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Biomedical subjects

M Mandel

Publications and source records attributed to M Mandel.

At least 55 records · Page 3Linked to original sources
PubMed1994

Hormonal treatment in pregnancy: a possible risk factor for neuroblastoma.

In the last 4 years, 24 cases of neuroblastoma were treated in the Pediatric Hematology-Oncology Unit at the Chaim Sheba Medical Center, 8 of whom were under 1 year of age. Four of them were the product of a pregnancy-induced or preserved by gonadotropins, clomiphene citrate, or progestational hormones. These drugs are known to produce a higher than normal level of estradiol or progesterone in the early stages of pregnancy. Our observation led to the hypothesis that high levels of progestational hormones given during pregnancy are a risk factor for neuroblastoma in infancy.

20-alpha-Dihydroprogesterone↗
PubMed1994

Primary central nervous system Burkitt's lymphoma presenting as Guillain-Barré syndrome.

A rare case of CNS Burkitt's lymphoma presenting as acute Guillain-Barré syndrome is presented. A 6-year-old previously healthy female presented with acute onset of limb and truncal weakness, involvement of ocular and bulbar nerves, and areflexia. The clinical diagnosis of Guillain-Barré syndrome prompted treatment with intravenous gammaglobulin with no response. A lumbar puncture following revealed marked pleocytosis, elevated protein, and decreased glucose. Immunological, cytological, and molecular studies of these cells confirmed the diagnosis of Burkitt's lymphoma IgM, kappa with t(8;14) and rearrangement of the J and kappa immunoglobulin chains. Aggressive systemic and intrathecal chemotherapy were started and within 5 days remission was achieved. The child is in complete remission 2 years from diagnosis. Although very rare, CNS lymphoma should be taken into account in every patient presenting with the clinical features of acute polyneuropathy.

Acute Disease↗
PubMed1994

Ependymoblastoma in an HIV-positive hemophilic girl.

A case of an HIV-positive hemophilic girl with an ependymoblastoma is presented. The unusual association between the HIV-related condition and her brain tumor is discussed, speculating a viral mechanism involved in the induction of neoplasia.

Adolescent↗
PubMed1994

Congenital haemolytic anaemia associated with adenylate kinase deficiency.

Chronic haemolytic anaemia associated with adenylate kinase (AK) deficiency is very rare and only seven cases in five families have been described. We present six children of one family who are deficient of this enzyme and in three of them a combined G6PD deficiency was found. AK deficiency was transmitted by an autosomal recessive gene and heterozygous state was not accompanied by disease, whereas homozygously affected individuals present a congenital chronic non-spherocytic haemolytic anaemia with haemoglobin levels of 8-9 g/dl. Patients also deficient in G6PD suffer from a more severe haemolytic anaemia with haemoglobin levels around 6 g/dl. The AK-deficient children are also mentally retarded. Splenectomy performed in five of the six patients resulted in complete remission of the haemolytic process.

Adenylate Kinase↗
PubMed1994

A point mutation in the human serum albumin gene results in familial dysalbuminaemic hyperthyroxinaemia.

Using DNA samples obtained from two unrelated patients, diagnosed as having familial dysalbuminaemic hyperthyroxinaemia (FDH), exons 1-14 which span the entire coding region of the human serum albumin (HSA) gene were amplified by the polymerase chain reaction. The sequence of each of the 14 DNA fragments was then determined. In each case a point mutation was identified at nucleotide 653 which causes an Arg to His substitution at amino acid position 218. The substitution was confirmed by amino acid sequencing of a mutant peptide resulting from tryptic digestion of the protein. Abnormal affinity of FDH HSA for a thyroxine (T4) analogue was verified by an adaptation of the procedure used in routine free T4 measurement. The location of the mutation is discussed in relation to other studies on the binding properties of HSA.

Amino Acid Sequence↗
PubMed1994

Familial leukemia: description of two kindreds and a review of the genetic aspects of the disease.

We describe two kindreds of Arab ancestry characterized by multiple cases of acute lymphoblastic leukemia. Consanguinity and intermarriages were prevalent in the two families. Age, mode of presentation, characteristics of the leukemic cells, response to treatment and prognosis were remarkably similar among the patients. A short review of the literature on familial leukemia is given.

Child↗
PubMed1994

Lymphomatous T-cell leukemia in two Arab children. Is there a role for an environmental effect.

Two Arab children from the Gaza strip presented with fever, weakness, hepatosplenomegaly, lymphadenopathy and leukocytosis. The peripheral and bone marrow blasts had an immunophenotype compatable with T-cell acute lymphoblastic leukemia, and exhibited unusual markers (CD2+, CD3+, CD4-, CD8-). Cytogenetic studies revealed t(8;14)(q24;q11), possibly involving the alpha/delta locus of the T-cell receptor gene on chromosome 14 rather than the immunoglobulin heavy-chain locus usually involved in the t(8;14)(q24;q32), which is typical for Burkitt's leukemia/lymphoma. One of the children had a brother who died of T-cell acute lymphoblastic leukemia a few years later, however, his blasts showed deletion of chromosome 12. The possible role for environmental factors associated with low socioeconomic status, as well as of genetic factors in leukemogenesis are discussed.

Child, Preschool↗
PubMed1994

In vivo clonal evolution of pre-B to B-cell acute lymphoblastic leukemia in childhood.

Two cases are described that provide further evidence for clonal evolution in pre-B-cell acute lymphoblastic leukemia. Two infants, whose lymphoblasts at diagnosis were morphologically subtyped as L1 and immunophenotyped as HLA DR+, CD19+, CD10+/- and C mu-, were induced and maintained in remission. One child relapsed 6 months after initiation of therapy. This time his lymphoblasts had L3 morphology and immunophenotyping demonstrated the appearance of surface immunoglobulins. The second child relapsed 18 months after initiation of therapy with a lymphomatous picture. He also had peripheral and bone marrow blasts with L3 morphology and surface immunoglobulins. A lymph node biopsy showed diffuse small non-cleaved lymphoma with a 'starry sky' appearance compatible with Burkitt's lymphoma. Only one case with a similar clonal evolution has been reported in the literature, but no surface immunoglobulins were demonstrated. The significance of clonal evolution in these cases and its potential practical implications are discussed.

Clone Cells↗
PubMed1993

Favorable response of pediatric AIDS-related Burkitt's lymphoma treated by aggressive chemotherapy.

We describe 4 male children infected by the human immunodeficiency virus (HIV) who developed Burkitt's lymphoma during their disease. The clinical picture was characterized by an insidious appearance of symptoms. All the children suffered for several months from abdominal discomfort and a gradual elevation of their blood lactic dehydrogenase (LDH) level prior to diagnosis. Bone marrow involvement was found in 2 of the patients and jaw involvement in the other 2. After confirming the diagnosis of Burkitt's lymphoma, they were treated according to conventional protocols, with no need to reduce the dose intensity. They all went into complete remission and did not suffer from major opportunistic infections during chemotherapy. None of them relapsed. Two patients died from opportunistic infections 1 and 3 years after diagnosis. The other 2 are alive, 7 years and 6 months after diagnosis. The various characteristics of this unique pediatric group are described and the comparison of the clinical picture in adults is made, together with a review of the relevant literature.

Adolescent↗
PubMed1993

Identification of DNA adducts at specific locations by sequencing techniques.

1. A simple procedure for the accurate identification of the positions of adduct formation when viral M13mp18 single stranded DNA is treated with chloroacetaldehyde (CAA) is presented. 2. The normal dideoxy sequencing reaction protocol was employed except no dideoxy nucleotides were used to cause chain termination. 3. Instead, the CAA adducted bases of the template DNA act as points of polymerase fall off causing the appearance of bands of DNA sequencing gel autoradiographs marking locations where adduct formation may have occurred.

Acetaldehyde↗
PubMed1993

Analysis of rearranged immunoglobulin genes indicating a process of clonal evolution in chronic lymphocytic leukaemia.

Chronic lymphocytic leukaemia (CLL) is known to be a stable monoclonal neoplasm. In contrast to early studies demonstrating no more than two hybridizing immunoglobulin heavy chain bands corresponding to the two expected alleles, we have demonstrated an unexpected multiband pattern when the HindIII-digested DNA samples from 38 CLL patients were analysed by Southern blot hybridization using JH and C mu gene probes. In order to characterize the genetic basis for the multiband pattern, we molecularly cloned the immunoglobulin heavy chain genes of one of the patients whose leukaemic DNA sample demonstrated three hybridizing JH bands and a loss of the germline band. The cloned rearranged immunoglobulin genes could be divided, based on the restriction mapping and the hybridization with the various probes, into two basic patterns representing two alleles. In one of the cloned rearranged immunoglobulin genes a secondary rearrangement occurred that resulted in the addition of 300 base-pair long sequence into the switch region, and the creation of a HindIII restriction site. The results of the study suggest that clonal evolution occurs in some CLL, and that many of these neoplasms are indeed oligoclonal due to the accumulation of secondary genetic changes.

Antibodies, Neoplasm↗
PubMed1993

Multiple copies of a DNA sequence from Pseudomonas syringae pathovar phaseolicola abolish thermoregulation of phaseolotoxin production.

Phaseolotoxin, a phytotoxin of Pseudomonas syringae pv. phaseolicola, is produced at 18 degrees C but not at 28 degrees C. Here we report that a fragment (24.4 kb) cloned from the wild-type strain, which does not harbour a gene(s) involved in phaseolotoxin biosynthesis, abolishes this thermoregulation in the wild type and suppresses a Tox- mutant at both temperatures. A subclone harbouring a 485 bp fragment contains motifs that are characteristic of DNA-binding sites. In mobility shift assays we have detected a protein(s) from the wild-type and the mutant strains, grown at appropriate temperatures, that specifically binds to the fragment containing the DNA-binding motifs. We propose that the binding protein is a repressor which is 'titrated' by this fragment when it is present in the cell on a multiple copy plasmid, thus allowing expression of phaseolotoxin genes.

Amino Acid Sequence↗
PubMed1992

Open controlled therapeutic trial of intravenous immune globulin in relapsing-remitting multiple sclerosis.

Ten patients with relapsing-remitting multiple sclerosis were treated with intravenous immune globulin, 0.4 g/kg per day for 5 consecutive days, and then with additional booster doses of immune globulin of 0.4 g/kg, once every 2 months, for the next 12 months. Ten untreated patients with relapsing-remitting multiple sclerosis who were matched with the study patients for age, disease duration, and number of attacks per year served as controls. Immune globulin treatment was well tolerated, with no side effects. The exacerbation rate decreased from 3.7 +/- 1.2 exacerbations per year before treatment to 1.0 +/- 0.7 exacerbations per year during the treatment in the immune globulin-treated patients, while it remained unaltered in the controls. The posttreatment Kurtzke Expanded Disability Status Scale score decreased from a mean of 4.45 to 4.15, whereas in controls it increased from 3.55 to 3.75. The results suggest that immune globulin suppresses the ongoing pathologic process in multiple sclerosis and may be a promising treatment to prevent disease exacerbations.

Adult↗