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1.
Breast J ; 7(1): 60-5, 2001.
Article in English | MEDLINE | ID: mdl-11348418

ABSTRACT

A case of bilateral infiltrating lobular carcinoma of the breast containing osteoclast-like giant cells is presented. Notable pathologic features include prominent tumor-associated angiogenesis and the presence of osteoclast-like giant cells in axillary lymph node metastases. Immunohistologic and ultrastructural examination support a nonepithelial, histiocytic origin for the giant cells, and results are similar to previous reports of osteoclast-like giant cells associated with breast carcinoma. This is the first report of bilateral pure infiltrating lobular carcinoma of the breast with osteoclast-like giant cells and the first case of pure lobular carcinoma with osteoclast-like giant cells present in lymph node metastases.


Subject(s)
Breast Neoplasms/pathology , Carcinoma, Ductal, Breast/pathology , Giant Cells/pathology , Lymph Nodes/pathology , Axilla , Biopsy, Needle , Breast Neoplasms/surgery , Carcinoma, Ductal, Breast/secondary , Carcinoma, Ductal, Breast/surgery , Female , Follow-Up Studies , Giant Cells/ultrastructure , Humans , Immunohistochemistry , Lymphatic Metastasis , Mammography , Mastectomy, Modified Radical/methods , Microscopy, Electron , Middle Aged , Osteoclasts/pathology , Osteoclasts/ultrastructure
2.
Am J Surg Pathol ; 24(12): 1675-7, 2000 Dec.
Article in English | MEDLINE | ID: mdl-11117790

ABSTRACT

There is a trend toward primary resection without prior colostomy in the surgical treatment of Hirschsprung's disease (HD) that renders evaluation of the initial pathologic specimen of utmost importance. To determine the accuracy of diagnostic methods for HD in routine practice, biopsies and resection specimens of all patients being evaluated for possible HD during a 3-year period were reviewed and correlated. Eighty patients underwent a total of 132 procedures related to the diagnosis or treatment of HD, including 93 intraoperative frozen-section (FS) evaluations. FS analysis was performed on 12 of the initial pathologic specimens, with concordance between the FS and permanent-section diagnoses in 67% of specimens. The concordance rate for all FS evaluations in patients with HD was 89%, which is substantially lower than the institutional rate for all patients. Pathologic diagnoses resulted in two patients receiving suboptimal surgical treatment. Both of these errors resulted from incorrect FS diagnoses on initial diagnostic specimens. In conclusion, there is a high rate of incorrect FS diagnoses in HD. It is obvious that if FS is being used as the initial diagnostic method, and primary reanastomosis is to be performed in the same procedure, an incorrect FS diagnosis has severe implications. FS as an initial diagnostic procedure for HD is not recommended.


Subject(s)
Hirschsprung Disease/pathology , Adolescent , Adult , Biopsy , Child , Child, Preschool , Female , Frozen Sections , Hirschsprung Disease/diagnosis , Hirschsprung Disease/surgery , Humans , Infant , Infant, Newborn , Male , Reproducibility of Results
3.
ASDC J Dent Child ; 67(2): 128-31, 83, 2000.
Article in English | MEDLINE | ID: mdl-10826049

ABSTRACT

This paper presents a review of 1018 oral biopsies in pediatric patients from the Oral Pathology Service, Minas Gerais Federal University, Brazil. The lesions were divided into ten main categories. The most common oral lesions in this study were follicular cyst in the maxillary anterior region, followed by inflammatory fibrous hyperplasia in the same region, and mucocele in the lower lip. Cysts of the jaws and oral soft tissues comprised 26.1 percent of total oral biopsies. The importance of these findings in oral diagnosis is discussed.


Subject(s)
Mouth Diseases/epidemiology , Biopsy/statistics & numerical data , Brazil/epidemiology , Child , Fibrosis , Follicular Cyst/epidemiology , Humans , Hyperplasia , Jaw Cysts/epidemiology , Jaw Neoplasms/epidemiology , Mandibular Diseases/epidemiology , Maxillary Diseases/epidemiology , Mouth Diseases/pathology , Mouth Mucosa/pathology , Mouth Neoplasms/epidemiology , Mucocele/epidemiology , Stomatitis/epidemiology
4.
Leuk Lymphoma ; 39(3-4): 365-71, 2000 Oct.
Article in English | MEDLINE | ID: mdl-11342317

ABSTRACT

A case report of a dramatic therapeutic response of Hodgkin's disease (HD) to diethylstilbestrol (DES) in a man who was being treated for concurrent prostate cancer suggested that there also may be a role for sex steroids in the pathogenesis of HD (1). High levels of estrogen receptors (ER) comparable to those seen in breast carcinoma cells were detected in that patient's Hodgkin's biopsy specimen. In order to determine whether this patient was unique or whether sex steroid receptors commonly are present in HD specimens, we examined expression of ER and progesterone receptors (PR) in diagnostic tissue from pediatric (n = 14) and adult (n = 41) patients with HD using immunohistochemistry. None of the 55 samples expressed PR. 16/55 (29%) demonstrated weak nuclear ER positivity, which was confined to germinal center and occasional mantle zone lymphocytes and was comparable to that seen in non-malignant control lymph nodes. (4/5)5 (7.3%) samples exhibited moderate positivity in Reed Sternberg cells, which in one case was nuclear. ER commonly are expressed weakly in some HD tumors unrelated to clinical stage or patient sex but are generally limited to germinal center and mantle zone lymphocytes. A rare patient displays moderate cytoplasmic or nuclear ER in Reed-Sternberg cells.


Subject(s)
Hodgkin Disease/metabolism , Receptors, Steroid/metabolism , Adolescent , Adult , Age Factors , Aged , Aged, 80 and over , Case-Control Studies , Child , Child, Preschool , Female , Frozen Sections , Humans , Immunohistochemistry , Lymph Nodes/chemistry , Male , Middle Aged , Receptors, Estrogen/metabolism , Receptors, Progesterone/metabolism , Sex Factors , Uterus/chemistry
5.
Curr Opin Hematol ; 7(1): 59-63, 2000 Jan.
Article in English | MEDLINE | ID: mdl-10608506

ABSTRACT

Chronic active Epstein-Barr virus (EBV) infection is an uncommon outcome of EBV infection and may present as a waxing and waning or fulminant syndrome. Unlike acute infectious mononucleosis, wherein EBV establishes lifelong infection and survives by maintaining a delicate balance with the host as a latent infection, in chronic active EBV infection the host-virus balance is disturbed. The mechanisms by which this balance becomes perturbed are likely to be heterogenous and may involve host immune factors, viral factors, or both. A number of subtle immunologic defects have been reported in patients with chronic active EBV infection. Enhanced expression of viral genes has also been noted in some cases. Treatment of chronic active EBV infection has proven difficult, but new modalities including etoposide-based regimens and adoptive transfer of EBV-specific cytotoxic T lymphocytes have shown promise.


Subject(s)
Epstein-Barr Virus Infections/complications , Epstein-Barr Virus Infections/immunology , Autoimmunity , Chronic Disease , Epstein-Barr Virus Infections/therapy , Humans , Immune System/physiopathology
6.
Article in English | MEDLINE | ID: mdl-10519756

ABSTRACT

OBJECTIVE: The purpose of the present study was to compare the immunohistochemical expression of cell cycle-associated proteins in neuroblastic and melanocytic cell populations of melanotic neuroectodermal tumor of infancy. STUDY DESIGN: Three cases of melanotic neuroectodermal tumor of infancy were selected. The immunohistochemical expression of MDM-2, p53, proliferating cell nuclear antigen, cyclin D1, and cyclin A was assessed through use of the streptavidin-biotin-peroxidase complex technique. RESULTS: Positive immunostaining for MDM-2, proliferating cell nuclear antigen, cyclin D1, and cyclin A was occasionally observed in the large melanin-containing epithelioid cells. CONCLUSIONS: These data suggest that MDM-2 expression may be important for the development of melanotic neuroectodermal tumor of infancy and that the melanocytic cell population, not the neuroblastic one, is the proliferative component of the tumor.


Subject(s)
Cell Cycle Proteins/metabolism , Maxillary Neoplasms/metabolism , Neuroectodermal Tumor, Melanotic/metabolism , Female , Humans , Immunohistochemistry , Infant , Proliferating Cell Nuclear Antigen/metabolism
8.
Pediatr Dev Pathol ; 2(1): 72-7, 1999.
Article in English | MEDLINE | ID: mdl-9841710

ABSTRACT

X-linked lymphoproliferative disease (XLP) is a rare familial disorder resulting in selective immunodeficiency to the Epstein-Barr virus (EBV), characterized by uncontrolled proliferation of EBV-infected lymphocytes. Phenotypes of this disease are variable and include fulminant infectious mononucleosis, hypogammaglobulinemia, and malignant lymphoma. In this article, we describe a case of a previously healthy 4-year-old boy with serologic evidence of acute EBV infection who died of fulminant hepatic failure. Histopathological examination of tissue obtained postmortem showed hemophagocytosis and prominent polymorphous infiltrates associated with necrosis in the liver, spleen, and lymph nodes. Semiquantitative polymerase chain reaction (PCR) utilizing primers complementary to the EBV gene LMP2a performed on samples of liver tissue demonstrated approximately 0.6 copies of the EBV gene per cell. Immunohistochemistry demonstrated light chain restriction and PCR studies of the immunoglobulin V-D-J region revealed two strong bands, consistent with a clonal B cell proliferation. Extended family history revealed that the boy's family was followed by the XLP Registry, which was established in 1978 to follow kindreds with XLP. The genetic abnormality associated with XLP has been localized to the Xq25, allowing RFLP analysis to identify female carriers and affected boys.


Subject(s)
Herpesviridae Infections/pathology , Lymphoproliferative Disorders/pathology , Tumor Virus Infections/pathology , Child, Preschool , Fatal Outcome , Fever , Genetic Carrier Screening , Hepatic Encephalopathy/etiology , Hepatic Encephalopathy/virology , Herpesviridae Infections/diagnosis , Herpesviridae Infections/genetics , Herpesvirus 4, Human/genetics , Herpesvirus 4, Human/immunology , Humans , Lymphoproliferative Disorders/diagnosis , Lymphoproliferative Disorders/genetics , Lymphoproliferative Disorders/virology , Male , Polymorphism, Restriction Fragment Length , Sex Chromosome Aberrations/diagnosis , Sex Chromosome Aberrations/genetics , Sex Chromosome Aberrations/pathology , Tumor Virus Infections/diagnosis , Tumor Virus Infections/genetics , X Chromosome
9.
Arch Pathol Lab Med ; 122(3): 277-81, 1998 Mar.
Article in English | MEDLINE | ID: mdl-9823869

ABSTRACT

Epstein-Barr virus (EBV) has been associated with nasopharyngeal carcinoma, some Burkitt's-type lymphomas, and posttransplantation lymphoproliferative disorder. Recently, an association between EBV and smooth muscle tumors, both malignant and benign, in the acquired immunodeficiency syndrome and posttransplantation populations has been made. We report, to our knowledge, the first case of a renal EBV-associated smooth muscle tumor. A 33-year-old man with acquired immunodeficiency syndrome presented with a mass of the left kidney that was radiographically suspicious for malignancy. He underwent left radical nephrectomy. The tumor measured 3.0 cm in the largest dimension, was well-circumscribed, and was composed of fascicles of bland spindle cells with blunt-ended nuclei, which often intersected at right angles. Focal areas of cell crowding and nuclear pleomorphism were present. No areas of lipomatous differentiation were identified. Immunohistochemically, the tumor cells were positive for desmin and muscle-specific actin and were negative for HMB-45 and CD21 (an EBV receptor). In situ hybridization with EBV-encoded RNA-1, a probe that recognizes a non-poly(A) RNA EBV transcript expressed in latently infected cells, was diffusely positive. At 6 months postnephrectomy, the patient showed no evidence of local recurrence or metastases. The incidence of this tumor is expected to increase as both the numbers of patients undergoing solid organ transplantation and the survival time of patients with the acquired immunodeficiency syndrome increase. A better understanding of the biology and pathogenesis of this entity will be important for future management of these patients.


Subject(s)
Epstein-Barr Virus Infections/complications , Kidney Neoplasms/complications , Muscle Neoplasms/complications , Muscle, Smooth , Adult , Humans , Immunohistochemistry , Kidney Neoplasms/metabolism , Kidney Neoplasms/pathology , Male , Muscle Neoplasms/metabolism , Muscle Neoplasms/pathology
10.
Am J Clin Pathol ; 107(6): 643-52, 1997 Jun.
Article in English | MEDLINE | ID: mdl-9169660

ABSTRACT

While plasmacytosis is a common occurrence in early post-bone marrow transplantation biopsy specimens, the significance of plasma cells in such specimens from patients with multiple myeloma (MM) is unknown. We attempted to retrospectively determine, by morphologic assessment of plasma cell percentage, immunohistologic assessment of plasma cell light chain ratio (LCR), and correlation with clinical outcome, the prevalence and significance of plasmacytosis in the posttransplantation bone marrow biopsy specimens of 25 patients with MM who underwent autologous peripheral blood stem cell transplantation (PBSCT). No pre-PBSCT morphologic or immunologic characteristics were significantly associated with the post-PBSCT outcome in this group of patients. While 9% of all biopsy specimens and 25% of hypocellular biopsy specimens obtained during the first 60 days after the PBSCT contained more than 10% plasma cells, 34% of all biopsy specimens obtained during this period had elevated LCRs. The dominant light chain in all cases with high LCRs was the same as that of the original tumors, implying that these plasma cells represent a portion of the patients' original tumors. However, the presence of tumoral plasma cells during the early post-PBSCT period was not associated with outcome (P>.5 at 30 days and 60 days after transplantation). Histologic features of recurrent MM and elevated LCR occurring at day 90 or later are correlated with progression of disease (P=.02 and P=.0001, respectively). We conclude that the presence of tumoral plasma cells in the early post-PBSCT period likely represents residual tumor and should not be regarded as indicating imminent relapse, while the presence of tumor as assessed by histologic or immunohistochemical evaluation during the late post-PBSCT period should raise the concern of relapse and disease progression.


Subject(s)
Bone Marrow Transplantation/immunology , Hematopoietic Stem Cell Transplantation , Immunoglobulin Light Chains/immunology , Multiple Myeloma/therapy , Plasma Cells/immunology , Adult , Aged , Bone Marrow/immunology , Bone Marrow/pathology , Disease Progression , Female , Humans , Immunoenzyme Techniques , Immunoglobulin G/analysis , Immunoglobulin Isotypes/analysis , Male , Middle Aged , Multiple Myeloma/immunology , Multiple Myeloma/pathology , Plasma Cells/pathology , Retrospective Studies , Survival Analysis
11.
Arch Pathol Lab Med ; 121(5): 528-32, 1997 May.
Article in English | MEDLINE | ID: mdl-9167612

ABSTRACT

We report the case of an 81-year-old man who underwent a segmental resection of the sigmoid colon for severe diverticular disease. Histopathologic diagnosis revealed extranodal Hodgkin's disease, and the diagnosis was confirmed by immunohistochemistry. The incidence of extranodal Hodgkin's disease is rare and represents an infrequent occurrence as a gastrointestinal neoplasm and primary gastrointestinal lymphoma. A review of the literature for gastrointestinal lymphomas with emphasis on the occurrence of Hodgkin's disease, the diagnostic features, and the site of gastrointestinal tract involvement is reported.


Subject(s)
Hodgkin Disease/pathology , Sigmoid Neoplasms/pathology , Aged , Aged, 80 and over , Diverticulum/pathology , Hodgkin Disease/diagnosis , Hodgkin Disease/metabolism , Humans , Immunohistochemistry , Male , Reed-Sternberg Cells/pathology , Sigmoid Neoplasms/chemistry , Sigmoid Neoplasms/diagnosis , Staining and Labeling
13.
Acta Haematol ; 98(2): 113-5, 1997.
Article in English | MEDLINE | ID: mdl-9286309

ABSTRACT

A 61-year-old male with Epstein syndrome and chronic renal failure was admitted to our institution for kidney transplantation. He was asymptomatic at the time of evaluation. Physical examination revealed pallor and marked splenomegaly measuring approximately 12 x 10 cm below the left costal margin. Because of this finding, and a history of resected non-small lung cancer, a CT scan of the abdomen was obtained. This demonstrated massive, diffusely nodular splenomegaly. This article describes the histopathologic and immunohistochemical findings of littoral cell angioma, a novel splenic tumor. Also, we discuss the differential diagnosis and include a description of the imaging study performed. To our knowledge, this is the first case report of littoral cell angioma occurring in a patient with Epstein syndrome, and the first radiographic appearance of this rare tumor.


Subject(s)
Deafness/complications , Hemangioma/pathology , Nephritis/complications , Splenic Neoplasms/pathology , Thrombocytopenia/complications , Carcinoma, Non-Small-Cell Lung/complications , Hemangioma/complications , Humans , Kidney Failure, Chronic/complications , Kidney Transplantation , Lung Neoplasms/complications , Male , Middle Aged , Splenic Neoplasms/complications , Syndrome
14.
Mod Pathol ; 10(12): 1188-93, 1997 Dec.
Article in English | MEDLINE | ID: mdl-9436962

ABSTRACT

Recent studies implicate Epstein-Barr virus (EBV) in the pathogenesis of an increasing number of lymphoid and epithelial tumors. EBV-related disorders are particularly prevalent in immunosuppressed patients. The most common neoplasms arising in persons receiving long-term immunosuppressive agents after organ transplantation include non-Hodgkin's lymphomas and skin and lip carcinomas. Because EBV plays a major role in the evolution of post-transplantation lymphoproliferative disorders and was recently identified in a squamous cell carcinoma of the lip in a renal transplant recipient, we examined squamoproliferative lesions of the skin and lips for the presence of latent EBV. Twenty-six paraffin-embedded specimens from 23 different squamoproliferative lesions occurring in 9 solid organ transplant recipients were examined for the presence of latent EBV by in situ hybridization for EBV-encoded small RNA (EBER-1). The squamoproliferative lesions included 16 squamous cell carcinomas, 3 re-excisions of squamous cell carcinomas, 5 basal cell carcinomas, and 2 actinic keratoses. Two lesions from a single patient exhibited clusters of positive dermal lymphocytes after in situ hybridization with the EBER-1 probe. This patient is currently without clinical evidence of a lymphoproliferative disorder 2 years after the first biopsy showing this phenomenon. The squamoproliferative lesions were all uniformly negative. EBV does not seem to play a role in the initiation or progression of the majority of cutaneous squamoproliferative lesions arising in immunosuppressed patients who received solid organ transplants.


Subject(s)
Herpesvirus 4, Human/isolation & purification , Lip Neoplasms/virology , Organ Transplantation , Skin Neoplasms/virology , Adult , Carcinoma, Basal Cell/virology , Carcinoma, Squamous Cell/virology , Female , Humans , In Situ Hybridization , Keratosis/virology , Male , Middle Aged , RNA, Viral/analysis
15.
Am J Respir Crit Care Med ; 154(6 Pt 1): 1712-7, 1996 Dec.
Article in English | MEDLINE | ID: mdl-8970360

ABSTRACT

Post-transplantation lymphoproliferative disorder (PTLD) is a widely recognized and often catastrophic complication of organ transplantation. The incidence of PTLD after lung transplantation ranges from 6.2 to 9.4% and is two-fold higher than that seen after organ transplantation of other organs. Primary Epstein-Barr virus (EBV) infection is a major risk factor for PTLD, but the incidence of PTLD in EBV seronegative (EBV-) patients seems to vary with type of organ transplant. The goal of this study was to quantify the risk of PLTD based on pre-lung transplantation EBV serostatus in lung transplant patients. Pre- and post-lung transplant serostatus was defined in 80 patients, and our six cases of PTLD occurred in this group. Six of 94 lung transplant patients (6.4%) who survived > 1 mo developed PTLD. All cases of PTLD involved thoracic structures at presentation and occurred in the first post-operative year. Patients who were EBV- before lung transplant were much more likely to develop PTLD than those who were seropositive (EBV+) (five of 15 [33%] versus one of 60 [< 2%], p < 0.001). Consistent with the prevailing adult (donor) EBV+ rate (85%), two of our EBV-patients remained EBV-after lung transplant. Therefore, the rate of PTLD was 42% in those with primary EBV infection. As compared with EBV-patients that remained tumor-free, those who developed PLTD had similar levels of immunosuppressants and doses of anti-viral therapy. We conclude that PLTD occurs predominantly in EBV-naïve patients (risk approximately 1/3). EBV-patients should be monitored more closely after lung transplantation and, possibly, managed with lower immunosuppression. Our data also suggest that anti-viral therapy alone does not decrease the incidence of PTLD in high risk patients, PTLD can be successfully treated in most cases, and EBV-naïve patients should not be excluded from lung transplant because their risk of death from PTLD is < 15%.


Subject(s)
Antibodies, Viral/analysis , Herpesvirus 4, Human/immunology , Lung Transplantation/adverse effects , Lymphoproliferative Disorders/etiology , Adolescent , Adult , Humans , Immunosuppression Therapy , Lymphoproliferative Disorders/microbiology , Risk Factors
16.
Hum Pathol ; 26(12): 1378-82, 1995 Dec.
Article in English | MEDLINE | ID: mdl-8522313

ABSTRACT

Sinus histiocytosis with massive lymphadenopathy (SHML/Rosai-Dorfman disease) has, on rare occasions been identified as an isolated phenomenon in lymph nodes affected by malignant lymphomas. The Registry includes four cases of SHML in patients with non-Hodgkin's lymphomas and one with multiple myeloma. SHML has more recently been recorded as a focal finding in lymph nodes involved by Hodgkin's disease of the mixed cellularity type. We report two patients presenting with lymphadenopathy caused by involvement by nodular lymphocyte predominant Hodgkin's disease with focal changes of SHML, an association not previously recorded in the literature. Responsiveness of the histiocytic cells of SHML to B-cell derived cytokines is postulated as a mechanism for this phenomenon, an hypothesis previously raised in regard to the association of focal Langerhans cell histiocytosis with Hodgkin's disease and with non-Hodgkin's lymphomas.


Subject(s)
Histiocytosis, Sinus/pathology , Hodgkin Disease/pathology , Lymph Nodes/pathology , Adult , Child , Histiocytosis, Sinus/complications , Hodgkin Disease/complications , Humans , Male
17.
Am J Gastroenterol ; 86(1): 79-81, 1991 Jan.
Article in English | MEDLINE | ID: mdl-1702579

ABSTRACT

Previous case reports have demonstrated that the intestinal pathology of Mycobacterium avium-intracellulare (MAI) infection in the acquired immune deficiency syndrome (AIDS) has a light microscopic appearance similar to Whipple's disease. This case report describes a 52-yr-old male patient with a clinical picture suggestive of AIDS, including diarrhea, weight loss, oral thrush, and intestinal cryptosporidiosis. The intestinal biopsy showed light microscopic features compatible with either MAI or Whipple's disease, but electron microscopy confirmed the presence of the Whipple bacillus. Markers of human immunodeficiency virus (HIV) infection were absent. Although immune abnormalities have been reported in Whipple's disease, this is the first report of opportunistic infections complicating this condition. A useful clinical pearl emerges from this and other cases: AIDS can mimic Whipple's disease; Whipple's disease can mimic AIDS.


Subject(s)
Acquired Immunodeficiency Syndrome/diagnosis , Cryptosporidiosis/diagnosis , Mycobacterium avium-intracellulare Infection/diagnosis , Opportunistic Infections/diagnosis , Whipple Disease/diagnosis , Cryptosporidiosis/complications , Diagnosis, Differential , Humans , Male , Middle Aged , Mycobacterium avium-intracellulare Infection/complications , Opportunistic Infections/complications , Whipple Disease/complications
18.
J Biol Chem ; 262(2): 538-41, 1987 Jan 15.
Article in English | MEDLINE | ID: mdl-3804998

ABSTRACT

A previously unidentified factor has been isolated from wheat germ that stimulates globin mRNA-directed polypeptide synthesis in vitro. This factor is separated from eukaryotic initiation factor (eIF)-4B by chromatography on m7GTP-Sepharose. eIF-4B binds to m7GTP-Sepharose, whereas the stimulatory factor does not. Further purification of the factor yields a preparation that contains one major polypeptide with a molecular weight of approximately 59,000, This factor enhances the binding of globin mRNA to 40 S ribosomal subunits in the presence of eIF-2, eIF-3, eIF-4A, and either eIF-4B or eIF-4F and has been designated eIF-4G.


Subject(s)
Peptide Initiation Factors/isolation & purification , Plants/metabolism , Globins/genetics , Kinetics , Molecular Weight , Peptide Chain Initiation, Translational , Peptide Initiation Factors/metabolism , Plants/genetics , RNA, Messenger/genetics , Ribosomes/metabolism , Triticum/genetics , Triticum/metabolism
19.
J Biol Chem ; 261(33): 15632-6, 1986 Nov 25.
Article in English | MEDLINE | ID: mdl-2946676

ABSTRACT

Eukaryotic initiation factors (eIF)-4A, -4B, and -4F isolated from wheat germ were tested for their ability to catalyze ATP hydrolysis in the absence and presence of RNA. We find that eIF-4B or eIF-4F alone exhibit ATPase activity in the presence of poly(U), satellite tobacco necrosis virus (STNV) RNA, or globin mRNA but not in the absence of RNA. eIF-4A alone exhibits ATPase activity in the absence of RNA, but this activity is not stimulated by the addition of RNA. eIF-4A does, however, enhance RNA-dependent ATP hydrolysis in the presence of either eIF-4B or eIF-4F. The RNA-dependent ATPase activities of eIF-4B and eIF-4F are additive, not synergistic. At saturating concentrations of eIF-4F, little or no stimulation of ATP hydrolysis is obtained upon the addition of eIF-4B and at saturating concentrations of eIF-4B little or no stimulation is obtained upon the addition of eIF-4F. This observation is in agreement with our previous finding (Lax, S., Fritz, W., Browning, K., and Ravel, J. (1985) Proc. Natl. Acad. Sci. U.S.A. 82, 330-333) that initiation of polypeptide synthesis is obtained in vitro with either eIF-4F or eIF-4B.


Subject(s)
Adenosine Triphosphatases/metabolism , Eukaryotic Initiation Factors , Peptide Initiation Factors/metabolism , Triticum/analysis , Adenine Nucleotides/pharmacology , Eukaryotic Initiation Factor-4A , Eukaryotic Initiation Factor-4F , Globins/genetics , Guanosine Triphosphate/pharmacology , Hydrolysis , Plant Viruses/genetics , Poly U/pharmacology , RNA, Messenger/pharmacology , RNA, Viral/pharmacology , Satellite Viruses/genetics
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