosis , Home Nursing , Monitoring, Physiologic/instrumentation , Sudden Infant Death/prevention & control , Airway Obstruction/diagnosis , Bradycardia/diagnosis , Humans , Infant , Infant, Newborn , Infant, Premature , Longitudinal Studies , Plethysmography , Proportional Hazards Models , Respiration Disorders/diagnosis , Risk Factors , Survival Analysis
12.
Am J Respir Crit Care Med ; 162(2 Pt 1): 471-80, 2000 Aug.
Article in English | MEDLINE | ID: mdl-10934073

ABSTRACT

As part of the Collaborative Home Infant Monitoring Evaluation (CHIME) we compared apnea identified by a customized home monitor using respiratory inductance plethysmography (RIP) with simultaneously recorded polysomnography-acquired nasal end-tidal CO(2) (PET(CO(2))) and nasal/oral thermistor in 422 infants during overnight laboratory recordings to determine concordance between techniques, sources of disagreement, and capacity of RIP to detect obstructed breaths within an apnea. Among 233 episodes of apnea identified by at least one method as >/= 16 s, 120 were observed by the CHIME monitor, 219 by PET(CO(2)), and 163 by thermistor. The positive predictive value of the CHIME-identified apnea was 89.2% (95% CI 83, 95) and 73% (95% CI 65, 81) for PET(CO(2)) and thermistor, respectively. However, the sensitivity of the CHIME monitor in identifying events detected by the other methods was only approximately 50%. Among 87 apnea events identified by all three techniques, no two methods showed high agreement in measurement of apnea duration: RIP and PET(CO(2)) (ICC = 0.54), RIP and thermistor (ICC = 0.13), PET(CO(2)) and nasal thermistor (ICC = 0.41). Among the 179 breaths identified by RIP as obstructed, 79.9% were judged to be obstructed on the PET(CO(2)) and 80.4% were judged to be obstructed on the thermistor channel. Among 238 breaths identified on PET(CO(2)) as obstructed, 54.2% were determined to be obstructed by RIP. Among 204 breaths identified on thermistor as obstructed, 55. 4% were determined to be obstructed by RIP. Reasons for discrepancies in apnea detection among channels included body movement, partial airway obstruction, and obstructed breaths. Despite these limitations the CHIME monitor provides an opportunity to record physiological data previously unavailable in the home.


Subject(s)
Apnea/diagnosis , Carbon Dioxide/analysis , Monitoring, Physiologic/methods , Plethysmography , Tidal Volume/physiology , Biosensing Techniques , Humans , Infant , Plethysmography/methods , Sensitivity and Specificity
13.
JAMA ; 283(16): 2135-42, 2000 Apr 26.
Article in English | MEDLINE | ID: mdl-10791506

ABSTRACT

CONTEXT: The success and simplicity of the 1994 national "Back to Sleep" campaign to reduce sudden infant death syndrome provides an opportunity to study which elements determine whether a behavior will change in the desired direction in response to a public health intervention. OBJECTIVE: To examine sociodemographic characteristics, motivation, and message exposure to ascertain which factors influenced a caregiver's choice of infant sleep position after implementation of the campaign. DESIGN: Annual nationally representative telephone surveys conducted between 1994 and 1998. SETTING: The 48 contiguous United States. PARTICIPANTS: Nighttime caregivers of infants born within the 7 months prior to interview between 1994 and 1998. Approximately 1000 interviews were conducted each year. MAIN OUTCOME MEASURES: The position the infant was usually placed in for sleep, sleep position recommendations received from specific sources, and reasons reported for position choice. RESULTS: Between 1994 and 1998, prone placement declined from 44% to 17% among white infants and from 53% to 32% among black infants. Supine placement increased from 27% to 58% among white infants and from 17% to 31% among black infants. During this period, reports of supine recommendations from at least 1 source doubled from 38% to 79%. From 1995 to 1998, 86% of caregivers who placed the infant prone reported receiving only nonprone recommendations. Infant comfort was given as a reason for prone placement by 82% of these caregivers. In multivariate analysis, physician recommendation of "supine not prone" had the strongest influence and was associated with decreased prone placement (odds ratio [OR], 0.25 [95% confidence interval [CI], 0.16-0.39]) and increased supine placement (OR, 3.37 [95% CI, 2.38-4.76]). Recommendations from all 4 sources (the physician, neonatal nurse, reading materials, and radio/television) further increased the probability of supine placement (OR, 6.01 [95% CI, 4.57-7.90]). Other factors independently associated with increased prone and decreased supine placement included maternal black race, parity of more than 1, and living in a southern or mid-Atlantic state. CONCLUSIONS: According to our study, as of 1998, approximately one fifth of infants were still placed prone, and only half were placed supine. Recommendations of supine placement during infancy by physicians at well-baby checks and by neonatal nursery staff and print and broadcast media have increased the proportion of infants placed supine. Caregiver beliefs regarding perceived advantages of prone sleeping should be addressed to attain further reduction in prone placement.


Subject(s)
Infant Care/trends , Sleep , Sudden Infant Death/prevention & control , Supine Position , Choice Behavior , Data Collection , Health Promotion , Humans , Infant , Infant Care/psychology , Infant Care/statistics & numerical data , Logistic Models , Multivariate Analysis , Prone Position , Socioeconomic Factors , United States/epidemiology
14.
Int J Artif Organs ; 22(8): 573-82, 1999 Aug.
Article in English | MEDLINE | ID: mdl-10533914

ABSTRACT

Because of the closed plasma (secondary) circuit in the Microspheres based Detoxification System (MDS), a convective blood purification system, the same amount of filtrated plasma is backfiltrated into the blood circuit. Therefore, there is no direct way to determine the ultrafiltrate production rate, which is an important factor of efficiency. The only possible way to estimate the filtration properties of the filter is to consider pressure values. In this study the pressure distribution in the filter was investigated in vitro. To explain the results and to calculate inaccessible parameters, a mathematical model was established which also considered the asymmetric behaviour of the filter membrane. The result was a linear pressure gradient, agreement with the measurements was reasonably good (calculated primary pressure loss differs <13% from measured value when using mean measured filter resistance as model parameter). Linear pressure distribution offers the possibility of easily calculating the filtration length, a parameter which can be used to estimate the filter condition. The comparison between calculated filtration and backfiltration rates offers an instrument of control for these values.


Subject(s)
Membranes, Artificial , Models, Biological , Sorption Detoxification/methods , Adsorption , Animals , Cattle , In Vitro Techniques , Materials Testing , Micropore Filters , Microspheres , Permeability , Pressure , Sensitivity and Specificity , Sorption Detoxification/instrumentation , Viscosity
16.
JAMA ; 280(4): 329-35, 1998.
Article in English | MEDLINE | ID: mdl-9686549

ABSTRACT

CONTEXT: Studies have demonstrated strong associations between the prone sleep position (on the stomach) and sudden infant death syndrome (SIDS). In 1992, the American Academy of Pediatrics recommended that infants be placed to sleep laterally (on their side) or supine (on their back) to reduce SIDS risk, and in 1994, the national public education campaign "Back to Sleep" was launched. OBJECTIVE: To determine the typical sleep position of infants younger than 8 months in the United States, the changes that occurred after these recommendations, and the factors associated with the placement of infants prone or supine. DESIGN: Annual nationally representative telephone surveys. SETTING: The 48 contiguous states of the United States. PARTICIPANTS: Nighttime caregivers of infants born within the last 7 months between 1992 and 1996. Approximately 1000 interviews were conducted per year. MAIN OUTCOME MEASURES: The position the infant was usually placed in for sleep, and the position the infant was most commonly found in when checked during the night's sleep. RESULTS: Ninety-seven percent of respondents in each wave of the survey usually placed their infant to sleep in a specific position. Infants were placed in the prone position by 70% of caregivers in 1992, prior to the campaign, but only 24% in 1996. Supine and lateral placements increased during this time period, from 13% in 1992 to 35% in 1996 and from 15% in 1992 to 39% in 1996, respectively. Significant predictors of prone placement included maternal race reported as black (odds ratio [OR], 2.34; 95% confidence interval [CI], 1.68-3.26), mother's age 20 to 29 years (OR, 1.28; 95% CI, 1.09-1.50), region reported as the mid-Atlantic (OR, 1.41; 95% CI, 1.12-1.78) or southern states (OR, 1.47; 95% CI, 1.22-1.70), mothers with a previous child (OR, 1.68; 95% CI, 1.43-1.97), and infants younger than 8 weeks (OR, 0.63; 95% CI, 0.46-0.85). Infants aged 8 to 15 weeks were significantly more likely to be placed nonprone over time compared with the other age groups. Most of the risk factors for prone were significantly related in the opposite direction to supine placement. CONCLUSIONS: The prevalence of infants placed in the prone sleep position declined by 66% between 1992 and 1996. Although causality cannot be proved, SIDS rates declined approximately 38% during this period. To achieve further reduction in prone sleeping, efforts to promote the supine sleep position should be aimed at groups at high risk for prone placement.


Subject(s)
Infant Care/standards , Prone Position , Sleep , Sudden Infant Death/prevention & control , Supine Position , Guidelines as Topic , Humans , Infant , Infant, Newborn , Logistic Models , Multivariate Analysis , Population Surveillance , Risk Factors , Sudden Infant Death/epidemiology , United States/epidemiology
17.
Am J Psychiatry ; 154(9): 1220-7, 1997 Sep.
Article in English | MEDLINE | ID: mdl-9286180

ABSTRACT

OBJECTIVE: An excess of obstetric complications in the histories of schizophrenic patients is a well-replicated finding, but less consistent results have been found concerning the relationships between obstetric complications and family history of schizophrenia, age at onset of schizophrenia, and gender. Small sample size limited the power of previous studies that attempted to assess such relationships. The aim of this study was to use data on individual patients from all available studies to examine the links between a history of obstetric complications and family history of schizophrenia, age at onset, and gender. METHOD: Raw data from 854 schizophrenic patients concerning history of obstetric complications rated according to the Lewis and Murray scale were obtained from 11 different research groups. Weighted average estimates were calculated with the use of regression techniques. RESULTS: A significant association was found between age at onset of schizophrenia and obstetric complications: the earlier the age at onset, the more likely the history of obstetric complications. Subjects with onset of schizophrenia before age 22 were 2.7 times more likely than those with onset at a later age to have had a history of abnormal presentation at birth and 10 times more likely to have had a history of complicated Cesarean birth. No association was found between obstetric complications and family history of schizophrenia or gender. CONCLUSIONS: The association between obstetric complications and early age at onset of schizophrenia indicates that the pathophysiology of early-onset schizophrenia involves neurodevelopmental impairment.


Subject(s)
Family , Pregnancy Complications/epidemiology , Schizophrenia/epidemiology , Adolescent , Adult , Age Factors , Age of Onset , Cesarean Section/statistics & numerical data , Child , Female , Humans , Infant, Newborn , Male , Middle Aged , Obstetric Labor Complications/epidemiology , Pregnancy , Regression Analysis , Schizophrenia/genetics , Sex Factors
18.
Sleep ; 20(7): 553-60, 1997 Jul.
Article in English | MEDLINE | ID: mdl-9322271

ABSTRACT

Infant polysomnography (IPSG) is an increasingly important procedure for studying infants with sleep and breathing disorders. Since analyses of these IPSG data are subjective, an equally important issue is the reliability or strength of agreement among scorers (especially among experienced clinicians) of sleep parameters (SP) and sleep states (SS). One basic issue of this problem was examined by proposing and testing the hypothesis that infant SP and SS ratings can be reliably scored at substantial levels of agreement, that is, kappa (kappa) > or = 0.61. In light of the importance of IPSG reliability in the collaborative home infant monitoring evaluation (CHIME) study, a reliability training and evaluation process was developed and implemented. The bases for training on SP and SS scoring were CHIME criteria that were modifications and supplements to Anders, Emde, and Parmelee (10). The kappa statistic was adopted as the method for evaluating reliability between and among scorers. Scorers were three experienced investigators and four trainees. Inter- and intrarater reliabilities for SP codes and SSs were calculated for 408 randomly selected 30-second epochs of nocturnal IPSG recorded at five CHIME clinical sites from healthy full term (n = 5), preterm (n = 4), apnea of infancy (n = 2), and siblings of the sudden infant death syndrome (SIDS) (n = 4) enrolled subjects. Infant PSG data set 1 was scored by both experienced investigators and trained scorers and was used to assess initial interrater reliability. Infant PSG data set 2 was scored twice by the trained scorers and was used to reassess inter-rater reliability and to assess intrarater reliability. The kappa s for SS ranged from 0.45 to 0.58 for data set 1 and represented a moderate level of agreement. Therefore, rater disagreements were reviewed, and the scoring criteria were modified to clarify ambiguities. The kappa s and confidence intervals (CIs) computed for data set 2 yielded substantial inter-rater and intrarater agreements for the four trained scorers; for SS, the kappa = 0.68 and for SP the kappa s ranged from 0.62 to 0.76. Acceptance of the hypothesis supports the conclusion that the IPSG is a reliable source of clinical and research data when supported by significant kappa s and CIs. Reliability can be maximized with strictly detailed scoring guidelines and training.


Subject(s)
Polysomnography , Humans , Infant , Reproducibility of Results , Sudden Infant Death
19.
Pediatr Ann ; 24(7): 358-64, 1995 Jul.
Article in English | MEDLINE | ID: mdl-7567180

ABSTRACT

The mortality attributed to sudden infant death syndrome ahs decreased significantly in Northern Europe and Australia in conjunction with the majority of infants being placed to sleep on their back or side instead of on their stomach. Since the AAP recommendation in 1992 to place healthy infants on their back or side to sleep, the fraction of infants sleeping prone in the United States has decreased to approximately 43%. It is hoped that the national "Back to Sleep" education campaign will accelerate the acceptance of back or side sleeping for healthy infants so that only a small fraction of infants will be sleeping on their stomach within the next few years. Health-care providers should promote the recommendation in the newborn nursery and at well-baby visits. They should encourage dialogue with caregivers regarding this and other early infant care practices. It is still too soon to know how predominantly nonprone sleeping will affect the rate of SIDS in the United States. It is important that providers continue to stress access to prenatal and well-baby care, and cessation of smoking and substance abuse, as these risk factors may play a larger role in the high-risk communities in the United States. Pediatric medical personnel should advocate for proper death certification for infants and children, to include state legislation that supports autopsies for sudden unexpected deaths in children, and the establishment of state child fatality investigation and review teams. They also should participate in the training of death scene investigators or be part of the death scene investigative team.(ABSTRACT TRUNCATED AT 250 WORDS)


Subject(s)
Sudden Infant Death/prevention & control , Humans , Infant , Infant Welfare , Maternal Age , Maternal Behavior , Prone Position , Risk Factors
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