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OBJECTIVE To explore/study/evaluate the relationships among umbilical twist direction, the degree of umbilical twist and differences of umbilical arterial diameters (UAD). METHODS All obstetric patients presenting for prenatal care of singleton fetuses between 18 and 25 weeks gestation to a single provider (MN) from 2015 to 2018 had detailed umbilical cord Doppler measurements. Data including the cord twist direction, degree of twist and number of twists per cord segment length, and the diameters of each UA (UAD) and the umbilical vein (UVD) were extracted from the records. UAs were described as right or left depending on their position at the fetal cord insertion. Three groups were identified: Group A: right UAD > left UAD and Group B: left UAD > right UAD Group C: equal UAD. The coiling index was calculated as the inverse of the length of cord required for one complete 360 degrees wrap of the UA around the cord. According to the difference of UADs, the variables of right and left UADs, the coiling index, and frequencies of umbilical twist direction were analyzed using non-parametric methods. RESULTS 485 singleton fetuses and umbilical cords were examined. The value of the antenatal coiling index in cases with left UAD greater than right was 0.43 ± 0.16, which was significantly higher than 0.38 ± 0.16 with right UAD greater than left (p = .001). There were significant differences between the two groups in the values of right and left UAD, value of right minus left UAD, absolute value between right and left UAD, antenatal coiling index, antenatal coiling index due to umbilical twist direction and frequencies of cord twist direction. CONCLUSION The direction of umbilical twist may be in part dependent on differences in diameters of the umbilical arteries, in addition to other fetal characteristics such as fetal movement, or handedness of fetus or mother, fetal hemodynamic forces and structure of muscles of umbilical vessels.

In esthetic dental care, porcelain-fused-to-metal crowns have long been used for dental restoration. Since a dental prosthesis is placed in the harsh environment of the oral cavity over long periods, metal allergy due to eluate from the metal frame has proved to be problem, prompting the development of new methods for tooth repair. Zirconia ceramics are used in dental prostheses for tooth restoration because of their excellent strength and high biocompatibility. They are widely used clinically for cosmetic dentistry. This study evaluates the suitability of yttria-based zirconia and ceria-based nano-zirconia for use in dentistry. The mechanical properties of zirconia powders with different compositions are evaluated in terms of sintering density, crystalline phases, structure, translucency, bending strength, fracture toughness, and impact toughness. In addition, a fracture strength test was carried out on sintered bodies that imitate a single crown coping assuming a molar tooth. Yttria-based zirconia was found to have a natural tooth tone and excellent light transmission. Ceria-based nano-zirconia was found to have more than double the fracture toughness (single-edge pre-cracked beam method) and bending strength compared to yttria-based zirconia and excellent strength for dental prostheses.

Pulmonary hypertension (PH) causes right ventricular (RV) hypertrophy and, according to the extent of pressure overload, eventual heart failure. We tested the hypothesis that the mechanical stress in PH-RV impairs the vasoreactivity of the RV coronary microvessels of different sizes with increased superoxide levels. Five-week-old male Sprague-Dawley rats were injected with monocrotaline ( n = 126) to induce PH or with saline as controls ( n = 114). After 3 wk, coronary arterioles (diameter = 30–100 μm) and small arteries (diameter = 100–200 μm) in the RV were visualized using intravital videomicroscopy. We evaluated ACh-induced vasodilation alone, in the presence of Nω-nitro-l-arginine methyl ester (l-NAME), in the presence of tetraethylammonium (TEA) or catalase with or without l-NAME, and in the presence of SOD. The degree of suppression in vasodilation by l-NAME and TEA was used as indexes of the contributions of endothelial nitric oxide (NO) and endothelium-derived hyperpolarizing factor (EDHF), respectively. In PH rats, ACh-induced vasodilation was significantly attenuated in both arterioles and small aretries, especially in arterioles. This decreased vasodilation was largely attributable to reduced NO-mediated vasoreactivity, whereas the EDHF-mediated vasodilation was relatively robust. The suppressive effect on arteriolar vasodilation by catalase was similar to TEA in both groups. Superoxide, as measured by lucigenin chemiluminescence, was significantly elevated in the RV tissues in PH. SOD significantly ameliorated the impairment of ACh-induced vasodilation in PH. Robust EDHF function will play a protective role in preserving coronary microvascular homeostasis in the event of NO dysfunction with increased superoxide levels.

Monocrotaline (MCT), a pyrrolizidine alkaloid plant toxin, is known to cause pulmonary hypertension (PH) in rats. Recent findings suggest that pulmonary inflammation may play a significant role in the pathogenesis in MCT-induced PH. Heme oxygenase-1 (HO-1), the rate-limiting enzyme in heme catabolism, is known to be induced by various oxidative stresses, including inflammation and free heme, and its induction is thought essential in the protection against oxidative tissue injuries. In this study, we examined expression of HO-1 as well as non-specific delta-aminolevulinate synthase (ALAS1), the rate-limiting enzyme in heme catabolism and biosynthesis, respectively, in a rat model of PH produced by subcutaneous injection of MCT (60 mg/kg). MCT treatment caused infiltration of inflammatory cells, fibrosis of the interstitium, and pulmonary arterial wall thickening with marked elevation of right ventricular (RV) pressure, which are characteristics of MCT-induced PH. Gene expression of tumor necrosis factor-alpha (TNF-alpha) as well as DNA binding activity of nuclear factor-kappaB (NF-kappaB) increased at 1 week after MCT treatment, reached a maximum at 2 weeks, and then decreased to the pretreatment level at 3 weeks. HO-1 expression was markedly increased at 1 week, and continued to increase by 3 weeks following MCT treatment, both at transcriptional and protein levels in the mononuclear cells in the lung. ALAS1 mRNA levels in the lung also significantly increased at 2 weeks after MCT treatment. These findings suggest that pulmonary HO-1 expression was presumably induced by proinflammatory cytokine(s) in MCT-treated rats, resulting in the derepression of heme-repressible ALAS1 expression, and that HO-1 induction plays a significant role as an inflammatory factor in this condition.

Using high-resolution intravital charge-coupled device video microscopy, we visualized the epicardial capillary network of the beating canine heart in vivo to elucidate its functional role under control conditions, during reactive hyperemia (RH), and during intracoronary adenosine administration. The pencil-lens video-microscope probe was placed over capillaries fed by the left anterior descending artery in atrioventricular-blocked hearts of open-chest, anesthetized dogs paced at 60–90 beats/min ( n = 17). In individual capillaries under control conditions, red blood cell flow was predominant during systole or diastole, indicating that the watershed between diastolic arterial and systolic venous flows is located within the capillaries. Capillary flow increased during RH and reached a peak flow velocity (2.1 ± 0.6 mm/s), twice as high as control (1.2 ± 0.5 mm/s), with enhancement of intercapillary cross-connection flow and enlargement of diameter (by 17%). With adenosine, capillary flow velocity significantly increased (1.8 ± 0.7 mm/s). However, the increase in volumetric capillary flow with adenosine estimated from red blood cell velocity and diameter was less than the increase in arterial flow, whereas that during RH was nearly equivalent to the increase in arterial flow. There was a time lag of ∼1.5 s for refilling of capillaries during RH, indicating their function as capacitance vessels. In conclusion, the coronary capillary network functions as 1) the major watershed between diastolic-dominant arterial and systolic-dominant venous flows, 2) a capacitor, and 3) a significant local flow amplifier and homogenizer of blood supply during RH, but with adenosine the increase in capillary flow velocity was less than the increase in arterial flow.

喘息重積発作の治療中に,Critical illness polyneuropathyを発症した症例を経験した.患者は呼吸筋の筋力低下と四肢麻痺を呈し,人工呼吸器を3週間必要とし,歩行までに8ヵ月を要した.今回の経験より,重症患者の管理では,早期から理学療法を開始し,neuropathy, myopathyの誘発因子,例えば,筋弛緩薬やステロイドの長期投与等は,極力避けるべきであると考えられた.また,麻痺が発症した際には,中枢神経系の評価のみならず,電気生理学的検査による筋および末梢神経系の評価も必要であると考えられた.

Parathyroid hormone-related protein (PTHrP), a multi-functional protein, is produced by many tissues in fetus. PTHrP concentration in amniotic fluid is reported to be significantly higher than in either fetal or maternal plasma. Other investigators have reported that PTHrP in amniotic fluid is derived mainly from amnion. The aim of this study was to investigate the contribution of fetus to PTHrP in amniotic fluid and the role of PTHrP in human fetal lung tissue. Samples of amniotic fluid, neonatal intra-tracheal fluid, gastric fluid, and the first urine of neonates were obtained at the time of elective cesarean section (n=11), and the concentrations of PTHrP were measured. The PTHrP level in intra-tracheal fluid (41.0+/-19.6 pmol/l, mean+/-SD) was significantly higher than the levels in amniotic fluid (22.1+/-0.8), neonatal gastric fluid (13.5+/-2.5), first urine (0.95+/-0.6), umbilical cord venous and arterial plasma (1.35+/-0.2, 1.63+/-0.3) and maternal plasma (1.05+/-0.1). PTHrP and PTH/PTHrP receptor mRNA were detected in human lung tissue obtained from a fetus stillborn at 36 weeks of gestation. The effects of PTHrP on fetal lung maturation were studied in H441 cells from a human lung epithelial cell line. PTHrP (10(-7)M) significantly suppressed cell proliferation (p0.05) to approximately 80% of the control level, while administration of PTHrP significantly increased surfactant protein A production (p0.01). We first demonstrated the high concentration of PTHrP in intra-tracheal fluid that may suggest the positive production of this protein from the fetal lung. The results obtained by in vitro study using a human lung epithelial cell line suggest that PTHrP derived from the fetal lung might modulate its own maturation.

In the present study, the effects of various cytokines on parathyroid hormone-related protein (PTH-rP) production and PTH-rP mRNA expression in human amnion cells were studied. Immunoreactive (ir) PTH-rP was measured by immunoradiometric assay and the expression of PTH-rP mRNA was determined by Northern blot analysis. The addition of interleukin-1beta (IL-1beta, 10 ng/ml) and IL-6 (10 ng/ml) in culture medium for 24 hours resulted in a significant increase in ir-PTH-rP levels by 1.5 and 1.6 fold, respectively. The effects of these agents were dose dependent. In contrast, IL-2 (10 ng/ml) and IL-8 (10 ng/ml) showed no effect on the production of ir-PTH-rP from amnion cells. Treatment with IL-1beta or IL-6 for 6 hours increased the expression of PTH-rP mRNA in amnion cells. The stimulatory effect of IL-1beta was reduced by IL-1 receptor antagonist (IL-1Ra) in a dose dependent manner. Both tetradecanoyl phorbol acetate (TPA), and forskolin increased PTH-rP mRNA levels and the PTH-rP production in amnion cells, and the effect of TPA was much greater than that of forskolin. The findings of the present study suggest of the participation of inflammatory cytokines for the regulation of PTH-rP production in human amnion cells.

The activation of latent transforming growth factor beta (L-TGFbeta) is essential for the action of TGFbeta, which, in turn, is involved in the regulation of expression of some progesterone-responsive genes. One mechanism by which TGFbeta is activated involves thrombospondin (TSP), a protein that binds extracellular proteins. Immunoreactive TSP (irTSP) protein and TSP-1 mRNA in myometrial tissues of ovulatory and pregnant women were localized by immunohistochemistry and in situ hybridization. IrTSP and TSP-1 mRNA were randomly distributed in myometrial smooth muscle cells of some, but not all, tissues of pregnant women at term before labor; but in some areas of most of these tissues, irTSP was intense and commonly localized extracellularly. Intense irTSP and TSP-1 mRNA in myocytes were more common in myometrium during labor. In myometrium from ovulatory women (n = 26), irTSP was localized primarily in vascular smooth muscle cells and was detected occasionally in scattered myocytes. Little TSP-1 mRNA was demonstrable by in situ hybridization in vessels or myocytes of myometrial tissue from ovulatory women (n = 7). By Northern analysis of total RNA, TSP-1 mRNA was detected in myometrial tissue of pregnant women and in human myometrial smooth muscle cells in culture. The levels of TSP-1 mRNA in myometrial tissues of pregnant women during labor (n = 18) were greater than those in myometrium at > 37 wk gestation before labor began (n = 25, p < 0.001). The ratios of TSP-1 to glyceraldehyde 3-phosphate dehydrogenase mRNAs in 3 myometrial tissues during oxytocin-induced labor were not statistically different from those in myometrium during spontaneous labor but were greater than those in myometrium before labor (p < 0.05). The level of TSP-1 mRNA in confluent human myometrial cells in culture was relatively high, was increased by treatment with fetal bovine serum, and was decreased by treatment with platelet-derived growth factor or activators of adenylyl cyclase or protein kinase C. Myometrial cells in culture constitute a useful model for studying the regulation of TSP-1 gene expression in human myometrium.

Biochemical investigations have shown the presence of the enzyme phenylethanolamine N-methyltransferase (PNMT), which converts norepinephrine (NE) to epinephrine (E) in human pregnant tissues, e.g. myometrium and fetal membranes. The enzymatic activity of PNMT in myometrium is known to decrease during labor. In the present study, PNMT activity in chorio-decidua was measured and the effect of labor and prostaglandins (PG) on PNMT activity was determined. A cytosol fraction of chorio-decidua was incubated with [14C]-S-adenosyl-L-methionine and normetanephrine for 60 min to measure PNMT activity. Fetal membranes were obtained at elective Cesarean section and normal vaginal delivery from full term pregnant women, and the activity of PNMT in chorio-decidua was compared. Significantly lower activity in chorio-decidua obtained from normal vaginal delivery than that from elective Cesarean section was observed. The concentration of 13, 14-dihydro-15-keto-prostaglandin F2 alpha (DHK-PGF2 alpha) in amniotic fluid obtained at normal vaginal delivery were measured by RIA, and the relationship of the DHK-PGF2 alpha level to PNMT activity was studied. There was a significantly negative correlation between the concentration of DHK-PGF2 alpha in amniotic fluid and PNMT activity in chorio-decidua. When various concentrations of PGF2 alpha were pre-incubated with mined chorio-decidua for 2 h, PNMT activity was decreased in a dose dependent manner. These results indicated that PGF2 alpha might affect the bioconversion of NE to E in fetal membranes. The presence of this enzyme in fetal membranes may play an important role in regulating the concentration of catecholamines during pregnancy and parturition.

Objectives To investigate whether umbilical venous velocity and venous velocity pulsation are associated with umbilical vein diameter, umbilical ring diameter and umbilical cord coiling index at midgestation. Methods Two hundred and eighty pregnant women were enrolled in the study at between 18 and 24 weeks of gestation. The diameter of the umbilical cord and internal diameter of the umbilical vein in a free loop and at the ring, and the umbilical coiling index, were measured using ultrasonography. Umbilical venous velocities were measured by Doppler ultrasonography at the umbilical ring and a free loop of the cord. Results All variables were successfully measured in 92% of the patients. There were negative correlations between the diameters of the umbilical ring and of the umbilical vein at the ring and the venous velocity at the umbilical ring. The venous velocity at the umbilical ring was significantly higher and the umbilical ring diameter was significantly lower in fetuses with umbilical venous pulsation at the free loop. Significant correlations were observed between the venous velocity and amplitude of pulsation. Venous pulsations at the free loop were frequently observed in fetuses with a hypercoiled cord. Conclusion High venous velocity and increased venous pulsation at the umbilical ring may be associated with umbilical cord constriction. Copyright © 2010 ISUOG. Published by John Wiley & Sons, Ltd.

Background: Independent predictive factors of preterm delivery were evaluated using clinical data at hospitalisation by multivariate analysis. Aim: The aim of this study was to clarify independent predictive factors related to preterm delivery by multivariate analysis of clinical data at hospitalisation of patients with threatened preterm delivery or premature rupture of membranes (PROM), and to realise the early and highly reliable prediction of preterm delivery in pregnant women at risk. Methods: The subjects were 200 patients, which diagnosed with threatened preterm delivery or PROM and admitted at gestational ages of 22–35 weeks. Univariate and multivariate analyses were performed; 20 factors were evaluated concerning clinical data, and we extracted prognostic factors using logistic regression analysis. Results: The mean age of the patients was 30.5 years, and the mean gestational age at admission was 30.0 weeks. Preterm delivery was observed in 55 (27.5%), and term delivery in 145 (72.5%). On multivariate analysis, haemorrhage, prepregnancy body mass index, fetal fibronectin and cervical length were extracted as independent predictive factors related to preterm delivery. Conclusions: If the reliable and reproducible prediction of preterm delivery becomes possible using the four factors extracted in this study, further evaluation of these factors may lead to clarification of the mechanism of preterm delivery.

Background: Hydrogen peroxide (H 2 O 2 ) is a well recognized candidate for EDHF. The aim of this study was to examine H 2 O 2 -EDHF function in coronary arterial microvessels under conditions of increased oxidative stress in RV of pulmonary hypertension (PH). Methods: Monocrotaline (60 mg/kg SC) was administrated in 5 week-age male Sprague-Dawley rats to induce PH (PH; n=52). Saline was injected in control rats (n=47). After 3 weeks, RV coronary arterioles (CA; 30 –100 μm) and small arteries (CSA; 100 –200 μm) were visualized in vivo using our intravital videomicroscopy. After cyclooxigenase blockade, Acetylcholine (ACh; 2 μg/kg/min IV) induced vasodilation was evaluated under three conditions; ACh alone, N ω nitro-L-arginine methyl ester (L-NAME), L-NAME+catalase. Differences of percentage vasodilation between ACh alone and L-NAME, and between L-NAME and L-NAME+catalase were used as relative indices for the contributions of NO and H 2 O 2 -EDHF, respectively. Malondialdehyde (MDA) in plasma was measured with colormetric assay. Superoxide production in RV was determined by lucigenin-derived chemiluminescence. Results: RV systolic pressure was significantly increased in PH (75±13 vs. 31±3 mmHg; p2 O 2 -EDHF in PH was greatly increased for both CA (from 48% to 60%) and CSA (from 28% to 53%) (both p2 O 2 produciton and contribute to the robust EDHF function. Conclusion: Under conditions of increased oxidative stress in PH, H 2 O 2 -EDHF plays a crucial role against NO dysfunction in RV coronary microcirculation.

A Polyaniline (PAn)/ DNA complex has been successfully prepared by the photopolymerization of dimeric aniline via photocatalytic reaction of Ru(bpy) 3 2+ in the presence of DNA. The reaction occurs even in the solution at pH 3.0 - 6.0, due to the specific local "lower-pH" environment provided by DNA. The PAn in the complex has ordered structure associated with double-helical DNA. The complex contains photocatalyst, Ru(bpy) 3 2+ , even after purification and the Ru(bpy) 3 2+ also works as emitting material. A Ru(bpy) 3 2+ complex-based red-emitting diode with a fast turn-on response was successfully fabricated by employing this novel, processable and water-soluble PAn/DNA complex.

Monocrotaline (MCT), a pyrrolizidine alkaloid plant toxin, is known to cause pulmonary hypertension (PH) in rats. Recent findings suggest that pulmonary inflammation may play a significant role in the pathogenesis in MCT-induced PH. Heme oxygenase-1 (HO-1), the rate-limiting enzyme in heme catabolism, is known to be induced by various oxidative stresses, including inflammation and free heme, and its induction is thought essential in the protection against oxidative tissue injuries. In this study, we examined expression of HO-1 as well as non-specific delta-aminolevulinate synthase (ALAS1), the rate-limiting enzyme in heme catabolism and biosynthesis, respectively, in a rat model of PH produced by subcutaneous injection of MCT (60 mg/kg). MCT treatment caused infiltration of inflammatory cells, fibrosis of the interstitium, and pulmonary arterial wall thickening with marked elevation of right ventricular (RV) pressure, which are characteristics of MCT-induced PH. Gene expression of tumor necrosis factor-alpha (TNF-alpha) as well as DNA binding activity of nuclear factor-kappaB (NF-kappaB) increased at 1 week after MCT treatment, reached a maximum at 2 weeks, and then decreased to the pretreatment level at 3 weeks. HO-1 expression was markedly increased at 1 week, and continued to increase by 3 weeks following MCT treatment, both at transcriptional and protein levels in the mononuclear cells in the lung. ALAS1 mRNA levels in the lung also significantly increased at 2 weeks after MCT treatment. These findings suggest that pulmonary HO-1 expression was presumably induced by proinflammatory cytokine(s) in MCT-treated rats, resulting in the derepression of heme-repressible ALAS1 expression, and that HO-1 induction plays a significant role as an inflammatory factor in this condition.

We studied x-ray diffraction from the left ventricular wall of an excised, perfused whole heart of a rat using x rays from the third-generation synchrotron radiation facility, SPring-8. With the beam at right angles to the long axis of the left ventricle, well-oriented, strong equatorial reflections were observed from the epicardium surface. The reflections became vertically split arcs when the beam passed through myocardium deeper in the wall, and rings were observed when the beam passed into the inner myocardium of the wall. These diffraction patterns were explained by employing a layered-spiral model of the arrangement of muscle fibers in the heart. In a quiescent heart with an expanded left ventricle, the muscle fibers at the epicardium surface were found to have a (1,0) lattice spacing smaller than in the rest of the wall. The intensity ratio of the (1,0) and (1,1) equatorial reflections decreased on contraction with a similar time course in all parts of the wall. The results show that it is possible to assign the origin of reflections in a diffraction diagram from a whole heart. This study offers a basis for interpretation of x-ray diffraction from a beating heart under physiologically and pathologically different conditions.

In the crossbridge theory of muscle contraction (Huxley, 1957), muscle shortening is caused by crossbridges rapidly attaching and detaching from actin. At a given moment the number of crossbridges formed during shortening is smaller than in isometric contraction because they cannot keep attached to allow filament sliding. In skeletal muscles, this prediction has been tested by the x-ray diffraction technique (Podolsky et al., 1976; Huxley, 1979; Amemiya et al., 1980; Yagi & Takemori, 1995). Generally, the intensities of the equatorial (1,0) and (1,1) reflections, which are related to the number of myosin heads in the vicinity of the thin filament (Haselgrove & Huxley, 1973) are affected only by shortening with a small load (0–30%). This observation has been explained by the presence of same myosin heads that are weakly attached to actin during shortening (Yagi & Takemori, 1995). They are not actively producing force but remain in the vicinity of the thin filament, making the equatorial intensities close to those during isometric contraction.

We investigated menstrual cycle-dependent changes in the expression of PTHrP and PTH/PTHrP receptor in the human endometrium by immunohistochemistry, and competitive reverse transcription and polymerase chain reaction (RT-PCR). Human endometrial tissues were obtained from patients who underwent gynecological surgery due to cervical cancer (carcinoma in situ) or ovarian cancer. The mean age of the 20 patients was 36.5 (range 31-44) years. For analysis of mRNA expression, specimens from proliferative (mid, n=5; late, n=5) and secretory (early, n=4; mid, n=4) phases were used. Immunohistochemical expression of PTHrP and PTH/PTHrP receptor was observed in the cytoplasm of both epithelial and stromal cells. Stronger staining of PTHrP was found in glandular epithelial cells than in stromal cells. The staining during the proliferative phase was stronger than that in the secretory phase and the difference was particularly remarkable when comparing samples from the same patient. PTH/PTHrP receptor was also present in both epithelial and stromal cells of the endometrium. However, no difference was observed in receptor expression between the proliferative and secretory phases. Competitive RT-PCR revealed that the expression of PTHrP mRNA was higher during the proliferative phase than in the secretory phase, although no difference was observed in PTH/PTHrP receptor mRNA expression. The data suggest that endometrial proliferation may be mediated by a local PTHrP autocrine and/or paracrine mechanism.

To study the role of decidual monoamine oxidase (MAO)-A and -B activities before delivery, the relationship between MAO activity in fetal membranes and catecholamine (CA) concentration in amniotic fluid (AF) was determined.Fetal membranes and AF were obtained at the time of elective Cesarean section (CS group, n = 11) and Cesarean section due to fetal distress without labor pains (FD group, n = 5). MAO-A and -B activities were radiometrically measured using 14C-5-hydroxytriptamine for MAO-A substrate and 14C-benzylamine for MAO-B substrate. CA concentrations in AF were measured by high performance liquid chromatograph with an electro-chemical detector.Both MAO-A and -B activities in decidua obtained from CS were significantly lower than those obtained from FD. Both norepinephrine (NE) and epinephrine (EP) concentrations were significantly lower in the CS group than the FD group. A significant positive correlation between decidual MAO-A activity and NE concentration in AF was observed. No significant correlation was observed between MAO-B activity and the concentration of NE in AF. There was no correlation between EP concentrations and MAO activities.These results suggest that CA concentration in AF may be related to the activity of MAO in fetal membranes, determined by certain physiological processes during pregnancy. It has been suggested that metabolism of monoamines in fetal membranes also plays an important role in reducing monoamine influx into maternal myometrium from the AF.

Achondroplasia is a short-limb disorder caused by a point mutation in a single gene. To diagnose such a disorder prenatally requires the use of invasive procedures such as amniocentesis. However, using PCR and restriction fragment length polymorphism analysis, we were able to detect the mutation in the plasma of a woman carrying a fetus suspected of having achondroplasia. The detection of a fetus-derived mutant gene from maternal plasma may therefore permit non-invasive prenatal diagnosis of single-gene disorders.