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Biomedical subjects

T A Seemayer

Publications and source records attributed to T A Seemayer.

At least 19 recordsLinked to original sources

Translocation t(1;3)(p36.3;q25) is a nonrandom aberration in epithelioid hemangioendothelioma.

The cytogenetic findings for two epithelioid hemangioendotheliomas are reported. An identical chromosomal translocation involving chromosomes 1 and 3 [t(1;3)(p36.3;q25)] was detected in both cases of epithelioid hemangioendothelioma, possibly representing a characteristic rearrangement for this histopathologic entity. The presence of clonal karyotypic abnormalities supports a neoplastic origin for the epithelioid variant of hemangioendothelioma. Identification of the 1;3 translocation may be useful diagnostically. Should additional studies confirm these data, this could lead to the identification of the gene(s) central to this neoplastic process.

Adult↗

Correlation of mutations of the SH2D1A gene and epstein-barr virus infection with clinical phenotype and outcome in X-linked lymphoproliferative disease.

The purposes of this study were to determine the frequency of mutations in SH2D1A in X-linked lymphoproliferative disease (XLP) and the role of SH2D1A mutations and Epstein-Barr virus (EBV) infection in determining the phenotype and outcome of patients with XLP. Analysis of 35 families from the XLP Registry revealed 28 different mutations in 34 families-large genomic deletions (n = 3), small intragenic deletions (n = 10), splice-site (n = 3), nonsense (n = 3), and missense (n = 9) mutations. No mutations were found in 25 males, so-called sporadic XLP (males with an XLP phenotype after EBV infection but no family history of XLP) or in 9 patients with chronic active EBV syndrome. Of 304 symptomatic males in the XLP Registry, 38 had no evidence of EBV infection at first clinical manifestation. When fulminant infectious mononucleosis (FIM) was excluded, there was no statistical difference in the frequency of EBV infectivity in the other XLP phenotypes. Furthermore, there was no difference at age of first clinical manifestation between EBV(+) and EBV(-) males or in survival when patients with FIM were excluded. In conclusion, it was found that mutations in the SH2D1A gene are responsible for XLP but that there is no correlation between genotype and phenotype or outcome. It was also found that though EBV infection often results in FIM, it is unnecessary for the expression of other manifestations of XLP, and it correlates poorly with outcome. These results suggest that unidentified factors, either environmental or genetic (eg, modifier genes), contribute to the pathogenesis of XLP.

Alternative Splicing↗

Acute thymic involution in fetuses and neonates with chorioamnionitis.

Chorioamnionitis represents the leading cause of preterm birth and related pathologic conditions as well as of fetal death and frequently occurs in symptom-free mothers. Recent radiologic findings have indicated that thymus size is significantly reduced in preterm infants born to mothers with subclinical, histologically proven chorioamnionitis. However, an accurate morphologic description of the thymus gland in fetuses and neonates with chorioamnionitis is lacking, although it is known that infection and other stress processes may cause lymphocyte depletion in the thymuses of infants and older babies (acute stress involution). We describe morphologic modifications in the thymus of fetuses with histologically proven chorioamnionitis and newborn infants with chorioamnionitis and proven sepsis. The main findings included (1) decreased organ volume (ANOVA, P < .0024); (2) reduced corticomedullary ratio (P < 10(-6)); (3) significant changes in the relationship between thymic parenchyma and thymic interstitial tissue with resulting increased organ complexity (P = .03); (4) severe reduction of thymocytes; and (5) other degenerative processes such as monocyte/macrophage infiltration of Hassall's bodies. These results indicate that chorioamnionitis, with or without sepsis, is associated with significant morphologic modifications in the thymus. We wish to note that the described thymic pathology is only one aspect of the fetal systemic inflammatory response syndrome with which chorioamnionitis is associated.

Abortion, Spontaneous↗

Adamantinoma-like Ewing's sarcoma: genomic confirmation, phenotypic drift.

Ewing's sarcoma, a highly malignant neoplasm, is characterized by an 11;22 translocation [t(11;22) (q24;q12)], resulting in the fusion of genes FLII and EWS. Adamantinoma of extragnathic bones, a low-grade malignant neoplasm with epithelial features, is not typically considered in the differential diagnosis of Ewing's sarcoma. In this study, three osseous Ewing's sarcomas with histological, immunohistochemical, or ultrastructural epithelial features were subjected to reverse transcription-polymerase chain reaction and sequencing studies for the Ewing's sarcoma molecular rearrangement. (Two of the three cases were originally described as adamantinomas or nontypical Ewing's sarcoma before the availability of genetic characterization.) In addition, traditional cytogenetic analysis and a unique combined interphase molecular cytogenetic/ immunocytochemical approach with bicolor 11;22 translocation breakpoint flanking probes (cosmids) and pancytokeratin antibodies were performed on one neoplasm. At(11;22) (q24;q12) was found in one neoplasm and a type II EWS/FLI-1 fusion transcript was detected in all three neoplasms. The combined genetic/immunocytochemical approach revealed the presence of the 11 ;22 translocation in the nuclei of cytokeratin immunoreactive cells. These genotypic and phenotypic findings delineate a novel Ewing's sarcoma histologic variant, "adamantinoma-like Ewing's sarcoma."

Adolescent↗

Treatment resistant small cell carcinoma of the cervix.

BACKGROUND: Small cell undifferentiated carcinoma of the cervix is an uncommon malignancy with a poor prognosis. Treatment of localized disease has an approximate 40% 5-year survival with multimodality therapies. CASE REPORT: We describe the case of a 24-year-old woman with small cell carcinoma of the cervix that recurred locally despite intensive chemotherapy and radiotherapy. Hysterectomy was performed and the patient is now 18 months disease free. Following treatment, the pathological appearance of the tumor had changed from a typical small cell neuroendocrine malignancy to a more intermediate neuroendocrine cell type. CONCLUSION: Small cell carcinoma of the cervix is a rare aggressive malignancy that may require cytostatic multimodality therapy including chemotherapy, radiotherapy and surgery, even in early stage disease.

Adult↗

Small bowel bacterial overgrowth as a cause of chronic diarrhea after liver transplantation in children.

Children who have undergone liver transplantation may develop chronic diarrhea for a number of reasons. Three children who underwent liver transplantation for liver failure, all of whom had had previous biliary and intestinal surgeries and whose postoperative course was marked by signs and symptoms of intestinal malabsorption including chronic diarrhea, are described. Duodenal aspirates showed a panoply of bacterial species, and duodenal histology featured villus atrophy in two: one associated with luminal gram-positive cocci and another with acute and chronic duodenitis. Oral antibiotics cleared the symptoms. Small bowel bacterial overgrowth may need to be considered in children with chronic diarrhea after liver transplantation, especially when previous intestinal surgery has taken place. Long-term antibiotic therapy may be required to effectively eradicate the offending organisms to suppress symptoms.

Administration, Oral↗

Cytodifferentiation of a Wilms' tumor pulmonary metastasis: theoretic and clinical implications.

BACKGROUND: Complete maturation (cytodifferentiation) of treated metastatic Wilms' tumor is an infrequent occurrence. In a large series of reports, Wilms' metastases have generally contained malignant blastemic elements admixed with lesser amounts of cytodifferentiated mesenchyme. The authors describe a patient in whom complete maturation of a pulmonary metastasis was documented after intensive chemoradiotherapy. METHODS: A MEDLINE search was employed to identify pertinent cases from 1966 to the present. Key words used in the search included Wilms' tumor, relapse, therapy, metastasis, maturation, and cytodifferentiation. Four patients were identified as having completely mature cytodifferentiated pulmonary metastases of Wilms' tumor after chemotherapy; one had also undergone irradiation of the pulmonary metastasis. RESULTS: The primary tumor was an extremely necrotic blastemic Wilms' tumor devoid of maturation, as studied after irradiation and chemotherapy. The lung metastases (examined 13 years later) were represented by a scar and a nodule comprised of bland epithelium and tubules admixed with mature smooth muscle. Immunohistochemical stains, used to assess the proliferative rate of these cells, revealed a nearly negligible proliferation index. CONCLUSIONS: This report suggests that therapy (chemotherapy and/or irradiation) may effect, on occasion, complete cytodifferentiation of Wilms' tumor pulmonary metastasis. Although this would appear to be an uncommon event, its true incidence is unknown, because few patients with metastatic pulmonary Wilms' tumor are subjected to biopsy. The findings of this study suggest that for children with radiologically stable Wilms' lung metastases (as determined by imaging studies) who are yet undergoing intensive chemoradiotherapy, the notion of a surgical biopsy should be entertained to determine the true nature of the radiologic images. For some, this might result in the cessation of further therapy that would be unnecessary and not without complications.

Antineoplastic Combined Chemotherapy Protocols↗

A yeast artificial chromosome (YAC) contig encompassing the critical region of the X-linked lymphoproliferative disease (XLP) locus.

X-linked lymphoproliferative disease (XLP) is characterized by a marked vulnerability to Epstein-Barr virus (EBV) infection. Infection of XLP patients with EBV invariably results in fatal mononucleosis, agammaglobulinemia, or malignant lymphoma. Initially the XLP gene was assigned to a 10-cM region in Xq25 between DXS42 and DXS37. Subsequently, an interstitial, cytogenetically visible deletion in Xq25 was identified in one XLP family, 43. In this study we estimated the deletion in XLP patient 43-004 by dual-laser flow karyotyping to involve 2% of the X chromosome, or approximately 3 Mb of DNA sequence. From a human chromosome Xq25-specific yeast artificial chromosome (YAC) sublibrary, five YACs containing DNA sequences deleted in patient 43-004 have been isolated. Sequence-tagged sites (STSs) from these YACs have been used to identify interstitial deletions in unrelated XLP patients. Three more families with interstitial deletions were found. Two of the patients (63-003 and 73-032) carried an interstitial deletion of 3.0 Mb overlapping the 43-004 deletion. In one XLP patient (30-011) who exhibited the characteristic postinfectious mononucleosis phenotype of XLP with hypogammaglobulinemia and malignant lymphoma, a deletion of approximately 250 kb was detected overlapping the deletion detected in patients 43-004, 63-003, and 73-032. A YAC contig of 2.2 Mb spanning the XLP critical region, whose orientation on chromosome X was determined by double-color fluorescence in situ hybridization and which consists of 15 overlapping YAC clones, has been constructed. A detailed restriction enzyme map of the region has been constructed. YAC insert sizes were determined by counter-clamped homogenous electric field gel electrophoresis. Chimerism of YACs was determined by FISH and restriction mapping. On the basis of lambda subclones, YAC end-derived plasmids, and STSs with an average spacing of 100 kb, a long-range physical map was constructed using 5 rare-cutter restriction enzymes. The STSs and lambda subclones were used in Southern hybridization and PCR analyses. The work presented here substantially refines the critical region for XLP. The YAC contig with the overlapping interstitial deletions constitutes the basis for the construction of a transcriptional map of the critical region and facilitates the identification of the XLP gene.

Chromosomes, Artificial, Yeast↗

Bronchopulmonary dysplasia of the premature baby: an immunohistochemical study.

Prematurely born infants who required assisted ventilation may develop chronic lung disease or bronchopulmonary dysplasia (BPD). The cells involved in the reparative process of the premature lung are not well defined. The repair of injured tissues is a highly standardized process and the most important cells are activated (modulated) fibroblasts (myofibroblasts). A key cytokine in controlling repair is transforming growth factor-beta (TGF-beta). To characterize the cells involved in the repair process of the premature lung, we employed immunocytochemical techniques and examined the lungs of 39 autopsied premature babies who had neonatal respiratory distress syndrome (RDS). All were treated in neonatal intensive care units and required mechanical ventilation and supplemental oxygen; all survived for at least 12 hours. Antibodies were employed against vimentin, alpha-smooth muscle (alpha-SM) actin, total muscle actin, desmin, MAC387, and TGF-beta. Our study indicates that myofibroblasts are normally present along terminal airways in the developing lung. These cells increase in number some days after lung injury, form bundles of cells encircling terminal air spaces, and acquire desmin contractile filaments shortly thereafter. Myofibroblasts do not lose their contractile filaments with time, suggesting a conversion to smooth muscle metaplasia. The proliferation and migration of such myofibroblasts at sites of lung injury is associated with the presence of TGF-beta. These findings suggest that myofibroblasts play an important role in premature lung repair. They may point the way to experimental and clinical trials that will identify drugs antagonistic to TGF-beta (or other cytokines). Such antagonists may protect the neonates who are at high risk of developing BPD.

Acute Disease↗

Posttransplant eosinophilic gastroenteritis in children.

The cause of eosinophilic gastroenteropathy in older children and adults is unknown. In this report, two post-liver transplantation children treated with low-dose cyclosporine A and alternate-day low-dose prednisone are described who were administered a single bolus administration of a lympholytic dose of corticosteroids without taper and who developed intestinal symptomatology several weeks later. Histologic examination of mucosal biopsy specimens from various regions of the gastrointestinal tract showed an intense eosinophilic infiltration of the mucosa and lamina propria. The patients recovered after corticosteroid administration was tapered. Post-transplant gastroenteric eosinophilic inflammation may need to be considered in patients on immunomodulatory medications who have chronic intestinal symptomatology.

Anti-Inflammatory Agents↗

Translocation (X;18) in primary synovial sarcoma of the lung.

Primary sarcomas of the lung are extremely rare. Among the most common to occur in this location are leiomyosarcoma, fibrosarcoma, and hemangiopericytoma. Many difficulties are encountered when establishing these sarcoma diagnoses, or one of another pathologic type, because of overlapping histologic features and morphologic similarities between primary and metastatic lesions. In this study, the diagnosis of a primary monophasic synovial sarcoma of the lung was aided by the observation of the X;18 translocation characteristic of this neoplasm. To the best of our knowledge, this is the first cytogenetic report of a primary pulmonary synovial sarcoma.

Chromosomes, Human, Pair 18↗

Extranodal Rosai-Dorfman disease in childhood.

We describe two children with Rosai-Dorfman disease who presented with exophthalmos, leukocytosis, an elevated sedimentation rate and hypergammaglobulinemia. Both became blind as a result of this condition. One child had associated bilateral cervical lymphadenopathy. Investigation revealed involvement of the nasal fossae and retro-orbital spaces by tumoural masses histologically consistent with the diagnosis of sinus histiocytosis with massive lymphadenopathy (SHML). Immunohistochemical studies suggest that these histiocytes are activated macrophages derived from a phenotype hybrid between "professional" phagocytic cells and immune accessory cells, expressing lysosomal antigens, S-100 protein but rarely, CDla. An underlying immune dysfunction may be central to the pathogenesis of this disease.

Antigens, CD1↗

Pleomorphic soft tissue myogenic sarcomas of adulthood. A reappraisal in the mid-1990s.

325 diverse sarcomas, 39 rhabdomyosarcomas (RMS), including all histologic variants, and 135 leiomyosarcomas (LMS) were identified. Within these two groups, 18 (46%) of the RMS and 14 (10%) of the LMS represented pleomorphic variants. These neoplasms were studied by morphology (histology and ultrastructure) and by immunohistochemical methods employing antibodies to intermediate filaments (vimentin and desmin) and actin isoforms [alpha-smooth (sm) and alpha-sarcomeric (sr) actins]. Twenty-four pleomorphic malignant fibrous histiocytomas (MFH) and eight pleomorphic liposarcomas (LS) were examined in a similar fashion. By light microscopy, the pleomorphic RMS, LMS, and MFH were indistinguishable, as each was dominated by pleomorphic cells disposed in a haphazard growth pattern; moreover, many featured fascicular, storiform, and sclerotic zones. The distinction between these neoplasms became apparent only following immunohistochemistry and/or ultrastructural study. All pleomorphic RMS disclosed rudimentary sarcomeres and exhibited the following cytoskeletal profile: vimentin (+) (18 of 18), desmin (+) (14 of 18), alpha-sr actin (+) (18 of 18) and alpha-sm actin (+) (five of 18). All the pleomorphic LMS featured smooth-muscle differentiation of variable degrees in the form of cytoplasmic bundles of microfilaments and associated dense bodies; their cytoskeletal profile was vimentin (+) (14 of 14), desmin (+) (seven of 14), alpha-sr actin (+) (none of 14), and alpha-sm actin (+) (eight of 14). The latter was demonstrated in all moderately differentiated, but absent or only focally expressed in poorly differentiated variants. All pleomorphic MFH and LS were devoid of myogenic (skeletal or smooth) ultrastructural features and expressed vimentin solely. This combined morphological and immunohistochemical study illustrates the following: First, these pleomorphic sarcomas are often indistinguishable by histologic growth pattern alone; thus, an accurate diagnosis requires study with all of these techniques. Second, pleomorphic myogenic sarcomas are restricted to adults and are not uncommon neoplasms among pleomorphic sarcomas: RMS (28%), LMS (21%), MFH (38%), and LS (13%). Third, the study defines desmin-negative and alpha-sm actin-positive pleomorphic RMS, and desmin-negative and alpha-sm-actin-negative pleomorphic LMS.

Actins↗