Early prenatal detection of diastrophic dysplasia

Diastrophic dysplasia, an autosomal recessive disorder, results in severe short-limbed dwarfism, progressive spinal and joint problems, and secondary psychosocial disability. The results of treatments are unsatisfactory. Four pregnant mothers at risk for an affected fetus were studied with an ultrasound scanner at 16 and 19 weeks of gestation. Each mother had a previous child with diastrophic dysplasia. The biparietal distance and the length of the long bones of the extremities were normal in three fetuses, whereas in one fetus there was a 30 per cent shortening of all long bones. The biparietal distance corresponded with the gestational age in all fetuses. In one fetus, diastrophic dysplasia was confirmed by fetoscopy and fetal radiograph at 19 weeks of gestation after the parents had decided to terminate the pregnancy. The skeletal radiograph and autopsy findings of the fetus verified the diagnosis. All other mothers were followed with repeated ultrasound examinations, and they delivered healthy babies. The retrospective follow-up of the four previous pregnancies and of the present one with affected fetuses disclosed that two mothers had had vaginal bleeding, two lymphedema, one abdominal pains, and one mother had had polyhydramnios. These complications were, however, mild and transient, and they could not be regarded as specific for pregnancies with affected fetuses.     

Antenatal ultrasonic diagnosis of dyssegmental dysplasia: A case report

Sonographic prenatal diagnosis and management of a pregnancy complicated by dys-segmental dysplasia of the Silverman-Handmaker type are presented. This is a documented case of this type of short-limbed dwarfism presenting in a family of Hispanic-American ancestry.     

Prenatal diagnosis of metatropic dwarfism

We present a case of prenatal diagnosis of severe metatropic dysplasia at 20 weeks' gestation. The characteristic prenatal features of this rare autosomal recessive chondrodysplasia appear to be significant dwarfism with an enlarged head and a narrow thorax associated with enlargement of the hands and feet, and the radiographic ‘dumb-bell’ appearance of the long bones.     

Mandible shape and dwarfism in squirrels (Mammalia, Rodentia): interaction of allometry and adaptation

Squirrels include several independent lineages of dwarf forms distributed into two ecological groups: the dwarf tree and flying squirrels. The mandible of dwarf tree squirrels share a highly reduced coronoid process and a condylar process drawn backwards. Dwarf flying squirrels on the other hand, have an elongated coronoid process and a well-differentiated condylar process. To interpret such a difference, Elliptic Fourier Transform was used to evaluate how mandible shape varies with dwarfism in sciurids. The results obtained show that this clear-cut difference cannot be explained by a simple allometric relationship in relation with size decrease. We concluded that the retention of anteriorly positioned eye sockets, in relation with distance estimation, allowed the conservation of a well-differentiated coronoid process in all flying species, despite the trend towards its reduction observed among sciurids as their size decreases. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Harlequin fetus and micromelia

A fetus was born prematurely after a 34-week pregnancy whose evolution was marked by the ultrasonic finding at 23 weeks of a considerable shortening of the long bones. At birth, the newborn infant bore the appearance of a harlequin fetus. There was no dwarfism, but the micromelia discovered in utero was confirmed both clinically and radiologically. Such global micromelia associated with this kind of pathology has never been described, not to mention witnessed, in utero and may be part of the fetal akinesia sequence phenotype.     

Achondrogenesis type II (Langer–Saldino) in association with jugular lymphatic obstruction sequence

The prenatal diagnosis of achondrogenesis in association with cystic hygroma is described. Ultrasound findings of severe short-limbed dwarfism, decreased vertebral ossification, and normal ossification of the calvarium were all consistent with achondrogenesis type II. Although the unusual finding of associated cystic hygroma raised the suspicion of a concurrent chromosome abnormality, the karyotype of both fetal lymphocytes and fetal fibroblasts was normal. Autopsy confirmed dilated lymphatic channels in the basal endothelial layer of the skin, cystic hygroma, and coarctation of the aorta. Although previously unreported, we suggest that the features of this case of achondrogenesis indicate an association with lymphatic stasis and jugular lymphatic obstruction sequence in this syndrome.     

Non-invasive prenatal detection of achondroplasia in size-fractionated cell-free DNA by MALDI-TOF MS assay

Achondroplasia is the most common form of short-limbed dwarfism in humans and is caused by mutations in the FGFR3 gene. Currently, prenatal diagnosis of this disorder relies on invasive procedures. Recent studies have shown that fetal single gene point mutations could be detected in cell-free DNA (cf-DNA) from maternal plasma by either the matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) assay with single allele base extension reaction (SABER) approach or the size fractionation of cf-DNA in maternal plasma. Here, we combined the two approaches to non-invasively examine the fetal G1138A mutation in maternal plasma. cf-DNA was extracted from maternal plasma samples obtained from two pregnant women at risk for achondroplasia. The fetal G1138A mutation was determined by the analysis of size-fractionated cf-DNA in maternal plasma using MALDI-TOF MS with SABER approach and homogenous MassEXTEND (hME) assay, respectively. The fetal G1138A mutation was detectable in the two achondroplasia-affected pregnancies by the analysis of cf-DNA in maternal plasma using MALDI-TOF MS. However, the size-fractionation approach led to a more precise detection of the fetal mutation in both analyses. This analysis would be suitable for non-invasive prenatal diagnosis of diseases caused by fetal single gene point mutations. Copyright © 2007 John Wiley & Sons, Ltd.     

Prenatal diagnosis of hypochondroplasia

Prenatal diagnosis of a fetus at risk for hypochondroplasia, a short limb dwarfism condition similar to achondroplasia, was performed by ultrasound at 22 weeks' gestation. The limb bones were measured and shown to be decreased in length. The pregnancy was terminated. Post abortion X-ray did not show caudal narrowing in the lumbar spine but the pelvis had the features of hypochondroplasia.     

Prenatal diagnosis of kyphomelic dysplasia

Kyphomelic dysplasia (KD) is a rare autosomal recessive entity characterized by disproportionate dwarfism with shortening and bowing of the limbs, narrow chest, 11 ribs and metaphyseal flaring. Mental development is generally normal. We report the in utero ultrasound appearances and post-mortem radiographic findings of a 22-week-old male fetus suggestive of KD. A review of 19 previously reported patients with KD is also presented. Copyright © 2001 John Wiley & Sons, Ltd.     

广州大气中异戊二烯浓度变化特征、化学活性和来源分析

在广州番禺大气成分站(GPACS)应用在线监测仪器对异戊二烯进行长达1年的观测,获得异戊二烯浓度变化特征、大气化学活性和来源规律.结果表明:广州地区异戊二烯日均浓度为1.12 ppbv,由于受光照和温度影响较大,各月日均浓度在0.07~2.72 ppbv范围内波动.异戊二烯在冬季的日变化规律与其他季节不同,呈现双峰值变化,较大峰值出现在下午14:00,主要受光照和温度影响;较小峰值出现在晚上22:00左右,主要受机动车排放影响.采用最大增量活性(Maximum Incremental Reactivity,MIR)因子加权法和等效丙烯浓度法均发现异戊二烯的大气化学活性在监测的VOCs物种中最强,分别占总活性的15.45%和36.74%.通过异戊二烯与机动车标志性物质3-甲基戊烷、顺-2-丁烯的比值发现,广州地区异戊二烯在冬季夜晚主要来源于机动车排放,在秋季和春季夜晚也受到机动车排放影响,而夏季夜晚受机动车排放最不明显.这主要是由于在冬季、秋季和春季,监测点主要受到来自广州城区污染物输送的影响,而在夏季污染物从广州郊区输送使监测点受机动车排放的影响很小.异戊二烯与3-甲基戊烷、顺-2-丁烯在各季节的白天都没有线性关系,表明白天异戊二烯的排放受机动车的影响不大.     

Prenatal detection of the autosomal dominant type of congenital hydronephrosis by ultrasonography

We report a family with clearly defined two generation, and probable four generation uropathy due to a congenital malformation of the genitourinary system. There appears to be variation in expression within this family and a severely affected fetus was detected by ultrasonography at 31 weeks gestation.     

Prenatal diagnosis of non-ketotic hyperglycinemia

We describe successful prenatal diagnosis in four pregnancies at risk for non-ketotic hyperglycinemia, two affected and two unaffected, using the glycine level and the glycine/ serine ratio in amniotic fluid obtained at 16 weeks gestational age. Although this method of prenatal diagnosis for non-ketotic hyperglycinemia has been effective in our hands the narrow differences between affected and unaffected pregnancies indicate the need for caution concerning its reliability.     

Prenatal detection of the congenital nephrotic syndrome (Finnish type) by trehalase assay in amniotic fluid

We report relatively high trehalase activity in the amniotic fluid of two fetuses affected with the congenital nephrotic syndrome of the Finnish type. The results suggest that prenatal detection of this condition can be done on this basis in conjunction with the α-fetoprotein and acetylcholinesterase tests in amniotic fluid.     

Diagnosis and prenatal diagnosis of epidermolysis bullosa herpetiformis (Dowling-Meara) in a mother,two affected children,and an affected fetus

In utero skin biopsy was performed on a fetus at risk of an uncertain form of epidermolysis bullosa (EB). The mother had produced two affected offspring diagnosed variously as having junctional or dystrophic EB. The two offspring and the fetus were products of different fathers. The mother claimed to have no disease and on clinical examination was without blisters. Examination of the fetal skin biopsy by light and electron microscopy revealed separation of the epidermal sheet from the majority of the biopsy sample, although occasional remnants of basal cells remained associated with the basement membrane. Aggregations of keratin filaments were observed within basal cells of the detached epidermis and in the attached basal cell remnants. The diagnosis was thus suggested to be epidermolysis bullosa Dowling-Meara. Re-review of the clinical and laboratory data from the affected infants revealed a clinical and histological pattern consistent with this diagnosis. Further discussion with the mother revealed that her skin had blistered as a child and that she presently had hyperkeratotic palms and soles. This history is consistent with the autosomal dominantly inherited epidermolysis bullosa herpetiformis (Dowling-Meara). This is the first reported prenatal diagnosis of EB Dowling—Meara. The morphological criteria of intraepidermal blistering and clumped keratin filaments within basal and immediately suprabasal cells characteristic of an affected individual postnatally also identified an affected fetus. There is, however, insufficient experience to be certain that these findings will hold from region to region in the body or among all affected fetuses, and thus prenatal diagnosis on a morphological basis should still be made with caution.     

成形工艺对轿车减振器座应变状态影响的研究

通过网格应变分析技术 ,对某轿车采用一次成形、两次成形工艺冲制减振器座的应变状态进行了定量研究 ,结果表明 ,成形工艺对减振器座的应变分布、应变路径、应变大小影响很大 ,一次成形较两次成形对材料的成形性能要求较高 ,两次成形工艺更有利于零件成形     

Ultrasonographic method for detection of haemoglobin Bart's hydrops fetalis in the second trimester of pregnancy

In nine pregnant women at risk for fetal alpha-thalassaemia, the two affected fetuses were diagnosed by ultrasonography at 18–20 weeks' gestation. In countries with limited resources, ultrasonography provides a cost-effective method of prenatal screening for this condition.     

Prenatal diagnosis of purine nucleoside phosphorylase deficiency in the first and second trimesters of pregnancy

Prenatal diagnosis was performed in two successive pregnancies of a mother with a previous child with purine nucleoside phosphorylase (PNP) deficiency. In one pregnancy, an affected fetus was diagnosed in the 18th week of gestation after the demonstration of PNP deficiency in cultured amniotic fluid cells. Also an abnormal purine nucleoside profile was found in the amniotic fluid. The diagnosis of an affected fetus was confirmed by the analysis of cultured fetal skin fibroblasts and placental villi. The complete deficiency of PNP activity in placental villi confirms that the prenatal diagnosis of this disorder is possible by the direct investigation of chorionic villi. In the subsequent pregnancy, a heterozygous fetus was predicted in the tenth week of pregnancy by using chorionic villi.     

Mucolipidosis type IV: Accumulation of phospholipids and gangliosides in cultured amniotic cells. A tool for prenatal diagnosis

Cultured amniotic fluid cells from two mucolipidosis type IV (MLIV)-affected fetuses demonstrated accumulation of phospholipids and gangliosides when compared with normal controls. Like cultured skin fibroblasts from MLIV patients, cultured amniotic cells from the affected fetuses accumulated primarily lyso phospholipids and this could be demonstrated by radioactive labelling with appropriate precursors, either inorganic phosphate or oleic acid. Furthermore, like cultured skin fibroblasts, there was significant retention of exogenously supplied GDIA ganglioside in the affected amniotic cells. This storage was previously demonstrated to be unique to MLIV and thus can be used at present as a specific procedure for prenatal diagnosis of MLIV.     

Prenatal diagnosis of pyruvate carboxylase deficiency

Prenatal diagnosis of pyruvate carboxylase (PC) deficiency was performed in a family at risk for the acute neonatal form of this disease which manifests secondary citrullinemia. The diagnosis of an affected child was confirmed by enzyme assay and ³H-biotin labelling of proteins in cultured fetal skin fibroblasts. Sufficient amniocytes were cultured in 3–4 weeks for enzyme analysis in two centres. Citrulline concentration in amniotic fluid (AF) was normal in the affected fetus.     

长江口悬沙对牟氏角毛藻(Chaetoceros muelleri)生长的影响

以牟氏角毛藻Chaetoceros muelleri为受试生物,通过不同浓度的悬沙对其生长影响的试验,探讨长江口悬沙对浮游植物生长的影响。研究结果表明,悬沙对浮游植物的影响有两个方面:一是悬沙影响水体的透明度,进而影响浮游植物的光合作用,对浮游植物生长起到抑制作用;二是悬沙中析出的污染物对浮游植物生长影响,悬沙浸出液浓度与浮游植物生长抑制率呈Logistic曲线关系。