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Biomedical subjects

R Gray

Publications and source records attributed to R Gray.

At least 145 records · Page 8Linked to original sources
PubMed1998

Survival advantage of adjuvant chemotherapy in high-risk node-negative breast cancer: ten-year analysis--an intergroup study.

PURPOSE: Preliminary analysis showed that adjuvant chemotherapy is effective in improving disease-free survival (DFS) among high-risk breast cancer patients. This report updates the analysis of the high-risk group and reports the results of the low-risk group. METHODS: Patients who had undergone a modified radical mastectomy or a total mastectomy with low-axillary sampling, with negative axillary nodes and either an estrogen receptor-negative (ER-) tumor of any size or an estrogen receptor-positive (ER+) tumor that measured > or = 3 cm (high-risk) were randomized to receive six cycles of cyclophosphamide, methotrexate, fluorouracil, and prednisone (CMFP) or no further treatment. Patients with ER+ tumors less than 3 cm (low-risk) were monitored without therapy. RESULTS: DFS and overall survival (OS) at 10 years were 73% and 81%, respectively, among patients who received chemotherapy, as compared with 58% and 71% in the observation group (P=.0006 for DFS and P=.02 for OS). Chemotherapy was beneficial for patients with large tumors, both ER+ and ER-, showing a 10-year DFS of 70% versus 51 % (P=.0009) and OS of 75% versus 65% (P=.06). Ten-year survival was 77% among low-risk patients, 85% among premenopausal patients, and 73% in the postmenopausal group. CONCLUSION: The observed 37% reduction in risk of recurrence and 34% reduction in mortality risk at 10 years, associated with a 15.4% absolute benefit in disease-free state and 10.1% in survival, reaffirm the role of adjuvant chemohormonal therapy in the management of high-risk node-negative breast cancer. Tumor size remains a significant prognostic factor associated with recurrence and survival in the low-risk group.

Adult↗
PubMed1998

Sixteen-week multidrug regimen versus cyclophosphamide, doxorubicin, and fluorouracil as adjuvant therapy for node-positive, receptor-negative breast cancer: an Intergroup study.

PURPOSE: The Intergroup conducted this breast cancer adjuvant trial to compare an investigational 16-week regimen with cyclophosphamide, doxorubicin, and fluorouracil (5-FU; CAF). The 16-week regimen features greater doxorubicin and 5-FU dose-intensity than CAF and improved scheduling of antimetabolites with sequential methotrexate and 5-FU, as well as infusion 5-FU. PATIENTS AND METHODS: A total of 646 node-positive, receptor-negative patients were randomly assigned to receive either the 1 6-week regimen or six cycles of CAF. Breast cancer outcomes included recurrence as well as disease-free and overall survival. Toxicity was evaluated by the Common Toxicity Criteria (CTC). Treatment-related quality of life was assessed by the Breast Chemotherapy Questionnaire (BCQ) before, during, and 4 months after treatment in 163 patients. The trial was designed to use one-sided tests of significance for power calculations, but is now reported with both one-sided and the traditional two-sided tests of significance. RESULTS: At a median follow-up of 3.9 years, the estimated 4-year recurrence-free survival rate was 67.5% with the 16-week regimen versus 62.7% with CAF (P = .19, two-sided; P = .095, one-sided). The estimated 4-year survival rate was 78.1% with the 16-week regimen versus 71.4% with CAF (P = .10, two-sided; P = .05, one-sided). CAF produced significantly higher grades of leukopenia, granulocytopenia, and thrombocytopenia, as well as liver and cardiac toxicity, whereas the 16-week regimen produced significantly higher grades of anemia, nausea, stomatitis, and weight loss, as well as skin and neurotoxicity. There were three treatment-related deaths with CAF but none with the 16-week regimen. During treatment, quality of life declined significantly more with the 16-week regimen than CAF, but by 4 months posttreatment, there was no difference. CONCLUSION: The 16-week regimen produced marginally better breast cancer outcomes than CAF with similar toxicity but a greater reduction in during-treatment quality of life. The 16-week regimen should not be used instead of a standard-dose regimen without careful consideration of the 16-week regimen's pros and cons, which include its complicated schedule. It should probably not be tested further, but its antimetabolite schedules and frequent drug administration (ie, dose density) should be considered in the development of new regimens.

Adult↗
PubMed1998

Consensus criteria for the classification of carpal tunnel syndrome in epidemiologic studies.

Criteria for the classification of carpal tunnel syndrome for use in epidemiologic studies were developed by means of a consensus process. Twelve medical researchers with experience in conducting epidemiologic studies of carpal tunnel syndrome participated in the process. The group reached agreement on several conceptual issues. First, there is no perfect gold standard for carpal tunnel syndrome. The combination of electrodiagnostic study findings and symptom characteristics will provide the most accurate information for classification of carpal tunnel syndrome. Second, use of only electrodiagnostic study findings is not recommended. Finally, in the absence of electrodiagnostic studies, specific combinations of symptom characteristics and physical examination findings may be useful in some settings but are likely to result in greater misclassification of disease status.

Carpal Tunnel Syndrome↗
PubMed1998

Esophageal strictures. A radiologic approach to diagnosis and management.

Strictures of the esophagus represent persistent luminal narrowing following an inflammatory insult to mural tissues or a manifestation of malignant disease. Barium studies remain the cornerstone of evaluation of patients with a suspected stricture. The diagnostic features of the various causes of strictures are discussed. Balloon dilatation and stent placement, as well as other radiologic interventions, often have an important role in the treatment of patients with advanced disease. This article discusses the indications and general application of these procedures as well as the nature and evaluation of the associated complications.

Barium Sulfate↗
PubMed1997

Physical, psychiatric and social characteristics of the temporomandibular disorder pain dysfunction syndrome: the relationship of mental disorders to presentation.

OBJECTIVE: To investigate the physical and psychosocial characteristics and to identify the prevalence of mental disorders in pain dysfunction syndrome (PDS). DESIGN AND SETTING: New referrals to temporomandibular disorder clinics at Manchester Dental Hospital and diagnosed with PDS. METHODS: Patients were assessed with a range of socio-demographic, dental and psychosocial measures including a psychiatric interview. Patients with PDS and a mental disorder were compared with those without a mental disorder. RESULTS: 97 patients were included; 32 (33%) had a mental disorder. There were no significant differences between those with and those without a mental disorder on any of the objective dental measures. Those with a mental disorder complained of more pain associated with PDS. They reported more anxiety and depression and also more physical symptoms unrelated to the PDS for which they had sought help and received more treatments. CONCLUSIONS: Psychosocial factors contribute to the presentation and possibly causation of PDS in the third of patients seen in a hospital setting who have a mental disorder. This factors should be considered when managing patients with PDS.

Adolescent↗
PubMed1997

Guidelines for drug donations.

Drug donations are usually given in response to acute emergencies, but they can also be part of development aid. Donations may be given directly by governments, by non-governmental organisations, as corporate donations (direct or through private voluntary organisations), or as private donations to single health facilities. Although there are legitimate differences between these donations, basic rules should apply to them all. This common core of "good donation practice" is the basis for new guidelines which have recently been issued by the World Health Organisation after consultation with all relevant United Nations agencies, the Red Cross, and other major international agencies active in humanitarian emergency relief. This article summarises the need for such guidelines, the development process, the core principles, and the guidelines themselves and gives practical advice to recipients and donor agencies.

Guidelines as Topic↗
PubMed1997

A qualitative study of breast cancer self-help groups.

This study reports on the experience of women in four community breast cancer self-help groups in Ontario, Canada. Semi-structured interviews were conducted with 24 women, asking them about benefits and limitations of their group involvement, and about their perspectives on group processes and structures. Overall, participants reported their group involvement to be extremely helpful for navigating the short and long-term impact of breast cancer. Emotional support benefits included connecting with other breast cancer survivors, feeling understood and sharing experiences, providing hope, and sharing healing laughter. Informational and practical support benefits included sharing of important information and learning how to get what you want. Even where there were concerns about limitations or tensions of group experience, these occurred against a backdrop of appreciation and commitment. From the discussion of group processes and structures, a number of issues were identified as problematic. Most notable were how to deal with deaths of group members and how to balance the group's primary purpose of providing mutual support with secondary goals of dealing with group business and engaging in meaningful advocacy.

Adaptation, Psychological↗
PubMed1997

Vernier step acuity and bisection acuity for texture-defined form.

Using as the stimulus a texture pattern of short lines, we compared positional acuity thresholds for an orientation-texture-defined (OTD) boundary and a luminance-defined (LD) boundary. Texture lines had different orientations but the same luminance on either side of the OTD boundary, and different luminances but the same orientation on either side of the LD boundary. For the LD boundary, both vernier step acuity threshold and bisection acuity threshold were inversely proportional to the number of texture lines per degree (i.e., the pattern's spatial sampling frequency) over the entire 1.9-59 samples/deg frequency range investigated, though thresholds were considerably lower than the distance between adjacent lines. For the OTD boundary, both thresholds were inversely proportional to spatial sampling frequency (though thresholds were again considerably less than the distance between adjacent lines) but only for sampling frequencies below 20 samples/deg. For sampling frequencies below 20 samples/deg, the ratio between positional acuity thresholds for OTD and LD boundaries was approximately constant (3.5:1 for vernier acuity and 1.4:1 for bisection acuity). As sampling frequency was increased beyond 20 samples/deg both vernier and bisection acuity thresholds for OTD boundaries rose steeply. Both thresholds fell to a minimum near 20 samples/deg. For vernier step acuity the minimum threshold was 2.3 and 2.4 min arc (two observers), and for bisection acuity 1.7 and 1.9 min arc. We propose that these minimum thresholds approach a physiological limit of positional acuity for an OTD boundary, and that the limit is determined by a balance between the progressive improvement of positional acuity caused by increasing the frequency of spatial sampling vs the progressive reduction in visibility of the OTD boundary caused by the associated reduction in the length of texture lines. These physiological limits are far higher than the corresponding limits for sharp-edged high-contrast LD targets (2-5 and 1-5 sec arc, respectively). For an OTD boundary the effect of orientation contrast on vernier step acuity threshold approximated a square root law, while the effect of orientation contrast on bisection acuity approximated a linear law. Observers can combine positional information carried by texture contrast with positional information carried by luminance contrast. As to the combination rule, our findings are consistent with probability summation between independent channels.

Adult↗
PubMed1997

Rapid analytical tryptic mapping of a recombinant chimeric monoclonal antibody and method validation challenges.

A rapid and reproducible analytical tryptic mapping method was developed as an identity test for a recombinant chimeric monoclonal antibody for lot release testing. The unfolding, reduction, carboxymethylation, trypsin digestion, and reversed-phase (RP) HPLC steps were optimized to provide a reproducible method. The optimized method requires 30 min for unfolding the protein, 30 min for carboxymethylation, 4 h for digestion with TPCK-trypsin and 140 min for RPHPLC analysis. The total time required is less than 8 h compared to conventional procedures, which must be performed over several days. The optimized method was validated for its precision, recovery, specificity, and robustness. The precision of the method was determined by repeatability and intermediate precision experiments. Relative standard deviation (RSD) values were < or = 10% for the relative peak areas of marker peaks. The mean recovery of these marker peaks was 88.4%. The specificity was demonstrated by the unique tryptic mapping patterns obtained compared with several other monoclonal antibodies. Robustness was demonstrated by the relative insensitivity of the tryptic map to small deliberate changes in key method parameters. Excessive relative peak area variability observed for one peak (RSD 52%) was traced to adsorption to glass autosampler vials. This variability was substantially reduced (RSD 11%) by substituting polypropylene autosampler vials. The data demonstrate that this method may be applicable to a wide range of pharmaceutically relevant monoclonal antibodies.

Antibodies, Monoclonal↗