Search PubMed⌕ Search

Biomedical subjects

Jerome Yankowitz

Publications and source records attributed to Jerome Yankowitz.

At least 19 recordsLinked to original sources

Association of single nucleotide polymorphisms in the thrombopoietin-receptor gene, but not the thrombopoietin gene, with differences in platelet count.

Little is known about the mechanisms explaining the wide variation in platelet counts (PLT) and other hematologic parameters in humans. We previously showed that the sex-based difference in hematocrit was associated with nucleotide variation in the erythropoietin receptor gene (EPOR). We sought to identify new polymorphisms of the human thrombopoietin (TPO) and thrombopoietin receptor (TPOR) genes to determine any associations with blood PLT counts. We screened TPO and TPOR for polymorphisms using single-strand conformation polymorphism (SSCP) and DNA sequencing. Association of polymorphisms was studied in 304 normal subjects with low or high PLT counts. Distribution of allelic frequency was analyzed by the Chi-square statistic. Single nucleotide polymorphisms (SNPs) with two alleles were found in TPO and TPOR. The TPO SNP was a G to A transition at nucleotide 5753, and the TPOR SNP was a C to A transversion at position 550 in the 5'-promoter area. The allelic frequencies were 0.54 for G and 0.46 for A of TPO, and 0.62 for C and 0.38 for A of TPOR in a Caucasian population. The frequency of the TPOR allele "C" was significantly higher in subjects with high PLT count (>258 k/mm3) versus low PLT count (<224 k/mm3) and in males with high PLT count (>258 k/mm3) versus males with low PLT count (<212 k/mm3). In contrast, the frequency of the TPO alleles was not related to blood PLT counts. An association of TPO and TPOR allele distribution to red and white blood cell parameters was seen. These new SNPs found for the human TPO and TPOR genes help explain variations in blood PLT counts and may be useful in patient studies related to the roles of TPO and/or TPOR in disease.

Adolescent↗

Amygdala and hippocampal volumes in Turner syndrome: a high-resolution MRI study of X-monosomy.

Turner syndrome (TS) results from partial or complete X-monosomy and is characterized by deficits in visuospatial functioning as well as social cognition and memory. Neuroimaging studies have demonstrated volumetric differences in the parietal region of females with TS compared to controls. The present study examined amygdala and hippocampus morphology in an attempt to further understand the neural correlates of psychosocial and memory functioning in TS. Thirty females with TS age 7.6-33.3 years (mean = 14.7 +/- 6.4) and 29 age-matched controls (mean age = 14.8 +/- 5.9; range = 6.4-32.7) were scanned using high resolution MRI. Volumetric analyses of the MRI scans included whole brain segmentation and manual delineation of the amygdala and hippocampus. Compared to controls, participants with TS demonstrated significantly larger left amygdala gray matter volumes, irrespective of total cerebral tissue and age. Participants with TS also showed disproportionately reduced right hippocampal volumes, involving both gray and white matter. Amygdala and hippocampal volumes appear to be impacted by X-monosomy. Aberrant morphology in these regions may be related to the social cognition and memory deficits often experienced by individuals with TS. Further investigations of changes in medial temporal morphology associated with TS are warranted.

Adolescent↗

Oral hypoglycemic agents in pregnancy.

UNLABELLED: Pregnancies in diabetic women are associated with increased risk of spontaneous abortion, congenital malformations, preeclampsia, preterm labor, macrosomia, shoulder dystocia, and cesarean section. Advances in antepartum cares and strict adherence to dietary and insulin regimens have been shown to significantly reduce the rate of maternal morbidity as well as perinatal morbidity and mortality. Historically, reports of potential fetal teratogenicity and hypoglycemic effects on the fetus contraindicated the use of oral hypoglycemic agents in pregnancies complicated with either type II diabetes mellitus (DM) or gestational diabetes mellitus (GDM). Recently, physicians increasingly prescribe newer generations of oral hypoglycemic agents to treat GDM and type II DM to pregnant patients. This review addresses the safety, current recommendations, and controversies surrounding use of the available oral hypoglycemic agents during pregnancy. TARGET AUDIENCE: Obstetricians & Gynecologists, Family Physicians LEARNING OBJECTIVES: After completion of this article, the reader should be able to describe the mechanisms of actions of the various oral hypoglycemic agents, to list the known side effects of these agents, and to summarize the data on the use of these agents during pregnancy.

Administration, Oral↗

Human papillomavirus prevalence and types in newborns and parents: concordance and modes of transmission.

BACKGROUND AND OBJECTIVES: The purpose of this investigation was to determine the risk of vertical and early contact transmission of human papillomavirus (HPV) in newborn infants based on concordance and sequence match to HPV types in parents. STUDY DESIGN: The genitals of pregnant women and newborns and oral cavity of parents and newborns were analyzed using polymerase chain reaction and DNA sequencing. Data were collected about reproductive health and risk factors for HPV. RESULTS: Only one mother/newborn and no father/newborn pair was concordant for an HPV type. All other infected newborns had uninfected or discordant type infected parents. CONCLUSION: The risk of vertical transmission to the oral or genital region of newborns is rare, and transmission between parents and the hospitalized newborn does not appear to occur. Lack of parent/child concordance suggests that newborns detected with HPV in their oral cavity or genitals could have become infected by their mother at untested intervals during pregnancy or in newborns with infection in the oral cavity by other contacts after birth.

Adolescent↗

Effects of X-monosomy and X-linked imprinting on superior temporal gyrus morphology in Turner syndrome.

BACKGROUND: Turner syndrome (TS) results from complete or partial monosomy X. The cognitive phenotype of TS involves preservation of verbal skills with visuospatial functioning deficits. The superior temporal gyrus (STG), which is involved in language capacities, has not been investigated in TS. METHODS: The STG was measured in 30 female subjects (mean age = 14.73 +/- 6.41; range = 7.56-33.30) with TS and 30 age-matched control subjects (mean age = 14.63 +/- 5.90; range = 6.35-32.65) using volumetric magnetic resonance imaging analyses. RESULTS: -Right STG, including both gray and white matter volumes, was significantly larger in TS compared with control subjects. Overall left STG volume was not significantly different between groups, although left white matter volume was increased in the TS subjects. The TS subgroup with a maternally derived X chromosome (Xm) demonstrated more aberrant STG volumes compared with subjects with a paternally (Xp) derived X and control subjects. The difference in STG volumes between Xm and control subjects involved both white and gray matter. The Xm subjects differed from Xp subjects only in terms of gray matter. CONCLUSIONS: These findings suggest that X-monosomy and X-linked imprinting negatively affect STG development, possibly by disrupting neural pruning mechanisms.

Adolescent↗

Prenatal detection of mosaic trisomy 1q due to an unbalanced translocation in one fetus of a twin pregnancy following in vitro fertilization: a postzygotic error.

Complete or mosaic trisomy for all of chromosome 1q has been seen rarely in a recognized pregnancy. A patient presented with twins following in vitro fertilization (IVF). Ultrasound showed twin A to have a diaphragmatic hernia, thick nuchal fold, and subtle intracranial abnormalities. Twin B appeared normal and a thick dividing membrane was seen. Amniocentesis of twin A showed a male karyotype with mosaic trisomy 1q in 57% of cells resulting from a translocation between chromosomes Yq12 and 1q12. Parental karyotypes were normal. The twins were delivered at 33 weeks. Twin A died at 1 hr of life. Autopsy confirmed the left diaphragmatic hernia and hypoplastic lungs. Autopsy also revealed a partial cleft palate, syndactyly of the second and third toes bilaterally, external deviation of the left 5th toe, and contractures of the index fingers bilaterally. A recent report documented formation of a chimera resulting from embryo amalgamation after IVF. Given the rarity of the cytogenetic findings in our case, we sought to determine if the mosaicism was a result of chimera formation related to the IVF. Thirteen polymorphic loci throughout the genome, in addition to four on 1q and four on 1p, were amplified by PCR. Only two alleles were observed at each of these loci in twin A, one paternal and the other maternal. We present further clinical findings of this case with a rare cytogenetic abnormality that appears to have originated from a postzygotic mitotic error and not embryo amalgamation.

Abnormalities, Multiple↗

Prenatal testing for infectious disease.

Prenatal testing for infectious diseases is performed frequently and for a variety of indications. The purpose of this article is to review the maternal and fetal infections that pose diagnostic concerns. Recent advances in diagnostic testing (such as avidity testing) is included. Testing issues focus on the diagnosis of maternal and fetal infection.

Adult↗

Sequence-based polymorphisms in members of the apoptosis Bcl-2 gene family and their association with hematocrit level.

OBJECTIVE: The Bcl-2 family mediates erythropoietin-dependent survival of erythroid progenitor cells and regulates erythropoiesis. We assessed for any association between Bcl-2 family nucleotide variation and hematocrit (HCT) in healthy blood donors. METHODS: We screened Bcl-w, Bcl-x, and Bax (members of Bcl-2 family) using polymerase chain reaction and singlestrand conformation polymorphism analysis. One polymorphism each was found in Bax and Bcl-w. Using these markers, we genotyped the 100 males and 100 females with the highest or lowest HCT in a population of 819 healthy people in Iowa. A comparison of the allelic frequencies and distribution of each polymorphism was made in males versus females, individuals with low versus high HCT, and other subgroups. RESULTS: One sequence-based polymorphism was found in Bax and Bcl-w having three and two alleles, respectively. No polymorphism was found for Bcl-x. The Bax polymorphism is caused by variation in nucleotide A repeat number (19, 25, 27) at position 360 in 5'-region of Bax. The Bcl-w polymorphism is a G to A transition at 123. The allelic frequencies of Bax polymorphism were significantly different between males and females (P = 0.004). There were no significant associations for Bcl-w polymorphism by gender or HCT level (P > 0.05). CONCLUSIONS: Polymorphism in the 5'-region of Bax was associated with gender-based HCT differences. This is theoretically due to gender-based hormonal effects on gene transcription mediated by the different polymorphisms.

Alleles↗

Brain development in Turner syndrome: a magnetic resonance imaging study.

Turner syndrome (TS) results from the absence of an X chromosome in females. This genetic condition is associated with specific cognitive deficits and variations in brain volumes. The goal of this study was to use high-resolution magnetic resonance imaging (MRI) to determine morphological variations in TS and to investigate the effects of parental origin of the X chromosome on brain development in TS. MRI brain scans were acquired from 26 girls with TS and 26 age- and gender-matched controls. Seventeen of the TS subjects had a maternally inherited X chromosome (Xm), and nine of the subjects had a paternally inherited X chromosome (Xp). Rater-blind morphometric analyses were conducted to compare tissue volume differences between girls with TS and controls. Three-way analyses were used to compare subgroups and controls. Subjects with TS demonstrated bilateral decreases in parietal gray and occipital white matter accompanied by increased cerebellar gray matter. Subjects with Xm showed decreased occipital white matter and increased cerebellar gray matter compared to controls. No differences were found in comparisons between subjects with Xp and controls or between subjects with Xm and Xp. Results suggest that X monosomy affects posterior cerebral and cerebellar anatomy in TS. While differences between comparisons of Xm and Xp to controls might suggest an imprinting effect, no significant differences were found when the two subgroups were directly compared to each other. Further investigation into the possible role of genomic imprinting is therefore warranted.

Adolescent↗

Conjoined twins in a monozygotic triplet pregnancy: prenatal diagnosis and X-inactivation.

BACKGROUND: The etiology of monozygotic twinning is not known. Some investigators have implicated abnormal X-inactivation, which could also be related to the increased female:male ratio in higher order multiple gestations in general, and in monozygotic and conjoined twins (CTS) in particular. CTS are rare, and even more unusual when part of a triplet pregnancy. METHODS: DNA polymorphism analysis using 13 markers in the buccal cells of the triplets and the lymphocytes of the parents were used to evaluate zygosity. We investigated the X-inactivation pattern of the triplets by analyzing methylation at the androgen receptor gene. RESULTS: We found a female triplet gestation consisting of CTS and a normal singleton. The thoracopagus CTS were joined from the clavicles to the umbilicus. Congenital heart disease was suspected antenatally, but the precise delineation of the heart defects required extensive postnatal evaluation. There was a single placental mass with a thin dividing membrane. Cesarean section was carried out at 32 weeks after the onset of labor. Histologically, the placenta was diamniotic monochorionic. The normal singleton did well after delivery; the CTS died at 35 days from cardiopulmonary collapse. The babies were monozygotic (>99.99% probability). Each baby in this triplet set exhibited a random and symmetric X-inactivation pattern. The degree of X-inactivation skewing fell in the range of 50-65%. CONCLUSION: Genetic or environmental factors other than abnormal X-inactivation must be involved in causing monozygous multiple gestation or CTS. Despite prenatal diagnosis, shared myocardium or cardiac anomalies in CTS often determine the prognosis.

Dosage Compensation, Genetic↗

Antenatal hydronephrosis: evaluation and outcome.

We present a comprehensive and current review of the etiology, evaluation, treatment, and outcome of antenatal hydronephrosis. When a diagnosis of antenatal hydronephrosis is made, many questions regarding pregnancy, prenatal care, intervention, and what may be expected after birth are raised. Debate and controversy exist on the diagnosis and subsequent evaluation and management of the child with antenatal hydronephrosis. A review of the literature and our own experience with antenatal hydronephrosis are presented in order to guide the physician who is caring for mother and child.

Algorithms↗

Ureterocele causing anhydramnios successfully treated with percutaneous decompression.

BACKGROUND: Ureteroceles are congenital cystic dilatations of the submucosal segment of the distal ureter. We present a case of an intravesical ureterocele causing anhydramnios at 31 weeks' gestation. CASE: A primiparous woman near 20 weeks' gestation had ultrasound evidence of a fetal duplicated right collecting system. At 31 weeks, an intravesical ureterocele was seen along with bilateral hydroureteronephrosis and anhydramnios. A single percutaneous needle decompression of the bladder and ureterocele successfully restored amniotic fluid volume. CONCLUSION: Follow-up ultrasounds are indicated when either a duplicated renal collecting system or a ureterocele is identified. In utero treatment is indicated only when amniotic fluid is compromised. Needle decompression should be first-line treatment, with more invasive methods reserved for failures of decompression.

Decompression, Surgical↗

Factors that predict low hematocrit levels in the postpartum patient after vaginal delivery.

OBJECTIVE: The purpose of this study was to provide a viable alternative to routine postpartum hematocrit measurement, by a determination of the clinical risk factors that identify patients with anemia and an examination of the resulting cost savings. STUDY DESIGN: In this retrospective review, cases (postpartum hematocrit level, <26%; subgroup hematocrit level, <23%) and control subjects were culled from the records of all vaginal deliveries from February 1997 to July 1998. Charts were reviewed for demographic characteristics, medical history, nursing assessments, and postpartum hematocrit measurements. Logistic regression modeling determined the best set of risk factors for the identification of low postpartum hematocrit levels. RESULTS: From 1484 vaginal deliveries, 117 of the women (8%) had postpartum hematocrit levels of <26%. Estimated blood loss of >500 mL, Hispanic ethnicity, dizziness, or third- or fourth-degree laceration were the factors that identified 82.9% of the women with hematocrit levels of <26% and identified 97.4% of the women with hematocrit levels of <23%. Only 39.3% of the women would have required postpartum hematocrit measurement to obtain these detection rates. CONCLUSION: Four risk factors (estimated blood loss of >500 mL, Hispanic ethnicity, dizziness, and third- or fourth-degree laceration) can safely determine the necessity of a postpartum hematocrit measurement.

Adult↗

Placental abruption.

UNLABELLED: Placental abruption complicates approximately 1% to 2% of all pregnancies and remains a significant cause of both maternal and fetal morbidity. Proposed pathophysiology of both acute placental abruption and the more common partial placental separation are discussed. The contribution of placental abruption to both preterm labor and preterm premature rupture of membranes is discussed. Recent evidence supporting maternal hypertensive disorders, maternal tobacco and cocaine use, age and parity, multiple gestations, maternal thrombophilias, and an unexplained elevated maternal serum alphafetoprotein as risk factors for abruption is reviewed. Emergency management of acute abruption is outlined. Finally, particular emphasis is given to the management of partial placental separation, including both immediate and delayed delivery and the use of tocolysis. TARGET AUDIENCE: Obstetricians and Gynecologists, Family Physicians. LEARNING OBJECTIVES: After completion of this article, the reader will be able to define the condition of placental abruption, list the conditions associated with abruption, and outline potential management options for patients with placental abruption.

Abruptio Placentae↗

Safe prescribing practices in pregnancy and lactation.

Midwives and other health care providers face a dilemma when a pregnant woman develops a condition that usually is treated with a pharmacologic agent. Understanding of basic teratology associated with drugs as well as the FDA categorization of agents can assist professionals in recognizing which pharmaceuticals should be used or avoided. In addition to reviewing teratology, this article addresses the use of common drugs for the treatment of upper respiratory conditions, minor pain, gastrointestinal problems, psychiatric illnesses, and neurologic disorders. In each category, current evidence is presented pertaining to which agents should be recommended for pregnant women.

Abnormalities, Drug-Induced↗