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Biomedical subjects

M Berant

Publications and source records attributed to M Berant.

At least 37 records · Page 2Linked to original sources

Plasmalogen phospholipids are involved in HDL-mediated cholesterol efflux: insights from investigations with plasmalogen-deficient cells.

Plasmalogens are ether-glycerophospholipids that exist in all mammalian cells, but their physiological function remains thus far an enigma. It has been previously suggested that the association of high-density lipoprotein (HDL) with cellular phospholipid is a pre-requisite for the process of HDL-mediated cholesterol efflux (HDL-MCE). To investigate our hypothesis that plasmalogens might play a role in HDL-MCE, we used a model composed of plasmalogen-deficient cells including RAW mutant macrophages and fibroblasts from patients with rhizomelic chondrodysplasia punctata type II. In mutant macrophages, HDL-MCE was reduced by 57% compared to control macrophages, after 16 hours. A similar phenomenon was observed in plasmalogen-deficient patients fibroblasts. Incubation of plasmalogen-deficient fibroblasts with 1-0-hexadecyl-sn-glycerol, which restored plasmalogen levels to that of control cells, resulted in a 35% increase in HDL-MCE, compared to a 10% increment in controls. The novel finding that HDL-MCE is reduced in plasmalogen-deficient cells and increases following plasmalogen restoration leads us to suggest that plasmalogen has an important function in the mediation of cellular cholesterol efflux.

Animals↗

Interventional catheterization decreases plasma levels of atrial natriuretic peptide (ANP) in children with congenital heart defects.

Atrial natriuretic peptide (ANP) is one of the cardiac peptides implicated in volume and sodium homeostasis. We investigated the effect of interventional catheterization on plasma levels of ANP, aldosterone, and cortisol in 28 children with various congenital heart defects (CHD). Patients were divided by age into two groups: group A--infants and children over 3 months of age (n = 22), and group B--newborns (n = 6). These were compared to age-matched control groups. In group A, interventions included pulmonic valvotomy (n = 8), aortic valvotomy (n = 4), balloon angioplasty of native coarctation of the aorta (n = 3), balloon dilatation of the mitral valve (n = 1), and Rashkind double umbrella closure of patent ductus arteriosus (n = 6). Group B interventions included pulmonic valvotomy (n = 3), aortic valvotomy (n = 1), and balloon atrial septosomy (n = 2). In group A, mean ANP levels were markedly higher than in age-matched controls (125.2+/-15.8 vs. 24.6+/-4.6 pg/ml) (P <0.0001), and decreased immediately after intervention (75.6+/-11.4 pg/ml, P <0.02), and more markedly on follow-up (42.9+/-5.0 pg/ml, P < 0.0001). In group B (newborns), mean basal plasma levels were high before and after intervention and were not different from age-matched controls (243+/-42.1 vs. 220.8+/-16.2 pg/ml). There was a significant decrease on follow-up measurement (62.1+/-12.7 pg/ml, P < 0.005). In both groups, plasma cortisol levels increased significantly immediately following catheterization (P < 0.02), and normalized on follow-up. Basal aldosterone levels were normal in group A and high in Group B (9.9+/-3.8 vs. 167.6+/-16.9 ng/dl) (P < 0.001). It is suggested that plasma ANP levels are increased in children with CHD, without overt heart failure, and decrease significantly following successful intervention. In newborns with CHD, the physiological high ANP levels obscure the effect of the CHD.

Aldosterone↗

Localization of a gene for molybdenum cofactor deficiency, on the short arm of chromosome 6, by homozygosity mapping.

Molybdenum cofactor deficiency (MoCoD) is a fatal disorder manifesting, shortly after birth, with profound neurological abnormalities, mental retardation, and severe seizures unresponsive to any therapy. The disease is a monogenic, autosomal recessive disorder, and the existence of at least two complementation groups suggests genetic heterogeneity. In humans, MoCoD leads to the combined deficient activities of sulfite oxidase, xanthine dehydrogenase, and aldehyde oxidase. By using homozygosity mapping and two consanguineous affected kindreds of Israeli-Arab origin, including five patients, we demonstrated linkage of a MoCoD gene to an 8-cM region on chromosome 6p21.3, between markers D6S1641 and D6S1672. Linkage analysis generated the highest combined LOD-score value, 3.6, at a recombination fraction of 0, with marker D6S1575. These results now can be used to perform prenatal diagnosis with microsatellite markers. They also provide the only tool for carrier detection of this fatal disorder.

Aldehyde Oxidase↗

[Transcatheter closure of atrial septal defect].

Isolated secundum atrial septal defect is one of the most common congenital heart defects. Surgical closure is the treatment of choice but is associated with a chest scar, some morbidity and a relatively long recovery and the use of cardiopulmonary bypass. Transcatheter closure of secundum atrial septal defect is therefore an attractive approach. 3 children, aged 5-10 years, underwent successful transcatheter closure of moderate to large central atrial septal defects with the Cardioseal device. The procedures were performed under x-ray and transesophageal echocardiographic guidance. Our initial experience, and that of others, indicates that transcatheter occlusion of secundum atrial septal defects is safe and effective and can be an appropriate alternative in approximately 60% of patients.

Cardiac Catheterization↗

Prenatal sonographic diagnosis of vermal agenesis.

Agenesis of the vermis as detected during gestation by ultrasonography may indicate the existence of various malformation arrays or syndromes. We report on our observations of five cases of complete vermal agenesis that were detected at 22-31 weeks of gestation. All had a vertex presentation and transvaginal sonography established the diagnosis of vermal agenesis. Two of the vermal agenesis cases had no associated anomalies outside the central nervous system (CNS). In one, the cerebellar cleft was the only abnormality present and the other also had lobar holoprosencephaly. The three remaining fetuses had trisomy 13 and featured various additional extra-CNS anomalies. The association of complete vermal agenesis and trisomy 13 has not been previously reported. Our experience with this series suggests that supplementation with vaginal fetal sonography is a valuable tool for obtaining a more accurate view of the posterior fossa whenever a cyst or a cyst-like abnormality is detected by transabdominal sonography. A finding of isolated vermal agenesis appears to mandate a careful search for additional anomalies and the performance of karyotype analysis.

Cerebellar Diseases↗

Progressive familial intrahepatic cholestasis among the Arab population in Israel.

BACKGROUND: Progressive familial intrahepatic cholestasis, which constitutes a heterogeneous group of imperfectly delineated syndromes and appears to be inherited as an autosomal recessive condition, has not been hitherto reported from the Middle East, in spite of the high rate of consanguineous marriage in this region. METHODS: Sixteen affected children from six Israeli Arab families were evaluated over 30 years. All were born to consanguineous parents. RESULTS: Jaundice appeared during the first 3 weeks of life in 15 babies. When first referred, 10 had hepatomegaly and nine had splenomegaly. A progression toward cirrhosis was the rule. Serum levels of conjugated bilirubin, liver enzymes, and alkaline phosphatase were raised; gamma-glutamyl transpeptidase levels were normal in all three infants in whom it was examined, but elevated in two siblings of another family at ages 2 and 3 years. No abnormal bile acids were detected in the serum and urine of patients. Histologic examination of the liver showed giant-cell transformation, paucity of intrahepatic bile ducts, cholestasis, fibrosis, or cirrhosis. The pattern of liver pathology differed at times among affected members within the same family. Therapeutic trials with phenobarbital, cholestyramine, or ursodeoxycholic acid were ineffective. Survival of the patients was from 5 to 18 months in four families; in the other two families, three children received liver transplants, and one is awaiting liver transplantation. CONCLUSIONS: Progressive familial intrahepatic cholestasis should be included in the differential diagnosis of infants with cholestatic jaundice of unknown etiology, especially those born to consanguineous Arab parents.

Arabs↗

"Immunity" of Ethiopian Jews to developmental dysplasia of the hip: a preliminary sonographic study.

Developmental dysplasia of the hip (DDH) is one of the most common problems affecting the pediatric musculoskeletal system. The condition represents a broad spectrum of sonographic (anatomic) pathoanatomical situations, ranging from very mild dysplasia to full dislocation, manifesting clinically as stable or unstable hip joints, particularly in the neonatal period. The cause of DDH is unclear. Various theories suggest genetic, hormonal, mechanical, and geographic factors, along with hemotypology and a great variety of other factors, as causes for this condition. In the present study, sonographic criteria for diagnosing DDH according to Graf were used. Although the overall incidence of DDH was 5.9% in white neonates, it was only 0.44% (two hips, one stable and one unstable) among 450 hips of black Ethiopian newborns. Left untreated, these hips became clinically and sonographically normal. Our results could be considered to indicate a zero incidence of DDH among Ethiopian Jews in this series.

Black People↗

Evaluation of febrile infants under 3 months of age: is routine lumbar puncture warranted?

Fever may be the sole clinically evident presentation of serious bacterial infection (SBI) in a very young infant, and therefore lumbar puncture is still widely regarded as a mandatory procedure in the sepsis workup of febrile infants under 2 months of age. In this retrospective study, we evaluated the frequency and the diagnostic value of cerebrospinal fluid examination in 492 infants aged less than 3 months who were hospitalized because of fever during 1988-1994. The patients were categorized as being at "high risk" or "low risk" for SBI according to current clinical and laboratory criteria. Among the 492 infants, 196 (40%) were identified as "high-risk" for SBI, and 296 (60%) were at low risk. Among the overall series of infants, 60 babies (12%) were subsequently proven with bacterial infection. Among the 196 "high-risk" babies, 26% had bacterial infection, compared to only 3% of the 296 infants at low risk (p < 0.0001), denoting a sensitivity of 85% and a specificity of 65% of the clinical classification criteria. Lumbar puncture was done to 186 (46%) infants upon hospital admission; 176 punctures yielded satisfactory samples of cerebrospinal fluid (CSF). Sixteen (3%) patients had abnormal CSF findings: 2 of them had positive bacterial cultures and 14 were compatible with aseptic meningitis. The 2 patients with purulent meningitis were clinically very ill and were immediately recognized as deserving a lumbar puncture. Of the 14 patients with aseptic meningitis, 13 were initially screened as being at high risk for serious infection, and therefore underwent a lumbar puncture. Over the years of this survey, a declining trend for performing lumbar puncture in "low-risk" young febrile infants became evident: during 1988-1992, evaluation of sepsis included a lumbar puncture in 45% of the infants, compared to 27% during the following 2 years (p < 0.0001). Not one instance of purulent meningitis evolved among the infants in whom lumbar puncture was not performed. Our observations suggest that hospitalized young febrile infants may safely be spared a lumbar puncture when they do not meet the proposed criteria for being at high risk, or when their clinical and laboratory picture suggests being at low risk for SBI.

Age Factors↗

Radiofrequency catheter ablation of ectopic atrial tachycardia.

Ectopic atrial tachycardia (EAT) is an uncommon type of supraventricular tachycardia. It is usually chronic, incessant and resistant to pharmacologic therapy. Radiofrequency catheter ablation, which has become one of the treatments of choice for the more common types of supraventricular tachycardia, has recently also been shown to be effective in EAT. Radiofrequency catheter ablation was attempted in three patients with incessant EAT. Two of the patients, aged 7 and 13 years, had signs of left ventricular dysfunction, and the EAT originated in the left atrium. The remaining patient, aged 72 years, had a right EAT with normal left ventricular function. Radiofrequency ablation was guided by endocardial atrial mapping to locate the site of earliest atrial activation. Ablation was successful in all three patients, with complete cure of the tachycardia for a follow-up period of 12 to 19 months. Radiofrequency catheter ablation of EAT is highly successful and should be considered as one of the treatments of choice for this arrhythmia.

Adolescent↗

Coexistence of hereditary homocystinuria and factor V Leiden--effect on thrombosis.

BACKGROUND: Venous and arterial thromboembolism occurs in only about one third of patients homozygous for homocystinuria, which suggests that other, contributory factors are necessary for the development of thrombosis in these patients. Factor V Leiden, an R506Q mutation in the gene coding for factor V, is the most common cause of familial thrombosis and could be a potentiating factor. METHODS: We determined activated partial-thromboplastin times in the presence and absence of activated protein C and tested for the factor V Leiden mutation in 45 members of seven unrelated consanguineous kindreds in which at least 1 member was homozygous for homocystinuria. RESULT: Thrombosis (venous, arterial, or both) occurred in 6 of 11 patients with homocystinuria (age, 0.2 to 8 years). All six also had the factor V Leiden mutation. One patient with prenatally diagnosed homocystinuria who was also heterozygous for factor V Leiden has received warfarin therapy since birth and has not had thrombosis (age, 18 months). Of four patients with homocystinuria who did not have factor V Leiden, none had thrombosis (ages at this writing, 1 to 17 years). Three women who were heterozygous for both homocystinuria and factor V Leiden had recurrent fetal loss and placental infarctions. CONCLUSIONS: Patients with concurrent homocystinuria and factor V Leiden can have an increased risk of thrombosis. Screening for factor V Leiden may be indicated in patient with homocystinuria and their family members.

Adolescent↗

In utero congestive heart failure due to maternal indomethacin treatment for polyhydramnios and premature labour in a fetus with antenatal closure of the foramen ovale.

A case of severe fetal congestive heart failure due to occlusion of the ductus arteriosus in a mother treated with indomethacin for polyhydramnios and premature contractions is described. Closure of the fetal foramen ovale that escaped detection by prenatal echocardiography was later demonstrated at neonatal autopsy. This case suggests that indomethacin treatment in a ductus-dependent fetus may be hazardous. Therefore, careful surveillance of the fetus exposed to indomethacin in utero is warranted.

Adult↗