[Classification of the types of pediatric posterior fossa brain tumors based on routine MRI using wavelet transformation analysis of whole tumor]

Objective: To evaluate the classification of the types of pediatric posterior fossa brain tumors based on routine MRI (T(1)WI, T(2)WI and ADC) using wavelet transformation analysis of whole tumor. Methods: MRI images of medulloblastoma (n=59), ependymoma (n=13) and pilocytic astrocytoma (n=27) confirmed by pathology before treatments in Children's Hospital of Nanjing Medical University from January 2014 to February 2019 were enrolled in this retrospective study as well as the clinical data of age, gender and symptoms. Registration was performed among the three sequences and wavelet features of ROI were acquired. Afterwards, the top ten features were ranked and trained among groups by using random forest classifier. Finally, the results were compared and analyzed according to the classification. Results: The top ten contribution three sequences and wavelet features of ROI were acquired from the ADC sequence. The random forest classifier achieved 100% accuracy on training data and was validated best accuracy (86.8%) when combined of first and third wavelet features. The sensitivity was 100%, 94.8%, 76.9%, and the specificity was 97.6%, 88.0%, 98.8% respectively. Conclusions: Features based on wavelet transformation of ADC sequence of entire tumor can provide more quantitative information, which could provide help in the differential diagnosis of pediatric posterior fossa brain tumors. The optimum combination to distinguish three pediatric posterior fossa brain tumors is sixth and twelfth wavelet features of ADC sequence.

[Clinical analysis of seven cases of rare hemolytic disease of the newborn]

Objective: To summarize the clinical features of 7 rare cases of hemolytic disease of newborn (HDN), and to improve the understanding of rare HDN. Methods: Data of clinical information, laboratory findings, treatments and outcomes were collected and analyzed for four cases with HDN due to anti-M, two cases due to anti-Kidd, and one case due to anti-Duffy. All of them were admitted to the Department of Neonatology, Beijing Children's Hospital Affiliated to Capital Medial University from July 2007 to June 2017. Results: Among the four MN hemolytic babies, two were males and two were females. Jaundice was found in three cases. Two cases had hyperbilirubinemia, one of them had severe hyperbilirubinemia. All the four cases developed anemia, including severe anemia in three cases. Two cases of Kidd hemolytic disease and 1 case of Duffy hemolytic disease had jaundice and anemia, but did not reach the level of severe hyperbilirubinemia and severe anemia. MN hemolytic disease babies got negative results in direct antiglobulin test, whereas the Kidd and Duffy hemolytic disease babies had positive findings in direct antiglobulin test. None of the babies had blood transfusion, and they were discharged from the hospital. Conclusions: Without maternal and fetal blood group incompatibility (ABO or Rh blood-group system), for early onset of jaundice, severe jaundice or anemia, antiglobulin test to mother and child earlier should be administered, and MN, Kidd, Duffy and other rare hemolytic disease of the newborn should be pay attention to.

Fabrication of SiO2 incorporated ordered mesoporous TiO2 composite films as functional Pt supports for photo-electrocatalytic methanol oxidation

SiO₂ incorporated ordered mesoporous TiO₂ composite films were fabricated as an active support for methanol oxidation and excellent photoelectrocatalytic activity was obtained, showing great potential application prospects.

Olfactory mucosal microstructural changes in a rat model of acute rhinosinusitis with dysosmia

This study aimed to examine olfactory mucosal changes in a rat model of acute rhinosinusitis and to determine how acute rhinosinusitis induces dysosmia. Total 100 rats were divided into the experimental (N = 80) and control (N = 20) groups. An acute rhinosinusitis model was established in the experimental rats. From the experimental group, 20 rats each were sacrificed at 1, 2, 3, or 4 weeks. The control group was sacrificed at 1 week without inoculation. Olfaction was tested by the buried food pellet test before killing the rats, and the duration until the pellet was recorded and analyzed by a statistical software program. Mature olfactory receptor neurons (ORNs) and olfactory ensheathing cells (OECs) were examined. The durations spent by the experimental group in the BFPT were 402.9 ± 9.3, 453.7 ± 7.3, 351.9 ± 8.9, and 278.7 ± 8.1 s at 1, 2, 3, and 4 weeks, respectively. These durations were greater than that of the control group (178.3 ± 6.6 s), and the difference was statistically significant (P < 0.01). A reduction in ORNs and thinning of the epithelium were detected in the experimental group, most notably in the 2nd week and less in the fourth week. OECs were reduced in the 1st week, increased in the 2nd week, and almost completely recovered in the fourth week. In addition, some growing OECs were detected in the experimental group. Acute rhinosinusitis decreased both the mature ORNs and OECs, but OECs increased faster than the ORNs.

Local tunneling spectroscopy across a metamagnetic critical point in the bilayer ruthenate Sr3Ru2O7

The local spectroscopic signatures of metamagnetic criticality in Sr(3)Ru(2)O(7) were explored using scanning tunneling microscopy (STM). Singular features in the tunneling spectrum were found close to the Fermi level, as would be expected in a Stoner picture of itinerant electron metamagnetism. These features showed a pronounced magnetic field dependence across the metamagnetic critical point, which cannot be understood in terms of a naive Stoner theory. In addition, a pseudogap structure was observed over several tens of meV, accompanied by a c(2 x 2) superstructure in STM images. This result represents a new electronic ordering at the surface in the absence of any measurable surface reconstruction.

Direct observation of the bandwidth-disorder induced variation of charge/orbital ordering structure in RE(0.5)(Ca(1-y)Sr(y))(1.5)MnO(4)

Changes in the charge/orbital ordering (CO/OO) structure with the bandwidth of the e(g) band and quenched disorder were investigated in doped manganites RE(0.5)(Ca(1-y)Sr(y))(1.5)MnO(4)(RE = Pr,Eu) with a single-layer perovskite structure. A systematic study of the modulation structure associated with the CO/OO phase demonstrated that the long-range commensurate structure changes to a short-range incommensurate structure with increasing Sr content through the enhancement of the bandwidth and quenched disorder in these systems. At the same time, the transition temperature of CO/OO (T(CO/OO)) decreases. Changes in structure and T(CO/OO) with different A-site combinations reveal that the CO/OO phase is strongly suppressed by the widening of the e(g) band and the stronger quenched disorder in these layered manganites.

In-plane anisotropy of the electronic structure for the charge- and orbital-ordered state in half-doped manganite with layered structure

We report on the in-plane anisotropy of the electronic response in the spin-, charge-, and orbital-ordered phase of a half-doped layered-structure manganite. The optical conductivity spectra for a single domain of Eu1/2Ca3/2MnO4 unambiguously show the anisotropic charge dynamics which well corresponds to the theoretical calculation: the optical conductivity with the polarization along the zigzag ferromagnetic chain direction exhibits a smaller gap and a larger intensity at lower energies than that of the perpendicular polarization mostly due to the charge and orbital ordering and the associated quantum interference effect.

Enhanced optical magnetoelectric effect in a patterned polar ferrimagnet

A simple method to dramatically enhance the optical magnetoelectric (ME) effect, i.e., nonreciprocal directional birefringence, is proposed and demonstrated for a polar ferrimagnet GaFeO3 as a typical example. We patterned a simple grating with a period of 4 microm on a surface of GaFeO3 crystal and used the diffracted light as a probe. The optical ME modulation signal for the Bragg spot of the order n=1 becomes gigantic in the photon energy 1-4 eV and reaches 1-2% of the bare diffracted light intensity in a magnetic field of 500 Oe. This is amplified by more than 3 orders of magnitude compared to that for the reflection of bulk GaFeO3. Fabricating a photonic crystal will make it possible to lead the way for the practical use of the optical ME effect.

[Reverse flow in fetal vessels and perinatal events]

BACKGROUND/PATIENTS: A reverse flow in the umbilical artery and/or fetal aorta is associated with a higher perinatal and neonatal mortality. 30 fetuses showed a reverse flow using pulsed wave Doppler sonography (group I). A matched-pair control group including 30 fetuses with the same gestational age as well as a normal Doppler flow pattern in the umbilical artery and/or fetal aorta was taken for comparison (group II).

RESULTS

In the group with reverse flow the rates of pregnancies with pre-eclampsia (n = 19/30, p < 0.0001), intrauterine growth retardation (n = 25/30, p < 0.0001), oligohydramnios (n = 21/30, p < 0.0001) and nicotine abuse (n = 15/30, p < 0.01) were significantly higher compared to the control group. Postnatal data showed significantly lower pH values in group I (p < 0.01). 40 % of the fetuses with reverse flow died in utero whereas in 67 % the reverse flow was accompanied by an insufficiency of the placenta (IUGR, oligohydramnios, histopathological abnormalities of the placenta). None of the fetuses in the control group died in utero. The incidence of IUGR (< 5ht percentile) was 83 % in group I but only 3 % in group II. The perinatal and overall mortality (including neonatal mortality 7 - 28 days after birth) amounted to 27 % and 53 % in group I, respectively, compared to 3 % and 0 % in the control group (p < 0.001). In addition cerebral anomalies could be found by ultrasound in 50 % of the neonates who presented a reverse flow prenatally. In 28 % of the surviving newborns an intracerebral hemorrhage (ICH) could be detected. None of the newborns of group II developed an ICH.

CONCLUSIONS

Pregnancies with a reverse flow in the umbilical artery and/or fetal aorta have to be considered as a high risk group with a poor prognosis. The reverse flow is mainly caused by chronic placental insufficiency with IUGR. With respect to the further neuromotor development the incidence and severity of cerebral lesions in affected fetuses should be considered when discussing the perinatal situation with the parents.

Optical magnetoelectric effect in the polar GaFeO3 ferrimagnet

The optical magnetoelectric (ME) effect, i.e., the change of optical absorption upon the reversal of the light propagation direction, has been investigated for a polar ferrimagnet GaFeO3. For dipole- and spin-forbidden d-d transition bands located at 1.2-2.3 eV, a clear signal of the optical ME effect (Deltaalphat approximately 3x10(-3)) is observed with an applied magnetic field as low as 500 Oe and a sample thickness (t) of 50 microm. The observation of a large ME effect in the present compound suggests a possible route to magnification of this novel phenomenon for application.

X-ray directional dichroism of a polar ferrimagnet

In a polar ferrimagnet GaFeO3, we have found a novel magneto-optical effect, termed x-ray nonreciprocal directional dichroism (XNDD), that the x-ray absorption at around the K edge of an Fe ion depends on whether the x-ray propagation vector is parallel or antiparallel to the outer product of the magnetization and electric-polarization vectors. The XNDD spectroscopy as demonstrated here can be a useful tool to probe the local magnetism in noncentrosymmetric systems such as magnetic interfaces and nanostructures.

Magnetization-induced second harmonic generation in a polar ferromagnet

Second harmonic generation (SHG) induced by spontaneous magnetization has been investigated for a polar ferromagnetic crystal of GaFeO3. The Kerr rotation of the second harmonic light becomes gigantic with decreasing temperature below the magnetic transition temperature (approximately =205 K), e.g., as large as 73 degrees at 100 K. The magnetic domains can be visualized by using that large nonlinear Kerr rotation. The spectrum of the magnetization-induced SHG as measured indicates the two-photon resonant electronic process on a Fe3+ ion in the crystal.

[Placental morphometry in pregnancies with reversed enddiastolic flow in the umbilical artery or fetal aorta]

BACKGROUND

Fetuses with a reversed enddiastolic flow in the umbilical artery and/or aorta are at risk pregnancies and show a higher incidence of perinatal morbidity and mortality. The aim of this study was to evaluate the pathological changes in the terminal villous tree in fetuses with a reverse flow in the fetal aorta or umbilical artery.

MATERIALS AND METHODS

In this retrospective study, 16 cases with a reverse flow in the fetal aorta or umbilical artery (Gr. 1) were compared with gestational age matched 16 healthy pregnant women (Gr. 2). The following morphometric parameters were evaluated in 50 sections in each placenta (1600 measurements): mean vessel diameter, volume density of the villous tissue, stem villi and terminal villi. Measurements were performed using a computerized Video Image Analysis system.

RESULTS

The mean gestational age at birth was similar in both groups (30 + 4 weeks gestation vs. 30 + 6 weeks gestation, respectively, for Gr. 1 and Gr. 2). The birth weights (985 g vs. 1780 g) and the placental weights (216 g vs. 385 g) were significantly lower in the reverse flow group. There was a significant reduction in the proportion of total villous tissue (19 % versus 45 %) and in the diameter of tissue at the terminal villi (2.1 % versus 7.6 %) in the reverse flow group. Although the mean number of vessels at the terminal villi was lower than the control group (4.1 versus 5.6), the mean and total areas of the vessels were not different.

CONCLUSION

Our observations showed a significant association between the placental morphometric parameters and reversed enddiastolic flow in the umbilical artery or fetal aorta. The reduced number of functional placental units is responsible for the diminished exchange function of the placental vessels in "reverse flow" cases. This could partially explain the adverse outcome in this clinical situation.

Change of electronic structure in Ca2RuO4 induced by orbital ordering

Optical conductivity spectra sigma(omega) were used to investigate the effect of orbital ordering on the electronic structure of Ca2RuO4. Our LDA+U calculation predicts Ru 4d(xy) ferro-orbital ordering at the ground state, and well explains the present sigma(omega) as well as the reported O 1s x-ray absorption spectra. Variation of temperature (T) causes a large change of spectral weight over several eV as well as collapse of a charge gap accompanied by elongation of the c-axis Ru-O bond length. These results clearly indicate that the d(xy) orbital ordering plays a crucial role in the metal-insulator transition and the T-dependent electronic structure on a large energy scale.

Time trends in sport-caught Great Lakes fish consumption and serum polychlorinated biphenyl levels among Michigan Anglers, 1973-1993

Polychlorinated biphenyls (PCBs) remain public health concerns because of their persistence in the environment and their potential health impact. We linked data from three mixed cross-sectional/longitudinal surveys of Michigan anglers conducted by the Michigan Department of Public Health in 1973-1974, 1979-1982, and 1989-1993 to examine the association between sport-caught fish consumption and serum PCBs. The reported weight of fish consumed declined over the three surveys (median 40, 38, and 31 lb/yr). Serum Aroclor 1260 levels were 2-3 times higher in fish-eaters than in nonfish-eaters in all three surveys in both men and women. In nonfish-eaters, serum PCB levels rose between 1973-1974 and 1979-1982 [adjusted change = 0.30 log(ppb), p = 0.01] and then declined between 1979-1982 and 1989-1993 [adjusted change = -0.16 log(ppb), p = 0.002]. Among fish-eaters, serum PCB levels also rose between 1973-1974 and 1979-1982 [adjusted change = 0.45 log(ppb), p < 0.001] but were unchanged between 1979-1982 and 1989-1993 [adjusted change = -0.09 log(ppb), p = 0.14]. Predictors of serum PCB levels included annual fish consumption, gender, and age. We conclude that background human serum levels of Aroclor 1260 had declined by 1989-1993 from earlier peak levels. Among consumers of sport-caught Great Lake fish, serum PCB levels did not significantly decrease, probably due to continued exposure and the long half-life of PCB.

A role for the deep orange and carnation eye color genes in lysosomal delivery in Drosophila

Deep orange and carnation are two of the classic eye color genes in Drosophila. Here, we demonstrate that Deep orange is part of a protein complex that localizes to endosomal compartments. A second component of this complex is Carnation, a homolog of Sec1p-like regulators of membrane fusion. Because complete loss of deep orange function is lethal, the role of this complex in intracellular trafficking was analyzed in deep orange mutant clones. Retinal cells devoid of deep orange function completely lacked pigmentation and exhibited exaggerated multivesicular structures. Furthermore, a defect in endocytic trafficking was visualized in developing photoreceptor cells. These results provide direct evidence that eye color mutations of the granule group also disrupt vesicular trafficking to lysosomes.

Pain-relief and movement improvement by acupuncture after ablation and axillary lymphadenectomy in patients with mammary cancer

INTRODUCTION

In the traditional Chinese medicine (TCM), pain and movement restrictions are considered as the result of a blocking of the "Jing-Luo-system" or of a disordered flow of the Jing-Qis in the "Jing-Luo-system".

PATIENTS AND METHODOLOGY

In this study 48 patients with mammary cancer after ablation and axillary lymphadenectomy were treated with acupuncture (group I); a control group of 32 patients with the same operation but without acupuncture was compared (group II).

RESULTS

The results showed a significantly higher maximum abduction angle (AA) at the first treatment immediately after acupuncture without pain (59.1 degrees vs. 80.4 degrees, p < 0.001) with respect to maximum tolerable pain barrier (73.6 degrees vs. 92.3 degrees, p < 0.001). Between group I (12.3%) and group II (50%) there was a statistically significant difference (p < 0.01) in the appearance of pain in the operation field in the rest position on the 5th postoperative day, while on the 7th postoperative day 8.3% vs. 12.5%) and at the time of discharge a significant difference could not be seen (p > 0.05). The percentage of patients with pain during arm movements showed a statistically significant difference between group I and group II on the 5th postoperative day (81% vs. 100%, p < 0.01), on the 7th postoperative day (43% vs. 96.9%, p < 0.01) and at time of discharge (27.1% vs. 65.6%, p < 0.001). The differences in the abduction angle between group I and group II were also statistically significant on the 5th postoperative day at indolency (89.3 degrees vs. 74.5 degrees, p < 0.001) with respect to maximum tolerable pain (105.8 degrees vs. 87.4 degrees, p < 0.001). The differences in the abduction angle on the 7th postoperative day at indolency (97.5 degrees vs. 81.2 degrees, p < 0.001) and at maximum tolerable pain (118.5 degrees vs. 93.4 degrees, p < 0.001) were statistically significant. This statistically significant difference in the maximum abduction angle between group I and group II at indolency (116.1 degrees vs. 91.5 degrees) with respect to maximum tolerable pain (129.4 degrees vs. 112.7 degrees, p < 0.001) could be observed until discharge.

DISCUSSION

Acupuncture seems to be an effective treatment to relieve pain and improve arm-movements after ablation and axillary lymphadenectomy. The "Xie-technique" is used at the main acupuncture points and the patient's feeling must be particularly considered. The combination of the different main points with the correctly selected additional acupuncture points--referred to the basic state and the pre- und post-operative state of the patient--are very important for a successful application of acupuncture.

[Placenta morphology and Doppler ultrasound of umbilical cord vessels in premature infants]

OBJECTIVE

There is a raised morbidity and mortality in fetuses with pathological waveforms in the umbilical arteries. Less differentiation of the placental villi could (partly) explain this finding.

MATERIALS AND METHODS

We examined a total of 51 placentas (28th to 35th week of gestation) as to a correlation between dopplersonographical findings in the umbilical arteries and placenta morphometry.

RESULTS

In the groups with pathological waveforms there was not only a reduction in the weight of the placenta and child, but also less differentiation of the placental villi. The occurrence of so-called sprouts did not correlate with the dopplersonographical findings.

CONCLUSIONS

The raised fetal morbidity and mortality in premature infants with pathological waveforms in the umbilical arteries can at least partly be explained less differentiation of the placental villi. We found no correlation with the occurrence of sprouts.

[Treatment of severe cholestatic hepatitis by integrated traditional Chinese and Western medicine]

OBJECTIVE

To study the curative effect of Chinese medicine in treating severe cholestatic-hepatitis (SCH).

METHODS

Three hundred and fifty patients of SCH with total bilirubin level > or = 171 mumol/L were treated with Chinese medicines. For those with Blood Stasis Syndrome, treated with the recipe mainly consisted of Radix Paeoniae Rubra, and for which accompanied with blood Heat, fluid retention in epigastric region. Dampness dissenubated in Sanjiao ([symbol: see text]) or both Spleen and Kidney Yang-Deficiency Syndrome, the recipe was used in modification according to the Syndrome.

RESULTS

Treatment was markedly effective in 288 cases and effective in 26 cases, the total effective rate being 89.7%.

CONCLUSION

It is difficult in treating severe cholestatic hepatitis, especially the chronic cholestatic hepatitis, which could develop to severe chronic hepatitis if the jaundice lasted for a long time. This study showed a good effect of Chinese herbal medicine in eliminating jaundice.

Mechanics of running under simulated low gravity

Using a linear mass-spring model of the body and leg (T. A. McMahon and G. C. Cheng. J. Biomech. 23: 65-78, 1990), we present experimental observations of human running under simulated low gravity and an analysis of these experiments. The purpose of the study was to investigate how the spring properties of the leg are adjusted to different levels of gravity. We hypothesized that leg spring stiffness would not change under simulated low-gravity conditions. To simulate low gravity, a nearly constant vertical force was applied to human subjects via a bicycle seat. The force was obtained by stretching long steel springs via a hand-operated winch. Subjects ran on a motorized treadmill that had been modified to include a force platform under the tread. Four subjects ran at one speed (3.0 m/s) under conditions of normal gravity and six simulated fractions of normal gravity from 0.2 to 0.7 G. For comparison, subjects also ran under normal gravity at five speeds from 2.0 to 6.0 m/s. Two basic principles emerged from all comparisons: both the stiffness of the leg, considered as a linear spring, and the vertical excursion of the center of mass during the flight phase did not change with forward speed or gravity. With these results as inputs, the mathematical model is able to account correctly for many of the changes in dynamic parameters that do take place, including the increasing vertical stiffness with speed at normal gravity and the decreasing peak force observed under conditions simulating low gravity.

Relation between changes of TXB2 and PGF1 alpha and the severity of the disease and pathological lesions in cases of severe icteric hepatitis

Clinically, 32 cases of intrahepatic cholestasis and 30 cases of severe chronic hepatitis with a bilirubin level higher than 171 mumol/L were studied. The results showed that bilirubin was 420 mumol/L in the first group, and 480 mumol/L in the second group (P greater than 0.05); TXB2 was 306 pg/ml and 271 pg/ml (P greater than 0.05) while PGF1 alpha was 253 pg/ml and 494 pg/ml (P less than 0.05) respectively, both were higher than their normal values (P less than 0.01). The cases were divided into acute, moderate and severe types according to their pathological lesions. Experimentally, intra- and extrahepatic cholestasis and necrotic liver tissues were induced by ANIT, ligation of common bile duct, and carbon tetrachloride respectively. Bilirubin was 629 mumol/L, 124.8 mumol/L, and lower than 17.1 mumol/L (P less than 0.01); plasma TXB2 was 634 pg/ml, 1036 pg/ml, and 239 pg/ml (P less than 0.01); PGF1 alpha was 186 pg/ml, 218 pg/ml, and 868 pg/ml (P less than 0.01) in the three groups respectively. No statistic difference was found in their TXB2 and PGF1 alpha. Our studies suggested that plasma TXB2 and PGF1 alpha in the liver was not related to the severity of liver lesions. TXB2 and PGF1 alpha are positively correlated with the increase of bilirubin while TXB2 is negatively correlated with PGF1 alpha, which might serve as an index for cholestasis, and be a cause for deepening jaundice.

[Prediction of infection complicating premature rupture of the membranes by monitoring fetal breathing movement with ultrasound]

Modified Vintzileos monitoring skill and scoring criteria of fetal biophysical profile (FBP), were used in assaying 48 patients with premature rupture of the membranes (PROM). The last determination before delivery was compared with the outcome of pregnancy. The results showed: (1) The infection rate in patients with low biophysical score (less than or equal to 7) was significantly higher than that of high score (greater than 7); (2) The infection rate in patients presenting fetal breathing movements (FBM) of greater than or equal to 60 sec. It was significantly lower than that in patients with a FBM of less than 60 sec. Infection was almost absent when FBM was present; (3) Fetal distress and neonatal asphyxia could be well predicted by FBP scoring in labor. The above suggested that FBP Scoring FBM is useful in prediction infection and the outcome of babies in patients with PROM.

[C-reactive protein and acute-phase proteins in monitoring infection caused by premature rupture of membranes]

Early detection of infection is of utmost importance during the conservative management of premature rupture of the membranes (PROM). Sensitivities of C-reactive protein (CRP) and acute-phase proteins (APP) in predicting the infection induced by PROM were studied. The results showed that CRP could demonstrate clinical or subclinical infection with a sensitivity of 100% and 86.7% respectively, and no false positivity was observed. CRP increased remarkably at least 24 hours earlier than that of other parameters when infection occurred. On the other hand the sensitivity of APP (64.1%) was lower with false positivity. Thus, CRP may be used in clinical practice to predict infection resulted from PROM during conservative management.

An epidemiological study on the effect of N, N'-methylene-bis-(2-amino-1,3,4-thiadiazole) (MATDA) on outcomes of pregnancy

A retrospective cohort study on the effect of the suspected teratogenic pesticide N, N'-methylene-bis-(2-amino-1,3,4-thiadiazole) (MATDA) on outcomes of pregnancy was conducted. The exposed group (6,173 pregnancies) was composed of childbearing women who, during their gestation, consumed rice harvested from a field where MATDA had been applied. The control I group (10,145) came from an adjacent county where MATDA had never been used; the control II group (3,326) consisted of women who had been pregnant previous to the introduction of this pesticide in the same region as the exposed group. The validity of the survey was verified by comparability and data-checking studies. After adjustment for the calendar year, maternal age, and pregnancy order, no significant differences were found in rates of spontaneous abortion, fetal death and stillbirth, birth defects, as well as in sex ratio and birth weight between the study groups. The same result was found in the comparison of individual categories of malformation. The rates of the birth defects were 23.84, 21.49, and 22.78 per 1,000 live births for the exposed, internal, and external control groups, respectively. No dose-response relationship was revealed. The results were consistent with previous reports and indicated the difference between animal experiments and human exposures. Although MATDA is teratogenic in animals, it is clear that the pesticide does not adversely effect outcomes of pregnancy in humans as currently applied.