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2.
N Engl J Med ; 345(24): 1719-26, 2001 Dec 13.
Article in English | MEDLINE | ID: mdl-11742045

ABSTRACT

BACKGROUND: Supportive-expressive group therapy has been reported to prolong survival among women with metastatic breast cancer. However, in recent studies, various psychosocial interventions have not prolonged survival. METHODS: In a multicenter trial, we randomly assigned 235 women with metastatic breast cancer who were expected to survive at least three months in a 2:1 ratio to an intervention group that participated in weekly supportive-expressive group therapy (158 women) or to a control group that received no such intervention (77 women). All the women received educational materials and any medical or psychosocial care that was deemed necessary. The primary outcome was survival; psychosocial function was assessed by self-reported questionnaires. RESULTS: Women assigned to supportive-expressive therapy had greater improvement in psychological symptoms and reported less pain (P=0.04) than women in the control group. A significant interaction of treatment-group assignment with base-line psychological score was found (P

Subject(s)
Breast Neoplasms/psychology , Psychotherapy, Group , Social Support , Adult , Affect , Breast Neoplasms/mortality , Breast Neoplasms/therapy , Female , Humans , Middle Aged , Neoplasm Metastasis , Pain/etiology , Pain/psychology , Pain Measurement , Psychotherapy, Group/methods , Survival Analysis
4.
Breast Cancer Res Treat ; 62(1): 19-33, 2000 Jul.
Article in English | MEDLINE | ID: mdl-10989983

ABSTRACT

Women who are members of breast cancer families are at increased risk for breast cancer. The cloning of BRCA1 and BRCA2 has made it possible to identify mutation carriers within some of these families. Management of breast cancer risk in these families, which presents enormous challenges to patients and clinicians, is addressed. Management should begin with a full evaluation of the patient, including construction of a three-generation pedigree, ascertainment of non-genetic factors that may impact on risk, information on previous and current breast health, practice of and attitudes toward screening, and the psychosocial impact of family history on the individual. Patient priorities in risk management should be explicitly reviewed; these may include survival, cancer prevention, breast preservation, optimization of quality of life or minimization of disruption of day-to-day activities. Approaches to risk management involve screening (usually considered the mainstay), anti-estrogens, prophylactic surgery and/or lifestyle modifications. Specific gene therapy may become available in the future. Management decisions should be individualized to reflect risk levels and patient priorities and goals, within bounds that are medically and scientifically reasonable. An explicit examination of different time-frames (1, 5, 10 years) is recommended given the rapid evolution of knowledge in this area.


Subject(s)
Breast Neoplasms/genetics , Genetic Predisposition to Disease , Risk Management , Adult , Aged , Attitude to Health , Breast Neoplasms/diagnosis , Breast Neoplasms/prevention & control , Chemoprevention , Decision Making , Female , Genetic Therapy , Humans , Mass Screening , Mastectomy , Middle Aged , Quality of Life
5.
Clin Genet ; 57(5): 376-83, 2000 May.
Article in English | MEDLINE | ID: mdl-10852372

ABSTRACT

The perceived benefits and risks of genetic testing may vary between groups of individuals with different cultural, demographic, and family history features. This multicentre study examined the factors that influenced the decision to undergo genetic testing for BRCA1 and BRCA2 in Canadian Jewish women with breast cancer. A self-administered questionnaire was developed and distributed to 134 individuals enrolled in a research-based testing program for Ashkenazi women. The questionnaire assessed demographic, social, and family history parameters, and the influence of medical, family, social, psychological, and cultural/religious factors on decision making about genetic testing. Seventy-six percent of women completed the questionnaire. Forty-one percent of study participants had no family history of breast or ovarian cancer. The most important factors influencing the decision to undergo testing were a desire to contribute to research, potential benefit to other family members, curiosity, and the potential for relief if not found to be a carrier (endorsed by 87, 78, 70, and 60% of participants, respectively). The main perceived risks of undergoing genetic testing related to insurance discrimination, confidentiality, accuracy and interpretability of results, potential impact on marriage prospects for family members, and focus on the Jewish community (endorsed by 28, 24, 30, 17, and 14% of participants, respectively). This study provides novel information on the motivating factors for BRCA1 and BRCA2 mutation testing in Canadian women of Ashkenazi Jewish descent. The focus on altruistic factors and those related to perceived psychological benefits of testing is notable.


Subject(s)
Breast Neoplasms/psychology , Genes, BRCA1/genetics , Genetic Predisposition to Disease/psychology , Genetic Testing/psychology , Jews/genetics , Neoplasm Proteins/genetics , Transcription Factors/genetics , Adult , Aged , Aged, 80 and over , BRCA2 Protein , Breast Neoplasms/diagnosis , Breast Neoplasms/genetics , DNA Mutational Analysis , Decision Making , Female , Humans , Middle Aged , Motivation , Ontario/epidemiology , Risk Assessment
6.
J Clin Epidemiol ; 53(1): 47-55, 2000 Jan.
Article in English | MEDLINE | ID: mdl-10693903

ABSTRACT

The BEST study, a multicenter randomized trial of group psychosocial support in metastatic breast cancer, had several unusual features that may have influenced recruitment, notably the group nature of the intervention and the need for close collaboration between medical and psychosocial investigators. The recruitment process was examined in light of these features. Establishment of study centers was facilitated by involvement of experienced medical investigators who had successfully collaborated in previous research projects. Systematic evaluation of potential subjects or direct recruitment by psychosocial investigators optimized recruitment; however, the group nature of the intervention prolonged recruitment. Overall, 652 women were approached and 237 (43.3% of those medically eligible) randomized. Using population-based estimates, 24.3% of women with metastatic breast cancer were assessed for the study and 8.7% randomized. A randomization ratio of 2:1 was required to form and maintain groups. Competing clinical trials were the greatest barrier to recruitment. Five lessons were learned during recruitment for this trial: (1) multicenter randomized trials of psychosocial interventions are feasible, even in very ill patients, (2) the use of a group intervention effectively increased the required sample size by 50%, (3) similarity of randomization rates suggests that generalizability of study results will probably be comparable to that of other randomized cancer trials, (4) multidisciplinary collaborations and involvement of experienced researchers facilitated enrollment, and (5) most challenges encountered in recruitment were similar to those seen in all clinical trials.


Subject(s)
Breast Neoplasms/psychology , Patient Selection , Randomized Controlled Trials as Topic , Social Support , Breast Neoplasms/pathology , Canada , Female , Humans , Multicenter Studies as Topic , Treatment Outcome
7.
Semin Respir Crit Care Med ; 21(5): 375-84, 2000.
Article in English | MEDLINE | ID: mdl-16088749

ABSTRACT

The purpose of this study is to review the economics of lung cancer management. The economic literature that relates to the diagnosis, treatment, and palliation of lung cancer as well as the pertinent methodological literature were reviewed. Lung cancer treatment is moderately expensive. The overall cost to society is significant given its high incidence. The cost of staging lung cancer can be minimized through the judicious use of diagnostic and staging procedures. The cost-effectiveness of combined modality therapy and palliative chemotherapy for lung cancer appears reasonable when compared with commonly accepted medical interventions. Based on this review, current approaches to lung cancer diagnosis and treatment are, for the most part, cost-effective. Reasons for inconsistent practice patterns in the management of lung cancer in the medical community should be further explored.

9.
J Clin Oncol ; 17(8): 2365-70, 1999 Aug.
Article in English | MEDLINE | ID: mdl-10561298

ABSTRACT

PURPOSE: Premenopausal women with breast cancer often enter a premature menopause during initial treatment of their malignancy, with resulting loss of childbearing capacity, onset of menopausal symptoms, and subsequent prolonged exposure to long-term risks of menopause. Adjuvant therapy is believed to contribute to this early menopause. PATIENTS AND METHODS: One hundred eighty-three premenopausal women with locoregional breast cancer (tumor-node-metastasis staging system classification, T1-3 N0-1 M0) who had undergone surgical treatment and provided information on menopausal status at diagnosis and 1 year later were enrolled. Systemic adjuvant therapy was recorded. Univariate and multivariate predictors of menopause were examined. RESULTS: Age, weight gain, tumor stage, nodal stage, and systemic adjuvant therapy (chemotherapy, tamoxifen) were all significant univariate correlates of menopause. In multivariate analysis, age, chemotherapy, and hormone therapy (tamoxifen) made significant independent contributions to the onset of menopause. CONCLUSION: Age and systemic chemotherapy are the strongest predictors of menopause in women with locoregional breast cancer. They independently contribute to menopause. A graphic representation of our multivariate model allows an estimation of risk of menopause according to patient age and planned adjuvant treatment, and it may facilitate clinical decision-making.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Breast Neoplasms/drug therapy , Menopause, Premature , Tamoxifen/therapeutic use , Adult , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Breast Neoplasms/pathology , Breast Neoplasms/surgery , Chemotherapy, Adjuvant/adverse effects , Cisplatin/administration & dosage , Cisplatin/adverse effects , Cyclophosphamide/administration & dosage , Cyclophosphamide/adverse effects , Cytarabine/administration & dosage , Cytarabine/adverse effects , Epirubicin/administration & dosage , Epirubicin/adverse effects , Female , Fluorouracil/administration & dosage , Fluorouracil/adverse effects , Humans , Mastectomy , Methotrexate/administration & dosage , Methotrexate/adverse effects , Middle Aged , Multivariate Analysis , Premenopause , Probability , Risk Factors , Tamoxifen/adverse effects
10.
J Clin Oncol ; 17(11): 3653-63, 1999 Nov.
Article in English | MEDLINE | ID: mdl-10550164

ABSTRACT

PURPOSE: To review the preclinical and clinical studies relevant to the prognosis and prognostic associations of BRCA1- and BRCA2-associated breast carcinomas, with an emphasis on research methodology. METHODS: Reports of relevant studies obtained from a MEDLINE search, and references from these articles, were critically reviewed. RESULTS: Consistent associations with both favorable (medullary or atypical medullary carcinoma) and unfavorable (high tumor grade, hormone receptor negativity, somatic p53 mutation) prognostic characteristics have been found for BRCA1-associated breast carcinomas. Inconsistent results have been demonstrated for prognostic associations of BRCA2-associated breast tumors. Clinical studies that have directly assessed the prognosis of these tumors have not shown a clear effect of BRCA1 or BRCA2 mutation, but no study has used optimal methodology. In vitro and animal model data suggest a possible influence of these mutations on response to agents that cause double-strand DNA breaks, but clinical data are limited. CONCLUSION: The elucidation of an identifiable subgroup of breast carcinomas that result from germline mutations in BRCA1 or BRCA2 may be an important step toward genotype-based understanding of prognosis and choice of therapy in this disease. However, currently there are inadequate data to support use of BRCA1 or BRCA2 status to counsel individuals regarding their prognosis or to select treatment. Well-designed studies of population-based inception cohorts of breast cancer patients, which have adequate sample size and complete follow-up, and which use objective outcome criteria and blinding of outcome assessment, are required to optimally address this question.


Subject(s)
Breast Neoplasms , Genes, BRCA1/genetics , Neoplasm Proteins/genetics , Transcription Factors/genetics , Animals , BRCA2 Protein , Breast Neoplasms/genetics , Breast Neoplasms/mortality , Breast Neoplasms/pathology , Clinical Trials as Topic , Female , Heterozygote , Humans , Phenotype , Prognosis
11.
J Biol Chem ; 274(41): 29413-9, 1999 Oct 08.
Article in English | MEDLINE | ID: mdl-10506203

ABSTRACT

Besides serving as the obligate electron donor to dinitrogenase during nitrogenase turnover, dinitrogenase reductase (NifH) is required for the biosynthesis of the iron-molybdenum cofactor (FeMo-co) and for the maturation of alpha(2)beta(2) apo-dinitrogenase (apo-dinitrogenase maturation). In an attempt to understand the role of NifH in FeMo-co biosynthesis, a site-specific altered form of NifH in which leucine at position 127 has been deleted, L127Delta, was employed in in vitro FeMo-co synthesis assays. This altered form of NifH has been shown to inhibit substrate reduction by the wild-type nitrogenase complex, forming a tight protein complex with dinitrogenase. The L127Delta NifH was found to inhibit in vitro FeMo-co synthesis by wild-type NifH as detected by the gamma gel shift assay. Increasing the concentration of NifNE and NifB-cofactor (NifB-co) relieved the inhibition of FeMo-co synthesis by L127Delta NifH. The formation of a complex of L127Delta NifH with NifNE was investigated by gel filtration chromatography. We herein report the formation of a complex between L127Delta NifH and NifNE in the presence of NifB-co. This work presents evidence for one of the possible roles for NifH in FeMo-co biosynthesis, i.e. the interaction of NifH with a NifNE.NifB-co complex.


Subject(s)
Molybdoferredoxin/biosynthesis , Nitrogenase/metabolism , Oxidoreductases , Azotobacter vinelandii , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Dinitrogenase Reductase/metabolism , Iron Compounds/metabolism , Molybdoferredoxin/metabolism , Mutagenesis, Site-Directed , Nitrogenase/genetics , Protein Binding
12.
Qual Life Res ; 8(4): 311-7, 1999 Jun.
Article in English | MEDLINE | ID: mdl-10472163

ABSTRACT

The underlying factor structure of a subset of 12 items, which comprise the psychosocial subscales of the EORTC QLQ-C30 was explored in a group of women, all with metastatic breast cancer who were participating in a psychosocial intervention study. Two main factors were identified in this exploratory factor analysis, representing "emotional distress" and "functional ability" dimensions. A preliminary assessment of the external validity of the two factor structure was undertaken. The results support the validity of a summative "emotional distress" and "functional ability" score in this sample of patients. The "functional ability" score discriminated well for subgroups defined by clinical status indicators (e.g., performance status, pain, chemotherapy treatment, fatigue). The "emotional distress" subscale discriminated with respect to suffering, fatigue and sleep disturbance. Both subscales converged with related concepts measured by independent instruments, providing support for convergent validity. Summative index scores may be advantageous for application in particular research situations; applying quality adjustments in health policy analyses; for screening purposes; to monitor populations and make comparisons across broad groups and as stratification variables in clinical trials. Further research to confirm the 2 factor structure is required in other samples before the interpretation can be accepted with confidence.


Subject(s)
Breast Neoplasms/psychology , Psychometrics , Quality of Life , Surveys and Questionnaires , Adult , Aged , Canada , Factor Analysis, Statistical , Female , Humans , Middle Aged , Neoplasm Metastasis , Reproducibility of Results
13.
J Clin Oncol ; 17(1): 120-9, 1999 Jan.
Article in English | MEDLINE | ID: mdl-10458225

ABSTRACT

PURPOSE: Weight gain is common during the first year after breast cancer diagnosis. In this study, we examined clinical factors associated with body size at diagnosis and weight gain during the subsequent year. PATIENTS AND METHODS: An inception cohort of 535 women with newly diagnosed locoregional breast cancer underwent anthropometric measurements at baseline and 1 year. Information was collected on tumor- and treatment-related variables, as well as diet and physical activity. RESULTS: Mean age was 50.3 years; 57% of women were premenopausal. Mean baseline body mass index (weight [kg] divided by height [m] squared) was 25.5 kg/m2. Overall, 84.1% of the patients gained weight. Mean weight gain was 1.6 kg (95% confidence interval, 1.2 to 1.9 kg), 2.5 kg (95% confidence interval, 1.8 to 3.2 kg) in those receiving chemotherapy, 1.3 kg (95% confidence interval, 0.7 to 1.8 kg) in those receiving tamoxifen only, and 0.6 kg (95% confidence interval, 0.01 to 1.3 kg) in those receiving no adjuvant treatment. Menopausal status at diagnosis (P = .02), change in menopausal status over the subsequent year (P = .002), axillary nodal status (P = .009), and adjuvant treatment (P = .0002) predicted weight gain in univariate analysis. In multivariate analysis, onset of menopause and administration of chemotherapy were independent predictors of weight gain (all P < or = .05). Caloric intake decreased (P < .01) and physical activity increased (P < .05) during the year after diagnosis; these factors did not explain the observed weight gain. CONCLUSION: Weight gain is common after breast cancer diagnosis; use of adjuvant chemotherapy and onset of menopause are the strongest clinical predictors of this weight gain.


Subject(s)
Breast Neoplasms/therapy , Chemotherapy, Adjuvant , Menopause , Weight Gain , Age of Onset , Anthropometry , Body Mass Index , Breast Neoplasms/surgery , Energy Intake , Exercise , Female , Humans , Lymphatic Metastasis , Middle Aged , Multivariate Analysis
14.
J Clin Epidemiol ; 52(7): 653-66, 1999 Jul.
Article in English | MEDLINE | ID: mdl-10391659

ABSTRACT

The Prostate Cancer Specific Quality of Life Instrument (PROSQOLI) is a measure of health-related quality of life (HRQL) that was designed to be an outcome measure for clinical trials in advanced hormone-resistant prostate cancer. The cross-sectional validity of the PROSQOLI was assessed using baseline data from a randomized trial in which HRQL was also assessed with the European Organisation for Research and Treatment of Cancer (EORTC) Core Quality of Life Questionnaire (QLQ-C30) and a trial-specific quality of life module (QLM-P14). Convergent validity was assessed with the multitrait-multimethod matrix approach; discriminative validity was assessed according to conventional clinical criteria; and predictive validity was assessed by the ability to predict survival duration. These assessments provided strong support for the validity of all PROSQOLI scales except those for family/marriage relationships and passing urine; modifications of these two scales are under evaluation. The strength, consistency, and independence of the prognostic information provided by the HRQL scales were striking. Differences between the instruments were generally subtle. These data support validity of the PROSQOLI and the analogous scales from the QLQ-C30 and QLM-P14 in symptomatic men with advanced hormone resistant prostate cancer. The PROSQOLI is a short, simple, and valid measure of HRQL in this setting.


Subject(s)
Antineoplastic Agents/therapeutic use , Mitoxantrone/therapeutic use , Prostatic Neoplasms/drug therapy , Quality of Life , Analysis of Variance , Antineoplastic Agents, Hormonal/therapeutic use , Bone Neoplasms/secondary , Cross-Sectional Studies , Discriminant Analysis , Humans , Linear Models , Male , Middle Aged , Pain Measurement , Prednisone/therapeutic use , Prostatic Neoplasms/classification , Prostatic Neoplasms/psychology , Randomized Controlled Trials as Topic , Reproducibility of Results , Sickness Impact Profile , Surveys and Questionnaires
16.
J Natl Cancer Inst ; 91(5): 469-73, 1999 Mar 03.
Article in English | MEDLINE | ID: mdl-10070948

ABSTRACT

BACKGROUND: Breast carcinomas occurring in carriers of BRCA1 gene mutations may have a distinctly different pathway of molecular pathogenesis from those occurring in noncarriers. Data from murine models implicate loss of p53 (also known as TP53) gene function as a critical early event in the malignant transformation of cells with a BRCA1 mutation. Therefore, breast tumors from BRCA1 mutation carriers might be expected to exhibit a high frequency of p53 mutations. This study examined the frequency of p53 mutations in the breast tumors of Ashkenazi Jewish carriers and noncarriers of BRCA1 mutations. METHODS: Tumor DNA from carriers and noncarriers of BRCA1 mutations was screened for mutations in exons 4 through 10 of the p53 gene by use of the polymerase chain reaction and single-strand conformation polymorphism (SSCP) analysis of the amplified DNA. Direct sequencing was performed on gene fragments that showed altered mobility in SSCP analysis. RESULTS: Mutations in the p53 gene were detected in 10 of 13 tumors from BRCA1 mutation carriers versus 10 of 33 tumors from non-carriers (two-sided P = .007). The p53 mutations were distributed throughout exons 4 through 10 and included both protein-truncating and missense mutations in both groups. CONCLUSIONS: A statistically significantly higher frequency of p53 mutations was found in breast tumors from carriers of BRCA1 mutations than from noncarriers, which adds to the accumulating evidence that loss of p53 function is an important step in the molecular pathogenesis of BRCA1 mutation-associated breast tumors. This finding may have implications for understanding phenotypic differences and potential prognostic differences between BRCA1 mutation-associated hereditary breast cancers and sporadic cancers.


Subject(s)
Breast Neoplasms/ethnology , Breast Neoplasms/genetics , Genes, BRCA1/genetics , Genes, p53/genetics , Heterozygote , Jews/genetics , Mutation , Tumor Suppressor Protein p53/genetics , Adult , DNA, Neoplasm/genetics , Female , Humans , Middle Aged , Polymerase Chain Reaction , Polymorphism, Single-Stranded Conformational
17.
Aust Vet J ; 77(12): 804-8, 1999 Dec.
Article in English | MEDLINE | ID: mdl-10685183

ABSTRACT

OBJECTIVE: To investigate the extent of heat load problems, caused by the combination of excessive temperature and humidity, in Holstein-Friesian cows in Australia. Also, to outline how milk production losses and consequent costs from this can be estimated and minimised. PROCEDURES: Long-term meteorological data for Australia were analysed to determine the distribution of hot conditions over space and time. Fifteen dairy production regions were identified for higher-resolution data analysis. Both the raw meteorological data and their integration into a temperature-humidity thermal index were compiled onto a computer program. This mapping software displays the distribution of climatic patterns, both Australia-wide and within the selected dairying regions. Graphical displays of the variation in historical records for 200 locations in the 15 dairying regions are also available. As a separate study, production data from research stations, on-farm trials and milk factory records were statistically analysed and correlated with the climatic indices, to estimate production losses due to hot conditions. RESULTS: Both milk yields and milk constituents declined with increases in the temperature-humidity index. The onset and rate of this decline are dependent on a number of factors, including location, level of production, adaptation, and management regime. These results have been integrated into a farm-level economic analysis for managers of dairy properties. CONCLUSION: By considering the historical patterns of hot conditions over time and space, along with expected production losses, managers of dairy farms can now conduct an economic evaluation of investment strategies to alleviate heat loads. These strategies include the provision of sprinklers, shade structures, or combinations of these.


Subject(s)
Cattle Diseases/physiopathology , Climate , Dairying/economics , Heat Stress Disorders/veterinary , Lactation/physiology , Animals , Australia , Cattle , Female , Heat Stress Disorders/physiopathology , Humidity , Meteorological Concepts , Temperature
18.
J Clin Oncol ; 16(12): 3900-12, 1998 Dec.
Article in English | MEDLINE | ID: mdl-9850036

ABSTRACT

PURPOSE: Lung cancer is a major source of morbidity, mortality, and health care costs in the developed and developing world. It is estimated that lung cancer is responsible for 20% of all cancer care costs. Concerns exist that this expenditure is associated with questionable benefits. DESIGN: The economic literature that relates to smoking was reviewed, followed by a summary of the economics of the diagnosis, treatment, and palliation of lung cancer. Methodologic considerations are also discussed in this section. RESULTS: Published studies suggest that the increased lifetime health care costs from smoking-related illnesses in smokers are partially or fully offset by the higher medical costs that result from increased longevity in nonsmokers. However, lost productivity costs, which result from morbidity and early mortality among smokers, result in an overall net cost of smoking to society. Discounting rates of 3% to 5% do not substantively alter these results. The per-patient cost to treat lung cancer is substantial. The major cost center is hospitalization; palliative or terminal treatment is associated with significant costs. Savings can be obtained through the judicious use of diagnostic and staging procedures. Furthermore, combined modality treatment approaches and the palliative use of combination chemotherapy appear to be associated with acceptable cost-effectiveness compared with commonly used therapies for other diseases. CONCLUSION: Although the increased medical care costs of treating smoking-related diseases are somewhat offset by the higher medical care costs due to increased longevity in nonsmokers, the lost productivity that results from smoking results in a net cost to society. Standard approaches to the management of lung cancer are associated with cost-effectiveness similar to that of other commonly used medical interventions.


Subject(s)
Health Care Costs , Lung Neoplasms/economics , Smoking/adverse effects , Canada , Combined Modality Therapy/economics , Cost-Benefit Analysis , Humans , Lung Neoplasms/etiology , Lung Neoplasms/therapy , Palliative Care/economics
19.
Am J Obstet Gynecol ; 179(2): 430-7, 1998 Aug.
Article in English | MEDLINE | ID: mdl-9731849

ABSTRACT

OBJECTIVE: This study was designed to examine the contribution of plasma lipids to the pathophysiology of cyclic mastopathy, before and after consideration of diet and sex hormones. STUDY DESIGN: Thirty-four women with severe cyclic mastopathy (case patients) and 29 women without cyclic mastopathy (control subjects) recorded their breast symptoms daily during 1 menstrual cycle. During each menstrual phase (follicular, early luteal, late luteal, and menstrual) they prospectively completed 2 24-hour dietary diaries, provided blood for lipid and hormone assays, and underwent anthropometric measurements. RESULTS: Mean age was 34 years. Premenstrual breast swelling and tenderness were significantly more severe in case patients (P < .0001). Cyclic change (late luteal vs follicular) of high-density lipoprotein cholesterol differed between case patients and control subjects, with case patients having a relative excess of high-density lipoprotein cholesterol in the premenstrual phase (P = .01). Dietary fat intake was greater throughout the cycle in case patients (37.5 vs 33.7% of calories, P = .02), and case patients reported increased appetite in the premenstrual phase (P = .01). In multivariate analyses the contributions of mean dietary fat intake and of cyclic change in high-density lipoprotein cholesterol were independently significant, with odds ratios for upper versus lower quintiles being slightly >5. CONCLUSIONS: Women with cyclic mastopathy had a relative excess of high-density lipoprotein cholesterol during the symptomatic late luteal phase of the menstrual cycle and a higher fat intake throughout the cycle than did control subjects. These observations support the hypothesis that lipids (notably high-density lipoprotein cholesterol) and a high-fat diet play a role in the pathophysiologic characteristics of cyclic mastopathy.


Subject(s)
Breast Diseases/etiology , Cholesterol, HDL/blood , Dietary Fats/administration & dosage , Pain/etiology , Adult , Case-Control Studies , Female , Humans , Multivariate Analysis , Progesterone/blood
20.
Biochemistry ; 37(36): 12611-23, 1998 Sep 08.
Article in English | MEDLINE | ID: mdl-9730834

ABSTRACT

A Zn-immobilized metal-affinity chromatography technique was used to purify a poly-histidine-tagged, FeMo-cofactorless MoFe protein (apo-MoFe protein) from a nifB-deletion mutant of Azotobacter vinelandii. Apo-MoFe protein prepared in this way was obtained in sufficient concentrations for detailed catalytic, kinetic, and spectroscopic analyses. Metal analysis and electron paramagnetic resonance spectroscopy (EPR) were used to show that the apo-MoFe protein does not contain FeMo-cofactor. The EPR of the as-isolated apo-MoFe protein is featureless except for a minor S = 1/2 signal probably arising from the presence of either a damaged P cluster or a P cluster precursor. The apo-MoFe protein has an alpha2beta2 subunit composition and can be activated to 80% of the theoretical MoFe protein value by the addition of isolated FeMo-cofactor. Oxidation of the as-isolated apo-MoFe protein by indigodisulfonate was used to elicit the parallel mode EPR signal indicative of the two-electron oxidized form of the P cluster (P2+). The midpoint potential of the PN/P2+ redox couple for the apo-MoFe protein was shown to be shifted by -63 mV when compared to the same redox couple for the intact MoFe protein. Although the apo-MoFe protein is not able to catalyze the reduction of substrates under turnover conditions, it does support the hydrolysis of MgATP at 60% of the rate supported by the MoFe protein when incubated in the presence of Fe protein. The ability of the apo-MoFe protein to specifically interact with the Fe protein was also shown by stopped-flow techniques and by formation of an apo-MoFe protein-Fe protein complex. Finally, the two-electron oxidized form of the apo-MoFe protein could be reduced to the one-electron oxidized form (P1+) in a reaction that required Fe protein and MgATP. These results are interpreted to indicate that the apo-MoFe protein produced in a nifB-deficient genetic background [corrected] contains intact P clusters and P cluster polypeptide environments. Small changes in the electronic properties of P clusters contained within the apo-MoFe protein are most likely caused by slight perturbations in their polypeptide environments.


Subject(s)
Apoproteins/metabolism , Azotobacter vinelandii/enzymology , Bacterial Proteins/genetics , Gene Deletion , Molybdoferredoxin/metabolism , Nitrogenase/metabolism , Alkylation , Apoproteins/biosynthesis , Apoproteins/genetics , Azotobacter vinelandii/genetics , Catalysis , Chromatography, Affinity , Electron Spin Resonance Spectroscopy , Electron Transport , Histidine/metabolism , Molybdoferredoxin/biosynthesis , Molybdoferredoxin/genetics , Mutagenesis, Insertional , Nitrogenase/chemistry , Peptides/metabolism , Spectrophotometry, Ultraviolet
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