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Biomedical subjects

P Imbach

Publications and source records attributed to P Imbach.

At least 91 records · Page 5Linked to original sources
PubMed1983

[Genetic factors linked to the HLA system conferring increased susceptibility to acute lymphoblastic leukemia in children].

Inheritance of HLA antigens in 55 families of patients with ALL was analyzed. Significantly increased sharing of DR antigens was observed among the parents of the affected children (p = 0.003). A similar increase was noted in the sharing of HLA-B antigens (p = 0.02). The observed number of DR homozygotes among the patients was twice the expected value in families where the parents shared a B and a DR antigen. Segregation analysis of the shared antigens disclosed significant prevalence of heterozygotes among the healthy siblings, which suggested the occurrence of gametic selection in such families. This study indicates that mating of certain shared alleles of the HLA system (especially of the DR locus) is associated with a risk for the offspring to develop ALL in childhood. Restricted heterogeneity of the parental HLA gene pool favours the expression of linked recessive genes and, presumably, of those involved in susceptibility to ALL.

Child↗
PubMed1983

Evidence for HLA-linked susceptibility factors in childhood leukemia.

To test the hypothesis that susceptibility to leukemia can be governed by (a) recessive gene(s) associated with the major histocompatibility complex (MHC) in man, we performed an analysis of the inheritance of HLA antigens in 55 families in which one of the children developed ALL. We found among the parents of affected children a highly significant increased compatibility at the DR locus (p = 0.003). A similar increase was observed in sharing HLA antigens of the B locus (p = 0.02). The observed number of homozygotes among the patients was twice the expected value in families where the parents shared a B and a DR antigen. In segregation analysis, heterozygotes for the shared parental HLA antigen were significantly more prevalent among the healthy siblings. Our genetical analysis indicates that mating of certain shared alleles of the HLA system (especially of the DR locus) is associated with the risk for the offspring to develop ALL in childhood. This situation favors the expression of recessive genes associated with the MHC, and presumably those involved in the susceptibility to acute leukemia. Because familial leukemia is a rare event, the susceptibility to childhood ALL must also implicate genes outside the MHC and important environmental factors.

Child↗
PubMed1983

Reactivity of acute lymphoblastic leukemia and normal bone marrow cells with the monoclonal anti-B-lymphocyte antibody, anti-Y 29/55.

Malignant lymphocyte populations in peripheral blood of patients with B-cell chronic lymphocytic leukemia, leukemic variant of B-cell non-Hodgkin's lymphoma, and hairy cell leukemia can be characterized by the use of a monoclonal murine antibody (anti-Y 29/55) which is directed against a cell membrane component normally confined to the sessile nonrecirculating cells of the B-lymphocyte population in lymphoid tissues. The present report describes the reactivity of the anti-Y 29/55 antibody with bone marrow cells obtained from children with acute lymphoblastic leukemia using an indirect immunofluorescence method in combination with morphological and cytokinetic studies. In 25 patients (acute lymphoblastic leukemia subtype: 14 common; 4 pre-B-cell; 4 null; and 3 T-cell), a maximum of 2% of cells (small lymphocytes) were stained. One patient presented with blasts exhibiting cytoplasmic and surface immunoglobulin M (IgM) (pre-B-B-cell acute lymphoblastic leukemia). About 11% of this patient's blast cells showed a positive reaction with anti-Y 29/55. They could not be differentiated by morphological criteria from the anti-Y 29/55-negative blast cell population. In another patient with pre-B-B-cell acute lymphoblastic leukemia, only 1% of anti-Y 29/55-positive cells was found. In bone marrow of children with relative lymphocytosis, 1.4 to 8.7% of mononuclear cells reacted with anti-Y 29/55. Morphologically, these cells were small lymphocytes and predominantly expressed surface IgM. In two of these children, a further subdivision of bone marrow cells could be achieved by combining anti-Y 29/55 and cytoplasmic IgM reactivity with [3H]thymidine pulse labeling. These studies revealed that the actively proliferating, normal pre-B-cell population was anti-Y 29/55-nonreactive, whereas a nonproliferating population of anti-Y 29/55-reactive, cytoplasmic IgM-positive cells probably represented B-cells with surface immunoglobulin M reacting when cytoplasmic IgM was assessed. We conclude that the reactivity of the monoclonal anti-B-cell antibody (anti-Y 29/55) is restricted to surface immunoglobulin-positive bone marrow cells and that neither leukemic or normal pre-B-cells nor common, null-cell, or T-cell acute lymphoblastic leukemia blasts react.

Antibodies, Monoclonal↗
PubMed1982

[Chance of a second remission in acute juvenile lymphoblastic leukemia with favorable prognosis].

24 children with low risk acute lymphoblastic leukemia (ALL) in first relapse were re-treated with an aggressive protocol. Therapy of the first episode had adopted two different but equivalent approaches (SAKK-ALL "low risk" 76 and CALGB protocol 7611). With one exception, relapse occurred in all children before discontinuation of therapy. complete remission was achieved in 20 of the 24 children (83%). Five of 11 children in whom the length of the second remission could be evaluated had, at the time of the cutoff, been in continuous remission for 18 to 40 months. The therapy displayed considerable toxicity. From this study it is concluded that remission is achieved in the majority of children with first relapse of ALL, but that the remission can be maintained beyond 18 months only in a few children.

Adolescent↗
PubMed1982

Conventional and spectral EEG analysis in children treated with cytotoxic agents.

One hundred and six EEG investigations were carried out in 17 children with various types of neoplastic disease without cerebral involvement during one or more courses of treatment with cytotoxic agents EEGs were recorded before and 24 hr after administration of the drugs. The EEGs were evaluated visually and by spectral analysis. A transient slowing of the dominant frequency in the alpha band by about 1 Hz and a decrease in the relative power of alpha activity by 20-30% was observed in only 4 patients. These children did not show any clinical or biochemical signs of neurotoxicity. The children did not receive the same antineoplastic treatment. One patient received very high dose methotrexate, 2 patients received vincristine combined with other cytotoxic agents and the other patient received L-asparaginase. It is suggested that EEG changes in patients receiving intravenous cytotoxic treatment usually occur only where there is pre-existing impairment of the blood--cerebrospinal fluid barrier or blood-brain barrier. No clinical signs of epilepsy, new epileptiform waves in the EEG or long-term changes in the background activity of the EEG were observed in this pilot study.

Adolescent↗
PubMed1982

[Diagnosis of acute leukemia in childhood].

The diagnosis of acute leukemia in childhood is based primarily on a morphologic evaluation of bone marrow smears. According to the French-American-British (FAB) classification three types (L1-L3) of acute lymphoblastic (ALL) and six types (M1-M6) of acute non-lymphoblastic leukemia (ANLL) are distinguished. Besides morphology cytochemical studies are used, particularly in cases where panoptic stains do not permit an unequivocal attribution to either ALL or ANLL. In addition, cytochemical reactions contribute to the distinction of myelocytic and monocytic types of ANLL. The heterogeneity of ALL in childhood is best revealed by immunological markers which permit to distinguish common, null, pre-T, T, pre-B and B subtypes. A discussion of published results demonstrates that the prognostic implications of these studies cannot be clearly evaluated as yet. By use of monoclonal antibodies new subtypes of ALL, and, very recently, of ANLL have been defined. One important aspect of these diagnostic refinements is to tailor antileukemic therapy to prognostic factors.

Acute Disease↗
PubMed1982

[Chronic idiopathic thrombocytopenic purpura in childhood].

In 12 of 95 children with idiopathic thrombocytopenic purpura (ITP) admitted to the Department of Pediatrics of the University Hospital in Bern between January 1st and December 31st 1979, the disease became chronic. Sex and age distribution were similar in children with acute and chronic ITP. Neither the history nor the initial symptomatology were useful for early detection of chronic ITP. For this purpose the initial raise of the platelet count after initiation of prednisone treatment appeared to be a more reliable parameter. Five of the 12 children received only drugs while 7 were splenectomized. After an observation period of 4 years none of 4 children who had received only drugs but 2 of 3 splenectomized children required intensive treatment. Prednisone and azathioprine, vincristine or cyclophosphamide, used alone or in various combinations, induced impressive but only temporary remissions.

Child↗
PubMed1981

High-dose intravenous gammaglobulin for idiopathic thrombocytopenic purpura in childhood.

Seven children with chronic or intermittent and six with acute idiopathic thrombocytopenic purpura (ITP) were treated with large intravenous doses of polyvalent, intact immunoglobulin (Ig). In all patients the platelet count rose sharply within 5 days, but the initial response and the subsequent course varied from patient to patient. Among children with chronic ITP the initial response was more marked in splenectomised than in non-splenectomised patients. Among those with acute ITP the two who remained Ig dependent had a smaller initial response than the four patients who required no maintenance treatment. During the 90-110 days of observation five of six patients with chronic ITP could be maintained with Ig alone. No untoward effects of Ig therapy were observed.

Child↗
PubMed1981

Low- and high-risk non-T and non-B and T-cell acute lymphoid leukemia (ALL) in childhood: different duration of remission and survival.

In a prospective, nonrandomized trial clinical (initial WBC and chest film) and immunological (surface immunoglobulin and rosetting with pretreated sheep red blood cells) criteria were used to stratify 69 children with previously untreated acute lymphoid leukemia (ALL). Forty of 61 evaluable patients had low-risk ALL (initial WBC less than or equal to 20,000/mm3, no mediastinal mass) and were treated less intensively. Twenty-one of 61 patients had high-risk ALL (initial WBC greater than 20,000/mm3 and/or mediastinal mass) and were treated more intensively. Of the high-risk patients 15 had non-T non-B and 6 T ALL. Sixty of 61 patients went into complete remission. After a median observation period of 27 months, 32 of 40 low-risk, 7 of 14 high-risk non-T non-B, and none of 6 high-risk T ALL patients were in continuous first remission. Thirty-six of 40 low-risk, 9 of 15 high-risk non-T non-B, and none of 6 T ALL patients were alive. Despite more intensive treatment, the duration of remission and the survival were significantly shorter in the high-risk than in the low-risk patients. Among the high-risk ALL, non-T non-B ALL did better than T ALL.

Adolescent↗
PubMed1981

High-dose intravenous gammaglobulin therapy of refractory, in particular idiopathic thrombocytopenia in childhood.

A new immunoglobulin (Ig) for intravenous use was given in high doses to 4 children with refractory idiopathic thrombocytopenic purpura (ITP) and 2 children with idiopathic aplastic anemia (IAA). Within 5-10 days after initiation of Ig therapy the platelets of the children with ITP rose to 300,000-650,000/mm3 and could be maintained at normal levels with one Ig infusion every 1-3 weeks. No reaction was observed in the 2 patients with IAA.

Adolescent↗
PubMed1981

Infectious mononucleosis: sequential immunologic, cytochemical, and cytokinetic studies on single lymphoid cells in peripheral blood.

Sequential immunologic, cytochemical, and cytokinetic studies were done on single lymphoid cells in the peripheral blood of 6 children with infectious mononucleosis (IM) and 1 child with toxoplasmosis 1-2 wk after onset of symptomatology. The absolute number of AET-SRBC rosetting (E+) cells was increased in all patients; the absolute number of cells with surface IgM (slgM+) was increased in 3 of 7 patients. On the average, 46% of all lymphoid cells were E+la+slgM-, 35% E+la-slgM-, and 5% E-la+slgM+. Of the E+la+slgM- cells, only 7% were shown to have a dot-like esterase reaction pattern. Of the E+la-slgM-cells, 17% were esterase positive. The mean labeling index of the former was 18.2%, the mean labeling index of the latter 4.4%. No proliferating slgM+ cells were observed in the 6 children with IM. The esterase reactions and the labeling indices of suppressor-cytotoxic and inducer-helper T cells were similar to those of E+la+slgM- and E+la-slgM- cells, respectively. These results suggest that the vast majority of the atypical cells in IM corresponds to activated suppressor cells, while a minority appears to be proliferating helper cells.

Child↗
PubMed1981

Adjuvant chemotherapy with procarbazine, vincristine and prednisone for medulloblastomas. A preliminary report.

The survival of 20 children with medulloblastoma who received adjuvant chemotherapy with procarbazine, vincristine and prednisone after resection and craniospinal irradiation is compared with the preliminary results of the Children's Cancer Study Group (CCSG) and the international Society of Pediatric Oncology (SIOP) medulloblastoma studies. Survival with the chemotherapy used in the SPOG study ws not superior to the survival of children who received craniospinal irradiation only.

Cerebellar Neoplasms↗
PubMed1980

[Carnitine deficiency myopathy (author's transl)].

Carnitine is a carrier for the transport of long-chain fatty acids from the cytoplasmic to the mitochondrial space. So far 18 cases of carnitine deficiency myopathy have been recognized, generally occurring as progressive or relapsing myopathy. In contrast episodic exercise-induced myalgia and paresis was found in a 46-year-old patient with carnitine deficiency myopathy which was quickly reversible at rest. As a consequence of this observation carnitine deficiency myopathy must be added to the differential diagnosis of the McArdle syndrome (muscular phosphorylase deficiency) and other "exercise myopathies".

Biopsy↗
PubMed1979

[Malignat non-Hodgkin Lymphoma in childhood. Therapeutic results in 47 patients].

A preliminary report is presented on survival in 16 children with non-Hodgkin's lymphoma treated since 1975, as compared with that in 31 similar children treated between 1962 and 1974. In the former group, 10 of 14 children (71%) survived one or more years and 5 of 9 children (56%) two or more years with no evidence of disease. In the latter group, the corresponding survival rates were 26% and 19% respectively. This improvement is due to the introduction of an aggressive multidrug chemotherapy combined with radiotherapy, similar to the LSA2-L2 protocol. Considerable toxicity was observed with the new treatment. 23 of the 46 patients with diffuse non-Hodgkin's lymphoma had a Burkitt-type tumor. Treatment failures occurred mainly in children with a Burkitt-type tumor with primary intraabdominal localization.

Adolescent↗