PubMed Health⌕ Search

Biomedical subjects

S Levitz

Publications and source records attributed to S Levitz.

13 recordsLinked to original sources
PubMed2000

Prevalence of germline truncating mutations in ATM in women with a second breast cancer after radiation therapy for a contralateral tumor.

Patients treated with conservative surgery and radiation therapy for early-stage breast cancer develop a contralateral breast cancer at a rate of approximately 0.75% per year. Ataxia-telangiectasia (AT) is an autosomal recessive disease that is characterized by increased sensitivity to ionizing radiation (IR) and cancer susceptibility. Epidemiologic studies have suggested that AT carriers, who comprise 1% of the population, may be at an increased risk for developing breast cancer, particularly after exposure to IR. To test this hypothesis, we analyzed blood samples from 57 patients who developed a contralateral breast cancer at least 6 months after completion of radiation therapy for an initial breast tumor. A cDNA-based truncation assay in yeast was used to test for heterozygous mutations in the ATM gene, which is responsible for AT. No mutations were detected. Our findings fail to support the hypothesis that AT carriers account for a significant fraction of breast cancer cases arising in women after exposure to radiation. Genes Chromosomes Cancer 27:124-129, 2000.

Adult↗
PubMed1999

Natural history of the rearfoot angle: preliminary values in 150 children.

The degree of valgus in the heel during weightbearing (the rearfoot angle) is commonly used as an angular criterion in the evaluation and treatment of flatfoot in children and adults. The rearfoot angle has been frequently reported to reduce with age to a vertical heel position attained at approximately 7 years old. The present study evaluated the rearfoot angle in 150 healthy children (age range, 6-16 years). The average rearfoot angle for all children in this study was 4 degrees of valgus (SD, 1.1 degrees; range, 0 degree - 9 degrees of valgus). There was no significant difference in the rearfoot angle in children of different ages. The rearfoot angle did not reduce to the vertical heel position by age 7 as had been reported previously.

Achilles Tendon↗
PubMed1999

Heterozygous germline ATM mutations do not contribute to radiation-associated malignancies after Hodgkin's disease.

PURPOSE: The successful treatment of Hodgkin's disease has been associated with an increased incidence of secondary malignancies. To investigate whether genetic factors contribute to the development of secondary tumors, we collected family cancer histories and performed mutational analysis of the ataxia-telangiectasia (AT) gene, ATM, in a cohort of Hodgkin's disease survivors with secondary malignancies. ATM was chosen for evaluation because of the increased radiosensitivity of cells derived from AT patients and obligate heterozygotes and the epidemiologic observation that AT carriers are at increased risk for radiation-induced breast cancer. PATIENTS AND METHODS: Fifty-two patients who developed one or more neoplasms after treatment for Hodgkin's disease participated in this study. Personal and family histories of cancer were obtained through patient interviews and review of medical records. ATM mutational analysis was performed using a yeast-based protein truncation assay. RESULTS: Seventy-six secondary neoplasms were observed in this cohort of 52 Hodgkin's disease survivors, with 18 patients (35%) developing more than one secondary neoplasm. Positive family histories of cancer were present in 11 (21%) of 52 patients, compared with three (4%) of 68 Hodgkin's disease patients in a comparison cohort who did not develop secondary neoplasms (P =.008; Fisher's exact test). No germline ATM mutations were identified, resulting in an estimated AT carrier frequency in this population of 0% (90% confidence interval, 0% to 4%). CONCLUSION: Analysis of the number of tumors per individual and the family history of cancer in our cohort suggests that genetic factors may contribute to development of secondary neoplasms in a subset of Hodgkin's disease survivors. Mutational analysis, however, does not support a significant role for heterozygous truncating ATM mutations. Future studies evaluating other genes involved in DNA damage response pathways are warranted.

Adolescent↗
PubMed1998

Inactivating mutations in an SH2 domain-encoding gene in X-linked lymphoproliferative syndrome.

X-linked lymphoproliferative syndrome (XLP) is an inherited immunodeficiency characterized by increased susceptibility to Epstein-Barr virus (EBV). In affected males, primary EBV infection leads to the uncontrolled proliferation of virus-containing B cells and reactive cytotoxic T cells, often culminating in the development of high-grade lymphoma. The XLP gene has been mapped to chromosome band Xq25 through linkage analysis and the discovery of patients harboring large constitutional genomic deletions. We describe here the presence of small deletions and intragenic mutations that specifically disrupt a gene named DSHP in 6 of 10 unrelated patients with XLP. This gene encodes a predicted protein of 128 amino acids composing a single SH2 domain with extensive homology to the SH2 domain of SHIP, an inositol polyphosphate 5-phosphatase that functions as a negative regulator of lymphocyte activation. DSHP is expressed in transformed T cell lines and is induced following in vitro activation of peripheral blood T lymphocytes. Expression of DSHP is restricted in vivo to lymphoid tissues, and RNA in situ hybridization demonstrates DSHP expression in activated T and B cell regions of reactive lymph nodes and in both T and B cell neoplasms. These observations confirm the identity of DSHP as the gene responsible for XLP, and suggest a role in the regulation of lymphocyte activation and proliferation. Induction of DSHP may sustain the immune response by interfering with SHIP-mediated inhibition of lymphocyte activation, while its inactivation in XLP patients results in a selective immunodeficiency to EBV.

Amino Acid Sequence↗
PubMed1998

Recent advances in cryptococcosis, candidiasis and coccidioidomycosis complicating HIV infection.

Concomitant with the decline in CD4+ T-cells seen as human immunodeficiency virus (HIV) infection progresses, the prevalence of opportunistic mycoses increases dramatically. This article reviews selected recent advances in our understanding of the immunology, molecular epidemiology and treatment of fungal infections in patients infected with HIV. For cryptococcosis, studies are reported on how HIV infection affects the immune response to Cryptococcus neoformans and, conversely, how stimulation with C. neoformans induces HIV production from latently HIV-infected cells. In addition, studies are presented examining the efficacy of triple combination antimycotic chemotherapy in cryptococcosis. For candidosis, investigations into genetic profiles of Candida albicans isolates obtained from patients, with resistance to antifungal agents, are demonstrated. Finally, for coccidioidomycosis, prospective studies are presented examining the clinical, epidemiological and immunological characteristics of a cohort of HIV-infected subjects residing in an endemic area.

AIDS-Related Opportunistic Infections↗
PubMed1996

Longitudinal epiphyseal bracket: associated foot deformities with implications for treatment.

The longitudinal epiphyseal bracket is a rare ossification defect of bones of the hands and feet and results in an abnormal epiphysis that is C-shaped, longitudinally oriented, and vertically extends into the diaphysis. The longitudinal epiphyseal bracket may exist as an isolated deformity, but is commonly associated with digital deformities such as polydactyly, duplicated digits, congenital hallux varus, and clinodactyly. Five case histories of children with the longitudinal epiphyseal bracket in different bones of the foot are described with three distinct clinical presentations. The development of the longitudinal epiphyseal bracket and implications for treatment are considered.

Adolescent↗
PubMed1995

Tuberculosis of the foot. A diagnostic challenge.

Two cases of tuberculosis of the foot are described. The diagnosis for each was delayed and unexpected. The clinical features of osteoarticular tuberculosis are reviewed along with practical guidelines for diagnosis.

Adult↗
PubMedDate not supplied

Delta phalanx.

Explore the source record for details and available documents.

Adult↗
PubMedDate not supplied

A literature review of the Ilizarov technique and some applications for treating foot pathology.

The Ilizarov technique is a method of stimulating new bone and/or soft tissue growth at the rate of 1 mm per day. This technique was developed in the former Soviet Union in the early 1950s to stimulate limb lengthening, correct malaligned appendicular skeletal deformities, heal nonunions and close soft tissue defects. This procedure has been used in the United States less than 10 years. While Professor Ilizarov recognized that his technique could be used to treat foot pathology such as clubfoot, physicians continue to expand the applications for the Ilizarov procedure in treating complex foot pathologies.

Bone Lengthening↗