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Biomedical subjects

M Mandel

Publications and source records attributed to M Mandel.

At least 37 records · Page 2Linked to original sources
PubMed1996

Vincristine treatment triggering the expression of asymptomatic Charcot-Marie-Tooth disease.

A 16-year-old male suffering from Ewing's sarcoma of the pelvis was treated with vincristine as part of his chemotherapeutic protocol. The boy was never known to suffer from any neurological problems. His father had a mild limp, attributed to prolonged "taxi driving," that was never investigated medically. The first course of treatment, which included 2 mg of vincristine, resulted in clinical improvement. However, at the same time the patient developed severe weakness of both upper and lower limbs, areflexia, and gradually a pes cavus deformity. Nerve conduction studies were suggestive of severe peripheral sensorimotor neuropathy, axonal and demyelinative. A definite diagnosis of Charcot-Marie-Tooth was confirmed by molecular analysis showing the typical duplication of 1.5 megabases at 17 p11.2. This unique manifestation of vincristine neurotoxicity is reported and discussed.

Adolescent↗
PubMed1996

In vitro proliferative advantage of bone marrow cells with tetrasomy 8 in Ewing sarcoma.

We describe a case of a 14.5-year-old boy with a clinically aggressive pelvic Ewing sarcoma. The tumor cells showed the presence of a typical t(11;22)(q24;q12) aberration and gains of chromosomes 8, 10, 14, and 21. To determine the size of the trisomy and tetrasomy 8 clones an interphase analysis by fluorescence in situ hybridization with a centromere-specific chromosome 8 probe was performed. Significant quantitative differences between metaphase and interphase data were obtained. It was shown that culturing of bone marrow cells leads to enrichment of tetrasomy 8 population that may be explained by the proliferative advantage of the tetrasomy 8 cells.

Adolescent↗
PubMed1995

Two embryonal cancers after in vitro fertilization.

BACKGROUND: In vitro fertilization is not considered to be associated with an increased rate of pediatric malignancies, and only three have been reported in the literature. Two additional rare pediatric tumors in children conceived through this technique are reported. METHODS: Two children 12 and 18 months of age, developed hepatoblastoma and clear cell sarcoma of the kidney, respectively. They were both products of uneventful pregnancies induced by in vitro fertilization. No other environmental, prenatal, or family factor was found. RESULTS: The first child died after a failed remission induction with cisplatin, doxorubicin, and vincristine, whereas the second child is alive with no evidence of disease 18 months after diagnosis and treatment according to NWTS protocol. CONCLUSIONS: A possible association between in vitro fertilization and pediatric malignancies is suggested.

Antibiotics, Antineoplastic↗
PubMed1995

Expression of a human serum albumin variant with high affinity for thyroxine.

In this study a protein expression system was used to synthesize recombinant human serum albumin containing a mutation that has been shown to result in familial dysalbuminemic hyperthyroxinemia. Equilibrium dialysis was used to measure the binding of this recombinant human serum albumin with thyroxine. The association constant determined for the binding of this human serum albumin variant with thyroxine was shown to be 65-fold greater than that of recombinant normal human serum albumin.

Amino Acid Sequence↗
PubMed1995

Translocation (2;14)(p13;q32) in CD10+ ;CD13+ acute lymphatic leukemia.

The rare t(2;14)(p13;q32) was previously described in the three pediatric patients with acute lymphatic leukemia. In these cases this abnormality was found at diagnosis, manifested the sole chromosomal abnormality, and was associated with a favorable prognosis. We here describe three cases of leukemia where such translocations were found at relapse, were associated in two of the cases with additional known characteristic chromosomal aberration, and were associated with a grave prognosis. Interestingly enough, the malignant cells of all three patients shared the same surface antigens: CD34, HLA DR, CD10, CD20, and the myeloid marker CD13. The leukemic clone exhibiting t(2;14) probably evolved from a t(1;19)6q- pre-B acute lymphatic leukemia in one of the cases, and from a chronic phase Ph1 chromosome in another. The significance of the translocation and the coexistence of CD10 and CD13 on the same cell are discussed.

Adolescent↗
PubMed1995

Detection of mutagen specific adduct formation in DNA using sequencing methodology.

It has been reported that single stranded viral DNA reacts with the carcinogen, chloroacetaldehyde at specific hot spots (Premaratne et al., 1993 Int. J. Biochem. 25, 1669-1672). We tested this occurrence with several other mutagens and potential carcinogens. A series of chemicals (chloroacetaldehyde, methyl, ethyl, and propyl nitro nitrosoguanidine, hydrazine, 2,4 dinitrophenyl hydrazine, hydroxylamine and methyl methanesulfonate) were each separately reacted with viral M13mp18 DNA for 2 hr at 37 degrees C and pH 4.9. The locations of adduction were identified as points of chain termination (or polymerase fall off) when the reacted DNA was subjected to a modified sequencing procedure that had ample regular labeled and unlabeled nucleotides but lacked dideoxy chain termination mixtures. Chain termination was observed to occur at specific, non-random, sites rather than with equal probability at all bases of the DNA. Chemicals with similar structures had identical points of "fall off". The pattern of chain termination appears to be unique to each class of compounds and is independent of temperature, pH, and salt concentration. Termination is believed to occur when the DNA polymerase encounters an adduct. Mutagens of different unrelated structures when reacted with this DNA produced different sites of adduct formation, while the alkyl nitro nitrosoguanidines, compounds with homologous structure showed identical points of chain termination.

Animals↗
PubMed1995

Relaxin gene expression in human reproductive tissues by in situ hybridization.

The expression of the two human relaxin genes termed H1 and H2 in human reproductive tissues ranges from high to very low copy number depending upon the tissue and reproductive state. The aim of this study was to use two approaches to identify total relaxin transcripts (HI and H2) at the cellular level by using a human relaxin H2 riboprobe and a series of six 48-mer synthetic oligoprobes. The results obtained with both methods were similar in all tissues studied; however, a lower background was achieved with the riboprobe. This was especially noticeable after long exposure times, and a better resolution was generally achieved without clustering of the signals. Treatment of the tissues with proteinase-K failed to increase the sensitivity in any tissue with either probe. The relative levels of expression of the total relaxin gene transcripts was estimated from the different exposure times needed to obtain a good hybridization signal. Thus, the order of expression was: corpus luteum of pregnancy > corpus luteum of the cycle > placenta and prostate > decidua parietalis. The results agree well with immunolocalization of the peptide hormone previously performed with both heterologous and homologous relaxin antibodies; the exception was the lack of hybridization signal over the cells of the chorionic cytotrophoblast of the chorion laeve. This suggests that the levels of relaxin gene expression was below the level of detectability with the in situ hybridization technique or that these cells sequester, but do not synthesize, relaxin. Expression in the term placenta varied greatly from tissue to tissue and within any one tissue. A similar variability has been noted for relaxin in this tissue by immunocytochemistry. Methodology for the detection of total relaxin transcripts at the cellular level when expressed in a wide range of copy number will allow the developmental regulation of relaxin gene expression in reproductive and nonreproductive tissues to be visualized.

Base Sequence↗
PubMed1994

Detection of small quantities of double stranded DNA by enhanced fluorescence of substituted aldehyde modified polydeoxynucleotide-ethidium bromide complexes.

A method for the detection of small amounts of double stranded DNA by a simple incubation procedure involving the reaction of the nucleotide bases in DNA with chloroacetaldehyde is described. Following incubation, the presence of DNA may be visualized by the orange fluorescence emitted when ethidium bromide (EtBr) is added. Alternatively, the aldehyde/DNA mixture may be separated by agarose gel electrophoresis and individual double stranded DNA visualized by exposing the gel to ethidium bromide and observing the orange ultraviolet light induced fluorescence of the aldehyde modified double stranded ethidium bromide complex (Waring, M.J. (1965) J. Mol. Biol. 13, 269-282). At least a 20-fold increase in the detection of double stranded DNA is possible by this procedure. An important aspect of this method is that the visualization of single stranded DNA is not enhanced.

Acetaldehyde↗
PubMed1994

Familial clustering of malignant germ cell tumors and Langerhans' histiocytosis.

Three sisters in a family with seven children whose grandmother had an ovarian embryonal carcinoma experienced development of malignant and a malignant-like situation in childhood. Two were diagnosed as having malignant germ cell tumors of the ovary, and the third was found to have Langerhans' histiocytosis. The two girls with germ cell tumor shared an identical human leukocyte antigen, whereas the sister with histiocytosis shared one identical haplotype with them. All three children have been treated successfully with chemotherapy and are doing well off of treatment.

Aged↗
PubMed1994

Physicochemical properties of aqueous xanthan solutions: static light scattering.

The secondary structure of xanthan in solutions of relatively low salt concentration and at room temperature has been investigated using static light scattering experiments. Additional evidence has been found for a dimeric structure at 25 degrees C in 0.01 M NaCl. From the experimental z-average mean square (ms) radius of gyration, a value for the persistence length p has been estimated, taking explicitly into account the polydispersity of the three samples used, which has been established by gel permeation chromatography (GPC) measurements. The experimental particle scattering functions of the three samples are consistent with theoretical estimates for polydisperse systems with the same value of p = 65 +/- 10 nm and the molar mass per unit length for a dimeric structure. This secondary structure remains unaffected by the ionic strength in the 0.005-0.01 M range. Partial aggregation seems to occur at higher NaCl concentrations. Light scattering and GPC data show that heating the xanthan 0.01 M NaCl solutions to about 70 degrees C considerably reduces the Mw of the low molar mass sample (2.3 x 10(5) g.mol-1), contrary to what is observed for the high molar mass sample (1.8 x 10(6) g.mol-1). These experimental findings can be accounted for by a partial temperature-induced dissociation of the xanthan dimers according to an all-or-none mechanism.

Carbohydrate Conformation↗
PubMed1994

CD10+ cell population in the bone marrow of patients with advanced neuroblastoma.

Immunocytologic analyses of bone marrow can provide clinically useful prognostic information in neuroblastoma. While analyzing the bone marrow with a panel of monoclonal antibodies, which detect neuroblasts and other defining B-, T-, and myloid lineage, we identified two infants with stage IV-S neuroblastoma whose bone marrow contained a large population of common acute lymphoblastic leukemia (ALL)-like cells. This population expressed HLA-DR, CD19(B1), CD10(CALLA), and occasionally CD20(B1). Since 1988, 17 additional patients with advanced neuroblastoma (IV-S, III, and IV) were studied by us. In 10 of the 19 patients, the bone marrow revealed an expanded CD10 population (20-70%). It appears that this group of patients has a better prognosis. Out of 9 patients who did not have an expanded CD10 population, 8 died within 9 months from diagnosis, whereas out of 10 patients with an expanded CD10 population only one died and the others are alive, 6-30 months from diagnosis (P < 0.001). An expanded CD10 population in the bone marrow of disseminated neuroblastoma patients may therefore serve as a prognostic factor. Apart from the prognostic value of this particular population in the single patient, its presence may shed light on the interrelationship between the immune system and the neuroendocrine compartment.

Adolescent↗
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↗