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Biomedical subjects

D Levine

Publications and source records attributed to D Levine.

At least 55 records · Page 3Linked to original sources
PubMed1999

Pravastatin therapy in hyperlipidemia: effects on thrombus formation and the systemic hemostatic profile.

OBJECTIVES: The study sought to determine the effects of lipid-lowering with pravastatin on the systemic fibrinolytic profile and on thrombus formation under dynamic flow conditions. BACKGROUND: Lowering cholesterol (C) decreases clinical events in coronary artery disease (CAD) patients, but an analysis of the effects of lipid-lowering on the entire hemostatic and thrombotic profile has not been conducted. METHODS: We prospectively studied 93 stable patients with untreated low-density lipoprotein cholesterol (LDL-C) >145 mg/dl. The CAD patients received pravastatin, and non-CAD patients were randomized to pravastatin versus placebo (double-blind). Thrombus formation upon an injured vascular surface was assessed in a substudy of 40 patients with a previously validated ex vivo perfusion chamber system. Systemic hemostatic markers and thrombus formation were evaluated at baseline, three and six months. RESULTS: Placebo produced no changes in either the lipid profile, any of the hemostatic markers, or the ex vivo thrombus formation. Both pravastatin groups (CAD and non-CAD) showed decreased LDL-C by 30% within 6 weeks (188 to 126 mg/dl, p < 0.001 vs. baseline), and decreased plasminogen activator inhibitor-1 at 3- and 6-month follow-up compared to baseline (15% to 18% decrease at 3 months and 21% to 23% at 6 months). For the tissue plasminogen activator antigen, CAD and non-CAD groups showed significant decreases at 6 months compared to baseline (10% and 13%, respectively). No significant changes were observed with treatment in d-dimer, fibrinopeptide A, prothrombin fragment F1.2, factor VIIa, von Willebrand factor, or C-reactive protein. Fibrinogen levels were significantly increased at 6 months compared to baseline, though still below the upper normal limit. In the perfusion chamber substudy, there was a decrease in thrombus area in non-CAD patients treated with pravastatin at both 3 and 6 months compared to baseline (by 21% and 34%, respectively). The CAD patients showed decreases in thrombus formation by 13% at 3 months, and by 16% at 6 months. The change in LDL-C- correlated modestly with the change in thrombus formation (r = 0.49; p < 0.01). CONCLUSIONS: Pravastatin therapy significantly decreased thrombus formation and improved the fibrinolytic profile in patients with and without CAD. These early effects may, in part, explain the benefit rendered in primary and secondary prevention of CAD.

Aged↗
PubMed1999

Pelvic Doppler.

This article reviews gray-scale and Doppler evaluation of the adexae and endometrium. Color Doppler is useful in distinguishing between cystic and solid masses. However, spectral Doppler is of limited utility in improving the gray-scale morphologic impression of a mass being either benign or malignant.

Adnexa Uteri↗
PubMed1999

Diagnostic accuracy with US: remote radiologists' versus on-site radiologists' interpretations.

PURPOSE: To compare the diagnostic accuracy of radiologists interpreting static ultrasonographic (US) images electronically transmitted to an academic medical center (remote radiologists) with that of radiologists performing "hands-on" US at a community-based outpatient site (on-site radiologists). MATERIALS AND METHODS: During 8 months, 80 patients underwent pelvic US at a community-based outpatient site. Images were electronically transmitted to a remote medical center as they were acquired at the community site and were printed on a laser printer identical to the one used at the outpatient site. The reference standard for correct diagnosis was based on histopathologic findings (n = 13), additional imaging results (n = 34), or review by a second independent observer (n = 33). Both an on-site and a remote radiologist interpreted the images, and their interpretations were rated as agree, both correct; agree, both incorrect; or disagree. Cases of disagreement were rated as major or minor. RESULTS: On-site and remote radiologists agreed in 69 of 80 patients (86%), and both radiologists were correct in all of these cases. There were 10 minor discrepancies and one major discrepancy. The diagnostic accuracies of the one-site and remote radiologists were 92% and 94%, respectively. CONCLUSION: High levels of diagnostic accuracy can be achieved by radiologists interpreting static US images. Strict protocols and excellent communication between the radiologist and sonographer are necessary to avoid diagnostic errors.

Academic Medical Centers↗
PubMed1999

Cortical maturation in normal and abnormal fetuses as assessed with prenatal MR imaging.

PURPOSE: To establish the appearance of normal fetal cortical development in utero and compare it with the appearance of abnormal cortical development. MATERIALS AND METHODS: Magnetic resonance (MR) images of the brain in 53 normal and 40 abnormal fetuses at 14-38 weeks gestational age (GA) were reviewed. The GAs at the time of MR imaging visualization of the fissures or sulci were compared with the GA guidelines based on neuroanatomic studies. RESULTS: In normal fetuses, the sulcation landmarks appeared on MR images in the order predicted by using anatomic studies, with a 0-8-week lag in the MR imaging visualization of the sulci compared with the reported time of visualization of the sulci in anatomic specimens. When landmarks were grouped by range of GAs, the expected MR imaging sulcation landmarks in the group with younger GAs than the actual GA were seen in 50 of 53 (94%) normal fetuses, in five of nine fetuses (56%, P < .05) with isolated mild ventriculomegaly, and in 24 of 31 fetuses (77%, P < .05) with other CNS anomalies. CONCLUSION: Normal fetal cortical maturation at MR imaging follows a predictable course that is slightly delayed compared with that described in neuroanatomic specimens. This maturation is often further delayed in fetuses with CNS abnormalities.

Agenesis of Corpus Callosum↗
PubMed1999

Obstetric MR imaging.

The surge in the development of fast magnetic resonance (MR) techniques has revolutionized our ability to image the pregnant patient and the fetus. Fast MR imaging techniques provide excellent resolution for imaging the maternal and fetal anatomies without the need for sedation. This article addresses the use of fast MR imaging techniques in the evaluation of the pregnant patient for adnexal masses, pelvimetry, hydroureteronephrosis of pregnancy, and placenta accreta. In addition, fetal anomalies for which MR imaging has proved useful, such as ventriculomegaly, arachnoid cysts, and abdominal masses, are described.

Female↗
PubMed1999

Lack of sensitivity of endometrial thickness in predicting the presence of an ectopic pregnancy.

The purpose of this study was to evaluate whether endometrial thickness measurements can be used to differentiate between patients with ectopic pregnancy and spontaneous abortion. Of 676 patients with clinical suspicion of ectopic pregnancy, no intrauterine pregnancy was seen in 128. Of these, 42 (33%) had ectopic pregnancy, 52 (40%) had spontaneous abortion, and 34 (27%) had intrauterine pregnancy. No significant difference was found in endometrial thickness between women with ectopic pregnancy (mean, 9.0 mm; range, 2 to 20 mm) and those with spontaneous abortion (mean, 8.4 mm; range, 2 to 18 mm). A thin endometrium seen on transvaginal sonography cannot be used to exclude the diagnosis of ectopic pregnancy.

Abortion, Spontaneous↗
PubMed1999

Sonographic appearance of early complete molar pregnancies.

Since our anecdotal experience indicates that the classically described "snowstorm" appearance on ultrasonography of early molar pregnancies is often not present and that theca-lutein cysts are also rare, we examined the ultrasonographic appearance of early complete molar pregnancies. We reviewed the ultrasonographic reports and clinical data of 21 cases of histologically diagnosed complete molar pregnancies with a mean gestational age at sonography of 10.5 weeks (range, 4 to 18 weeks). The diagnosis of molar pregnancy was made on ultrasonography in 12 (57%) cases, was second in the differential diagnosis of one (4.8%) case, and was not considered in eight (38%) cases. No theca-lutein cysts were identified. Five of five (100%) molar pregnancies of 13 weeks or over were diagnosed prospectively, while only eight of 16 (50%) earlier pregnancies were correctly diagnosed prospectively. In a retrospective review of the available images of 16 patients, only nine of 16 (56%) images demonstrated the classic appearance, and no theca-lutein cysts were seen. We conclude that the classic appearance of complete moles on ultrasonography is seen in less than two thirds of cases and even less commonly in the first trimester. The prevalence of theca-lutein cysts is very low.

Adult↗
PubMed1998

Sonographic assessment of the cervix in pregnancy.

Recent studies using transvaginal and transperineal sonography to monitor the cervix have dramatically increased our knowledge of morphological changes of the cervix throughout pregnancy. Knowledge of the normal and abnormal appearance of the cervix gives insight into the processes of premature labor and cervical incompetence. The finding of a short cervix can be used to identify (and possibly treat) patients at risk for premature delivery. This article reviews the use of cervical sonography in obstetric care, including the diagnosis of incompetent cervix, the detection and monitoring of premature labor, and the evaluation of placenta previa.

Cervix Uteri↗
PubMed1998

Jarcho-Levin syndrome: two consecutive pregnancies in a Puerto Rican couple.

This report describes two consecutive pregnancies in a Puerto Rican woman that were complicated by the autosomal recessive form of Jarcho-Levin syndrome (spondylothoracic dysplasia). This syndrome, with multiple vertebral and rib malformations, leads to respiratory insufficiency and early neonatal death. The prenatal sonographic appearance is characterized by the presence of fanned-out ribs from fused thoracic vertebral bodies. The features that distinguish spondylothoracic dysplasia and another subtype of Jarcho-Levin syndrome, spondylocostal dysplasia, are discussed. Prenatal diagnosis allows for parental counselling and the possibility of termination of pregnancy if the lethal type of spondylothoracic dysplasia is diagnosed prior to fetal viability.

Adult↗
PubMed1998

Fetal fast MR imaging: reproducibility, technical quality, and conspicuity of anatomy.

PURPOSE: To evaluate the normal appearance of fetal anatomy, the conspicuity of fetal organs, the reproducibility of images, and the limitations to image quality with the use of half-Fourier, single-shot rapid acquisition with relaxation enhancement (RARE) magnetic resonance (MR) imaging. MATERIALS AND METHODS: Fifty-four fetuses of 49 pregnancies underwent MR imaging with the half-Fourier, single-shot RARE technique. Two reviewers attempted to identify 47 organs and anatomic regions in each fetus. Organ or region conspicuity, image quality, and the limitations of image quality were graded. RESULTS: Fetal anatomy was well depicted in fetuses over 20 weeks in gestational age. Fetal imaging was limited by gestational age of 20 weeks or less usually owing to the small size of the organ or region being evaluated and, less frequently, by motion. CONCLUSION: Half-Fourier, single-shot RARE MR imaging provided a detailed and reproducible evaluation of normal fetal anatomy, which can be used as a standard of reference in MR imaging of fetal anomalies.

Artifacts↗
PubMed1998

Chorioamniotic separation after second-trimester genetic amniocentesis: importance and frequency.

PURPOSE: To determine the frequency and importance of chorioamniotic separation (CAS) after second-trimester genetic amniocentesis. MATERIALS AND METHODS: In part 1 of the study, ultrasonography (US) databases were reviewed for cases of CAS. In part 2, a study population of 388 women undergoing amniocentesis underwent directed US examination for assessment of CAS 15 minutes and/or 2 weeks after amniocentesis. CAS, when present, was graded. A control population consisted of 363 women undergoing amniocentesis in whom the membranes were not assessed. RESULTS: In part 1, a review of 23,883 records revealed seven cases of complete CAS, with three deaths, two preterm deliveries, and one emergency cesarean section delivery due to fetal distress. In two of these cases, there were extremity deformities at birth. In part 2, CAS was present in 98 (25%) of 388 women at some point. There was no association between CAS and procedural variables. There was no substantial difference in morbidity between patients with and those without CAS, between patients with different grades of CAS, or between the study and control populations. CONCLUSION: Small degrees of CAS are frequently present after amniocentesis but are not detected because the membranes are not specifically evaluated. Complete CAS is less frequent.

Adult↗
PubMed1998

Distention of the fetal duodenum: abnormal finding?

We investigated whether a fluid-filled duodenum is observed in normal fetuses. In part 1 of the study a view in the region of the duodenum was obtained during routine obstetric ultrasonography from 123 low-risk patients. All examinations demonstrated a collapsed duodenum. No gastrointestinal abnormalities were found in these infants. In part 2 of the study, 1163 fetuses (both high-risk and low-risk) were evaluated with real-time scanning, and duodenal fluid without a "double bubble" was seen in one fetus who had a duodenal web. We conclude that a nondistended fetal duodenum is the norm. If fetal duodenal dilation is visualized, this may allow for earlier detection of duodenal obstructions.

Body Fluids↗
PubMed1998

Effect of maternal hydration on mild fetal pyelectasis.

The aim of our study was to determine whether maternal hydration status prior to prenatal sonography affects fetal renal pelvic diameter. The renal pelvic diameters of fetuses from two different institutions were compared prospectively. At one institution 74 women were asked to drink 32 to 48 ounces of water prior to undergoing sonography (hydration group), whereas at the second institution, no specific hydration regimen was requested of 176 subjects. The inclusion criteria were as follows: greater than 15 weeks' gestation, otherwise normal obstetrical sonogram, normal amniotic fluid volume, and negative family history for renal disease. Renal pelvic diameter, degree of maternal bladder fullness, and gestational age were compared between the two groups using logistic regression analysis and log-linear analysis. A P value < 0.01 was considered significant. Bladder fullness in the two groups differed significantly (P < 0.001). Logistic regression analysis showed a very strong effect of maternal bladder fullness on fetal renal pelvic diameter (P < 0.001). The log-linear analysis model showed a highly significant association between maternal bladder fullness and fetal renal pelvic diameter (P < 0.001). We conclude that maternal hydration influences fetal renal pelvic diameter. The larger fetal renal diameters seen in the hydrated group support physiologic theories that the effects of maternal hydration on amniotic fluid volume are partially mediated via fetal urine production.

Dilatation, Pathologic↗
PubMed1998

Prenatal neurosurgical diagnosis and counseling.

Neonatal neurosurgical management occasionally begins with prenatal counseling. New imaging techniques have made the detection and diagnosis of structural anomalies of the fetal central nervous system commonplace. The neurosurgeon can be called on to interpret the meaning of diagnostic studies and must be ready to meet this emerging challenge. The most frequently encountered antenatal diagnoses are reviewed here, with a special emphasis on ultrasound and MR image findings.

Counseling↗