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Biomedical subjects

Y Burstein

Publications and source records attributed to Y Burstein.

At least 55 records · Page 3Linked to original sources
PubMed1991

Human recombinant CuZn-superoxide dismutase. Amino acid sequence and location of the disulfide bond.

The complete amino acid sequence of recombinant human Cu-Zn superoxide dismutase (CuZnSOD) is presented. The S-carboxymethylated protein was cleaved at lysine residues (with Achromobacter protease I) to provide a set of nine non-overlapping fragments accounting for 90% of the sequence. These fragments were then overlapped and aligned, and the sequence was completed by using peptides generated by cleavage at glutamic acid residues (with S. aureus V8 protease) and at arginine (with clostripain). The recombinant protein contains a single disulfide bond between cysteine residues 57 and 146. The primary sequence of recombinant human CuZnSOD is identical to that predicted by its cDNA sequence.

Alcaligenes↗
PubMed1990

A synthetic thymic hormone, THF-gamma 2, repairs immunodeficiency of mice cured of plasmacytoma by melphalan.

BALB/c mice cured of large MOPC-315 plasmacytomas by melphalan remain deficient in their spleen T-cell functions. This was manifested by impairment of the allogeneic and the antibody responses in vitro to SRBC and in decreased numbers of T-cells including their subsets CD4 and CD8. IL-2 production and specific cytotoxicity against MOPC-315 tumor cells were, on the other hand, maintained. Treatment of these cured mice by in-vivo administration of THF-gamma 2, an octapeptide from calf thymus, repaired these deficits. This was evidenced by in vitro tests with spleen cells which manifested an increased allogeneic response and elevated generation of primary antibody response, restoration of T-cell subpopulations to normal and an enhanced IL-2 production above normal levels. The potential use of THF-gamma 2 as supportive therapy in cancer treatment is suggested.

Animals↗
PubMed1990

[Israel national childhood acute lymphoblastic leukemia study].

A national childhood acute lymphoblastic leukemia (ALL) study was initiated in Israel in 1984 with the aim of improving results in difficult aspects of treatment including: high-risk groups, the problems of late relapses, and the effect of cranial irradiation for CNS prophylaxis in leading to late neuropsychiatric sequelae and secondary tumors. Induction of chemotherapy with a combination of 6 drugs (vincristine, cyclophosphamide, cytosine arabinoside, adriamycin, prednisone and L-asparaginase), followed by intensification with methotrexate and L-asparaginase, was introduced in both the usual and the high-risk groups. In a selected group with better prognostic factors, therapy was reduced. In an attempt to minimize the sequelae of CNS prophylactic therapy, cranial irradiation was omitted in half the patients and intrathecal (IT) triple therapy was given instead. Following 2 years of unsatisfactory preliminary results in a very high-risk group (VHR; non-T- and T-cell leukemia with WBC counts of greater than 100,000 and greater than 20,000, respectively), treatment was modified and intensified. Between Nov. 1984 and Feb. 1989, 143 patients were enrolled from 10 hospitals. During follow-up of a median of 2.5 years, there were 32 failures (2 failed remissions, 27 relapsed and 3 died of bleeding and sepsis). 107 patients are alive in first remission and an additional 8 in second and third remissions. By Kaplan-Meier life table analysis, the rates of leukemia-free interval (LFI) and event-free interval (EFI) for 4 years were 60% and 57%, respectively. Improved LFI results of 71% for 4 years were achieved in a group with non-T-cell ALL with WBC less than 100,000 (the largest group, 65% of the patients). In the small "good risk" group (10% of patients), and the T-cell group with WBC less than 100,000, LFI for 4 years were 56% and 54%, respectively. In the VHR group, modification seemed to have improved results: LFI of 41% for 3 years. CNS prophylaxis with IT triple therapy was as effective as cranial irradiation in the standard risk group. In 1 out of 33 children on this protocol a single CNS relapse occurred, as compared to 2 out of 35 matched controls with cranial irradiation. These results warrant extension of IT triple therapy to higher risk groups of childhood ALL. As for systemic treatment, increased up-front high-dose intensive therapy is recommended for all groups with ALL, but with reduction of cumulative dose to minimize late effects.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1990

THF-gamma 2, a synthetic thymic hormone, increases effectiveness of combined chemotherapy and immunotherapy against RPC-5 murine plasmacytoma.

The effect of a synthetic thymic hormone, THF-gamma 2, on the anti-tumor activity of spleen cells was studied in mice immunized against the RPC-5 tumor. Following two courses of the THF-gamma 2 treatment, the mean RPC-5 specific cytotoxic response of immune spleen cells was significantly increased when compared to normal cells (P less than 0.001) and to untreated immune spleen cells (P less than 0.04). In addition, THF-gamma 2 treatment improved the competence of immune spleen cells in adoptive immunotherapy (AIT) when performed in combination with chemotherapy by melphalan. Recipients of spleen cells from THF-gamma 2 treated mice showed a 35% increase in survival when compared to AIT with immune cells alone. The results suggest that THF-gamma 2 treatment of donors for AIT might be applicable to cancer therapy in humans.

Animals↗
PubMed1990

Hepatomegaly as a single presenting sign of stage IV-S neuroblastoma.

This article presents the case of an infant who on routine physical examination at the age of 5 months was found to have hepatomegaly. The initial investigation revealed borderline liver function tests, and ultrasonography showed multiple space-occupying lesions. Further workup using different imaging techniques, urinary vanillylmandelic acid, serum catecholamines, and liver biopsy led to the diagnosis of stage IV-S neuroblastoma. No primary site outside of the liver could be demonstrated. The tumor regressed spontaneously.

Hepatomegaly↗
PubMed1990

Therapy of a fatal murine cytomegalovirus infection with thymic humoral factor (THF-gamma 2) treated immune spleen cells.

Infection of mice with murine cytomegalovirus (CMV) presents a model for the study of the role of the immune system in the pathogenesis of human CMV. We performed adoptive transfer experiments to evaluate the prospects for enhancing the anti-viral potential of murine CMV immune spleen cells by THF-gamma 2. Adult BALB/c mice resistant to murine CMV become highly susceptible following immunosuppression by cyclophosphamide. Recipient mice were injected with murine CMV and cyclophosphamide concomitantly, and 24 h later adoptive transfers of syngeneic immune spleen cells were performed. We showed that passive transfers of murine CMV immune spleen cells prevented the development of a fatal disease in 38% of the recipient mice. Daily injections of murine CMV immune donor mice with THF-gamma 2 enhanced considerably (93%) the therapeutic potential of virus-specific immune cells. These experiments provide direct evidence for the antiviral capacity of THF-gamma 2 through its immunomodulatory effect on immune T cells.

Animals↗
PubMed1990

Infantile idiopathic thrombocytopenic purpura.

Idiopathic thrombocytopenic purpura (ITP) in childhood is a benign disease, as only 10% to 20% of the patients have a chronic course. A retrospective study of 57 ITP patients ranging in age from four months to two years revealed that 30% of them proceeded to chronicity. Unlike ITP in the general pediatric population, chronic infantile ITP was characterized by male predominance, a high frequency of preceding viral infections, and lack of responsiveness to any of the known modalities of treatment.

Child↗
PubMed1990

Immune modulation exerted by thymic humoral factor (THF-gamma 2), on T-cell subsets and IL-2 production of umbilical cord blood lymphocytes.

The effect of a synthetic thymic humoral factor, THF-gamma 2, on the immune competence of T-cells was investigated in vitro on lymphocytes from human cord blood (UCBL). It was found that preincubation of UCBL with THF-gamma 2 caused an increase in the percentage of cells expressing the CD4 or the CD8 differentiation antigens, but did not affect the percentage of CD3 cells. The effect of THF-gamma 2 on PHA-induced IL-2 secretion was also studied and found that a 3hr preincubation with THF-gamma 2, prior to suboptimal PHA stimulation caused an increase in the IL-2 activity of the treated UCBL cultures. This effect was THF-gamma 2 dose dependent with an optimum in the range of 300-600 ng/ml and was not influenced by irradiation of the UCBL. These results indicate that THF-gamma 2, a synthetic octapeptide, modulates the immune state and response of human umbilical cord blood lymphocytes.

Antigens, Differentiation, T-Lymphocyte↗
PubMed1989

Amino acid sequence of alcohol dehydrogenase from the thermophilic bacterium Thermoanaerobium brockii.

The complete amino acid sequence of alcohol dehydrogenase of Thermoanaerobium brockii (TBAD) is presented. The S-carboxymethylated protein was cleaved at methionine residues (with cyanogen bromide) to provide a set of 10 nonoverlapping fragments accounting for 90% of the sequence. These fragments were then overlapped and aligned, and the sequence was completed by using peptides generated by proteolytic cleavage at lysine residues (with Achromobacter protease I). The protein subunit contained 352 amino acid residues corresponding to a molecular weight of 37,652. The sequence showed about 35% identity with that of the prokaryotic Alcaligenes eutrophus alcohol dehydrogenase and about 25% identity with any one of the eukaryotic alcohol/polyol dehydrogenases known today. Of these, only 18 residues (5%) are strictly conserved: 11 Gly, 2 Asp, and 1 each of Cys, His, Glu, Pro, and Val.

Alcohol Dehydrogenase↗
PubMed1989

THF-gamma 2, a thymic hormone, increases immunocompetence and survival in 5-fluorouracil-treated mice bearing MOPC-315 plasmacytoma.

The effect of the thymic hormone, THF-gamma 2, on the immunocompetence of 5-fluorouracil (5-FU)-treated BALB/c mice, bearing MOPC-315 tumor, was examined. Treatment of noninoculated or tumor-bearing mice with THF-gamma 2 after 5-FU injection, resulted in an increase in the antibody response to sheep red blood cells and in the allogeneic response in spleen cell cultures and had no effect on the concanavalin-A-induced interleukin-2 secretion beyond that caused by 5-FU alone. Treatment with either 5-FU alone or 5-FU and THF-gamma 2 resulted in restoration to normal values of Lyt1- and L3T4-positive populations in tumor-bearing mice. THF-gamma 2 prolonged the survival time of mice bearing MOPC-315 tumor beyond that observed in mice treated with 5-FU alone.

Animals↗
PubMed1988

Thymic humoral factor gamma 2: purification and amino acid sequence of an immunoregulatory peptide from calf thymus.

Thymic humoral factor gamma 2 (THF-gamma 2), an octapeptide essential for immune regulation, was purified from calf thymus. The purification of THF-gamma 2, monitored in vitro and in vivo in mouse splenocyte proliferation assays, was achieved by gel filtration of low molecular weight thymus extracts followed by ion-exchange chromatography and sequential reversed-phase high-performance liquid chromatography. The process yielded 5 micrograms of THF-gamma 2/1000 kg of thymus tissue. The concentration of THF-gamma 2 required for augmentation of lymphocyte proliferation and interleukin 2 production was 5 ng/mL in vitro and 10 ng/kg per mouse in vivo. THF-gamma 2 has the amino acid sequence Leu-Glu-Asp-Gly-Pro-Lys-Phe-Leu. The proposed structure has been confirmed because a peptide was synthesized on the basis of this sequence that showed activity identical with that of the biological molecule. It shows no homology to the amino acid sequence of other thymic hormones nor is it part of any peptide or protein of known sequence. THF-gamma 2 retains essentially all of the biological activity of the thymus extract from which it is derived.

Amino Acid Sequence↗
PubMed1988

Chicken immunoglobulin gamma-heavy chains: limited VH gene repertoire, combinatorial diversification by D gene segments and evolution of the heavy chain locus.

cDNA clones encoding the variable and constant regions of chicken immunoglobulin (Ig) gamma-chains were obtained from spleen cDNA libraries. Southern blots of kidney DNA show that the variable region sequences of eight cDNA clones reveal the same set of bands corresponding to approximately 30 cross-hybridizing VH genes of one subgroup. Since the VH clones were randomly selected, it is likely that the bulk of chicken H-chains are encoded by a single VH subgroup. Nucleotide sequence determinations of two cDNA clones reveal VH, D, JH and the constant region. The VH segments are closely related to each other (83% homology) as expected for VH or the same subgroup. The JHs are 15 residues long and differ by one amino acid. The Ds differ markedly in sequence (20% homology) and size (10 and 20 residues). These findings strongly indicate multiple (at least two) D genes which by a combinatorial joining mechanism diversify the H-chains, a mechanism which is not operative in the chicken L-chain locus. The most notable among the chicken Igs is the so-called 7S IgG because its H-chain differs in many important aspects from any mammalian IgG. The sequence of the C gamma cDNA reported here resolves this issue. The chicken C gamma is 426 residues long with four CH domains (unlike mammalian C gamma which has three CH domains) and it shows 25% homology to the chicken C mu. The chicken C gamma is most related to the mammalian C epsilon in length, the presence of four CH domains and the distribution of cysteines in the CH1 and CH2 domains. We propose that the unique chicken C gamma is the ancestor of the mammalian C epsilon and C gamma subclasses, and discuss the evolution of the H-chain locus from that of chicken with presumably three genes (mu, gamma, alpha) to the mammalian loci with 8-10 H-chain genes.

Amino Acid Sequence↗
PubMed1988

Burkitt's lymphoma protruding through the anus. Report of an unusual case.

A four-year-old boy had a cecoanal intussusception prolapsing through the anus. A 4 x 4 cm cecal tumor served as the leading point of the intussusception. Laparotomy and histology revealed that the tumor was a solitary Burkitt's lymphoma of the cecum. Isolated Burkitt's lymphoma, as presented here, is rare, and such a combination has never been reported. Intussusception prolapsing through the anus and Burkitt's lymphoma are discussed, as well as a possible reason for the rarity of the condition.

Burkitt Lymphoma↗
PubMed1988

Osteoclast-like cells grow in cultures of multipotent hematopoietic progenitors in thrombocytopenia and absent radii (TAR) syndrome.

Cultures of bone marrow multipotent hematopoietic progenitors were performed in a case of TAR syndrome and normal bone marrow. It was found that clones of large multinucleated cells formed after 2 weeks of cultures from the TAR bone marrow but not in that of control subjects of the same age. Those cells contained a tartrate-resistant acid phosphatase activity and were negative for both monocytes and megakaryocytic markers. The data suggest that the multinucleated cells have several characteristics of osteoclasts. It was also found that growth of multipotent and megakaryocytic colonies was reduced when compared with normal control subjects (36 and 24%, respectively). This new finding of osteoclast or osteoclast-like cells derived from cultures of bone marrow hematopoietic precursors in TAR syndrome is discussed in relation to the lack of megakaryocytic characteristics in this disorder.

Abnormalities, Multiple↗
PubMed1987

Analyses of chicken immunoglobulin light chain cDNA clones indicate a few germline V lambda genes and allotypes of the C lambda locus.

cDNA libraries of chicken spleen and Harder gland (a gland enriched with immunocytes) constructed in pBR322 were screened by differential hybridization and by mRNA hybrid-selected translation. Eleven L-chain cDNA clones were identified from which VL probes were prepared and each was annealed with kidney DNA restriction digests. All VL probes revealed the same set of bands, corresponding to about 15 germline VL genes of one subgroup. The nucleotide sequences of six VL clones showed greater than or equal to 85% homology, and the predicted amino acid sequences were identical or nearly identical to the major N-terminal sequence of L-chains in chicken serum. These findings, and the fact that the VL clones were randomly selected from normal lymphoid tissues, strongly indicate that the bulk of chicken L-chains is encoded by a few germline VL genes, probably much less than 15 since many of the VL genes are known to be pseudogenes. Therefore, it is likely that somatic mechanisms operating prior to specific triggering by antigen play a major role in the generation of antibody diversity in chicken. Analysis of the constant region locus (sequencing of CL gene and cDNAs) demonstrate a single CL isotype and suggest the presence of CL allotypes.

Amino Acid Sequence↗
PubMed1987

Cerebellar ataxia and opsoclonus as the initial manifestations of myoclonic encephalopathy associated with neuroblastoma.

Cerebellar ataxia and opsoclonus were the initial manifestations of an associated neuroblastoma in a 20-month-old girl. Two months after the initial symptomatology, a physical examination revealed an abnormal mass palpable left to the midline. Urinary catecholamines were within normal limits. The child's neurological findings improved immediately after surgery, and steroid treatment and the follow-up on her after 2 years revealed normal general and neurological development. The syndrome of myoclonic encephalopathy including cerebellar ataxia, myoclonus and opsoclonus, and its relationship to neuroblastoma is reviewed. Failure to recognize this association can result in delays in both diagnosis and treatment and could be fatal.

Abdominal Neoplasms↗
PubMed1987

Immunoreconstitution of T-cell impairments in asymptomatic male homosexuals by thymic humoral factor (THF).

The feasibility of using Thymic Humoral Factor (THF) for immunomodulation in asymptomatic male homosexuals was evaluated in a study on fifteen subjects with T-cell impairments, selected on the basis of a 2SD reduction in T helper/inducer (T4+) cells and one additional lymphocytic defect. Following two biweekly courses of treatment, mean relative increments of T4+ (P less than 0.002), T3+ (P less than 0.02) and total lymphocyte (P less than 0.05) populations of the group receiving THF (n = 7) were significantly increased when compared to the placebo group (n = 8). In addition, a transient increase in T4+ lymphocytes was observed after the first course in the two individuals of the THF-treated group who were seropositive for HTLV-III/LAV but not in those who were seronegative. No difference was found between the groups in fluctuations of serum interferon (IFN) or proliferation of peripheral mononuclear cells to mitogens. The results of this limited trial demonstrate that THF is capable of correcting T-cell impairments that may predispose asymptomatic homosexuals to infection by HTLV-III, without affecting IFN production. These findings suggest that future strategies for AIDS prevention in high-risk groups should include institution of large controlled trials in immunodeficient, asymptomatic, HTLV-III/LAV-seronegative male homosexuals to study the potential of selective immunoreconstitution as a preventive measure against HTLV-III/LAV infection.

Acquired Immunodeficiency Syndrome↗