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E Chase

Publications and source records attributed to E Chase.

11 recordsLinked to original sources
PubMed2000

The structure of cucumber mosaic virus and comparison to cowpea chlorotic mottle virus.

The structure of cucumber mosaic virus (CMV; strain Fny) has been determined to a 3.2-A resolution using X-ray crystallography. Despite the fact that CMV has only 19% capsid protein sequence identity (34% similarity) to cowpea chlorotic mottle virus (CCMV), the core structures of these two members of the Bromoviridae family are highly homologous. As suggested by a previous low-resolution structural study, the 305-A diameter (maximum) of CMV is approximately 12 A larger than that of CCMV. In CCMV, the structures of the A, B, and C subunits are nearly identical except in their N termini. In contrast, the structures of two loops in subunit A of CMV differ from those in B and C. These loops are 6 and 7 residues longer than the analogous regions in CCMV. Unlike that of CCMV, the capsid of CMV does not undergo swelling at pH 7.0 and is stable at pH 9.0. This may be partly due to the fact that the N termini of the B and C subunits form a unique bundle of six amphipathic helices oriented down into the virion core at the threefold axes. In addition, while CCMV has a cluster of aspartic acid residues at the quasi-threefold axis that are proposed to bind metal in a pH-dependent manner, this cluster is replaced by complementing acids and bases in CMV. Finally, this structure clearly demonstrates that the residues important for aphid transmission lie at the outermost portion of the betaH-betaI loop and yields details of the portions of the virus that are hypothesized to mediate binding to aphid mouthparts.

Amino Acid Sequence↗
PubMed1999

Strength of indication for cesarean delivery: comparison of private physician versus resident service labor management.

OBJECTIVE: Our purpose was to compare the strength of indication for cesarean delivery for 2 groups of patients who had undergone cesarean delivery-those treated by physicians in private or group practice and those treated by a clinic or resident service. STUDY DESIGN: From records of 119 cesarean deliveries performed in 1992, data concerning patient history, labor course and management, fetal monitor tracings, and indications for cesarean delivery were extracted, summarized, and presented to 3 reviewers. Each reviewer rated the strength of indication for cesarean delivery on a 10-point visual analog scale and specified how often they would have chosen an alternative management plan. Reviewers were blinded to the research hypothesis and to patient age, type of provider, and insurance status. RESULTS: Using a multivariate linear regression model to adjust for differences in age and indication for cesarean delivery, we found that strength of indication scores were higher among patients treated by a resident service than among those treated by private physicians (P <.0001) and that an alternative action plan was more often suggested for deliveries managed by private physicians (P <.0001). CONCLUSIONS: Among women who underwent cesarean delivery, the strength of indication judged by a panel of reviewers not involved with the patient's care was stronger among resident-treated patients than among cases treated by private physicians. Although there are several possible explanations, the findings may suggest that physicians in private practice use different criteria than do resident physicians for deciding to perform a cesarean.

Adult↗
PubMed1998

Chemotherapy alone compared with chemotherapy plus radiotherapy for localized intermediate- and high-grade non-Hodgkin's lymphoma.

BACKGROUND: Patients with clinically localized, intermediate- or high-grade non-Hodgkin's lymphoma usually receive initial treatment with a doxorubicin-containing regimen such as cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP). Pilot studies suggest that eight cycles of CHOP alone or three cycles of CHOP followed by involved-field radiotherapy are effective in such patients. METHODS: We compared these two approaches in a prospective, randomized, multi-institutional study. The end points were progression-free survival, overall survival, and life-threatening or fatal toxic effects. Two hundred eligible patients were randomly assigned to receive CHOP plus radiotherapy, and 201 received CHOP alone. RESULTS: Patients treated with three cycles of CHOP plus radiotherapy had significantly better progression-free survival (P=0.03) and overall survival (P=0.02) than patients treated with CHOP alone. The five-year estimates of progression-free survival for patients receiving CHOP plus radiotherapy and for patients receiving CHOP alone were 77 percent and 64 percent, respectively. The five-year estimates of overall survival for patients receiving CHOP plus radiotherapy and for patients receiving CHOP alone were 82 percent and 72 percent, respectively. The adverse effects included one death in each treatment group. Life-threatening toxic effects of any type were seen in 61 of 200 patients treated with CHOP plus radiotherapy and in 80 of 201 patients treated with CHOP alone (P=0.06). The left ventricular function was decreased in seven patients who received CHOP alone, whereas no cardiac events were recorded in the group receiving CHOP plus radiotherapy (P=0.02). CONCLUSIONS: Three cycles of CHOP followed by involved-field radiotherapy are superior to eight cycles of CHOP alone for the treatment of localized intermediate- and high-grade non-Hodgkin's lymphoma.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1995

Putative receptor binding sites on alphaviruses as visualized by cryoelectron microscopy.

The structures of Sindbis virus and Ross River virus complexed with Fab fragments from monoclonal antibodies have been determined from cryoelectron micrographs. Both antibodies chosen for this study bind to regions of the virions that have been implicated in cell-receptor recognition and recognize epitopes on the E2 glycoprotein. The two structures show that the Fab fragments bind to the outermost tip of the trimeric envelope spike protein. Hence, the same region of both the Sindbis virus and Ross River virus envelope spike is composed of E2 and is involved in recognition of the cellular receptor.

Antibodies, Monoclonal↗
PubMed1994

The dangers of managerial perversion: quality assurance in primary health care.

The promotion of primary health care (PHC) at the Alma Ata conference has been followed by a variety of managerial initiatives in support of the development of PHC. One of the more promising vehicles has been the implementation of quality assurance mechanisms. This paper reviews recent examples of this genre and argues that the thrust of both primary health care and quality assurance are in danger of being distorted by a rather antiquated approach to management.

Community Health Planning↗
PubMed1993

Long-term follow-up of patients with low-grade malignant lymphomas treated with doxorubicin-based chemotherapy or chemoimmunotherapy.

PURPOSE: We reviewed survival data of patients with low-grade lymphoma entered on Southwest Oncology Group (SWOG) lymphoma trials in 1972 to 1983 to determine the utility of doxorubicin-containing therapy (cyclophosphamide, doxorubicin, vincristine, and prednisone [CHOP]) in such patients. PATIENTS AND METHODS: We identified all patients with low-grade lymphoma, no prior therapy, and stage III or IV disease who were treated with full-dose CHOP induction therapy on any arm of SWOG studies 7204, 7426, or 7713. Survival data for this group of patients were correlated with pretreatment prognostic factors, including histology, patient age, sex, symptom status, performance status, bone marrow or extranodal involvement, and the number of disease sites. The effect of maintenance treatment was also assessed. RESULTS: Four hundred fifteen patients met criteria for inclusion in the study group. With median follow-up periods of 12.8 years (maximum, 19.8 years), the median survival duration was 6.9 years. Survival was significantly shorter in patients with follicular mixed or small lymphocytic histology, age greater than 40 years, male sex, B-symptom status, and SWOG performance status greater than 1. Multivariate regression analysis showed histology, age, and sex to be independent predictors of survival. There was no definite survival plateau of cured patients in any subgroup, although the survival curve for follicular mixed histology patients showed long-term survival of approximately 25%. Maintenance therapy did not prolong survival. CONCLUSION: Doxorubicin-containing treatment did not prolong the overall median survival of low-grade lymphoma patients compared with results with less-aggressive programs.

Adult↗
PubMed1992

HIV infection in American Indians and Alaska Natives: surveys in the Indian Health Service.

A network of surveys of HIV seroprevalence in American Indians and Alaska Natives (AI/AN) was begun in 1989. From July 1, 1989 through June 30, 1991, 37,681 serologic specimens were collected from prenatal and sexually transmitted disease patients in 58 facilities operated or funded by the Indian Health Service. Specimens from AI/AN women receiving initial prenatal care showed an overall HIV prevalence of 0.3/1,000, while specimens obtained during the third trimester of pregnancy showed an overall prevalence of 1.0/1,000. The rate for rural third trimester prenatal patients (0.9/1,000) was similar to that for urban patients (1.1/1,000). HIV rates among third trimester AI/AN patients in three western states were 4 to 8 times higher than rates observed in childbearing women of all races in those states. The overall HIV seroprevalence in AI/AN seeking care for sexually transmitted diseases was 4.5/1,000 for males (urban 10.8/1,000; rural 2.0/1,000) and 0.7/1,000 for females (urban 0.9/1,000; rural 0.6/1,000). Approximately 1,210 to 4,250 (midpoint of range = 2,730) AI/AN in the U.S. are projected from survey findings to be currently infected with HIV. The presence of HIV in multiple specimens from rural areas and the similarity of HIV infection rates for female patients from rural and urban locations provides evidence of diffusion of the HIV epidemic to rural AI/AN, and emphasizes the need for effective HIV prevention for this population.

Adolescent↗
PubMed1991

Factors associated with success among southern Cheyenne and Arapaho Indians.

Researchers in applied social science are seeking ways of approaching the facilitation of community-based development at the grass-roots level. Much research to date has focused on negative social aspects in communities, such as substance abuse and high numbers of school drop-outs. An innovative approach was developed that involved looking instead at successful individuals in communities. Individuals identified as successful were interviewed about the factors they associated with their own success. The experience of supportive parenting during their childhoods and moderation in alcohol and other substance use as adults were strongly correlated with success in life. The interview process provided an effective springboard for discussions and the development of intervention strategies at the community level.

Achievement↗
PubMed1982

Adjuvant treatment of node-positive breast cancer with adriamycin-cyclophosphamide with or without radiation therapy: interim results of an ongoing clinical trial.

During 1974-1980, 138 women with node-positive stage II breast cancer were treated with either eight courses of adriamycin-cyclophosphamide (AC) chemotherapy (82 patients) or AC chemotherapy plus comprehensive regional radiotherapy (56 patients). The overall relapse-free survival of the treated patients was significantly superior (P less than 0.001) to a comparable group of women who underwent surgery alone. This effect of adjuvant therapy was clearly manifest in all groups of patients irrespective of nodal involvement or menopausal status. To date, relapse-free survival for patients receiving AC compared to AC plus radiotherapy is not different (P = 0.7). In summary, wer have demonstrated that a brief 6-month course of adjuvant chemotherapy with AC can significantly reduce the recurrence rate in women with stage II breast cancer.

Adult↗