Mark P. Johnson

Bio: Mark P. Johnson is an academic researcher from Children's Hospital of Philadelphia. The author has contributed to research in topics: Fetal surgery & Prenatal diagnosis. The author has an hindex of 59, co-authored 270 publications receiving 12701 citations. Previous affiliations of Mark P. Johnson include University of Pennsylvania.

A Randomized Trial of Prenatal versus Postnatal Repair of Myelomeningocele

Abstract: The trial was stopped for efficacy of prenatal surgery after the recruitment of 183 of a planned 200 patients. This report is based on results in 158 patients whose children were evaluated at 12 months. The first primary outcome occurred in 68% of the infants in the prenatal-surgery group and in 98% of those in the postnatalsurgery group (relative risk, 0.70; 97.7% confidence interval [CI], 0.58 to 0.84; P<0.001). Actual rates of shunt placement were 40% in the prenatal-surgery group and 82% in the postnatal-surgery group (relative risk, 0.48; 97.7% CI, 0.36 to 0.64; P<0.001). Prenatal surgery also resulted in improvement in the composite score for mental development and motor function at 30 months (P = 0.007) and in improvement in several secondary outcomes, including hindbrain herniation by 12 months and ambulation by 30 months. However, prenatal surgery was associated with an increased risk of preterm delivery and uterine dehiscence at delivery. Conclusions Prenatal surgery for myelomeningocele reduced the need for shunting and improved motor outcomes at 30 months but was associated with maternal and fetal risks. (Funded by the National Institutes of Health; ClinicalTrials.gov number, NCT00060606.)

Improvement in hindbrain herniation demonstrated by serial fetal magnetic resonance imaging following fetal surgery for myelomeningocele.

Abstract: ContextHindbrain herniation occurs in a large percentage of children with myelomeningocele and is the leading cause of death in this population. The effect of early fetal closure of myelomeningocele on hindbrain herniation is unknown.ObjectiveTo determine whether early fetal closure of myelomeningocele affects hindbrain herniation.DesignCase series of patients undergoing fetal myelomeningocele closure with serial measurements of hindbrain herniation and a mean follow-up of 182 days.SettingTertiary care medical center.ParticipantsTen patients undergoing fetal myelomeningocele closure at 22 to 25 weeks' gestation between March 1998 and February 1999.Main Outcome MeasuresNeed for shunt placement; degree of hindbrain herniation (grades 0-3) found on magnetic resonance imaging (MRI) performed prior to surgery and 3 and 6 weeks after fetal surgery, as well as shortly after birth; gestational age at delivery.ResultsAll initial fetal MRI scans performed at 19 to 24 weeks' gestation showed significant (grade 3) cerebellar herniation and absence of spinal fluid spaces around the cerebellum. Six fetuses were delivered electively at 36 weeks' gestation after lung maturity was established. The other 4 were delivered prematurely, at 25, 30, 30, and 31 weeks of gestation, and the 25-week gestation neonate died. All 9 surviving neonates showed improvement in the hindbrain hernia at the 3-week postoperative fetal scan (grade 2, n = 4; grade 1, n = 5). On the postnatal scan, all patients showed grade 1 hindbrain herniation. Only 1 patient required placement of a ventriculoperitoneal shunt.ConclusionIn this series of patients, fetal myelomeningocele closure resulted in improvement in hindbrain herniation as demonstrated by serial MRI scans.

A Randomized Trial of Prenatal Versus Postnatal Repair of Myelomeningocele

Abstract: Myelomeningocele is one of the most common birth defects, characterized by a defect in the bony spine and resultant extrusion of the spinal cord into a sac filled with cerebrospinal fluid. It occurs in 3 to 4 per 10,000 live births in the United States, and the death rate of live-born infant

Ehlers‐Danlos syndromes: Revised nosology, Villefranche, 1997

Abstract: Categorization of the Ehlers-Danlos syndromes began in the late 1960s and was formalized in the Berlin nosology. Over time, it became apparent that the diagnostic criteria established and published in 1988 did not discriminate adequately between the different types of Ehlers-Danlos syndromes or between Ehlers-Danlos syndromes and other phenotypically related conditions. In addition, elucidation of the molecular basis of several Ehlers-Danlos syndromes has added a new dimension to the characterization of this group of disorders. We propose a revision of the classification of the Ehlers-Danlos syndromes based primarily on the cause of each type. Major and minor diagnostic criteria have been defined for each type and complemented whenever possible with laboratory findings. This simplified classification will facilitate an accurate diagnosis of the Ehlers-Danlos syndromes and contribute to the delineation of phenotypically related disorders.

A Randomized Trial of Prenatal versus Postnatal Repair of Myelomeningocele

Abstract: The trial was stopped for efficacy of prenatal surgery after the recruitment of 183 of a planned 200 patients. This report is based on results in 158 patients whose children were evaluated at 12 months. The first primary outcome occurred in 68% of the infants in the prenatal-surgery group and in 98% of those in the postnatalsurgery group (relative risk, 0.70; 97.7% confidence interval [CI], 0.58 to 0.84; P<0.001). Actual rates of shunt placement were 40% in the prenatal-surgery group and 82% in the postnatal-surgery group (relative risk, 0.48; 97.7% CI, 0.36 to 0.64; P<0.001). Prenatal surgery also resulted in improvement in the composite score for mental development and motor function at 30 months (P = 0.007) and in improvement in several secondary outcomes, including hindbrain herniation by 12 months and ambulation by 30 months. However, prenatal surgery was associated with an increased risk of preterm delivery and uterine dehiscence at delivery. Conclusions Prenatal surgery for myelomeningocele reduced the need for shunting and improved motor outcomes at 30 months but was associated with maternal and fetal risks. (Funded by the National Institutes of Health; ClinicalTrials.gov number, NCT00060606.)

eMedicine

Abstract: eMedicine创建于1996年，由近万名临床医师作为作者或编辑参与此临床医学知识库的建设，其中编辑均是来自美国哈佛、耶鲁、斯坦福、芝加哥、德克萨斯、加州大学等各分校医学院的教授或副教授。

Maternal Overweight and Obesity and the Risk of Congenital Anomalies: A Systematic Review and Meta-analysis

Abstract: Context Evidence suggests an association between maternal obesity and some congenital anomalies. Objective To assess current evidence of the association between maternal overweight, maternal obesity, and congenital anomaly. Data Sources MEDLINE, EMBASE, CINAHL, and Scopus (January 1966 through May 2008) were searched for English-language studies using a list of keywords. Reference lists from relevant review articles were also searched. Study Selection Observational studies with an estimate of prepregnancy or early pregnancy weight or body mass index (BMI) and data on congenital anomalies were considered. Of 1944 potential articles, 39 were included in the systematic review and 18 in the meta-analysis. Data Extraction and Synthesis Information was extracted on study design, quality, participants, congenital anomaly groups and subtypes, and risk estimates. Pooled odds ratios (ORs) comparing risk among overweight, obese, and recommended-weight mothers (defined by BMI) were determined for congenital anomaly groups and subtypes for which at least 150 cases had been reported in the literature. Results Pooled ORs for overweight and obesity were calculated for 16 and 15 anomaly groups or subtypes, respectively. Compared with mothers of recommended BMI, obese mothers were at increased odds of pregnancies affected by neural tube defects (OR, 1.87; 95% confidence interval [CI], 1.62-2.15), spina bifida (OR, 2.24; 95% CI, 1.86-2.69), cardiovascular anomalies (OR, 1.30; 95% CI, 1.12-1.51), septal anomalies (OR, 1.20; 95% CI, 1.09-1.31), cleft palate (OR, 1.23; 95% CI, 1.03-1.47), cleft lip and palate (OR, 1.20; 95% CI, 1.03-1.40), anorectal atresia (OR, 1.48; 95% CI, 1.12-1.97), hydrocephaly (OR, 1.68; 95% CI, 1.19-2.36), and limb reduction anomalies (OR, 1.34; 95% CI, 1.03-1.73). The risk of gastroschisis among obese mothers was significantly reduced (OR, 0.17; 95% CI, 0.10-0.30). Conclusions Maternal obesity is associated with an increased risk of a range of structural anomalies, although the absolute increase is likely to be small. Further studies are needed to confirm whether maternal overweight is also implicated.