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Biomedical subjects

A T Meadows

Publications and source records attributed to A T Meadows.

At least 127 records · Page 7Linked to original sources
PubMed1983

Histiocytosis X in children: patterns of disease and results of treatment.

The pathologic materials and clinical courses of 36 children aged 1 month-22 years, with histiocytosis X (H-X) seen at the Philadelphia Children's Cancer Research Center from 1970 to 1979 were reviewed. The pathologic subtype of H-X was favorable (type II) in 31 patients, unfavorable (type I) in one patient, and unclassified in four patients whose specimens were limited to a skin biopsy. Sixteen patients had localized H-X involving bone (14 patients), soft tissue (1 patient), or skin only (1 patient); all are alive and well after treatment with surgery alone (12 patients), radiation therapy (RT) (3 patients), or observation (1 patient); only 1 of the 16 developed recurrent H-X. The other 20 patients presented with multifocal H-X involving the skeleton alone (3 patients); the skeleton and soft tissues other than liver (7 patients); soft tissue exclusive of the liver (3 patients); soft tissue including the liver (4 patients); or soft tissues, skeleton, and liver (3 patients). These 20 patients were treated with surgery alone (1 patient), RT (4 patients), or multiple drugs +/- RT (15 patients). Seven of the 20 patients are alive and well without recurrence at a median of 4 years after diagnosis. Nine of the 20 patients, including 3 with liver dysfunction, responded completely to initial therapy but developed recurrence; each was retreated with drugs and is alive and well at a median of 4 years. The remaining 4 patients had widespread disease with dysfunction of the liver and/or hematopoietic system at diagnosis, failed to respond, and died. We conclude that (1) patients with multiple bony lesions with or without associated soft tissue disease or skin involvement have a favorable outlook and do not require systemic chemotherapy; (2) systemic treatment also is unnecessary for patients with localized H-X since recurrence is rare; (3) drugs can benefit patients with multifocal H-X, although the optimal duration of therapy is unclear; and (4) favorable response to treatment indicates high probability of disease-free survival. However, organ dysfunction at diagnosis is ominous: four of seven patients with liver dysfunction are dead, as are all three patients who presented with peripheral blood count depression.

Adolescent↗
PubMed1983

CT of sarcomatous degeneration in neurofibromatosis.

Neurofibromatosis is a relatively common disorder that often involves many organ systems. One of the least understood aspects of this malady is a well documented potential for sarcomatous degeneration of neurofibromas. The inability to identify patients at risk and the lack of noninvasive screening methods for symptomatic patients often leads to late diagnosis. In six of seven subsequently proven neurofibrosarcomas, CT demonstrated low-density areas that histopathologically appeared to be due to necrosis, hemorrhage, and/or cystic degeneration. The density differences within these sarcomas were enhanced by the intravenous administration of iodinated contrast agents.

Adolescent↗
PubMed1983

Survival in childhood acute lymphocytic leukemia: effect of protocol and place of treatment.

The objective of this study was to determine the effect of place and type of initial treatment on survival from acute lymphocytic leukemia (ALL). Every one of the 327 children under 15 years of age diagnosed with ALL from 1970 to 1975 in a 31-county area designated the Greater Delaware Valley, were studied. Treatment according to protocol was associated with improved survival, yielding a 4 year survival of 60% vs 19% for nonprotocol treated patients (p less than 0.001). There was also a significantly improved survival rate among patients treated in a cancer center, especially for those with a low white blood count (WBC) at diagnosis. The prognostic importance of WBC, age, and sex was confirmed.

Adolescent↗
PubMed1983

Incidence of childhood cancer: experience of a decade in a population-based registry.

Incidence rates of cancer among children aged 0-14 for the period 1970-79 have been generated with the use of data from the Greater Delaware Valley (GDV) Pediatric Tumor Registry. This population-based registry covers a 31-county area and has a pediatric base population of 2 million. During the period, approximately 2,300 cases of childhood cancer were diagnosed in the region. Incidence rates for all histologic types combined are similar to rates from other large surveys conducted in the United States and Western Europe. However, certain histology-specific rates in the GDV vary by race. In the GDV nonwhites relative to whites have higher rates of Wilms' tumor, soft tissue sarcomas other than rhabdomyosarcoma, and retinoblastoma. These contrasts are supported by surveys in African populations showing relatively higher rates of these tumors among African black children. GDV whites exceed nonwhites in incidence of acute leukemia, neuroblastoma, and Ewing's sarcoma. African black children also experience low rates of these tumors. The frequency of central nervous system tumors is similar for GDV whites and nonwhites, despite reports of a rarity of these neoplasms in African blacks. Variations in incidence rates reveal population subgroups with particular tumor susceptibilities and may provide clues as to the relative influence of heredity and environment on patterns observed.

Adolescent↗
PubMed1982

Incidence of second malignant neoplasms in children: results of an international study.

The incidence of second malignant neoplasms (SMNs) in children was estimated from data provided by ten paediatric oncology centres. During 1950-70 nearly 15 000 new patients were seen at these institutions. With follow-up through 1979, 113 eligible cases of SMN were reported. To estimate the number of person-years at risk, a common set of survival distributions, specific for tumour type and calendar period, was applied to the patient entry data at each institution. The annual incidence of SMNs 5-15 years after diagnosis of first tumour was found to be 188/100 000; this represents an approximate ten-fold increase over the age-adjusted expected rate of cancer in the general population. The corresponding incidence during the first 5 years was 85/100 000/year, a seven-fold increase in risk. The estimated cumulative probability of SMN reached 3.3% at 20 years.

Adolescent↗
PubMed1982

Extraskeletal osteogenic sarcoma after treatment for Wilms' tumor.

A large proportion of children with Wilms' tumor will become long-term disease-free survivors. A small number of these children are at risk of developing second malignant neoplasms. There have been no previous reports of osteogenic sarcoma of the chest wall following treatment of Wilms' tumor. Our patient was age seven years when he received surgery, radiation therapy and chemotherapy for Wilms' tumor, eight years when he received radiation and chemotherapy for pulmonary metastases of Wilms' tumor, and 13 years when he developed osteogenic sarcoma of the chest wall.

Child↗
PubMed1982

Acute and long-term cytogenetic effects of treatment in childhood cancer: sister-chromatid exchanges and chromosome aberrations.

The incidence of chromosomal aberrations in banded karyotypes and of sister-chromatid exchanges (SCEs) was determined in the lymphocytes of survivors of childhood cancer as 2 parameters which are pertinent in assessing the genetic damage induced by chemotherapy. The proportion of cells with chromosome breakage or structural rearrangement-type aberration was 1 cell in 67 in a control group of 8 untreated cancer patients and 2 parents of cancer patients, 1 cell in 8 in 12 patients currently on therapy, and 1 cell in 50 in 17 patients sampled 6 months to 35 years post-treatment. The range of mean SCE levels per cell was 4.5-6.5 in the untreated cancer patients, 4.0-9.6 in non-cancer controls, 3.3-33.7 in patients on therapy, and 4.6-9.7 in post-therapy survivors. Considerably variability was observed between individuals with both SCE and breakage assays but therapy-induced increases in SCEs were not necessarily correlated with increased levels of aberrations arising from chromosomal breakage.

Adult↗
PubMed1982

Bilateral retinoblastoma with ectopic intracranial retinoblastoma: trilateral retinoblastoma.

In 11 patients, bilateral retinoblastoma presented at a mean age of 6 months and pineoblastoma at 4 years. We suggest that the hereditary multicentric retinoblastoma arose in vestigeal photoreceptors in the pineal as well as in the hypothetical retinoblasts of the retina. In certain lower animals, the pineal functions as a photoreceptor organ, resembles the retina histologically, and is described as a "third eye." Hence, the patients we describe may be considered as having "trilateral retinoblastoma." Two possible variants of this entity were also noted: (1) three children without retinoblastoma with rosettes and photoreceptor differentiation characteristic of retinoblastoma, and (2) three additional cases involving children who presented with retinoblastoma-like tumors in the suprasellar or parasellar region 2 to 6 months before the discovery of intraocular retinoblastoma. These observations suggest that the retinoblastoma gene confers a previously unappreciated susceptibility to a narrow spectrum of neuroblastic tumors, which usually present in the retina but which can also occur ectopically.

Brain Neoplasms↗
PubMed1982

Abnormalities of chromosome #13 in retinoblastomas from individuals with normal constitutional karyotypes.

Constitutional chromosome abnormalities have been associated with retinoblastoma, Wilm's tumor, and a familial form of renal carcinoma. For each tumor type, the particular chromosome segment involved in the observed rearrangements is different: in retinoblastoma, that segment is band q14 on chromosome #13. We now present evidence that in retinoblastoma, structural abnormalities involving the particular chromosome segment identified in the constitutional cases can also occur in the tumors of individuals with normal constitutional karyotypes. Six cases with retinoblastoma in one or both eyes were analyzed; deletions/rearrangements involving 13q14 were found in the tumor cell karyotypes of five of the six. These observations suggest that changes in a gene or genes at a common site (13q14) play a role in tumorigenesis in all forms of retinoblastoma, sporadic as well as heritable.

Child, Preschool↗
PubMed1981

Declines in IQ scores and cognitive dysfunctions in children with acute lymphocytic leukaemia treated with cranial irradiation.

Intellectual and other neuropsychological dysfunctions have been observed in survivors of childhood acute lymphocytic leukaemia (ALL). The possible relationship of therapy to these dysfunctions was investigated in a prospective study of children with newly diagnosed ALL seen at the Children's Hospital of Philadelphia. They were evaluated with standardised intelligence tests during the first month of treatment and periodically thereafter. There were two therapy schedules--one using standard drugs for induction and maintenance, the other a more intensive schedule. Central-nervous-system prophylaxis (2400 rad cranial radiation and six doses of intrathecal methotrexate) was given to all. Significant reductions were found in overall IQ score for the majority of children, younger patients being most affected. More extensive testing of surviving children, with and without decline in IQ, all of whom were normal on the first test, revealed patterns of functional deficits and residual strengths that could not be characterised with IQ testing alone. These deficits, which could affect learning and academic performance, were not seen in six children studied years after receiving similar chemotherapy that included intrathecal and oral methotrexate but not cranial irradiation.

Adolescent↗
PubMed1981

A deleted chromosome no. 13 in human retinoblastoma cells: relevance to tumorigenesis.

In this report of banded karyotypes prepared after short-term culture (72 hr) from human retinoblastoma tumor tissue, on del(13)(pter leads to q14:) chromosome and one normal chromosome #13 were found in all of the metaphases examined. Similar deletions (always involving 13q14) have previously been described in the somatic cells of individuals with one form of retinoblastoma. In the present case, however, the constitutional karyotype is normal. The presence of tumors in both eyes suggests that this is the genetic form of retinoblastoma, even though the patient's family history is negative for this tumor. The normal constitutional karyotype argues that the chromosome deletion occurred as a postzygotic event. The modal chromosome number of the tumor cells is 47 and rearrangements involving chromosomes #2, #17, and #20 were also identified.

Child, Preschool↗
PubMed1981

Management of solid tumors in children: contribution of computed tomography.

To evaluate the impact of computed tomography (CT) on therapeutic management decisions in solid tumors of the chest and abdomen, 92 examinations on 54 children with 13 histologic tumor types were analyzed. The CT impact on the management decisions was analyzed in relation to other diagnostic procedures of the same body part including sonography, chest films with tomography, abdominal/pelvic films, and excretory urography. Overall, CT provided the essential information of 47% of management decision. By confirming non-CT examination results it helped direct therapeutic decisions in 28%. No additional information was derived from CT in 20%. Technically poor studies in 5% resulted in CT errors. According to the procedural method, CT provided additional information in 42% when compared with sonography, in 38% when compared with chest films and tomography, in 41% when compared with abdominal/pelvic films, and in 27% when compared with intravenous urography. The investigation showed that CT provided information directly affecting the therapeutic management decision in a significant number of patients.

Abdominal Neoplasms↗
PubMed1980

Bone sarcoma as a second malignant neoplasm in children: influence of radiation and genetic predisposition for the Late Effects Study Group.

Osteosarcoma or chondrosarcoma developed as a second malignant neoplasm (SMN) in 40 of 188 individuals with SMN whose first neoplasm occurred in childhood. A genetic susceptibility to cancer was found in 23; the SMN developed in an irradiated field in 32; both factors wer present in 16; neither in one. When a genetic predisposition was present, radiation shortened the interval to SMN. The intervals between tumors and the age at which the bone sarcomas developed in relation to genetic disease and therapy were analyzed by a two-mutation hypothesis. Studies of SMN in childhood permit us to make observation about the role of genetic factors and environmental mutagens in cancer etiology.

Adolescent↗
PubMed1980

A new therapy schedule for pediatric non-Hodgkin lymphoma toxicity with preliminary results.

A pilot study of the toxicity and efficacy of a new treatment schedule for childhood non-Hodgkin's lymphoma was conducted by members of the Children's Cancer Study Group (CCSG) prior to its use in a randomized phase III trial. Chemotherapeutic agents used were cyclophosphamide (CPM), vincristine (VCR), and prednisone, together with intravenous (IV) and intrathecal methotrexate (IT MTS). Radiation therapy was also employed. From September 1976 to April 1977, 27 eligible, newly diagnosed patients with non-Hodgkin's lymphoma were entered onto this pilot study. Toxicity was acceptable with minor adjustments in dosage and timing of the myelosuppressive agents. Fourteen of the 22 patients entered onto maintenance remain entirely disease-free, and all have completed the prescribed course of chemotherapy. None of the 12 patients characterized as having a "favorable" prognosis has relapsed, with a median follow-up of 27 months from on study.

Adolescent↗
PubMed1979

Leukemia in a black child with Bloom's syndrome: somatic recombination as a possible mechanism for neoplasia.

A 5 1/2-year-old child with Bloom's syndrome developed acute lymphocytic leukemia (ALL). Bloom's syndrome is associated with chromosomal aberrations, and affected individuals have an increased incidence of leukemia and solid tumors. The skin on our patient had adjacent areas of decreased and increased pigmentation similar to the "twin-spots" seen in Drosophila. "Twin-spots" are the manifestation of somatic cell DNA recombination and provide evidence that clones of cells in Bloom's syndrome have become homozygous for a particular gene. Somatic cell recombination is proposed as a mechanism to explain the increased incidence of neoplasia in Bloom's syndrome and supports the hypothesis that cancer may be a recessive disorder at the cellular level.

Black People↗