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A Perez-Atayde

Publications and source records attributed to A Perez-Atayde.

At least 37 records · Page 2Linked to original sources
PubMed1996

Specific mitochondrial DNA deletions in idiopathic dilated cardiomyopathy.

OBJECTIVE: Structural changes in human mitochondrial DNA (mtDNA) have been implicated in a number of clinical conditions with dysfunctions in oxidative phosphorylation called OX-PHOS diseases, some of which have cardiac involvement. The objective of this study was to assess the frequency and extent of specific mitochondrial DNA deletions in idiopathic dilated cardiomyopathy. METHODS: DNA extracted from tissue derived from the left ventricle of 41 patients with idiopathic dilated cardiomyopathy and 17 controls was amplified by polymerase chain reaction using specific primers to assess the incidence and proportion of 5-kb and 7.4-kb deletions in mitochondrial DNA. RESULTS: In reactions using primers to detect the 5-kb deletion, an amplified product of 593 bp was found in low abundance relative to undeleted mitochondrial DNA but with high frequency in a number of controls and patients. A second deletion of 7.4 kb in size was also frequently present in controls and patients. In contrast to previous reports, these deletions were found to be present in both controls and in cardiomyopathic patients, 18 years and younger, including several infants. The 7.4-kb deletion was prominently increased in both frequency and in its proportion relative to undeleted mitochondrial DNA in patients 40 years and older with idiopathic dilated cardiomyopathy. CONCLUSIONS: At variance with current literature our study reports a significant presence of both 5 and 7.4-kb deletions in the young and a higher frequency and quantity of the 7.4-kb deletion in the older cardiomyopathic patients in comparison with controls. The increased accumulation of the 7.4-kb deletion as both a function of aging and cardiomyopathy is suggestive that this specific mitochondrial DNA deletion arises more likely as an effect of heart dysfunction rather than as a primary cause of cardiomyopathy.

Adolescent↗
PubMed1995

Cutaneous melanoma and atypical Spitz tumors in childhood.

BACKGROUND: Malignant melanoma in childhood is rare. As a result, the biology and natural history of melanoma in this age group is still poorly understood. Although the majority of Spitz nevi are benign regardless of atypical features, a particular problem is the continued confusion of Spitz nevi with atypical features with melanoma and the lack of specific criteria for their distinction. The latter discrimination is perhaps not so difficult when Spitz nevi are minimally atypical; however, the greater the atypia, the more challenging is this discrimination. METHODS: All cases of malignant melanoma referred to Children's Hospital (Boston, MA) and to one of the authors were examined during the period of 1959-1995. Criteria for inclusion in the study included: (1) age up to 15 years; (2) availability of microscopic slides; and (3) availability of demographic data. RESULTS: There were 11 males and 12 females, ranging in age from 2 to 15 years (mean age, 9.4 years). Histopathologically, the 23 tumors were categorized into four subgroups: (1) small cell melanoma (5); (2) adult-like melanoma (6); (3) Spitz-like melanoma (3), and (4) atypical Spitz tumors (9). The small cell melanomas were notable for localization to the scalp, significant thickness, and fatal outcome. The adult-like melanomas resembled typical tumors occurring in adults. The one fatal Spitz-like melanoma was located on the neck of a 14-year-old male. Two tumors in this group metastasized to regional lymph nodes, but were not associated with further aggressive disease on follow-up despite treatment with surgical excision only. The atypical Spitz tumors were characterized by significant thickness and abnormal features including prominent cellularity and mitotic activity. CONCLUSIONS: Anatomic site and cell type may be important prognostic factors in addition to tumor thickness for childhood melanoma, but these tumors require further study. In addition, the biologic potential of atypical Spitz tumors has not been characterized sufficiently.

Adolescent↗
PubMed1995

Renal dysplasia in infants: appearance on 99mTc DMSA scintigraphy.

Infantile renal dysplasias, including multicystic dysplastic kidneys (MCDK), are reported rarely to accumulate radiopharmaceuticals on renal scintigraphy. 99mTc DMSA is a highly sensitive tracer for detecting functioning renal cortical tissue and may be more suited to studying renal dysplasia than 99mTc DTPA. We reviewed the ultrasound studies and 99mTc DMSA scintigrams of 42 infants (age range 1-12 months) with known or suspected MCDK. Overall, uptake on 99mTc DMSA scintigraphy was evident in 6/41 (15%) dysplastic kidneys. Of the 18 patients who underwent nephrectomy, histopathological examination revealed that uptake correlated closely with the presence of mature renal cortical tissue in the affected kidney. Our study shows that a small, but significant number of MCDK will show low-grade uptake on DMSA scintigraphy. This finding may be relevant given the reliance placed on renal scintigraphy in planning treatment for infants with suspected MCDK, particularly with the increasing trend for the non-operative management of this condition.

Female↗
PubMed1994

Infantile dilated cardiomyopathy. Relation of outcome to left ventricular mechanics, hemodynamics, and histology at the time of presentation.

BACKGROUND: For patients with acute dilated cardiomyopathy, definition of prognosis and of clinical features predictive of outcome is particularly important due to the availability of cardiac transplantation and other innovative treatment strategies. METHODS AND RESULTS: We reviewed our experience with 24 children under 2 years of age with dilated congestive cardiomyopathy to determine outcome and potential predictive variables. Clinical, serological, ECG, echocardiographic, hemodynamic, and histological findings were analyzed. Idiopathic cardiomyopathy or myocarditis constituted 29% of the patients presenting with congestive heart failure without structural heart disease. Among these patients, 45% recovered completely, 25% survived with persistent left ventricular dysfunction, and 30% died. All except one of the deaths occurred during the first 2 months after presentation. Poorer outcome and higher mortality were associated with a more severely depressed left ventricular ejection fraction and/or a more spherical left ventricular shape at presentation. Histological evidence of myocardial inflammation was a favorable prognostic indicator, whereas histological evidence of endocardial fibroelastosis was associated with a poor outcome. During the recovery phase, diastolic volume fell rapidly. Ventricular mass was elevated from the earliest observations and fell more slowly, with persistent elevation of the mass-to-volume ratio up to 2 years. Function and contractility improved over the first several months in most patients who recovered, although in occasional patients continued improvement was seen for as long as 2 years after presentation. CONCLUSIONS: Histological and echocardiographic features can be used to identify patients at particularly high risk for death. To have any impact on outcome, decisions about cardiac transplantation must be reached rapidly, since almost all deaths occurred within the first 2 months after presentation. Recovery of function is often rapid, but continued improvement may be seen for as long as 2 years.

Cardiomyopathy, Dilated↗
PubMed1994

Salivary gland anlage tumor ("congenital pleomorphic adenoma"). A clinicopathologic, immunohistochemical and ultrastructural study of nine cases.

Salivary gland anlage tumor (SGAT) is a polypoid lesion of the nasopharynx that presents with respiratory distress at birth or within the first few days or weeks of life. Among our nine cases, there was a male predilection (7M:2F). All tumors were in the midline and attached to the posterior pharyngeal wall by a delicate pedicle. The largest tumor measured 3 cm. A biphasic histologic pattern of squamous nests and duct-like structures at the periphery blended into solid, predominantly mesenchymal-appearing nodules centrally. The surrounding submucosal mantle of epithelial structures was consistently immunoreactive for cytokeratin and epithelial membrane antigen, whereas the stromal-like cells of the central nodules showed variable immunopositivity for cytokeratin, vimentin, and muscle-specific actin. Both components were equally reactive for salivary gland amylase. Ultrastructurally, some of the stromal-like cells had features of myoepithelial cells. The histologic and architectural features of SGAT are similar in some respects to the developing salivary gland. It is proposed that the SGAT is a probable hamartoma of minor salivary gland derivation whose origin in the nasopharynx is potentially life-threatening in an infant.

Adenoma, Pleomorphic↗
PubMed1993

Sinus complications in mucopolysaccharidosis IH/S (Hurler-Scheie syndrome).

Hurler-Scheie syndrome is a genetic compound of two mucopolysaccharidoses, the Hurler and Scheie syndromes. The genetic error of metabolism caused by this syndrome produces intermediary systemic effects in the affected individuals. Lacking the enzyme alpha-L-iduronidase, glycosaminoglycans are deposited in the tissues, causing multiple systemic effects and creating many problems for the otolaryngologist. Although early bone marrow transplantation is currently being performed to prevent or reverse many of the systemic manifestations of this disorder, there remains a large population of children past the age at which bone marrow transplantation can be effective. Sinus complications have not previously been reported in the mucopolysaccharidoses and may be more frequently recognized as these patients' longevity increases. We present a patient with Hurler-Scheie syndrome who developed severe nasal polyposis requiring sinus endoscopic removal.

Adolescent↗
PubMed1992

Pneumatocele complicating hyperimmunoglobulin E syndrome (Job's Syndrome).

The case of a boy with hyperimmunoglobulin E syndrome or Job's syndrome is presented to demonstrate the occurrence of pneumatoceles in this syndrome as well as their unusual natural history and failure to spontaneously resolve. Surgical resection was required for two complications in this patient, persistent bronchopleural fistula and a pulmonary abscess that destroyed one lung and required pneumonectomy. Pathologic examination of the specimens demonstrated the wall of the cysts consisted of granulation tissue with chronic active inflammation surrounded by infarcted pulmonary parenchyma with coagulative necrosis. The mechanism responsible for increased immunoglobulin E production in this syndrome is unknown, as is the manner in which elevated immunoglobulin E levels impair normal immune function.

Aspergillosis↗
PubMed1991

Human intestine matures as nude mouse xenograft.

This report describes a novel system for the study of the development and function of human intestine. Human fetal bowel transplanted into a subcutaneous tunnel on the back of athymic nude (nu/nu) mice develops a new microcirculation within 4 weeks. Tissues undergo morphological development, become similar to adult human bowel tissue, and may survive for 6 months after transplantation. Monoclonal antibody immunoperoxidase staining shows that the epithelial and some endothelial elements are of human phenotype, but the circulating blood cells and migrating mucosal lymphocytes are of mouse origin.

Animals↗
PubMed1991

Ovarian granulosa-stromal cell tumors are characterized by trisomy 12.

Eleven ovarian granulosa-stromal cell tumors including 1 thecoma, 2 fibromas, 6 fibrothecomas, and 2 granulosa cell tumors, were karyotyped after direct harvest and/or short-term tissue culture. Bilateral fibrothecomas from one patient appeared to lack cytogenetic aberrations: the remaining nine tumors were characterized by trisomy for chromosome 12. Cytogenetic aberrations in the two granulosa cell tumors were much less complex than those described previously in undifferentiated carcinomas; accordingly cytogenetic analyses might be useful in distinguishing these categories. The consistent occurrence of trisomy 12 in different varieties of granulosa-stromal cell tumors suggests a common mechanism of oncogenesis within this diverse group of neoplasms. That mechanism probably involves promotion of low-grade, orderly cell proliferation.

Chromosomes, Human, Pair 12↗
PubMed1990

Surgery only for the treatment of patients with stage I (Cassady) Wilms' tumor.

A prospective pilot study was undertaken to examine the outcome of patients with Stage I (Cassady) Wilms' tumor treated with nephrectomy only. Eight consecutive patients fulfilling the criteria for Stage I (Cassady) Wilms' tumor (age less than 2 years with unilateral, nonmetastatic, favorable histopathologic type, and tumor weight less than 550 g) underwent nephrectomy with no further therapy. All eight patients were alive and free of disease with a mean follow-up period of 5 years. There was one tumor recurrence that involved a metachronously occurring bilateral tumor. Overall survival (100%) and event-free survival (88%) were comparable with clinical trials in which patients received adjuvant therapy. Patients with Stage I (Cassady) Wilms' tumor can be successfully treated with nephrectomy alone, thereby eliminating the toxicity of adjuvant therapy.

Female↗
PubMed1990

A proposed cause for the hepatic dysfunction associated with parenteral nutrition.

Total parenteral nutrition (TPN) is associated with cholestasis and hepatic steatosis, which can be lethal in infants who cannot be fed orally. It was determined that route of administration was not the critical variable in the development of hepatic steatosis. Two groups of young rats received equivalent amounts of a standard TPN solution either orally or intravenously for an 8- to 10-day period during which they received no other nutrition. Both groups gained equivalent weight and developed marked hepatic steatosis. To test whether the solution was toxic or deficient, three groups of rats were given TPN solution orally and a fraction of their usual daily intake of rat chow. Rats receiving less than 10% of their usual chow intake developed steatosis; rats receiving more than that did not. To determine the solubility of the protective material in chow, two groups of rats were given TPN solution orally and chow that been extracted with either water or the organic solvent chloroform. Rats eating the water-extracted chow developed steatosis, rats eating chloroform-extracted chow did not. Although the protective component in chow was apparently water soluble, addition of a water soluble extract of chow to the TPN solution fed another two groups of rats did not prevent steatosis at 0.1 mg/mL and only partially, if at all, at 10 mg/mL. TPN-related hepatic dysfunction, as measured by the development of hepatic steatosis in this model, may be due to a deficiency in the TPN solution. The missing constituent(s) appears to be present in rat chow and can be extracted with water, but not with an organic solvent.

Animals↗