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R Maymon

Publications and source records attributed to R Maymon.

At least 37 records · Page 2Linked to original sources
PubMed2001

Reconstructed measurements produced from ultrasound images using a computerized system.

OBJECTIVE: The aim of this study was to evaluate the feasibility and accuracy of reconstructed measurements produced from video-printed ultrasound images. DESIGN: Reproduction of reconstructed measurements using designated software and comparison of the results with regular measurements derived from the same images. SUBJECTS: Seventy regular sonographic examinations of biparietal diameter (BPD) and nuchal translucency (NT) thickness. METHODS: The study included 35 conventional-size (BPD) and 35 small-size (NT) measurements. Each image was measured twice during a dynamic ultrasound examination (regular measurements) and twice using a computerized system (reconstructed measurements). The latter comprised three steps: (i) computerization (computer-generated images by scanning); (ii) calibration (using the scale located alongside the image); (iii) measurement (placing the calipers at the desired points). RESULTS: All images were successfully scanned, and the computer-generated images were of sufficient quality for proper measurement. There was no difference between mean values of regular and reconstructed BPD measurements, 63.9 mm (3.7 mm, SE) and 63.6 mm (3.8 mm, SE), respectively. Similarly, mean values of regular NT measurements were similar to the reconstructed ones, 1.48 mm (0.09 mm, SE) and 1.49 mm (0.09 mm, SE), respectively. Repeated regular BPD and NT measurements exhibited repeatability coefficients of 1.6 mm and 0.4 mm, respectively. These values were smaller than those obtained by repeated reconstructed measurements of 2.1 mm and 0.52 mm, respectively. CONCLUSIONS: Reconstructed measurements of ultrasound video-printed images are feasible, require modest facilities and exhibit more than reasonable accuracy. This option may contribute to medical research, audit, quality control and training, as well as to medico-legal issues.

Feasibility Studies↗
PubMed2001

Comparison of triple serum screening and pregnancy outcome in oocyte donation versus IVF pregnancies.

The current study compared triple serum screening results and outcomes in 37 oocyte donation (OD) and 46 self oocyte IVF-conceived singletons of similarly aged women (28.8 +/- 4.4 years and 30.7 +/- 4.5 years respectively). Both groups were followed from their embryo transfer and throughout pregnancy. Although the daily pattern of first-trimester serum beta-human chorionic gonadotrophin (HCG) was similar in both groups, higher mid-gestation HCG serum concentrations were found, i.e. 1.38 and 1.32 multiples of the median (median MoM) for IVF and OD respectively, in comparison with 0.99 median MoM from the same reference laboratory. Only the OD group had significantly increased alpha fetoprotein (AFP) concentrations (1.45 median MoM) (P = 0.002) compared with the reference laboratory. A total of 11% of the IVF and 13% of the OD women were found to be screen positive. In neither group were chromosomal abnormalities detected and no fetal or neonatal deaths were recorded. Seven (15%) of the OD and seven (19%) of the IVF women had an adverse obstetric outcome. Of those cases, six IVF and four OD women had serum HCG > or = 1.2 MoM and five OD women had AFP >1.2 MoM. Therefore, in those pregnancies the high serum HCG concentrations may alert for adverse obstetric outcome rather than indicating a high risk for Down's syndrome fetuses.

Adult↗
PubMed2001

Transvaginal sonographic assessment of cervical length changes during triplet gestation.

The current study aimed to evaluate the contribution of transvaginal sonography (TVS) for monitoring cervical changes during the second half of triplet gestation. Forty-five pregnant women with triplets pregnancies were prospectively scanned by TVS from approximately 26 weeks gestation and were longitudinally followed-up until delivery. Based on a receiver-operating curve it was found that a cervical length of 25 mm is the most accurate parameter (94% sensitivity and 45% specificity) for predicting premature delivery < or =33 gestational weeks. Thus, a single cervical length measurement of < or =25 mm at 26 weeks gestation correlated well with premature delivery at < or =33 weeks (chi(2); P = 0.002). Using the linear regression model, a mathematical equation [(Week of delivery = 27.4 + 1.6 x cervical length; R(2) = 0.46; P = 0.01)] for predicting the gestational age of delivery (dependent variable) was determined based on mid-gestation cervical measurements (predictors). In parturient women with triplet gestation, TVS assessment of the uterine cervix offers insight into the cervical status and provides valuable information for prenatal care. This includes both monitoring the cervical changes throughout third trimester as well as predicting the likelihood of premature delivery.

Adult↗
PubMed2001

Nuchal translucency measurement and pregnancy outcome after assisted conception versus spontaneously conceived twins.

BACKGROUND: Nuchal translucency (NT) measurement for Down's syndrome screening or detecting various fetal anomalies is a reliable sonographic marker. This study evaluates the contribution of NT screening in spontaneously conceived and assisted conception twin pregnancies. METHODS AND RESULTS: Maternal age at measurement, chorionicity, ultrasound features, karyotype results and pregnancy outcome were recorded prospectively and compared in 83 assisted reproduction treatment and 91 spontaneously conceived twins. Pregnancy outcome was evaluated according to maternal age, method of conception, NT data and chorionicity. NT measurements (> or =95 centiles of the normal range) were considered screen-positive and mid-pregnancy fetal karyotyping was advised. Complicated pregnancy outcome, which could be signalled by increased NT, was defined as either chromosomal abnormalities, severe structural defects or fetal demise. Based on NT measurements, 16 fetuses (4.6%) were found to be screen-positive. Five of them had chromosomal aneuploidy and selective termination was performed. The parents also opted for this procedure in another five fetuses because of major structural abnormality diagnosed during NT assessment. No other chromosomal or major fetal abnormality were found post-natally. Although no difference was found in NT, crown-rump length and maternal age between spontaneous and assisted reproduction technology twin pregnancies, the former group had a significantly higher rate of screen-positive results (7 versus 2%, P = 0.047), amniocentesis uptake (33 versus 22%, P = 0.014), monochorionic twining (32 versus 4%, P = 0.001) and complicated pregnancy outcome (11 versus 5%, P = 0.02). CONCLUSION: The present study confirms that first trimester target scanning can improve outcome by early detection and management of cases with an anomalous co-twin. It also identifies some differences between spontaneously and artificially conceived twin pregnancies in relation to this area of testing.

Abortion, Induced↗
PubMed2001

[Prenatal Down's syndrome screening at 10-14 weeks gestation using the combined nuchal translucency and maternal serum biochemistry: preliminary results of the first 358 cases].

We report our preliminary experience of prenatal screening for Down's syndrome (DS) using nuchal translucency (NT) measurement combined with the serum biochemistry analysis of Free beta-human chorionic gonadotropin (F beta hCG) and pregnancy associated plasma protein A (PAPP-A) all measurement at 10-14 weeks of gestation. Of the 358 parturient women which enrolled in the study, 9 cases were not included because of fetal anomalies or miscarriages. Thus the study group included 349 singleton pregnancies in which complete prenatal and infant follow-up was available. Forty-four pregnant women were found to be screen positive (12.6%) and in 13 cases (27%) of them fetal chromosomal aneuploidies were diagnosed. Looking into the markers profile we found that the NT was a sensitive marker which was abnormally increased in all the fetal aneuploidies. Serum F beta hCG was found to be a promising marker as well, being significantly elevated (2.26 +/- 0.86 multiple of the medians, MoM) in DS cases, and decreased (< 0.5 MoM) in two cases of Edward's syndrome. On the contrary, PAPP-A was found less sensitive, and its mean MoM values were not significantly different between DS versus euploid fetuses. Our preliminary results support the promising success of DS screening using NT and F beta hCG.

Adult↗
PubMed2000

Combined first trimester nuchal translucency and second trimester biochemical screening tests among normal pregnancies.

We prospectively examined whether first trimester nuchal translucency (NT) and second trimester triple test (TT) results are correlated, and determined overlapping and mutual screen-positive rates. Results of NT, TT, amniocentesis and pregnancy outcome were obtained in 508 normal pregnancies. Inter-test correlation was performed by comparing the likelihood ratios (LR). Overlapping of screen-positive cases, of NT and TT, was determined by comparing mutual risks for Down syndrome (DS) livebirth of > or = 1:380. Combined screen-positive rates were evaluated by using summation risk (NT and/or TT exhibiting a risk > or = 1:380) and calculated risk (new risk > or / =1:380, based on multiplication of LR(NT) and LR(TT)). Screen-positive rates between NT and TT differed significantly and when either test showed an increased risk for DS, the probability of the other to predict the same was negligible (p<0.001). Overall screen-positive rates, at a risk > or = 1:380, were 2% and 5.7% for NT and TT, respectively. Summation and calculated combining methods were associated with 7.5% and 2.0% screen-positive rates, respectively. Amniocentesis was performed on 20.7% of the cases, mostly screen-negative ones. Our results showed that, in normal pregnancies, NT and TT do not correlate and that their combined calculated risk in normal pregnancies is associated with a low screen-positive rate of 2.0%.

Adult↗
PubMed2000

On-to-on versus on-to-out nuchal translucency measurements.

OBJECTIVE: To analyze variables affecting the differences between on-to-on and on-to-out methods of nuchal translucency measurement. DESIGN: Prospective comparison of two methods of caliper placement. SUBJECTS: A total of 245 women undergoing transabdominal and 37 women undergoing transvaginal nuchal translucency scanning. METHODS: Nuchal translucency was measured using both on-to-on and on-to-out methods of caliper placement on the same frozen images. Differences between the methods were evaluated according to fetal size, nuchal thickness and mode of examination. Regression analysis was performed for the calculation of the expected difference between the methods at various combinations. Results among 1254 singleton pregnancies were used to set 50th, 95th and 97.5th centiles for the on-to-on method. The calculated differences were used to set 50th, 95th and 97.5th centiles for the on-to-out method. RESULTS: The mean difference between on-to-out and on-to-on nuchal translucency, using transabdominal scanning, was 0.95 +/- 0.14 mm. The differences were shown to correlate directly with fetal size and with nuchal thickness. In addition, scans performed transvaginally exhibited a smaller difference between the methods (0.90 mm vs. 0.94 mm; P < 0.05). CONCLUSION: The difference between on-to-on and on-to-out nuchal translucency measurements may have a considerable effect on the calculated risk for aneuploidy.

Abdomen↗
PubMed2000

Diminished expression of placental isoferritin p43 component in first trimester abnormal pregnancies.

Human placental isoferritin (PLF) is a sub-type of human ferritin mainly composed of a 43 kD protein, which has an immunosuppressive activity and may be involved in the downregulation of the maternal immune system during pregnancy. The aim of this study was to evaluate the distribution of p43 in the placental tissue of abnormal first trimester pregnancies. Samples of villous and decidual tissues were collected between 7 and 12 weeks' gestation from 28 missed abortions and eight complete moles. Samples of placental tissue from 20 normal pregnancies of similar gestational age were used as controls. The localization of p43 was determined by immunohistochemical techniques using CM-H9 monoclonal antibody. Compared to controls, specific p43 immunoreactivity was low in the villous syncytiotrophoblast of missed abortions and absent from all villous cellular types in complete moles. These findings correlate well with the low level of maternal serum PLF found previously in early pregnancy failures and molar gestation. This suggests that PLF may be involved in the pathogenesis of early pregnancy disorders related to an abnormal placentation.

Abortion, Missed↗
PubMed2000

Localization of p43 placental isoferritin in human maternal-fetal tissue interface.

OBJECTIVE: Human placental isoferritin, which is composed of a 43-kd protein subunit, is exclusively reactive with the CM-H9 monoclonal antibody. The p43 exerts immunosuppressive activity during pregnancy. The aim of this study was to localize the expression of p43 in the maternal-fetal tissue interface during normal gestation. STUDY DESIGN: Villous tissues samples were collected between 5 and 20 weeks' gestation and at term from uncomplicated pregnancies. Immunohistochemical localization of p43 was performed with CM-H9 monoclonal antibody. RESULTS: During the first trimester p43 was highly expressed in syncytiotrophoblast, Hofbauer cells, and decidual macrophages. From 15 weeks' gestation onward expression in the syncytiotrophoblast was below the level of detection; however, p43 was demonstrated in villous Hofbauer cells and decidual macrophages throughout gestation. CONCLUSIONS: Expression of p43 was demonstrated on both sides of the maternal-fetal tissue interface, with localization dependent on gestational age. This may suggest its immunologic function throughout pregnancy. First-trimester syncytiotrophoblast displayed high p43 levels, which disappeared later on, whereas maternal serum p43 level continued to increase, which suggests an extraplacental source for p43.

Chorionic Villi↗
PubMed2000

Pregnancy outcome and infant follow-up of fetuses with abnormally increased first trimester nuchal translucency.

The numbers of fetuses with an abnormal increased first trimester nuchal translucency (NT) but a confirmed normal anatomy and karyotyping is relatively small and therefore a challenge for prenatal counselling. The aim of the current study was to assess the long-term pregnancy outcome and infancy prognosis of 78 fetuses with NT > 95th centile of the normal range for crown-rump length (CRL). The most common abnormalities in this group were aneuploidy, which affected 32 of the fetuses followed by four and three cases which were miscarried or had cardiac defects respectively. The remaining euploid fetuses with normal detailed scans were followed throughout their infancy (mean 24 months; range 12-36 months). Post-natally, except for a correctable case of ventricular septal defect and a case of posterior urethral valve, no other abnormalities were detected. After excluding all aneuploid cases and using the maternal age as a second variable, an uncomplicated pregnancy outcome could be anticipated in 17 cases (100%) when the maternal age was <30 years and NT between 95th centile and 5 mm. However, the chance of a normal outcome dropped to 50% in four cases with maternal age > or =30 years and NT > or =5 mm (Fisher's exact test; P: = 0.02). These findings suggest that the long-term prognosis of the euploid fetuses with large NT (<5 mm) is reassuring in younger women.

Abortion, Spontaneous↗
PubMed2000

Detection of the immunoregulator p43-placental isoferritin in the human embryo and fetus.

Human placental isoferritin (PLF) is known to exert an immunosuppressive activity in vitro and is involved in the down-regulation of the maternal immune system during pregnancy. We have investigated the presence of PLF in the human embryo and early fetus and its secretion into amniotic fluid (AF) and fetal blood. Immunohistochemistry was performed on 25 normal embryos and fetuses, at 7-22 weeks gestation, using the CM-H9 monoclonal antibody (mAb), generated specifically against the human p43-PLF protein. The amount of p43 was measured in AF of 81 fetuses at 11-22 weeks and in the blood of 19 fetuses at 15-22 weeks by means of an enzyme-linked immunosorbent assay with the same mAb. Positive p43-PLF immunostaining was found from 7 weeks gestation in proximal tubules of the primitive nephron and macrophages of the liver sinusoids, blood vessels and mesenchymal tissue. In the AF samples, p43-PLF was first detected at week 15 gestation and thereafter steadily increased with advancing gestation whereas in fetal blood, p43-PLF was below or just above the lower limit of the assay. The gap between the first appearance of 43-PLF in embryonic tissue and its secretion into the amniotic fluid is probably linked to maturation of the renal function. The detection of the p43-PLF immunomodulator protein in macrophages at a very early stage of embryonic development and its very low concentration in fetal blood suggests that its immunoregulatory role is limited to the feto-maternal interface.

Adjuvants, Immunologic↗
PubMed2000

Serum inhibin A levels in pregnant women with systemic lupus erythematosus or antiphospholipid syndrome.

Maternal serum inhibin A levels are increased on average in pregnancies affected by Down syndrome (DS). However, some reports have found increased serum levels in women with pre-eclamptic toxaemia as well. In the current study, maternal serum inhibin A was retrospectively measured in a series of 32 serum samples from pregnant women previously diagnosed as having either systemic lupus erythematosus (SLE) or primary antiphospholipid syndrome (APS). For comparison, normal medians were calculated from 57 unaffected control pregnancies together with a total of 854 samples tested at 13-19 weeks of gestation as part of the routine antenatal DS screening. All results were expressed in multiples of the gestation specific normal medians (MoM). A cubic regression formula was fitted, weighting for the number of women tested at each gestation. The median MoM value in the 16 cases of SLE and the 16 cases of primary APS is 0.60 (95% confidence interval 0.40-0.91) and 0.88 (95% confidence interval 0.66-1.17), respectively. For primary APS this was not statistically significant, whereas the SLE patients had a highly statistically significant reduction of serum inhibin A (p<0.002, Wilcoxon Rank sum Test, 2 tailed). Six pregnancies in the SLE group had a complicated obstetric outcome, i.e. missed abortion, placental abruption, exacerbation of the underlying disease which necessitated delivery, and severe postpartum haemorrhage. In 85% of this subgroup, serum inhibin A levels were below the normal 10th centile. The current data suggest that serum inhibin A is decreased on average in SLE patients. Those preliminary results might have various obstetric implications such as antenatal DS screening of SLE patients, identification of pregnant women at risk of developing SLE, who have presented for routine DS screening and for monitoring SLE patients throughout their pregnancy.

Antiphospholipid Syndrome↗
PubMed2000

Screening for trisomies 21 and 18 with maternal serum placental isoferritin p43 component.

A component of placental isoferritin, p43, is an immuno-regulatory protein associated with suppression of the immune system. Maternal serum p43 levels increase throughout pregnancy and low serum levels have been associated with various pathological pregnancies, particularly those with a defect of placentation. We measured maternal serum p43 retrospectively in banked samples from 42 Down syndrome, 20 Edwards' syndrome and 281 unaffected pregnancies to assess its screening potential in both the first and second trimesters. The median maternal serum p43 level in Down syndrome was 1.58 times higher than that in the unaffected pregnancies (p=0.01, two-tail). The median level was slightly, but not significantly, reduced in Edwards' syndrome. Statistical modelling, including parameters for alpha-fetoprotein, free beta-human chorionic gonadotrophin, and unconjugated oestriol suggested that it might have a role in Down syndrome screening when combined with two or three of these markers. Larger scale studies are now needed.

Chorionic Gonadotropin, beta Subunit, Human↗
PubMed2000

Tel Aviv University postgraduate training program for overseas physicians: a decade of experience, 1989-99.

BACKGROUND: Training of overseas physicians is a challenging mission of potential mutual benefit to the trainees and their hosts. Back in 1989, a 3 months individual clinical training program was established by the Tel Aviv University in conjunction with the Ministry of Foreign Affairs and is conducted through the affiliated medical institute. An informative brochure is available at Israeli embassies worldwide. A meticulous recruitment process, extensive follow-up procedures, and the offering of incentives to the host department tutors are integral features of the program. OBJECTIVE: Upon the programs' tenth anniversary, we aimed to evaluate the 3 month training scheme from the perspective of our graduates. METHODS: An anonymous questionnaire was sent to all the physicians, who had graduated at least 6 months previously, in order to evaluate the program and their level of satisfaction. RESULTS: Of the 639 physicians, 398 (62%) responded. The theoretical level of the program was rated as "good" by 48% and "excellent" by 27% of the participants, and the practical level as "good" by 40% and "excellent" by 32%. Most (313, 82%) stated that this program contributed to their professional advancement. CONCLUSIONS: An international training program such as this can become an invaluable asset to local and overseas medical programs as well as for future collaborative projects, thereby contributing to the raising of medical practice standards in all participating countries.

Adult↗
PubMed1999

[Screening for Down's syndrome at week 10-14 by measuring fetal nuchal translucency thickness].

Increased fetal muchal translucency (NT) thickness at 10-14 weeks of gestation may indicate underlying fetal chromosomal abnormalities, anatomical anomalies and genetic syndromes. Between January 1997 and May 1998, 1400 women 10-14 weeks pregnant underwent sonographic screening for detection of Down's syndrome (DS). Follow-up was complete in 1208 (86%). Maternal age ranged from 17-44 years (mean 18.0). 87% were found by screening to have a higher risk (1:380) for DS diagnosed at birth. All these fetuses were karyotyped and 8 had chromosomal abnormalities. 2 fetuses with normal NT were diagnosed later as having DS, 1 by the mid-gestation triple test and 1 by amniocentesis because of advanced maternal age. Thus sonographic screening identified 8 out of 10 fetuses found to have chromosomal abnormalities at birth. Neonates not karyotyped before birth had no traits at birth that justified chromosomal analysis. Results of this study suggest that NT measurement, combined with maternal age, is an effective 1st trimester screening method for DS in an unselected obstetric population.

Adolescent↗
PubMed1999

[Pregnancy outcome in fetuses with increased nuchal translucency thickness at 10-14 weeks of pregnancy].

Increased thickness of fetal nuchal translucency (TNT) measured at 10-14 weeks of gestation, may suggest underlying fetal chromosomal defects, structural abnormalities or genetic syndromes. We examined the relationship between increased TNT and pregnancy outcome, especially in fetuses with normal karyotypes. 1400 pregnant women underwent first trimester scanning and screening for chromosomal abnormalities and measurement of fetal TNT. 25 fetuses (2%) with increased TNT (> 3 mm) were identified. 8 (30%) had an abnormal karyotype. Of these, 5 pregnancies were aborted, 3 ended in spontaneous abortions before karyotyping, and 2 were terminated, all before detailed cardiac scanning. There was a high association between increased TNT and karyotype abnormalities. The total incidence of favorable outcome in fetuses with normal chromosomal and cardiac features but enlarged TNT was 56%.

Abortion, Induced↗
PubMed1999

Smith-Lemli-Opitz syndrome presenting with persisting nuchal oedema and non-immune hydrops.

Smith-Lemli-Opitz syndrome (SLO) is a recognized clinical entity with distinctive anomalies. Recently it has been shown that a specific defect in cholesterol metabolism, 7-dehydroxycholesterol reductase deficiency, causes the multiple abnormalities seen in SLO. There have been two reports of first-trimester nuchal translucency associated with SLO. We report two cases of SLO in the third trimester, one with persisting nuchal oedema and the other presenting with hydrops. These findings may explain a proportion of the perinatal loss associated with this syndrome.

Adult↗