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Biomedical subjects

I Berkel

Publications and source records attributed to I Berkel.

At least 19 recordsLinked to original sources
PubMed1993

Periodical gingival bleeding as a presenting symptom of periodontitis due to underlying cyclic neutropenia. Case report.

A 13-year-old boy presenting with spontaneous and periodical gingival bleeding accompanied by fever was thoroughly examined in order to determine the underlying aetiology of the gingival bleeding. Following repeated blood tests, the patient was diagnosed as having cyclic neutropenia. Thus, it was suggested, gingival bleeding, especially when spontaneous and periodical, should be carefully investigated to eliminate the possibility of cyclic neutropenia.

Adolescent↗
PubMed1988

Localization of an ataxia-telangiectasia gene to chromosome 11q22-23.

Ataxia-telangiectasia (AT) is a human autosomal recessive disorder of childhood characterized by: (1) progressive cerebellar ataxia with degeneration of Purkinje cells; (2) hypersensitivity of fibroblasts and lymphocytes to ionizing radiation; (3) a 61-fold and 184-fold increased cancer incidence in white and black patients, respectively; (4) non-random chromosomal rearrangements in lymphocytes; (5) thymic hypoplasia with cellular and humoral (IgA and IgG2) immunodeficiencies; (6) elevated serum level of alphafetoprotein; (7) premature ageing; and (8) endocrine disorders, such as insulin-resistant diabetes mellitus. A DNA processing or repair protein is the suspected common denominator in this pathology. Heterozygotes are generally healthy; however, the sensitivity of their cultured cells to ionizing radiation is intermediate between normal individuals and that of affected homozygotes. Furthermore, heterozygous females are at an increased risk of breast cancer. These findings, when coupled with an estimated carrier frequency of 0.5-5.0%, suggest that (1) as many as one in five women with breast cancer may carry the AT gene and that (2) the increased radiation sensitivity of AT heterozygotes may be causing radiation therapists to reduce the doses of radiation used for treating cancer in all patients. To identify the genetic defect responsible for this multifaceted disorder, and to provide effective carrier detection, we performed a genetic linkage analysis of 31 families with AT-affected members. This has allowed us to localize a gene for AT to chromosomal region 11q22-23.

Ataxia Telangiectasia↗
PubMed1984

Epstein-Barr virus (EBV)-specific cell-mediated and humoral immune responses in ataxia-telangectasia patients.

As a part of studies on cell-mediated immune (CMI) responses of immunocompromised, Epstein-Barr virus (EBV)-infected patients who can or cannot restrict the proliferation of EBV-transformed B cells, we have studied 16 Turkish patients with ataxia-telangectasia (AT). Fifteen were EBV seropositive; one was seronegative. Among the seropositives, eight had no or only low anti-EBV-determined nuclear antigen (EBNA) antibody titers, while seven had normal anti-EBNA levels. EBV-seropositive and -seronegative healthy Turkish children were used as controls. We have particularly asked the question whether low EBNA antibody titers can be correlated with the level of EBV-specific and -nonspecific cell-mediated immunity. Non-EBV-specific tests included cell count, phenotypical characterization with monoclonal antibodies, assessment of natural killer (NK)-cell activity, and ability to suppress mitogen-induced immunoglobulin production. Two EBV-specific CMI tests were used: outgrowth inhibition (OI) and leukocyte migration inhibition (LMI). The majority of the patients of the low-EBNA antibody group was IgA deficient and had high levels of alpha-fetoprotein (a-FP). Cells reacting with OKT8 monoclonal antibody predominated in both AT patient groups. In contrast, the suppressor activity was present in only a few patients and NK and interferon-activated killing (IAK) activities were normal. EBV-specific cell-mediated responses were defective in seven of eight patients in the low-anti-EBNA group and five of seven patients in the group with normal anti-EBNA titers. It is concluded that AT patients are often defective in their EBV-specific cell-mediated immune responses and with regard to their EBNA antibody levels. These defects are associated with a predominance of T cells reacting with OKT8 monoclonal antibody.

Adolescent↗
PubMed1984

Cell mediated immunity in patients with subacute sclerosing panencephalitis.

Cell mediated immunity was assessed on the basis of total lymphocytes (TL), total T lymphocytes (TTL) counts, delayed skin test responses and in vitro leucocyte migration inhibition test (LIF) production in 25 patients with SSPE, classified according to the clinical stages of the disease. The patients in stage I of the disease did not show any defect in cellular immunity while the patients in stage II showed decreased TL and TTL counts, more negative skin test responses to PHA, SKSD and PPD, and unresponsiveness to SKSD of LIF production. When the patient group was evaluated as a whole, only the TL counts and the skin test responses against SKSD differed from those in the controls. These results suggest that the defects in cellular immunity demonstrated in the patients with SSPE may be due to SSPE or the measles virus itself rather than to a genetic factor predisposing patients to SSPE.

Adolescent↗