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Biomedical subjects

S K Clarren

Publications and source records attributed to S K Clarren.

At least 19 recordsLinked to original sources
PubMed2001

Screening for fetal alcohol syndrome in primary schools: a feasibility study.

BACKGROUND: This project was undertaken as a feasibility study to determine the possibility of screening for fetal alcohol syndrome (FAS) in early school-age children for epidemiological and interventional purposes. METHODS: All elementary schools in two counties in Washington State were asked to screen first graders for possible FAS. A child was screen positive if found to be growth deficient, to have certain specific facial abnormalities, or have a known history of substantial alcohol exposure in gestation. All screen-positive children were invited to "special diagnostic clinics" for final diagnosis and treatment planning. RESULTS: In County A, virtually all students were screened. In County B only about 25% of children were screened. This difference was related to the number of schools that agreed to participate in the project and the methods employed by each county to obtain parental permission. In each county, only about one-half of the screen-positive children were seen in the special clinics for diagnostic considerations. Only one of the seven children found to have FAS had been diagnosed previously. The minimal prevalence of FAS in County A was 3.1 in 1,000 students. The minimal prevalence of FAS in County B could not be calculated. The most efficient component in the screening process leading to a diagnosis of FAS was finding the specific facial features of the disorder. The diagnosis of FAS was generally helpful in improving educational planning. CONCLUSIONS: This study demonstrated that population-based FAS screening within a school system may be possible, but participation is dependent on local trust and understanding of the project before its inception within the schools and the community at large.

Child↗
PubMed2000

Long-term developmental outcomes in patients with deformational plagiocephaly.

OBJECTIVES: To determine whether there was an increased rate of later developmental delay in school-aged children who presented as infants with deformational plagiocephaly without obvious signs of delay at the time of initial evaluation. METHODS: A retrospective medical record review of 254 patients evaluated at the Craniofacial Center of the Children's Hospital and Regional Medical Center in Seattle, Washington, from 1980 through 1991 was completed. Consenting patient families were interviewed via telephone to determine what, if any, special medical or educational problems had occurred for the children who had had plagiocephaly in infancy or their siblings with normal head shapes. RESULTS: A total of 181 families from the medical record review could be notified about the study and 63 families agreed to participate in a telephone interview. The sample of participants for the telephone interview was random to and representative of the group as a whole. The families reported that 25 of the 63 children (39.7%) with persistent deformational plagiocephaly had received special help in primary school including: special education assistance, physical therapy, occupational therapy, speech therapy generally through an Individual Education Plan. Only 7 of 91 siblings (7.7%), serving as controls, required similar services (chi(2) = 21.24). Delays could not be specifically anticipated at the time of the diagnosis of deformational plagiocephaly from any simple set of factors including treatment with helmet therapy, although effected males with reported uterine constraint were at the highest risk for subsequent school problems. CONCLUSIONS: Infants with deformational plagiocephaly comprise a high-risk group for developmental difficulties presenting as subtle problems of cerebral dysfunction during the school-age years. There is a need for additional research on the long-term developmental problems in infants with deformational plagiocephaly. plagiocephaly, facial asymmetry, torticollis, developmental delay.

Developmental Disabilities↗
PubMed1999

Number of axons in the corpus callosum of the Mature macaca nemestrina: increases caused by prenatal exposure to ethanol.

The effects of prenatal exposure to ethanol on the number of callosal axons were examined. Pregnant Macaca nemestrina were treated with ethanol (1.8 g/kg b.wt.) 1 day per week during the first 6 weeks (Et6) or full 24 weeks (Et24) of gestation. Control macaques were intubated with an isocaloric amount of sucrose water (Ct). The mid-sagittal area of the corpus callosum in 4- to 5-year-old offspring was examined in magnetic resonance (MR) images and in fixed brains. The number of callosal axons was determined by using electron microscopy. In both MR images and fixed brains of macaques treated with ethanol, the corpus callosum was 26% larger than in the controls. The rostral portion was particularly affected by ethanol; it was 55% larger in Et6- and Et24-treated macaques. Axonal size and myelin thickness were unaffected by ethanol, but ethanol-treated macaques had more callosal axons (13.7 x 10(7)) than did controls (9.4 x 10(7) axons). The increase in the rostral corpus callosum suggests that parietal and frontal cortices are particularly susceptible to ethanol. The altered callosal connectivity may be a component of the structural abnormalities that underlie executive processing problems associated with fetal alcohol syndrome.

Animals↗
PubMed1999

Fetal alcohol syndrome: changes in craniofacial form with age, cognition, and timing of ethanol exposure in the macaque.

One component of the fetal alcohol syndrome (FAS) facial phenotype is a frontonasal anomaly characterized by a thin upper lip and a smooth philtrum. The expression of this anomaly can diminish with age and occurs infrequently in prenatal alcohol-exposed individuals. This study sought to explain these observations. Standardized craniofacial cephalograms of 18 nonhuman primates exposed weekly to ethanol or sucrose solution in utero were measured at ages 1, 6, 12, and 24 months to assess skeletal changes in craniofacial form with age, cognition, and timing of ethanol exposure. The data suggest that there may be a critical period for induction of alcohol-induced craniofacial alterations that occurs very early in gestation and is very short in duration (gestational days 19 or 20). The alterations were scarcely detectable at age 1 month, were most prominent at 6 months, and diminished progressively at 12 and 24 months in the macaque. The appearance and disappearance of the thin upper lip and smooth philtrum may be explained by underlying changes in skeletal structure with age. The infrequent occurrence of the FAS frontonasal anomaly may be explained, in part, by its short critical period of induction.

Animals↗
PubMed1999

Fit of bicycle safety helmets and risk of head injuries in children.

BACKGROUND: Although bicycle helmets are effective in preventing head and brain injury, some helmeted individuals nevertheless sustain head injury. One of the possible reasons may be poor fit of the helmet on the head. This study was undertaken to examine the relationship between helmet fit and risk of injury. METHODS: 1718 individuals who were helmeted riders in a crash were queried on helmet fit and position. A sample of 28 children 2-14 years of age who sustained a head injury while wearing a bicycle helmet and 98 helmeted individuals of the same age treated in the same hospital emergency departments for injuries other than to the head, underwent anthropometric measurements of helmet fit. Measurements were made of the child's head, the helmet, and on a cast made of the child's head. RESULTS: Individuals whose helmets were reported to fit poorly had a 1.96-fold increased risk of head injury compared with those whose helmets fit well. Children with head injuries had helmets which were significantly wider than their heads compared with children without head injuries. Helmet fit was poorer among males and among younger children. CONCLUSIONS: Poor fit of helmets may be associated with an increased risk of head injury in children, especially in males. Helmets may not be designed to provide optimal protection.

Adolescent↗
PubMed1997

Incidence of fetal alcohol syndrome and prevalence of alcohol-related neurodevelopmental disorder.

We critique published incidences for fetal alcohol syndrome (FAS) and present new estimates of the incidence of FAS and the prevalence of alcohol-related neurodevelopmental disorder (ARND). We first review criteria necessary for valid estimation of FAS incidence. Estimates for three population-based studies that best meet these criteria are reported with adjustment for underascertainment of highly exposed cases. As a result, in 1975 in Seattle, the incidence of FAS can be estimated as at least 2.8/1000 live births, and for 1979-81 in Cleveland, approximately 4.6/1,000. In Roubaix, France (for data covering periods from 1977-1990), the rate is between 1.3 and 4.8/1,000, depending on the severity of effects used as diagnostic criteria. Utilizing the longitudinal neurobehavioral database of the Seattle study, we propose an operationalization of the Institute of Medicine's recent definition of ARND and estimate its prevalence in Seattle for the period 1975-1981. The combined rate of FAS and ARND is thus estimated to be at least 9.1/1,000. This conservative rate--nearly one in every 100 live births--confirms the perception of many health professionals that fetal alcohol exposure is a serious problem.

Female↗
PubMed1996

Purkinje cell deficits in nonhuman primates following weekly exposure to ethanol during gestation.

The most serious features of fetal alcohol syndrome (FAS) are mental retardation and other behavioral problems resulting from alcohol-induced damage to the developing central nervous system (CNS). The mechanism by which alcohol induces its neuroteratogenic effects is unknown. One hypothesis is that gestational alcohol exposure results in a reduction in neuronal number. This study demonstrates that gestational exposure to ethanol in a non-human primate species induces permanent dose-related deficits in the number of cerebellar Purkinje cells. Ethanol was administered via nasogastric tube once per week to 15 gravid pigtailed macaques (Macaca nemistrina) in one of the following doses: 0.0 (intubated controls), 1.2, 1.8, 2.5, 3.3, and 4.1 g/kg/dose. Offspring were reared with parental surrogates and were sacrificed at 6 months of age; 8-microns-thick, parasagittal sections were cut through the paraffin-embedded cerebellar vermis. Purkinje cells were quantified, the length of the Purkinje cell line was determined stereologically, and Purkinje cell linear frequency was calculated. The number of Purkinje cells and their linear frequencies were significantly reduced in the alcohol-treated subjects, and the deficits were dose-dependent. The groups receiving 2.5 g/kg/dose and above were most severely affected and had an average deficit in Purkinje cell number of 11.8%, relative to controls. Alcohol had no effect on the length of the Purkinje cell line. The findings suggest that alcohol-induced reduction in neuronal number may be an important factor underlying the CNS dysfunction in FAS.

Animals↗
PubMed1996

A case definition and photographic screening tool for the facial phenotype of fetal alcohol syndrome.

OBJECTIVES: The purpose of this study was to demonstrate that a quantitative, multivariate case definition of the fetal alcohol syndrome (FAS) facial phenotype could be derived from photographs of individuals with FAS and to demonstrate how this case definition and photographic approach could be used to develop efficient, accurate, and precise screening tools, diagnostic aids, and possibly surveillance tools. STUDY DESIGN: Frontal facial photographs of 42 subjects (from birth to 27 years of age) with FAS were matched to 84 subjects without FAS. The study population was randomly divided in half. Group 1 was used to identify the facial features that best differentiated individuals with and without FAS. Group 2 was used for cross validation. RESULTS: In group 1, stepwise discriminant analysis identified three facial features (reduced palpebral fissure length/inner canthal distance ratio, smooth philtrum, and thin upper lip) as the cluster of features that differentiated individuals with and without FAS in groups 1 and 2 with 100% accuracy. Sensitivity and specificity were unaffected by race, gender, and age. CONCLUSIONS: The phenotypic case definition derived from photographs accurately distinguished between individuals with and without FAS, demonstrating the potential of this approach for developing screening, diagnostic, and surveillance tools. Further evaluation of the validity and generalizability of this method will be needed.

Adolescent↗
PubMed1996

The differential diagnosis of posterior plagiocephaly: true lambdoid synostosis versus positional molding.

The diagnosis and treatment of posterior plagiocephaly is one of the most controversial aspects of craniofacial surgery. The features of true lambdoid synostosis versus those of deformational plagiocephaly secondary to positional molding are inadequately described in the literature and poorly understood. This has resulted in many infants in several craniofacial centers across the United States undergoing major intracranial procedures for non-synostotic plagiocephaly. The purpose of this study was to describe the detailed clinical, imaging, and operative features of true lambdoid synostosis and contrast them with the features of positional plagiocephaly. During a 4-year period from 1991 to 1994, 102 patients with posterior plagiocephaly were assessed in a large multidisciplinary craniofacial program. During the same period, 130 patients with craniosynostosis received surgical treatment. All patients were examined by a pediatric dysmorphologist, craniofacial surgeon, and pediatric neurosurgeon. Diagnostic imaging was performed where indicated. Patients diagnosed with lambdoid synostosis and severe and progressive positional molding underwent surgical correction using standard craniofacial techniques. Only 4 patients manifested the clinical, imaging, and operative features of unilambdoid synostosis, giving an incidence among all cases of craniosynostosis of 3.1 percent. Only 3 among the 98 patients with positional molding required surgical intervention. All the patients with unilambdoid synostosis had a thick ridge over the fused suture, identical to that found in other forms of craniosynostosis, with compensatory contralateral parietal and frontal bossing and an ipsilateral occipitomastoid bulge. The skull base had an ipsilateral inferior tilt, with a corresponding inferior and posterior displacement of the ipsilateral ear. These characteristics were completely opposite to the findings in the 98 patients who had positional molding with open lambdoid sutures and prove conclusively that true unilambdoid synostosis exists as a specific but rare entity. Awareness of the features of unilambdoid synostosis will allow more accurate diagnosis and appropriate treatment of posterior plagiocephaly in general and in particular will avoid unnecessary surgical intervention in patients with positional molding.

Cranial Sutures↗
PubMed1996

Intracranial and extracranial reduction osteoplasty for craniodiaphyseal dysplasia.

Craniodiaphyseal dysplasia is a rare, sporadic form of craniotubular bone dysplasia, characterized by massive generalized hyperostosis and sclerosis, particularly of the skull and facial bones, leading to severe deformity. The clinical course is typically characterized by progressive encroachment of the craniofacial foramina and brain by the relentless deposition of bone. Compression of cranial nerves, the foramen magnum, and intracranial contents commonly leads to blindness, loss of hearing, and death. This report describes a unique case of craniodiaphyseal dysplasia manifesting with asymmetric craniofacial and axial hyperostosis. The tubular bones demonstrated the characteristic diaphyseal endostosis, undertubulation, and relative overgrowth on the involved side. Significant brain compression with signs and symptoms of increased intracranial pressure was managed successfully with decompressing craniectomy at age 12 years, enlarging the anterior and middle fossae. Calvarial thickness measured nearly 4 cm. Further calvarial, midfacial, and mandibular recontouring were performed 6 and 22 months later. Follow-up in our case indicates that close observation is mandatory to manage further progression of the disease.

Bone Diseases, Developmental↗
PubMed1995

A fetal alcohol syndrome screening tool.

The purpose of this study was to derive a multivariate, quantitative case definition of the fetal alcohol syndrome (FAS) facial phenotype from a dysmorphologist-derived gold standard and use it to develop an effective screening tool for identification of children at risk for FAS. The facial and physical features of a racially mixed group of children (0.2-10.0 years of age), evaluated by a single dysmorphologist in the University of Washington FAS Clinic, were used to determine which feature or set of features best differentiated between children with and without a diagnosis of FAS. The study population was divided into two groups balanced on gender, age at examination, race, diagnosis, and date of examination. Group 1 was used to identify the most differentiating feature(s), and group 2 was used to validate the differentiating capability of the feature(s). Group 1 included 97 children (20 with FAS and 77 without FAS). Group 2 included 97 children (19 with FAS and 78 without FAS). Discriminant analysis identified smooth philtrum, thin upper lip, and short palpebral fissures as the cluster of features that best differentiated children with and without FAS based on the discriminant function [D = 1.7953086 + 0.8116083 (thin upper lip) + 2.6411562 (smooth philtrum)-3.4073780 (% predicted right palpebral fissure length)]. Patients with a D-score > or = 1.5 were classified as at-risk for FAS (screen positive). Using this cut-off value for the D-score, children in group 1 were classified with 100% sensitivity (20 of 20 true positives) and 90.0% specificity (70 of 77 true negatives). The children in group 2 were classified with 100% sensitivity (19 of 19 true positives) and 87.3% specificity (68 of 78 true negatives). Across all 194 patients, sensitivity was 100% [95% confidence interval (97-100)] and specificity was 89% [95% confidence interval (85 to 93)]. Seventy-one percent (n = 12) of the 17 false-positives had a true classification of possible fetal alcohol effects. Sensitivity and specificity were unaffected by race, gender, and age through 10 years. The screening tool is effective at differentiating children with and without FAS as diagnosed by a single dysmorphologist (S.K.C) at the University of Washington FAS Clinic. Assessment of diagnostic interrater agreement between trained dysmorphologists and testing in other clinic populations will be needed to assess the tool's external validity.

Anthropometry↗
PubMed1994

Genetic heterogeneity among craniosynostosis syndromes: mapping the Saethre-Chotzen syndrome locus between D7S513 and D7S516 and exclusion of Jackson-Weiss and Crouzon syndrome loci from 7p.

Saethre-Chotzen, Crouzon, and Jackson-Weiss syndromes are craniosynostotic autosomal dominant conditions with a wide variability in expression. Saethre-Chotzen has been mapped to chromosome 7p by L. A. Brueton et al. (1992, J. Med. Genet. 29: 681-685), the Greig cephalopolysyndactyly gene was identified at 7p13 by A. Vortkamp et al. (1991, Nature 352: 539-540), and many cases of craniosynostosis have been associated with 7p deletions. We confirmed linkage of the Saethre-Chotzen syndrome locus to chromosome 7p. The tightest linkage was to locus D7S493 (Z = 5.04, theta = 0.00), and linkage and haplotype analyses refined the location of the gene to the region between D7S513 and D7S516. Jackson-Weiss and Crouzon syndrome loci were analyzed using markers spanning the entire 7p arm and were excluded, proving that they are nonallelic to Saethre-Chotzen, Greig cephalopolysyndactyly, and the del(7p) syndromes.

Abnormalities, Multiple↗
PubMed1993

Immune function in offspring of nonhuman primates (Macaca nemestrina) exposed weekly to 1.8 g/kg ethanol during pregnancy: preliminary observations.

A preliminary investigation of immune host response was conducted in a group of fetal alcohol-exposed nonhuman primates (Macaca nemestrina) who were part of a broader ongoing study of ethanol teratogenicity. The mothers of the offspring received weekly oral doses of ethanol (1.8 g/kg) for the first 3 or 6 or the entire 24 weeks of gestation. A control group received sucrose solution weekly throughout pregnancy. Four of the 18 ethanol-exposed animals (22%) died or were euthanized after infectious disease or failure to thrive during the first year of life; none of the seven control animals died. This imbalance in survival prompted the present review of immune function in the remaining offspring. Parameters assessed included: (1) white blood cell count (WBC), (2) peripheral blood leucocyte subsets (CD4+, CD8+, CD20+, and CD11c+), (3) T-cell proliferation after activation with phytohemagglutinin (PHA), staphylococcus enterotoxin B (SEB), and tetanus toxoid (TT), (4) phagocytic activity of monocytes, and (5) serum immunoglobulin levels and serum antibody titers after TT vaccination. Mean T-cell proliferation to TT was significantly decreased (p = 0.01) in all ethanol-exposed animals relative to controls, with near-significant decreases (p = 0.06) in response to SEB in the ethanol-exposed animals. Lymphocyte proliferation in response to PHA was not altered. Ethanol-exposed animals had significantly lower TT titers than controls after initial vaccination and booster. WBC, leukocyte subsets, serum immunoglobulins, and monocyte phagocytic activity were not significantly different from control values. These preliminary observations suggest that T-cell proliferation and antigen-specific memory responses may be altered in offspring exposed to weekly doses of ethanol in utero and warrant further evaluation for confirmation.

Animals↗
PubMed1993

Psychological functioning of children with craniofacial anomalies and their mothers: follow-up from late infancy to school entry.

Twenty-three mothers and their 5- to 7-year-old children with craniofacial anomalies (CFA) who were assessed during the child's infancy were followed. Three types of CFA were included: cleft lip and palate (CLP), isolated cleft palate (CP), and sagittal synostosis. Measures of child status focused on behavior-problem frequency and self-concept. Mothers completed self-report measures of emotional well-being, marital satisfaction, and social support. Results indicated that (1) a sizable minority (18%) of the children with CFA had clinically significant behavior-problem scores shown in concordant reports by parent and teacher of behavior problems; (2) individual differences in child functioning within the CFA group were predicted by observational measures of earlier mother-infant interaction during play and teaching situations; (3) mothers of children with CLP reported less favorable social support than mothers of children with CP or sagittal synostosis.

Analysis of Variance↗
PubMed1993

Mutations in the paired domain of the human PAX3 gene cause Klein-Waardenburg syndrome (WS-III) as well as Waardenburg syndrome type I (WS-I).

Waardenburg syndrome type I (WS-I) is an autosomal dominant disorder characterized by sensorineural hearing loss, dystopia canthorum, pigmentary disturbances, and other developmental defects. Klein-Waardenburg syndrome (WS-III) is a disorder with many of the same characteristics as WS-I and includes musculoskeletal abnormalities. We have recently reported the identification and characterization of one of the first gene defects, in the human PAX3 gene, which causes WS-I. PAX3 is a DNA-binding protein that contains a structural motif known as the paired domain and is believed to regulate the expression of other genes. In this report we describe two new mutations, in the human PAX3 gene, that are associated with WS. One mutation was found in a family with WS-I, while the other mutation was found in a family with WS-III. Both mutations were in the highly conserved paired domain of the human PAX3 gene and are similar to other mutations that cause WS. The results indicate that mutations in the PAX3 gene can cause both WS-I and WS-III.

Amino Acid Sequence↗
PubMed1992

Pregnancy outcomes after weekly oral administration of ethanol during gestation in the pig-tailed macaque: comparing early gestational exposure to full gestational exposure.

An oral dose of 1.8 g/kg ethanol given once per week throughout gestation to gravid pig-tailed macaques (Macaca nemestrina) has been established previously as teratogenic. This study was designed to use this nonhuman primate model to mimic a common problematic human circumstance in which women intermittently abuse alcohol into early pregnancy, realize that they are in fact pregnant, and then want to know the chance that the conceptus is harmed. In order to evaluate this situation, gravid macaques were assigned to one of four dosing cohorts. Animals were given the 1.8 gm/kg dose of ethanol once per week for the first 3, 6, or 24 weeks (full gestation) of pregnancy. Control animals received an isocaloric, isovolemic sucrose solution once per week for 24 weeks. The pregnancies were carefully monitored and the infants were comprehensively evaluated for the first 24 months of life. This paper describes the pregnancies while subsequent papers will describe the infants. Peak plasma ethanol levels ranged from 175 to 250 mg/dl. Weekly maternal exposure to this intoxicating dose of ethanol, starting early in pregnancy, did not influence risk of pregnancy failure during the first 30 days of gestation but appeared to be associated with an increased risk of abortion occurring between gestational days 30 and 160. Of the pregnancies that were successfully carried to full term, the potentially teratogenic dose of ethanol did not alter pregnancy outcome in any clinically significant way.

Abortion, Spontaneous↗