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Biomedical subjects

D L Levy

Publications and source records attributed to D L Levy.

At least 37 records · Page 2Linked to original sources
PubMed1994

Outcome of pregnancies complicated by sickle cell and sickle-C hemoglobinopathies.

Retrospective analysis was made of office and hospital records of patients with sickle cell hemoglobinopathies. Blood products were transfused only when indicated for symptomatic anemia, severe anemia with a hematocrit less than 18%, sickle crisis, cardiovascular instability, and preoperatively. The Fisher exact test and the Student t test were used for statistical analysis; P < 0.05 was considered significant. All mean values are reported +/- 1 standard deviation. From 1981 to 1991, 40 patients with sickle cell hemoglobinopathies had a total of 61 singleton pregnancies: 36 were complicated by SS disease (SSD), 22 by sickle cell disease (SCD), two by sickle-thalassemia, and one had CC disease (CCD). Only patients with SSD and SCD are reported here. The mean maternal age was 24.3 +/- 5.3 and 19.5 +/- 0.6 years in patients with SSD and SCD, respectively. There was a high occurrence of preterm labor (45% and 20%), preeclampsia (20% and 8.7%), pain crisis (50% and 34.2%), pulmonary complications (25% and 16.7%), and cesarean sections (52.6% and 37.1%) in SSD and SCD, respectively. An average of two units of blood was required by 43.1% of the patients. Two patients with SSD had unpreventable deaths. The mean gestational age at delivery was 35.5 +/- 4.3 and 37.0 +/- 3.7 weeks (P < 0.05), and the mean birthweight was 2443 +/- 926 and 2997 +/- 807 g (P < 0.05), respectively. There were two intrauterine fetal deaths and one neonatal death in the SSD group and one neonatal death in the SCD group. The perinatal mortality was 10.5% and 2.9%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Eye tracking and schizophrenia: a selective review.

The replications of the finding of eye tracking dysfunction (ETD) in schizophrenia patients and their first-degree relatives suggest that ETD may be informative in studies of a schizophrenia genotype having broadly defined phenotypes. We review and critically assess the literature on ETD with respect to syndrome and familial specificity and discuss the quantitative assessment of eye tracking.

Attention↗
PubMed1994

Prenatal sonographic findings in trisomy 13, 18, 21 and 22. A review of 46 cases.

A study of 46 patients with trisomic fetuses was performed to determine if there are one or more second-trimester ultrasonic findings predictive of aneuploidy. Videotapes of ultrasonography performed prior to amniocentesis on the 46 fetuses with autosomal trisomy and from a control group of 50 chromosomally normal fetuses were reviewed without knowledge of the karyotype. Fetuses with autosomal trisomies had short long bones, especially femurs, as well as high biparietal diameter/femur length ratios. In addition, a nuchal thickness of > 5 mm, abnormal heart anatomy, slight pyelectasis, increased bowel echogenicity and/or abnormal flexion of the hands were all predictive of autosomal trisomies.

Adult↗
PubMed1993

Brain morphology, dopamine, and eye-tracking abnormalities in first-episode schizophrenia. Prevalence and clinical correlates.

OBJECTIVE: To characterize the pathophysiology of schizophrenia and to identify biologic markers in first-episode patients with no or little prior treatment exposure. DESIGN: Prospective study of an inception cohort. SETTING: Psychiatric division of an academic medical center with a suburban metropolitan catchment area. PATIENTS: 70 patients in their first episode of schizophrenia (77%) or schizoaffective disorder (23%) with no (70%) or limited prior neuroleptic exposure (30%), and 50 healthy volunteer control subjects. ASSESSMENT MEASURES: Demographic and clinical evaluations of natural history and psychopathology; methylphenidate hydrochloride and apomorphine hydrochloride stimulation tests as measures of central nervous system dopamine activity; brain magnetic resonance imaging; eye-tracking examinations. RESULTS: Preliminary analyses demonstrate that pathobiologic features previously identified in heterogeneous and primarily chronically ill patients are also present in subgroups during their first episode. These include psychotogenic response to methylphenidate (59%), abnormal growth hormone (GH) secretion (50%), abnormal brain morphology (31%), and eye-tracking dysfunction (51%). An association of pathobiologic variables with increased symptom severity and earlier age of onset was observed but not statistically significant. The strongest associations among biologic variables were for the following: GH secretion and psychotogenic response to methylphenidate, which may reflect increased dopamine agonist neural activity; decreased GH response to apomorphine and third-ventricle enlargement, which may represent a neuropathologic correlate of anterior pituitary abnormalities; and morphologic abnormalities of the medial temporal lobe and third ventricle were associated with normal eye tracking, suggesting that these pathobiologic features are mediated by distinct processes. CONCLUSIONS: These phenomena appear to be a consequence of the disease rather than the effects of chronicity, drug treatment, or institutionalization. It remains to be determined if these biologic phenomena will remain stable over time or change with disease progression. A companion article examines the clinical significance of these findings.

Adolescent↗
PubMed1993

Obstetrical complications in patients with bipolar disorder and their siblings.

Although indirect evidence suggests that obstetric complications are risk factors for bipolar disorder, few studies have directly addressed this question. Probands with bipolar disorder and their adult siblings were diagnosed according to DSM-III-R criteria by clinicians who had no knowledge of the subjects' obstetrical histories. Hospital records on gestations and births of 16 probands and 20 of their siblings without major mood disorders were scored for obstetric complications without knowledge of diagnosis. The assessment of obstetrical history was based on rating scales that have proved reliable and that reflect the number and severity of complications. Overall complication scores were significantly more severe in probands than siblings. Differences were most marked for perinatal complications.

Adult↗
PubMed1993

Eye tracking dysfunction and schizophrenia: a critical perspective.

Eye tracking dysfunction (ETD) has been found in large numbers of schizophrenia patients and their first-degree relatives. Because of the many replications of the central findings, ETD has been proposed as a useful way of expanding the schizophrenia phenotype in genetic studies. We critically review the literature on ETD with respect to issues of measurement and the search for quantitative indices of ETD; syndrome and familial specificity of ETD for schizophrenia; statistical, interpretive, and methodological considerations in the use of mixture analysis; the association of ETD with clinically and psychometrically defined schizotypy; and the questions of trait stability and medication effects.

Arousal↗
PubMed1992

Gene expression in mental illness: a navigation chart to future progress.

An initial course in disentangling complex causal interactions in psychiatric illnesses, we suggest, is finding co-familial traits with classical Mendelian segregation. Starting with non-Mendelian traits, three methods can be used to find underlying Mendelian phenotypes. (1) Statistically-inferred latent traits, with more nearly Mendelian transmission than the measures from which they are derived, can serve as pointers to concrete Mendelian phenotypes. (2) Linkage of non-Mendelian traits to genetic markers, if it can be established, can be followed by searching for phenotypes that discriminate carriers from non-carriers of the imputed trait gene. (3) In the long run, the most successful method is likely to be direct refinement of non-Mendelian behavioral and physiological traits into more fundamental components.

Bipolar Disorder↗
PubMed1992

Normal eye tracking is associated with abnormal morphology of medial temporal lobe structures in schizophrenia.

Eye tracking and brain morphology assessed by magnetic resonance imaging were examined in 48 patients in their first episode of schizophrenia and in 15 normal controls. Schizophrenic patients showed higher rates of eye tracking dysfunction and more abnormal brain morphology involving the lateral ventricles, medial temporal lobe (MTL) structures and the frontal-parietal cortex than controls. Enlargement of the lateral ventricles and global rating of abnormal brain morphology were significantly more prevalent in male schizophrenics than female schizophrenics. These findings indicate that abnormalities in a variety of brain regions are present in some schizophrenics during the period shortly after the first hospitalization and could not be a function of treatment or chronic illness. We found no relation between abnormal eye tracking and any single feature of abnormal brain morphology. However, normal eye tracking was significantly associated with MTL abnormalities in schizophrenics, reflecting an inverse association between quality of eye tracking and degree of abnormality in MTL structures. These results suggest that abnormal eye tracking is not mediated by the same processes that lead to structural brain anomalies in schizophrenia.

Adolescent↗
PubMed1991

Value of a random single Doppler study of the umbilical artery for predicting perinatal outcome.

A prospective blinded study was performed on 191 high-risk patients with pregnancies ranging from 25 to 42 weeks gestation to investigate the value of a single Doppler analysis of the umbilical artery blood flow waveform (systolic-to-diastolic ratio, S/D) for predicting poor perinatal outcome. This was defined as the presence of heavy meconium, delivery of a growth-retarded infant, an umbilical cord arterial pH less than 7.2, or a 5-minute Apgar score less than 7. The interval between Doppler examination and delivery ranged from 12 hours to 15 weeks. No clinical data were available to the examiner performing the Doppler study. Moreover, the Doppler measurements were unknown to the attending physicians. The sensitivity, specificity, and positive and negative predictive values of the Doppler study in predicting outcome were 30.4%, 92.9%, 36.8%, and 92.6%, respectively, with an adverse outcome prevalence of 12%. These results indicate that a single random S/D ratio from the umbilical artery is not an adequate screening test for the risk of perinatal complications.

Female↗
PubMed1990

Placental histology in fetuses between 18 and 23 weeks' gestation with abnormal karyotype.

Placentas from karyotypically abnormal fetuses (18 to 23 weeks' gestation) were analyzed prospectively at the light microscopic level. Group I consisted of 14 control placentas. Group II consisted of 14 placentas from fetuses with an abnormal karyotype. Secondary and tertiary stem villi counts, small muscular artery counts, and total vessel counts were determined per 100 x field. There were no differences in secondary and tertiary stem villi counts between groups. A significant decrease in small muscular artery counts (p less than 0.01) and total vessel counts (p less than 0.01) was noted in group II. Placental and fetal weights were comparable between groups. This undervascularization may represent placental immaturity as a result of arrested or delayed angiopoiesis. It appears that this abnormality is established before the third trimester and may be enhanced by late vascular obliteration as reported by others. These data substantiate the concept that the structure and function of the placenta is determined to a great degree by fetal karyotype and may help explain the morbidity and mortality seen in these fetuses.

Chorionic Villi↗
PubMed1989

Congenital cystic hygroma of the neck diagnosed prenatally: outcome with normal and abnormal karyotype.

Twenty-two cases of cystic hygromas were diagnosed prenatally at Eastern Virginia Medical School and followed through the neonatal period. Our series was combined with 131 cases which have been described in the literature. Karyotypes were obtained in 110 fetuses and 80 (72.7 per cent) were abnormal. Fifty-one were not terminated: 30 with abnormal and 21 with normal karyotypes. There were no neonatal survivors in the group with abnormal karyotypes. There were five survivors in the 21 with normal karyotypes but only 2/21 without severe medical complications. Combining our series with those previously reported in the literature would suggest only a 2-3 per cent rate of intact survivors when fetal cystic hygromas are diagnosed in utero. This information should be helpful when counselling patients whose pregnancies carry this diagnosis.

Amniotic Fluid↗
PubMed1989

Doppler study of umbilical artery blood flow waveform. Should we use an instrument-adapted nomogram?

Doppler studies of umbilical artery blood flow waveform are becoming an accepted tool of antenatal estimation of fetal well-being. The S/D ratio of the systolic peak (S) to the end-diastolic (D) frequency is the most commonly used parameter. Nomograms relating S/D ratio to gestational age have been published both for normal and pathologic pregnancies. Three hundred twelve analyses of umbilical artery blood flow were performed by continuous Doppler technology in normal, well-dated pregnancies using either one of the following instruments: GE 3600 (GE) or Multigon 500A (MG). Both instruments showed a decrease of S/D with GA, but, by use of a nonpaired t test, a statistically significant difference was found between the two machines. Data on the system used for a particular study should be provided; nomograms for this particular instrument should be consulted and the same machine should be employed for repeat testing in longitudinal studies.

Blood Flow Velocity↗
PubMed1989

Doppler analysis of the umbilical artery. The importance of choosing the placental end of the cord.

Thirty normal pregnancies were studied with continuous or pulsed Doppler ultrasound (50 measurements). The ratio of systolic (S) to end-diastolic (D) measurement, or S/D ratio, was obtained at both ends of the cord: the placental insertion and the fetal abdominal insertion. A statistically significant difference was demonstrated between the two sets of measurements. Normal values were obtained at the placental insertion, whereas, simultaneously, the fetal abdominal insertion generated highly abnormal values. When performing Doppler waveform analysis of the umbilical artery, if abnormal values are obtained, one should be cautious to be certain that they originated from the placental insertion.

Blood Flow Velocity↗