Integrated screening for Down's syndrome on the basis of tests performed during the first and second trimesters.
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BACKGROUND: Both first-trimester screening and second-trimester screening for Down's syndrome are effective means of selecting women for chorionic-villus sampling or amniocentesis, but there is uncertainty about which screening method should be used in practice. We propose a new screening method in which measurements obtained during both trimesters are integrated to provide a single estimate of a woman's risk of having a pregnancy affected by Down's syndrome. METHODS: We used data from published studies of various screening methods employed during the first and second trimesters. The first-trimester screening consisted of measurement of serum pregnancy-associated plasma protein A in 77 pregnancies affected by Down's syndrome and 383 unaffected pregnancies and measurements of nuchal translucency obtained by ultrasonography in 326 affected and 95,476 unaffected pregnancies. The second-trimester tests were various combinations of measurements of serum alpha-fetoprotein, unconjugated estriol, human chorionic gonadotropin, and inhibin A in 77 affected and 385 unaffected pregnancies. RESULTS: When we used a risk of 1 in 120 or greater as the cutoff to define a positive result on the integrated screening test, the rate of detection of Down's syndrome was 85 percent, with a false positive rate of 0.9 percent. To achieve the same rate of detection, current screening tests would have higher false positive rates (5 to 22 percent). If the integrated test were to replace the triple test (measurements of serum alpha-fetoprotein, unconjugated estriol, and human chorionic gonadotropin), currently used with a 5 percent false positive rate, for screening during the second trimester, the detection rate would be higher 85 percent vs. 69 percent), with a reduction of four fifths in the number of invasive diagnostic procedures and consequent losses of normal fetuses. CONCLUSIONS: The integrated test detects more cases of Down's syndrome with a much lower false positive rate than the best currently available test. (+info)
Endovascular treatment of a cervical paraspinal arteriovenous malformation via arterial and venous approaches.
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We describe a cervical congenital paraspinal arteriovenous malformation (AVM) drained by paraspinal and epidural ectatic veins, which caused massive erosion of the C6 and C7 vertebral bodies, threatening the cervical stability and necessitating treatment. During the first session, six arterial embolizations were performed to reduce the size and the flow of the AVM. Two months later, a venous approach was used to occlude the remnant venous exit of the AVM and achieve a complete cure. All embolizations were performed using N-butylcyanoacrylate. (+info)
Craniocervical junction venous anatomy on enhanced MR images: the suboccipital cavernous sinus.
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BACKGROUND AND PURPOSE: The suboccipital cavernous sinus, a vertebral venous plexus surrounding the horizontal portion of the vertebral artery at the skull base, provides an alternative pathway of cranial venous drainage by virtue of its connections to the cranial dural sinuses, the vertebral venous plexus, and the jugular venous system. Knowledge of the anatomy of this system facilitates interpretation of images and might reduce the number of false-positive diagnoses of lesions, such as adenopathy or schwannoma. We hypothesized that this circulation could be visualized on contrast-enhanced, fat-suppressed T1-weighted MR images. METHODS: The craniocervical junctions of 14 patients were scanned using fat-suppressed, contrast-enhanced, T1-weighted MR sequences and evaluated for visibility of the following venous structures: suboccipital cavernous sinus, vertebral artery venous plexus, anterior and posterior condylar veins, vertebral venous plexus, internal jugular vein, and the marginal sinus. Both the right and left sides were assessed in at least two planes. The venous diameters were also measured. RESULTS: All the evaluated venous structures were seen routinely in all three planes, with the exception of the posterior condylar vein, known to be variably present, which was seen only one third of the time in the sagittal plane and two thirds of the time in the other planes. The posterior condylar vein also showed the greatest variability in size and symmetry. CONCLUSION: The suboccipital cavernous sinus and most of its associated venous circulation at the skull base are easily identified on contrast-enhanced, fat-suppressed T1-weighted MR images. The posterior condylar vein, known to be variably present, was not well seen in the sagittal plane and displayed the greatest variability in size and symmetry. (+info)
Extraorbital inflammatory pseudotumor of the head and neck: CT and MR findings in three patients.
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We review the clinical history and imaging (CT and/or MR) studies in three patients with histologically proved extraorbital inflammatory pseudotumor of the head and neck. The imaging findings in all three cases were nonspecific, mimicking a malignant tumor or granulomatous disease. (+info)
Midline spinal cord hamartomas: MR imaging features of two patients.
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Congenital midline spinal hamartomas are relatively rare. Patients harboring this anomaly are generally asymptomatic, but present with an overlying skin anomaly. MR imaging depicts a mass that is isointense with the spinal cord on all sequences, and may show a dermal sinus tract that tethers the cord at the level of the lesion. We report the MR features of congenital midline spinal hamartoma in two children. (+info)
Mutations in the COL5A1 coding sequence are not common in patients with spontaneous cervical artery dissections.
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BACKGROUND AND PURPOSE: The dermal connective tissue of most patients with spontaneous cervical artery dissections (sCAD) contains abnormal collagen fibers. This suggests a predisposing connective tissue defect. The ultrastructural abnormalities in the skin of patients with sCAD have similarity with the morphological alterations in patients with Ehlers-Danlos syndrome type II, a dominant hereditary disorder that has been correlated in some patients to mutations within the genes encoding type V collagen. The aim of this study was to assess the alpha 1 chain of type V collagen (COL5A1) as a candidate gene for sCAD. METHODS: We searched for mutations in the COL5A1 gene in cDNA from cultured fibroblasts of 19 patients with sCAD using single-strand conformational polymorphism analysis and nucleotide sequence analysis of polymerase chain reaction-amplified fragments of the whole COL5A1 coding sequence. RESULTS: We detected 1 missense mutation leading to a predicted amino acid (192D/N) substitution within the N-terminal propeptide in 2 siblings. All other patients showed regular COL5A1 sequences with some silent polymorphisms. CONCLUSIONS: Mutations in the COL5A1 gene do not appear to be a major factor in the etiology of sCAD. (+info)
Synaptic inhibition of cat phrenic motoneurons by internal intercostal nerve stimulation.
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Intracellular recordings from 65 phrenic motoneurons (PMNs) in the C5 segment and recordings of C5 phrenic nerve activity were made in 27 pentobarbitone-anesthetized, paralyzed, and artificially ventilated adult cats. Inhibition of phrenic nerve activity and PMN membrane potential hyperpolarization (48/55 PMNs tested) was seen after stimulation of the internal intercostal nerve (IIN) at a mean latency to onset of 10.3 +/- 2.7 ms. Reversal of IIN-evoked hyperpolarization (n = 14) by injection of negative current or diffusion of chloride ions occurred in six cases, and the hyperpolarization was reduced in seven others. Stimulation of the IIN thus activates chloride-dependent inhibitory synaptic inputs to most PMNs. The inhibitory phrenic nerve response to IIN stimulation was reduced by ipsilateral transection of the lateral white matter at the C3 level and was converted to an excitatory response by complete ipsilateral cord hemisection at the same level. After complete ipsilateral hemisection of the spinal cord at C3 level, stimulation of the IIN evoked both excitatory and inhibitory postsynaptic potentials (EPSPs and IPSPs) in PMNs (n = 10). It was concluded that IIN stimulation can evoke both excitatory and inhibitory responses in PMNs using purely spinal circuitry, but that excitatory responses are normally suppressed by a descending pathway in intact animals. Fifteen PMNs were tested for possible presynaptic convergence of inputs in these reflex pathways, using test and conditioning stimuli. Significant enhancement (>20%) of IPSPs were seen in seven of eight IIN-evoked responses using pericruciate sensorimotor cortex (SMC) conditioning stimuli, but only one of five IIN-evoked responses were enhanced by superior laryngeal nerve (SLN) conditioning stimuli. The IIN-evoked IPSP was enhanced in one of two motoneurons by stimulation of the contralateral phrenic nerve. It was concluded that presynaptic interneurons were shared by the IIN and SMC pathways, but uncommonly by other pathways. These results indicate that PMNs receive inhibitory synaptic inputs from ascending thoracocervical pathways and from spinal interneurons. These inhibitory reflex pathways activated by afferent inputs from the chest wall may play a significant role in the control of PMN discharge, in parallel with disfacilitation following reduced activity in bulbospinal neurons projecting to PMNs. (+info)
Clinical and morphological correlations for transglutaminase 1 gene mutations in autosomal recessive congenital ichthyosis.
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Autosomal recessive congenital ichthyosis (ARCI) is a group of inherited disorders of cornification in which progress has recently been made in the identification of pathogenic mechanisms causing the disease. Transglutaminase 1 (TGM1) has been found as a defective gene in a large fraction of patients with lamellar ichthyosis (LI), a severe inherited scaling disorder of the skin. We have previously performed molecular genetic studies of 38Finnish ARCI families and found six different mutations in 13 families of 38 (34%). In this study we compared the molecular genetic alterations with clinical and electron microscopic findings of these patients. Families were classified by electron microscopy in ichthyosis congenita (IC) types I, II, III, IV and a non-defined group. TGM 1 gene mutation was found in all of the IC type II and 1/3 of the IC type 1 families. Although electron microscopy is not always used to classify ARCI patients, it can distinguish groups which are parallel with molecular genetic findings. This finding might be useful in the classification of ARCI patients for further linkage studies. Clinically typical phenotype of the TGM1 mutation carrier includes large, thick, brownish scales, but ichthyosis of some of these patients tends to be milder. (+info)