Search PubMed⌕ Search

Biomedical subjects

J T Ellis

Publications and source records attributed to J T Ellis.

At least 73 records · Page 4Linked to original sources
PubMed1988

Clinical presentation and natural history of patients with essential thrombocythemia and the Philadelphia chromosome.

Six women presented with the clinical picture of essential thrombocythemia (ET) without the anemia, marked splenomegaly, and extreme leukocytosis characteristic of chronic myelogenous leukemia (CML). All had the Philadelphia chromosome on karyotype analysis of the bone marrow. Peripheral basophilia was present in four cases, providing a clinical clue that the Philadelphia chromosome might be present. Marrow biopsy showed granulocytic hyperplasia and either small megakaryocytes or sheets of megakaryocytes with marked atypia, findings that are more typical of CML than ET. The clinical importance of finding the Philadelphia chromosome in patients who seem to have ET is in assessing prognosis. ET generally follows a chronic, indolent course. However, five of these six patients who had the Philadelphia chromosome underwent clinical transition to the accelerated phase of CML or blastic leukemia in 4-7 years.

Adult↗
PubMed1986

Cellular proliferation in the rat mammary gland during pregnancy and lactation.

Cellular proliferation during different stages of pregnancy and lactation in the rat mammary gland was studied by use of autoradiography at the ultrastructural level or in combination with immunocytochemistry. The study consisted of two groups of animals, young 45-day-old rats undergoing their first pregnancy and old multiparous rats undergoing their third pregnancy. Both groups of animals were injected with [3H]thymidine, 2 hours before sacrifice. The timing of proliferative activity through pregnancy and lactation was similar in the two groups. A peak level of proliferation was observed on the 5th day of gestation and the rate of proliferation was at its lowest at the end of gestation. A second small peak was observed on the 3rd day of lactation. In virgin animals, both epithelial and myoepithelial cells showed a high level of proliferative activity. The epithelial cells continued to divide during all stages of their differentiation, throughout pregnancy and lactation. Myoepithelial cells showed active division in early pregnancy but their rate of proliferation declined as the cells acquired abundant cytoplasmic filaments for their contractile function. Intra-alveolar dendritic cells, which have been recently identified in the lactating rat breast, showed a high proliferative rate at the end of gestation.

Animals↗
PubMed1986

Studies of the bone marrow in polycythemia vera and the evolution of myelofibrosis and second hematologic malignancies.

The PVSG study is unique in that it is prospective and composed of 432 patients randomized to three treatment arms. This study also provides the opportunity for serial studies of numerous sequential biopsies. Large numbers of cases with sequential biopsies covering the entire long course are essential to appreciate the full spectrum of tissue changes in this disease. The PVSG was initiated in 1967 and in mid-1985 approximately one third of the patients are alive and on protocol. For these reasons, the results must still be considered preliminary. Pretreatment biopsies from patients randomized in the PVSG have been analyzed for total cellularity, megakaryocyte concentration, and reticulin content. Considerable variation in these elements was found in these biopsies. Sequential posttreatment biopsies from these patients have also been studied and correlated with the clinical course of the disease. None of the morphologic parameters analyzed was shown to be of prognostic significance. Early in the course of PV the marrow reticulin content is almost always normal. The length of the developmental stage is unknown and the precise timing of the clinical onset may be difficult. Therefore, the 11% of patients that showed a significant increase in reticulin on initial evaluation may have had PV longer than was indicated clinically. If large numbers of sequential biopsies are studied, an increase in reticulin content can frequently be demonstrated during the active phase of the disease and before the onset of the spent phase. Currently 39 patients (9%) have developed the spent phase, or PPMM. PPMM occurred in about the same incidence in the patients treated with myelosuppressive therapy as by phlebotomy alone, the spent phase occurring in 16 patients treated by phlebotomy alone, 11 with chlorambucil, and 12 with 32P. The course of the reticulin fibrosis is slowly progressive. There is some evidence for regression in a few patients in the erythrocytotic phase, but sampling variation cannot be completely ruled out. At this time in the study, AL has developed in 37 patients (8.6%). The incidence of AL is quite low in the phlebotomy group (three cases). Presumably this represents the natural incidence in PV unmodified by therapeutic agents. The frequency is approximately equal and quite high in the chlorambucil and 32P groups. There are 19 cases in the chlorambucil-treated group and 15 in the 32P-treated group. The leukemias that developed in the PV patients occurred either de novo or following PPMM.(ABSTRACT TRUNCATED AT 400 WORDS)

Acute Disease↗
PubMed1984

Myelofibrosis in the myeloproliferative disorders.

There is an extensive descriptive literature concerning both the clinical and pathologic features of myelofibrosis as it occurs in the setting of myeloproliferative disease. These initial chapters of this book have reviewed these aspects of the problem, and will therefore serve as a background against which recent new advances in the biology of collagen in particular, and connective tissue in general, can be viewed. These newer advances will constitute the remainder of this book.

Aged↗
PubMed1981

Increased incidence of acute leukemia in polycythemia vera associated with chlorambucil therapy.

In studies to determine the optimal treatment for polycythemia vera, 431 previously untreated patients whose disease met established diagnostic criteria were entered into a prospective, randomized controlled trial between 1967 and 1974. Three treatment regimens were used: phlebotomy alone, chlorambucil supplemented by phlebotomy, or radioactive phosphorus supplemented by phlebotomy. Despite minor differences in age and sex, the three groups were comparable in initial hematocrit, white-cell and platelet counts, and disease-related symptoms. The median duration of follow-up is now more than 6 1/2 years. As of February 15, 1980, there were no statistically significant differences in survival among the groups. However, the risk of acute leukemia in patients given chlorambucil was 2.3 times that in patients given radioactive phosphorus and 13 times that in patients treated with phlebotomy alone. The increased incidence of leukemia during chlorambucil treatment is statistically significant (P less than or equal to 0.002); accordingly, the Polycythemia Vera Study Group has discontinued the use of chlorambucil in the treatment of polycythemia vera.

Acute Disease↗
PubMed1981

Resistance to therapy of acute leukemia developing in the course of polycythemia vera.

Thirteen patients in whom acute leukemia developed in the course of polycythemia vera were initially treated with vincristine and prednisone in an attempt at remission induction. None responded, and four died during this initial course of therapy. Induction was then attempted in the nine survivors, using cytosine arabinoside and adriamycin. Only one complete remission of 38 weeks and one partial remission were achieved, while median survival was 32 days. Poor results may reflect both the intrinsic biologic properties of the acute leukemia occurring in this setting and the advanced age of the patients.

Acute Disease↗
PubMed1979

The bone marrow in polycythemia vera.

The sequential biopsies and the careful clinical and laboratory studies in this large prospective study of PV patients offer a unique opportunity to properly evaluate the diagnostic and prognostic importance of the biopsy and to study the complications of this condition. The results of the study to date confirm and extend previous studies. Because of the long natural history of PV, the results of studies relating to leukemia, other myeloproliferative diseases, myelofibrosis, and effects of therapy are tentative at this time, even though the study is in its eleventh year. Hypercellularity of the marrow, together with hyperplasia and hypertrophy of megakaryocytes, is an almost constant finding in untreated PV. A very few cases (7 of 281) had relatively normal cellularities and normal megakaryocytic concentrations. Whether these findings were the result of sampling errors could not be determined, since only one site was biopsied. In any event, we found no unique clinical or laboratory features to distinguish these patients. At this time, the course of these patients appears to be the same as that of the other patients. Although increases in reticulin were regularly found during the spent phase of polycythemia, the relationship was not a precise one. For example, a moderate to marked increase in reticulin was found in 12 percent of the patients early in the course of the disease and was not predictive that the spent phase with myeloid metaplasia was imminent. In addition, in a given patient with serial biopsies taken over several years, some variability in reticulin was noted among the biopsies. Whether this represented variation in sampling or fluctuation in reticulin content could not be decided at this time. Using the standard criteria for examination of the marrows, we have found it impossible to predict which patients will develop leukemia, since the pretreatment and posttreatment biopsies almost up to the clinical onset cannot be separated from the remainder of the group.

Acute Disease↗
PubMed1975

The effects of cosmic particle radiation on pocket mice aboard Apollo XVII: X. Results of ear examination.

In the five pocket mice flown on Apollo XVII, no evidence was found that the inner ear had been damaged, though poor fixation precluded detailed study. On the other hand, the middle ear cavity was involved in all the mice, hemorrhage having occurrred in response to excursions in pressure within the canister that housed the mice during their flight. The same occurred in flight control mice which had been subjected to pressure excursions of much the same magnitude. A greater degree of exudation into air cells and greater leukotaxis were noted in the flight animals than in the control animals. There was no increase in leukocyte population along the paths of the 23 cosmic ray particles registered in the subscalp dosimeters that traversed the middle ear cavities of the flight mice. The increased exudation and the greater response by leukocytes in the flight mice may have been causally related to the lesions found in their olfactory mucosa but there were no data in support of this possibility.

Animals↗
PubMed1975

The effects of cosmic particle radiation on pocket mice aboard Apollo XVII: appendix III. evaluation of viscera and other tissues.

Histopathological findings in the lungs, livers, bone marrows, small intestines, gonads, kidneys, and other tissues of the four pocket mice (Perognathus longimembris) that survived the Apollo XVII flight were evaluated in the light of their immediate environment and as targest of HZE cosmic ray particles. Results of this study failed to disclose changes that could be ascribed to the HZE particle radiation. Decreased numbers of erythropoietic cells in the bone marrow of the flight mice were probably related to the increased oxygen pressure. The small intestine showed no changes. Ovaries and tests appeared normal. Two of the three surviving male flight mice displayed early stages of spermatogenesis, just as ground-based controls did at the same season. Abnormalities were also not found in the thyroid, parathyroids, adrenals, or kidneys. The status of the juxtaglomerular apparatus could not be evaluated. The lungs exhibited nonspecific slight rections. A variety of incidental lesions were noted in the livers of both the flight mice and their controls. The heart muscle showed nothing that could be regarded as pathological. Sections of skeletal muscle examined were free from significant change.

Adrenal Cortex↗
PubMedDate not supplied

An automated method for analysis and visualization of laser Doppler velocimetry data.

The analysis and visualization of large data sets collected by use of laser Doppler velocimetry has presented a challenge to researchers using this technique to investigate complex flow fields. This paper describes an automated procedure for analysis and animation of two- and three-dimensional laser Doppler velocimetry data. The procedure consists of a suite of FORTRAN programs for calculating phase window averages of velocity and the Reynolds stress tensor, calculating the principal normal stresses, maximum shear stresses, and preparation of data files for input into Plot-3D compatible data visualization software. An example application of these techniques to data collected from an in vitro investigation of the retrograde flow field associated with a bileaflet mechanical heart valve is also presented.

Algorithms↗
PubMedDate not supplied

Posttraumatic renal infarction versus tumor: a helpful angiographic finding.

We report a case of segmental renal infarction due to a traumatic dissecting hematoma of a renal artery branch. Some features of the cross-sectional imaging studies were atypical of infarct and suggestive of tumor. Renal arteriography demonstrated aneurysmal dilatation of an approximately 3-cm portion of a segmental renal artery, an uncommon but highly suggestive finding of traumatic arteriopathy.

Abdominal Injuries↗
PubMedDate not supplied

Assessment instruments used in the education and treatment of persons with autism: brief report of a survey of national service centers.

Although assessment is a critical component in the education and treatment of persons who have autism, there is insufficient information about the types of assessment instruments that are used routinely by practitioners. This brief report describes a survey of national service centers to determine their use of standardized instruments and the purposes of their assessment practices. Data from centers representing 30 states revealed that (a) the number of assessment instruments endorsed by centers increased as centers adopted a "multidisciplinary" approach to education and treatment, (b) the largest proportion of instruments fell within intellectual, motor, and language/communication domains, and (c) instruments were used most frequently for diagnostic and curriculum design purposes. Agreement among practitioners on the selection of instruments occurred most frequently in the domains of projective, adaptive behavior, and family assessment. The implications from these findings for assessment practices in autism are discussed.

Autistic Disorder↗