Search PubMed⌕ Search

Biomedical subjects

I Blickstein

Publications and source records attributed to I Blickstein.

At least 55 records · Page 3Linked to original sources

Quantitative assessment of gray-level perception: observers' accuracy is dependent on density differences.

Sonographic image density represents tissue echogenicity, or the acoustic nature of scanned tissue. It has the potential to distinguish normal from abnormal tissue. Humans are poor assessors of tissue echogenicity, yet their abilities have not been quantitatively compared to more objective methods. We compared the accuracy of image density differentiation by the human eye and by densitometry in the fetal liver model. A group of 60 observers was asked to compare the echogenicity of three pairs of images of a fetal liver. Twenty-three repeated the comparison several weeks later. Image density was measured by electro-optical densitometry. The two-tailed signed rank test was used to compare the observer's perceptions with the density values and the repeated observations with the original responses. The density of each fetal liver image in pair A was the same. Image B1 had a 12.3% lower density than image B2, and image C1 had a 6.3% greater density than image C2. Observers were accurate more often when comparing images with large density differences (pair B) than they were when comparing images with the same density (pair A) or with small density differences (pair C). Accuracy was not related to being medically qualified or from an obstetric or gynecological department. Intraobserver variation was not significant. We conclude that the human eye is extremely inaccurate at discerning differences in echogenicity when images have small or no differences in optical density. Densitometry is, therefore, indispensable for accurate image density assessment.

Densitometry↗

Computed sonography: requiem to echogenicity assessment?

We studied the influence of changes in gain settings, log compression, persistence, preprocessing, and postprocessing on image density in the fetal liver model. Each parameter was studied while the others were held constant. The image density was objectively measured by electrooptical transmission densitometry using a transparent film output. Neither the persistence nor the preprocessing levels significantly changed image density. Postprocessing of sonographic images produced significant differences (p < 0.02) in mean image density of most of the various postprocessing curves and is a serious confounder of tissue echogenicity assessment. The data reconfirmed that there is a linear relationship (r = -0.94 to -0.997) between image density and gain setting. However, each log compression setting significantly changed (p < 0.0000001) this relationship, obviating possible image density calibration. Our data suggest that manipulation of image parameters by computed sonographic technology obviates accurate echogenicity assessment.

Densitometry↗

Maternal mortality in twin gestations.

OBJECTIVE: To review various aspects of maternal morbidity and delivery complications leading to maternal death in twin gestations. STUDY DESIGN: Literature research. RESULTS: The incidence of maternal mortality associated with twin gestation is not known but can be estimated from a few community-based series and from studies on maternal morbidity related to twins. The combination of physiologic changes and perinatal pathologies that are either unique or more common in twin gestations (e.g., preeclampsia/eclampsia, need for tocolysis, anemia, abruption placentae, special delivery circumstances and cesarean section) is certainly increasing the maternal risk for serious morbidity and even mortality. CONCLUSION: Twin pregnancies should be included among the categories of pregnancy-related maternal death in order to learn how to eliminate avoidable mortality in twin gestations.

Abruptio Placentae↗

Post-traumatic vulvar endometriosis.

We report a case of vulvar endometriosis presenting as a vulvar mass following trauma in a 12 years old, 3 months post-menarcheal girl. The presumptive etiology is the direct implantation of endometrial cells. Painful swelling of the vulvar mass appeared gradually during menses. Excision of suspected vulvar endometriosis is suggested as the definite treatment.

Child↗

Is intertwin birth weight discordance predictable?

OBJECTIVE: To compare the efficacies of intertwin difference in abdominal circumferences (ACs) and estimated fetal weight (EFWs) to predict birth weight discordance in twin gestations. METHODS: Ninety pairs of twins with sonographic measurements of AC and femur length, performed within 2 weeks before delivery, were included in the study. The EFW was calculated (Hadlock's formula). We used Bayes' theorem and the Mantel-Haenszel chi 2 test to calculate and compare the rates of false-positive and false-negative prediction of the cutoff values of 15, 20, and 25% intertwin birth weight discordance by the intertwin EFW difference and an intertwin AC difference of > or = 18 mm. RESULTS: There were no significant difference between the two methods to predict birth weight discordance at 15-25% discordance (p = 0.254, OR = 0.33, 95% CI = 1.45-0.24) and at > 25% discordance (p = 0.112, OR 0.18, 95% CI = 0.03-1.34). CONCLUSIONS: Both the intertwin AC difference (> or = 18 mm) and intertwin EFW difference have similar negative predictive values and the same efficacy to exclude discordant growth. Because of the relatively low positive predictive values, birth weight discordance cannot be accurately predicted by either method.

Bayes Theorem↗

Hyperestrogenemia and presence of estrogen receptors associated with an epithelial ovarian tumor of low malignant potential.

An 80-year-old woman presented with breast congestion, tenderness and pain. Mammography was normal. Circulating estradiol was markedly elevated, while LH and FSH were low. Pelvic examination and imaging revealed an ovarian mass which was extirpated during total abdominal hysterectomy and bilateral salpingo-oophorectomy. Histopathology revealed an ovarian mucinous cystadenocarcinoma of low malignant potential, stage 1. The tumor was positively stained for estrogen receptors. Estradiol levels returned to normal post-operatively, with a corresponding adjustment of LH/FSH. Possible autocrine steroid production is discussed.

Aged↗

The intrauterine ponderal index in relation to birth weight discordance in twin gestations.

OBJECTIVE: To establish the relationship between the fetal ponderal index and birth weight discordance in twins. METHOD: The fetal ponderal index (estimated fetal weight divided by femur length3) was calculated in 86 pairs of twins delivered within 2 weeks of the last sonography and analyzed in relation to birth weight discordance. RESULTS: A weak but significant correlation between fetal ponderal index and birth weight (r = 0.26, P < 0.0007) but no correlation with gestational age (r = 0.035, P = 0.65) were found. Members of concordant pairs (< 15% birth weight difference) had a significantly higher fetal ponderal index compared with members of mildly (15-25%) discordant pairs (P < 0.02), but not as compared with members of severely discordant (> 25%) pairs. CONCLUSION: The characteristics of the fetal ponderal index in twins are similar to those in singletons. Fetal size seems to be diminished in severe but not in mild discordants. However, in its present form, the fetal ponderal index is a poor predictor of discordant growth and therefore should be employed cautiously in twin gestations.

Birth Weight↗

Menopause is associated with a significant increase in blood monocyte number and a relative decrease in the expression of estrogen receptors in human peripheral monocytes.

PROBLEM: The clinical significance of the differential expression of estrogen receptor (ER) in human monocytes was evaluated. METHOD: Two color flow cytometry analysis was used on peripheral blood samples of young and postmenopausal females and postmenopausal females treated with estrogen replacement therapy. In addition, the monocyte and lymphocyte counts and the blood estrogen levels of each patient were determine. RESULTS: During menopause there is a significant decrease in the percentage of ER positive monocytes, and an increase in blood monocyte number, which declines following estrogen replacement therapy to values of the young. CONCLUSIONS: These findings suggest that estrogen modulates the monocyte numbers and its effects may be mediated through the ER in the monocytes.

Adolescent↗

Can placental surface area and neonatal weight be predicted from placental surface measurements? Preliminary observations on normal-term pregnancies.

OBJECTIVE: To evaluate the relations between chorionic plate measurements and neonatal weight as prerequisites for possible prediction of fetal weight using antenatal placental measurements. METHODS: We examined freshly delivered placentas. The surface area (chorionic plate) was measured using millimeter paper, and the two longest diameters (at right angles to each other) were determined (L1 and L2). The mean longest diameter [Lm = (L1 + L2)/2] was calculated. The relation of these diameters to neonatal and placental weight was studied. RESULTS: We examined 57 randomly selected placentas after normal pregnancy and delivery. The three chorionic plate diameters significantly correlated with the surface area and the placental and neonatal weights. The strongest correlation (r = 0.94; p < 10(-6) was found between Lm and placental surface area. CONCLUSIONS: Our preliminary results suggest that chorionic plate measurements may be suitable to predict placental surface area and neonatal birth weight in normal-term pregnancies. Further studies to verify prospectively these relations at various gestational ages and in cases of abnormal fetal growth are required.

Birth Weight↗

Assessment of estrogen receptor distribution in human endometrium by direct immunofluorescence.

OBJECTIVE: To use a direct immunofluorescence technique employing a fluorescein labeled anti-idiotypic antibody that recognizes the estrogen receptor (ER) order to assess the distribution of ER in the uteri of normal women throughout the normal menstrual cycle and of a woman exposed prenatally to diethylstilbestrol (DES). SUBJECTS: Included in the study were 25 women aged between 35 and 50 years and an amenorrheic patient diagnosed as "DES Syndrome". LOCALIZATION: Localization of ER expression in frozen sections of uterine tissue was achieved by direct immunofluorescence using a fluorescein labeled anti-idiotypic antibody that interacts with ER. RESULTS: Analysis of the immunofluorescence staining indicated that in the normal human endometrium the intensity of ER staining varied according to the phase of the cycle as well as according to the cell type. On the other hand, endometrial ER evaluation of the patient with DES syndrome showed minimal expression of ER and after treatment with conjugated estrogens, endometrial biopsy revealed a significant increase in ER expression. CONCLUSIONS: These findings indicate that the fluorescein labeled anti-idiotypic antibody can be used to detect ER in normal and pathological human endometrium and to monitor changes in ER expression in the endometrium during hormonal therapy.

Adult↗

Quantitative comparison of two distinct echogenic structures appearing on the same image using gain-assisted densitometric evaluation of sonograms (GADES).

Gain-assisted densitometric evaluation of sonograms with two distinct echogenic structures appearing on each image was performed to establish if their density-gain setting curves have similar inclinations. We used the breast model (n = 67) in which hyperechoic masses were compared to the surrounding hyperechoic tissue at the optimal gain (Gopt) and at Gopt + 5. Both structures had significantly different film-corrected densities and showed a linear decline of density as the system gain increased from Gopt - 5 to Gopt + 5. The least squares regression lines were almost parallel. The density-gain unit decrease from Gopt - 5 to Gopt was not different, but the decrease from Gopt to Gopt + 5 reached statistical significance. The data suggest that skewed values are theoretically possible in comparing two distinct echogenic structures. However, within the gain intervals used in GADES, these differences are negligible and comparisons are as accurate as with the assessment of a single echogenic structure.

Breast Neoplasms↗

Echogenicity of fibroadenoma and carcinoma of the breast. Quantitative comparison using gain-assisted densitometric evaluation of sonograms.

The purpose of this study was to evaluate the role of ultrasonography in differentiation between the echogenic characteristics of carcinoma and those of fibroadenoma of the breast. Two mathematical transformations of the measured density on a sonographic image of the breast lesion at three different system gain settings were used in cases of carcinoma (n = 16) and fibroadenoma (n = 31) to provide standardized density values. A significant correlation was found between the tumor and the surrounding tissue densities in both carcinomas (r = 0.77, P = 0.0004) and fibroadenomas (r = 0.79, P < 0.000001. The mean standardized density of the tumor was significantly higher (P < 0.0001) than the surrounding tissue in both carcinomas (2.03 +/- 0.64 D versus 1.23 +/- 0.38 D) and fibroadenomas (2.09 +/- 0.48 D versus 1.33 +/- 0.3 D). However, the differences between density values of carcinoma and fibroadenomas were not significantly different. The data suggest that it may not be possible to differentiate breast carcinoma and fibroadenomas on the basis of the echogenicity of solid breast masses.

Adolescent↗

Pregnancy order. A factor influencing birth weight in twin gestations.

To test the hypothesis that increased twin birth weight is expected with increased parity, we conducted a retrospective, cross-sectional evaluation of 430 twins, focusing on birth weight and growth discordance parameters in five parity groups (para 1-4 and > or = 5). The mean birth weight of twin A, B and both twins was significantly lower in primiparous patients as compared to para 2-4 but not as compared to para > or = 5 patients. The frequency of twins weighing < 1,500 g was similar in all groups, but a significantly higher frequency of twins weighing 1,500-2,500 g and lower frequency at > 2,500-g twins were found in the para 1 group as compared to the groups with higher parities. Presentation combinations were not different in the five parity groups, nor were the frequencies of growth discordance categories. However, discordants among pairs, with each infant weighing < 2,500 g, occurred almost twice as often in para > or = 5 as compared to the other parity groups. Our data indicate that primiparae seem to have significantly smaller twins as compared to multiparae. This trend was independent of the presentation combinations and growth discordance pattern and seems to result from a higher frequency of twins weighing 1,500-2,500 g in primiparae.

Birth Order↗

Hemoglobin levels during twin vs. singleton pregnancies. Parity makes the difference.

A retrospective, case-control study of 200 consecutive twin and singleton gestations matched for parity was conducted to challenge the hypothesis that lower hemoglobin values appear more often during twin gestations. The database consisted of hemoglobin levels recorded during each trimester. Comparisons were made between the mean hemoglobin levels and incidence of values > 11, 9-11 and < 9 g/dL. Significantly lower mean (+/- SD) hemoglobin values were observed during the first (11.94 +/- 1.1 vs. 12.17 +/- 1.0, P = .026) and second (11.1 +/- 1.0 vs. 11.48 +/- 0.9, P = .00001) trimesters in twin vs. singleton pregnancies, respectively. The differences resulted from lower values in multiparas with twins as compared with their singleton-pregnancy controls (11.8 +/- 1.2 vs. 12.2 +/- 0.9, P = .015, for the first trimester and 11.0 +/- 1.0 vs. 11.5 +/- 0.9, P = .0001, for the second trimester). During the second trimester, the lower incidence of values > 11 g/dL (P = .005, odds ratio = .475, 95% confidence interval = .31-.73) and higher incidence of values between 9 and 11 g/dL (P = .0008, odds ratio = 2.06, 95% confidence interval = 1.34-3.19) may account for the significant differences in mean values. There were no differences between third-trimester values, between nulliparas in both groups or between nulliparas and multiparas in each group. We conclude that the lower hemoglobin levels in twin gestations were associated with multiparity and were statistically significant during the first and second trimesters. This subgroup of twin pregnancies may benefit from further research and possibly from closer hematologic care and monitored iron supplementation.

Adult↗

Successful resolution of persistent trophoblastic disease after partial mole with the EMA-CO regimen.

A 29-year-old nullipara with partial hydatidiform mole at 8 weeks had pre-evacuation hCG levels of 275,000 mIU/ml. Free beta-hCG levels were measured as 3% (normal value below 4%). The patient developed persistent gestational trophoblastic disease, failed to respond to methotrexate and actinomycin D, but has responded to combination chemotherapy with EMA-CO. Such a response to EMA-CO was not reported previously.

Adult↗

Prenatal diagnosis of twin zygosity by DNA 'fingerprint' analysis.

A twin pregnancy with one hydrocephalic fetus with oligohydramnios is presented. Sonographic evaluation could not exclude monochorionicity. Before considering selective feticide, blood samples from both fetuses were examined for DNA 'fingerprint' analysis. The different banding patterns of the blood samples established dizygosity. This procedure is suggested in cases where sonography fails to determine chorionicity.

Abortion, Therapeutic↗