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Biomedical subjects

A Abrahamov

Publications and source records attributed to A Abrahamov.

At least 37 records · Page 2Linked to original sources
PubMed1998

Asymptomatic Gaucher disease implications for large-scale screening.

Gaucher disease, the most prevalent genetic disorder among Ashkenazi Jews, is characterized by significant phenotypic heterogeneity. Because seven mutations account for more than 96% of the disease alleles in this population, large-scale screening is feasible, and genotyping is commercially available. To date, only 400 Gaucher patients have been diagnosed in Israel, although 2,500 patients are predicted by gene frequency; hence, there is the probability that those uncovered by population screening will prove to be very mild or asymptomatic since these patients have generally escaped medical attention until now. We studied objective and subjective aspects in 68 asymptomatic/very mild patients, followed for a mean of 2.6 years, to assess the implications of identifying many more such patients if large-scale screening were to be implemented. We found there were no medically significant changes in disease severity during follow-up. The patients' subjective reports of their general health status were similar to those of normal subjects, and there were no significant changes in quality of life during follow-up. Our findings suggest that asymptomatic/mild Gaucher patients do not require frequent monitoring; there is no justification for "prophylactic" enzyme therapy in this group, and, hence, no rationale for large-scale screening in the Ashkenazi population. Furthermore, one needs to be concerned with the adverse effects of labeling large numbers of asymptomatic individuals as affected because of the potential for stigmatization and discrimination.

Adolescent↗
PubMed1998

Low-dose low-frequency imiglucerase as a starting regimen of enzyme replacement therapy for patients with type I Gaucher disease.

The issue of the interplay of optimal dosage and frequency regimens for enzyme replacement therapy in type I Gaucher disease has been a source of controversy during the 7 years since the introduction of the placenta-derived enzymatic preparation in 1991. We present the results of treatment with the human recombinant form of the enzyme in 28 type I Gaucher patients, who have been treated for 6 to 24 months. As long as cost is an important factor in the management of patients with Gaucher disease, low-dose low-frequency imiglucerase promises satisfactory clinical improvement without compromising quality of life.

Adolescent↗
PubMed1998

Ethical considerations for enzyme replacement therapy in neuronopathic Gaucher disease.

Enzyme replacement therapy for Gaucher diseases, the most prevalent lysosmal storage disease, was originally approved by the FDA for type I patients and has proven to be both safe and effective in reducing hepatosplenomegaly and improving the hematological parameters. However, the use of enzyme treatment in both neuronopathic forms has heretofore been on an investigational or trial basis, with reports of progression of neurological deterioration even at very high doses. To date, there are no guidelines for clinicians with regard to enzyme replacement therapy in the neuronopathic forms of metabolic diseases. Herein. we discuss strategies derived from the literature vis-à-vis treatment of very premature babies and from the Jewish Halachic point of view. In conclusion. we describe recommendations for the ethical treatment and/or withdrawal of treatment, as well as practical guidelines for dosage regimens, in children with neuronopathic Gaucher disease.

Ethics, Medical↗
PubMed1998

Effect of vitamin K1 on glucose-6-phosphate dehydrogenase deficient neonatal erythrocytes in vitro.

AIM: To determine whether vitamin K1, which is routinely administered to neonates, could act as an exogenous oxidising agent and be partly responsible for haemolysis in glucose-6-phosphat-dehydrogenase (G-6-PD). METHODS: G-6-PD deficient (n = 7) and control (n = 10) umbilical cord blood red blood cells were incubated in vitro with a vitamin K1 preparation (Konakion). Two concentrations of Vitamin K1 were used, both higher than that of expected serum concentrations, following routine injection of 1 mg vitamin K1. Concentrations of reduced glutathione (GSH) and methaemoglobin, indicators of oxidative red blood cell damage, were determined before and after incubation, and the mean percentage change from baseline calculated. RESULTS: Values (mean (SD)) for GSH, at baseline, and after incubation with vitamin K1 at concentrations of 44 and 444 microM, respectively, and percentage change from baseline (mean (SD)) were 1.97 + 0.31 mumol/g haemoglobin, 1.89 +/- 0.44 mumol/g (-4.3 +/- 13.1%), and 1.69 +/- 0.41 mumol/g (-14.5 +/- 9.3%) for the G-6-PD deficient red blood cells, and 2.27 +/- 0.31 mumol/g haemoglobin, 2.09 +/- 0.56 mumol/g (-7.2 +/- 23.2%), and 2.12 +/- 0.38 mumol/g (-6.0 + 14.1%) for the control cells. For methaemoglobin (percentage of total haemoglobin), the corresponding values were 2.01 +/- 0.53%, 1.93 +/- 0.37% (-0.6 +/- 17.4%) and 2.06 +/- 0.43% (5.7 +/- 14.2%) for the G-6-PD deficient red blood cells, and 1.56 +/- 0.74%, 1.70 +/- 0.78% (12.7 +/- 21.9%), and 1.78 +/- 0.71% (20.6 +/- 26.8%) for the control red blood cells. None of the corresponding percentage changes from baseline was significantly different when G-6-PD deficient and control red blood cells were compared. CONCLUSIONS: These findings suggest that G-6-PD deficient red blood cells are not at increased risk of oxidative damage from vitamin K1.

Biomarkers↗
PubMed1997

Abdominal ultrasound findings mimicking hematological malignancies in a study of 218 Gaucher patients.

Gaucher disease, the most prevalent sphingolipidosis, generally presents with splenomegaly, anemia, and thrombocytopenia. Hence, hematologists are often the specialists involved in diagnosis and management of these patients. We present ultrasonographic characteristics in a cohort of 218 consecutive Gaucher patients evaluated in our clinic during the past 5 years. Our data emphasize the high prevalence of lesions mimicking hematological malignancies in Gaucher disease. One fifth of 184 non-splenectomized patients had intra-splenic lesions, 6% of all patients had similar lesions in the liver, and 32% of 34 splenectomized patients (but none of the other patients) had marked retroperitoneal or peri-portal lymphadenopathy. The presence of splenic lesions correlated with age and splenic size, but not with extent of bone involvement or genotype. Interestingly, they were not affected by reduction in splenomegaly following enzyme replacement therapy. The importance of these findings is to include Gaucher disease in the differential diagnosis of splenic or hepatic lesions, especially in Ashkenazi Jews. Conversely, they are relevant for follow-up of all Gaucher patients, including asymptomatic individuals, because of the reported increased incidence of hematological malignancies in Gaucher disease.

Adolescent↗
PubMed1997

Aggressive bone destruction in acute megakaryocytic leukemia: a rare presentation.

Acute megakaryocytic leukemia (AMKL) is a rare subtype of acute myeloid leukemia which is more common in children. Although the bone changes in leukemia are well documented, there are only a few reports of the AMKL subtype. We present an exceptional case of a young girl with very aggressive AMKL, who demonstrated symmetrical destructive lesions of the long bones characteristic of this disease. Lytic lesions of the skull and jaws were also present, and these have not been previously described in AMKL.

Bone and Bones↗
PubMed1997

Use of enzyme replacement therapy for Gaucher disease during pregnancy.

OBJECTIVE: To date there has been little published experience with enzyme replacement therapy in pregnant women with symptomatic type I Gaucher disease. STUDY DESIGN: We describe six patients, including three with repeated early pregnancy loss, five of whom successfully carried pregnancies to term; the last pregnancy was terminated because of pulmonary hypertension. RESULTS: All pregnancies were uneventful and five resulted in healthy newborns. CONCLUSION: We concluded that in patients with Gaucher disease of childbearing age,for whom obstetric complications are an important symptom of the disease, pregnancy is not contraindicated (unless there is evidence or suspicion of pulmonary hypertension) and treatment should not be interrupted because the clinical improvement engendered by enzyme replacement therapy is conducive to fewer complications during pregnancy and delivery and post partum.

Abortion, Habitual↗
PubMed1997

Castleman disease in pregnancy.

BACKGROUND: Castleman disease, a rare disorder characterized by benign proliferation of lymphoid tissues, generally presents as a solitary mediastinal mass. We report the first case of this disease during pregnancy. CASE: A 32-year-old woman presented with a large abdominal mass and vaginal bleeding during the second trimester of pregnancy. Abdominal ultrasound demonstrated a large, retroperitoneal solid mass of mixed echogenicity and increased vascularity. The patient underwent explorative laparotomy that revealed a mesenteric mass, histologically consistent with Castleman disease of the hyaline-vascular type. The mass was excised completely, and the immediate postoperative course was uneventful, although the patient went into spontaneous preterm labor during the 29th week of pregnancy. CONCLUSION: Castleman disease should be considered one of the benign etiologies for an abdominal or retroperitoneal mass during pregnancy.

Adult↗
PubMed1997

A practical approach to diagnosis and management of Gaucher's disease.

The diagnosis of Gaucher's disease is established by demonstration of reduced acid beta-glucosidase activity in peripheral blood leukocytes. Genotyping at the glucocerebrosidase gene locus can give additional prognostic information and facilitate carrier detection. However, extreme phenotypic diversity precludes reliable prediction of prognosis in individual patients. Histological diagnosis of Gaucher's disease is unnecessary and can be misleading. A range of clinical, radiological and laboratory parameters are useful for staging disease activity which is central to achieving optimal timing to initiate enzyme therapy. Treatment should be individualized to obtain maximum therapeutic response. The recent introduction of chitotriosidase measurements has provided a valuable indicator of total cellular burden of storage cells. Serial measurements of chitotriosidase activity are useful for monitoring disease progression as well as response to therapy. A number of adjuvant therapies are available for use in conjunction with enzyme treatment. Special considerations apply to management of affected children.

Gaucher Disease↗
PubMed1997

Accuracy of ultrasonography in assessing spleen and liver size in patients with Gaucher disease: comparison to computed tomographic measurements.

A comparison was made between volume measurements of spleen and liver by ultrasonography and by computed tomography, the two most common modes of assessment of organ size in patients with Gaucher disease, who require frequent follow-up measurements. The two measurements showed a high degree of correlation within a broad range for both spleen and liver volumes. An algorithm for conversion of one measurement to the other was derived for both spleen and liver.

Adolescent↗
PubMed1996

Effect of low-dose enzyme replacement therapy on bones in Gaucher disease patients with severe skeletal involvement.

Gaucher disease, the most common glycolipid storage disorder, is characterized by hepatosplenomegaly and skeletal involvement. Enzyme replacement therapy in both the high- and low-dose regimens has been shown to be effective in reducing the organomegaly and improving the hematological parameters of symptomatic patients with type I disease. Herein we report subjective and objective responses of bone-related complications after 2 to 4 years of low-dose enzyme replacement therapy in 14 adult type I patients with severe skeletal involvement pre-treatment. We discuss our results relative to those reported in patients on the high-dose regimen, as well as with reference to a single patient who developed new avascular necrosis despite objective improvement in radiological studies.

Adolescent↗
PubMed1996

The glucocerebrosidase D409H mutation in Gaucher disease.

Gaucher disease, resulting from the decreased activity of the lysosomal enzyme glucocerebrosidase, is the most prevalent sphingolipid storage disease. Due to considerable heterogeneity of phenotypic expression, it has been subdivided into the nonneurological type 1 disease, and types 2 and 3, the neurological types. We describe homozygosity for the D409H mutation within the glucocerebrosidase gene associated with a unique form of type 3 Gaucher disease. Twelve patients, originating from three Arab sibships, were found to be homozygous for the D409H mutation. They all presented with oculomotor apraxia and a progressive cardiac valve defect with minimal organomegaly. When expressed in human cells in tissue culture, using the T7/EMC/vaccinia virus hybrid expression system, we were able to demonstrate that the mRNA carrying the D409H mutation was less stable than the normal counterpart. Pulse-chase experiments demonstrated that the mutated protein exhibited lower stability than the normal counterpart. Its activity toward the artificial substrate 4-methyl umbelliferyl glucopyranoside was similar to that of the mutated enzymes carrying the N370S or the L444P mutations. However, in loading experiments using lissamine-rhodamine conjugated glucosyl ceramide as a substrate, the recombinant mutated protein carrying the D409H mutation exhibited 28.63 +/- 6.05% of the activity exhibited by the normal enzyme. L444P and N370S mutations exhibited 51.90 +/- 7.16 and 115.75 +/- 12.64% of normal enzyme activity, respectively. Loading of cells homozygous for the D409H mutation demonstrated 10. 05% of the activity shown by normal cells. L444P and N370S homozygous cells demonstrated 25.3 and 98.5% of foreskin fibroblast glucocerebrosidase activity, respectively. We demonstrate that homozygosity for the D409H mutation is a unique case of a peculiar phenotype associated with a specific intracellular glucocerebrosidase activity.

DNA, Complementary↗
PubMed1996

Occurrence of Parkinson's syndrome in type I Gaucher disease.

Gaucher disease, the most prevalent glycolipid storage disorder, is classically subdivided into types according to the presence or absence of neurological involvement. Type I has hitherto been considered non-neuronopathic. We present six cases and a review of the literature of Parkinsonian symptoms in type I Gaucher disease patients. The hallmark of this atypical Parkinsonian syndrome is a relatively severe clinical course with early appearance of neurological signs in the 4th to 6th decade of life, aggressive progression of the signs and refractoriness to conventional anti-Parkinson therapy. We discuss the implications of these findings in the light of enzyme replacement therapy for Gaucher disease.

Adolescent↗
PubMed1996

Pulmonary function abnormalities in type I Gaucher disease.

The purpose of this study was to determine the prevalence of pulmonary function and radiographic abnormalities among patients with type I Gaucher's disease, and to analyse the relationship between the pulmonary involvement and genotype and clinical severity score. All patients attending the Gaucher clinic at the Shaare Zedek Medical Center, Jerusalem, Israel, during the years 1992-1993 were prospectively evaluated. Each patient had pulmonary function tests, chest radiography, clinical assessment in terms of degree of organ involvement, and genotype analysis. Of the 95 patients included in the study (mean +/- SD age 29 +/- 15 yrs), 68% had some pulmonary function abnormalities, most commonly a reduced FRC and transfer coefficient for carbon monoxide (Kco), found in 45% and in 42% of the patients respectively. Total lung capacity (TLC) was reduced in 22% of the patients and forced expiratory flows in approximately one third of the patients. Signs of airtrapping (elevated residual volume (RV) or RV/TLC) were seen in 18% of the patients. Males had a higher incidence of reduced expiratory flow than females, (forced expiratory volume in one second (FEV1) was reduced in 36% of males vs 5% of females). Chest radiographic abnormalities were found in 17% of the patients, although only 4% had severe changes. Patients with abnormal pulmonary function had a significantly higher severity score index than those with normal pulmonary function tests. There was no association between abnormal pulmonary function and genotype or age. In conclusion, abnormal pulmonary function is common among type I Gaucher patients. Pulmonary function tests show airways obstruction, with reduced expiratory flows, reduction in lung volumes and alveolar-capillary diffusion abnormality. The rate of progression and the clinical significance need to be determined.

Adolescent↗
PubMed1996

Elevation of serum creatine phosphokinase and its MB isoenzyme during normal labor and early puerperium.

BACKGROUND: Chest pain or discomfort are infrequent complaints among women during labor and early puerperium, but when present they raise the suspicion of myocardial ischemia. The diagnosis of the latter is based upon serum elevatIon of certain enzymes, such as aspartate amino transferase, lactate dehydrogenase and creatine phosphokinase. Nevertheless, the normal patterns of these enzymes in the serum during labor and early puerperium have not been characterized well. OBJECTIVE: To determine serum creatine phosphokinase, lactate dehydrogenase and aspartate amino transferase levels in late pregnancy, and throughout labor and early puerperium. METHODS: Fifty women having normal pregnancies followed by uneventful vaginal deliveries were prospectively studied for serum lactate dehydrogenase, aspartate amino transferase and creatine phosphokinase including its MB isoenzyme before, during and after labor. Cardiac status was evaluated in all women using serial electrocardiographic and physical examinations. RESULTS: All women were found to have low to normal antepartum serum enzymes levels. However, during labor total creatine phosphokinase increased markedly, reaching a peak of 2-4 fold baseline levels 24 hours postpartum. It then declined gradually back to baseline. Nulliparous women reached substantially higher levels than multiparous women. The MB or so-called cardio-specific isoenzyme was found to be an important contributor to creatine phosphokinase surge in most women. Correlation was demonstrated between length of the active phase of labor and both total and MB creatine phosphokinase activity. There was no clinical or electrocardiographic evidence for cardiac muscle damage in any of the study patients. Serum lactate dehydrogenase and aspartate amino transferase were not altered during or after labor. CONCLUSIONS: Serum total creatine phosphokinase and its MB isoenzyme increase substantially during normal vaginal labor without evidence of myocardial ischemia. The uterus and placenta, two organs which were reported to embody substantial amounts of these enzymes, and which participate actively in the process of labor, are thought to release these enzymes to the circulation during labor. Knowing the normal patterns of these enzymes in the serum during labor and puerperium may prevent erroneous diagnoses of myocardial ischemia or infarction. Lack of electrocardiographic abnormalities and low lactate dehydrogenase and aspartate amino transferase levels may assist in excluding such diagnoses.

Aspartate Aminotransferases↗
PubMed1995

Gaucher's disease variant characterised by progressive calcification of heart valves and unique genotype.

Gaucher's disease is the most prevalent sphingolipid storage disease, characterised by substantial genetic and phenotypic variability. Cardiac manifestations are rare. We report 12 Arab Gaucher's disease patients, 2-20 years of age, who presented with oculomotor apraxia but only slight classic signs of the disease. All but the youngest had calcifications of the aortic or mitral valves or both. All these patients were homozygous for the rare point mutation D409H (1342C). Valvular calcifications increased with age and showed progression during 2 years of follow-up. Two of the oldest patients underwent aortic valve replacement, and one sibling had died suddenly at age 16, before this study, Corneal opacities were another common feature. The potentially fatal course of this Gaucher's disease variant, and the availability of a reliable PCR-based method for heterozygote detection, mean that population screening and genetic counselling in the geographic area at risk are important. Affected individuals should be closely monitored by echocardiography to gauge the need for valve replacement. The potential of enzyme replacement to prevent these cardiac complications cannot be ascertained at present, because of the high cost of therapy.

Adolescent↗
PubMed1995

Deferiprone (L1) chelates pathologic iron deposits from membranes of intact thalassemic and sickle red blood cells both in vitro and in vivo.

Red blood cell (RBC) membranes from patients with the thalassemic and sickle hemoglobinopathies carry abnormal deposits of iron presumed to mediate a variety of oxidative-induced membrane dysfunctions. We hypothesized that the oral iron chelator deferiprone (L1), which has an enhanced capacity to permeate cell membranes, might be useful in chelating these pathologic iron deposits from intact RBCs. We tested this hypothesis in vitro by incubating L1 with RBCs from 15 patients with thalassemia intermedia and 6 patients with sickle cell anemia. We found that removal of RBC membrane free iron by L1 increased both as a function of time of incubation and L1 concentration. Thus, increasing the time of incubation of thalassemic RBCs with 0.5 mmol/L L1 from 0.5 to 6 hours, enhanced removal of their membrane free iron from 18% +/- 9% to 96% +/- 4%. Dose-response studies showed that incubating thalassemic RBC for 2 hours with L1 concentrations ranging from 0.125 to 0.5 mmol/L resulted in removal of membrane free iron from 28% +/- 15% to 68% +/- 11%. Parallel studies with sickle RBCs showed a similar pattern in time and dose responses. Deferoxamine (DFO), on the other hand, was ineffective in chelating membrane free iron from either thalassemic or sickle RBCs regardless of dose (maximum, 0.333 mmol/L) or time of incubation (maximum, 24 hours). In vivo efficacy of L1 was shown in six thalassemic patients whose RBC membrane free iron decreased by 50% +/- 29% following a 2-week course of L1 at a daily dose of 25 mg/kg. As the dose of L1 was increased to 50 mg/kg/d (n = 5), and then to 75 mg/kg/d (n = 4), 67% +/- 14% and 79% +/- 11%, respectively, of their RBC membrane free iron was removed. L1 therapy--both in vitro and in vivo--also significantly attenuated the malondialdehyde response of thalassemic RBC membranes to in vitro stimulation with peroxide. Remarkably, the heme content of RBC membranes from L1-treated thalassemic patients decreased by 28% +/- 10% during the 3-month study period. These results indicate that L1 can remove pathologic deposits of chelatable iron from thalassemic and sickle RBC membranes, a therapeutic potential not shared by DFO. Furthermore, membrane defects possibly mediated by catalytic iron, such as lipid peroxidation and hemichrome formation, may also be alleviated, at least in part, by L1.

Anemia, Sickle Cell↗