Variations in breast carcinoma treatment in older medicare beneficiaries: is it black or white

BACKGROUND

To evaluate associations between race and breast carcinoma treatment.

METHODS

Data from 984 black and 849 white Medicare beneficiaries 67 years or older with local breast carcinoma and a subset of 732 surviving women interviewed 3-4 years posttreatment were used to calculate adjusted odds of treatment, controlling for age, comorbidity, attitudes, region, and area measures of socioeconomic and health care resources.

RESULTS

Sixty-seven percent of women received a mastectomy and 33% received breast-conserving surgery. The odds of radiation omission were 48% higher (95% confidence interval [CI] 1.01-2.19) for blacks than for whites after considering covariates, but the absolute number of women who failed to receive this modality was small (11%). In race-stratified models, the odds of having radiation omitted were significantly higher among blacks living greater distances from a cancer center (vs. lesser) or living in areas with high poverty (vs. low), but these factors did not affect radiation use among whites. Among those interviewed, blacks reported perceiving more ageism and racism in the health care system than whites (P = 0.001). The independent odds of receiving mastectomy (vs. breast conservation and radiation) were 2.72 times higher (95% CI 1.25-5.92) among women reporting the highest quartile of perceived ageism scores, compared with the lowest, and higher perceived ageism tended to be associated with higher odds of radiation omission (P = 0.06).

CONCLUSIONS

Older black women with localized breast carcinoma may have a different experience obtaining treatment than their white counterparts. The absolute number of women receiving nonstandard care was small and the effects were small to moderate. However, if these patterns persist, it will be important to evaluate whether such experiences contribute to within-stage race mortality disparities.

Breast Cancer Treatment in Older Women: Does Getting What You Want Improve Your Long-Term Body Image and Mental Health?

Purpose

Little is known about the impact of surgical treatment on body image and health outcomes in older breast cancer patients. The purpose of this article is to evaluate whether concordance between treatment received and treatment preferences predicts posttreatment body image and whether body image, in turn, affects mental health in older women with breast cancer 2 years after treatment.

Patients and Methods

A longitudinal cohort of 563 women who were 67 years old or older and who had stages I and II breast cancer were surveyed by telephone at 3, 12, and 24 months after surgery. All women were clinically eligible for breast conservation. Body image was measured using questions adapted from the Cancer Rehabilitation Evaluation System–Short Form, and mental health was evaluated using a Medical Outcomes Study subscale.

Results

Body image was an important factor in treatment decisions for 31% of women. Women who received breast conservation had better body image 2 years after treatment than women who had mastectomies (P < .0001). Women who preferred breast conservation but received mastectomy had the poorest body image. Using generalized estimating equations, we found that body image, in turn, predicted 2-year mental health.

Conclusion

Body image is important for many older women, and receiving treatment consistent with preferences about appearance was important in long-term mental health outcomes. Health professionals should elicit preferences about appearance from women and provide treatment choices in concordance with these preferences. Enhancing shared decision making has the potential to improve mental health in older breast cancer survivors.

Predictors of long-term outcomes in older breast cancer survivors: perceptions versus patterns of care

PURPOSE

There are few data on sequelae of breast cancer treatments in older women. We evaluated posttreatment quality of life and satisfaction in a national population.

PATIENTS AND METHODS

Telephone surveys were conducted with a random cross-sectional sample of 1,812 Medicare beneficiaries 67 years of age and older who were 3, 4, and 5 years posttreatment for stage I and II breast cancer. Regression models were used to estimate the adjusted risk of decrements in physical and mental health functioning by treatment. In a subset of women (n = 732), additional data were used to examine arm problems, impact of cancer, and satisfaction, controlling for baseline health, perceptions of ageism and racism, demographic and clinical factors, region, and surgery year.

RESULTS

Use of axillary dissection was the only surgical treatment that affected outcomes, increasing the risk of arm problems four-fold (95% confidence interval, 1.56 to 10.51), controlling for other factors. Having arm problems, in turn, exerted a consistently negative independent effect on all outcomes (P </=.001). Processes of care were also associated with quality of life and satisfaction. For example, women who perceived high levels of ageism or felt that they had no choice of treatment reported significantly more bodily pain, lower mental health scores, and less general satisfaction. These same factors, as well as high perceived racism, were significantly associated with diminished satisfaction with the medical care system.

CONCLUSION

With the exception of axillary dissection, the processes of care, and not the therapy itself, are the most important determinants of long-term quality of life in older women.

Communication between physicians and older women with localized breast cancer: implications for treatment and patient satisfaction

PURPOSE

To identify factors associated with patient-physician communication and to examine the impact of communication on patients' perception of having a treatment choice, actual treatment received, and satisfaction with care among older breast cancer patients.

MATERIALS AND METHODS

Data were collected from 613 pairs of surgeons and their older (greater-than-or-equal 67 years) patients diagnosed with localized breast cancer. Measures of patients' self-reported communication included physician- and patient-initiated communication and the number of treatment options discussed. Logistic regression analyses were conducted to examine the relationships between communication and outcomes.

RESULTS

Patients who reported that their surgeons mentioned more treatment options were 2.21 times (95% confidence interval [CI], 1.62 to 3.01) more likely to report being given a treatment choice, and 1.33 times (95% CI, 1.02 to 1.73) more likely to get breast-conserving surgery with radiation than other types of treatment. Surgeons who were trained in surgical oncology, or who treated a high volume of breast cancer patients (greater-than-or-equal 75% of practice), were more likely to initiate communication with patients (odds ratio [OR] = 1.62; 95% CI, 1.02 to 2.56; and OR = 1.68; 95% CI, 1.01 to 2.76, respectively). A high degree of physician-initiated communication, in turn, was associated with patients' perception of having a treatment choice (OR = 2.46; 95% CI, 1.29 to 4.70), and satisfaction with breast cancer care (OR = 2.13; 95% CI, 1.17 to 3.85) in the 3 to 6 months after surgery.

CONCLUSION

Greater patient-physician communication was associated with a sense of choice, actual treatment, and satisfaction with care. Technical information and caring components of communication impacted outcomes differently. Thus, the quality of cancer care for older breast cancer patients may be improved through interventions that improve communication within the physician-patient dyad.

Physician's case volume of intensive care unit pneumonia admissions and in-hospital mortality

RATIONALE

Although several studies have investigated volume-outcome relationships for surgical procedures, there has been no such study of intensive care unit (ICU) patients admitted for pneumonia.

OBJECTIVES

This study examines associations between in-hospital mortality of ICU-admitted pneumonia patients and their attending physician's case volume.

METHODS

We used 2002-2004 claims data from Taiwan's National Health Insurance for all 87,479 adult ICU admissions for pneumonia. Patients were assigned to one of four groups, on the basis of their physician's ICU pneumonia case volume (low volume, <36 cases; medium volume, 37-114 cases; high volume, 118-314 cases; and very high volume, > or =315 cases). Generalized estimating equations (conditional on hospital, and unconditional) were used, adjusting for physician demographics and specialty, hospital characteristics, patient characteristics (including clinical severity and comorbidities), and physician-level random effect (clustering effect) to assess whether physicians' case volume predicts in-hospital mortality.

MEASUREMENTS AND MAIN RESULTS

In-hospital mortality systematically declined with increasing physician case volume: 14.7, 14.3, 11.4, and 8.1% from low-volume to very-high-volume groups. Adjusted unconditional odds of mortality among low-volume physicians' patients were 2.04 times those of very-high-volume physicians, 1.35 times that of high-volume physicians, and 1.09 times those of medium-volume physicians (all P < 0.001). The relationship is sustained when the odds are estimated conditional on hospital, when initial 5-day mortality is separated from 30-day mortality, and when pulmonologists' and critical care specialists' patients are studied separately.

CONCLUSIONS

Physician volume significantly predicts inpatient mortality among ICU patients with pneumonia. Detailed study of clinical approaches, decision algorithms, and treatment plans of high-volume physicians is recommended to identify possible mediating factors in this phenomenon.

Effects of mutations in the Exo III motif of the herpes simplex virus DNA polymerase gene on enzyme activities, viral replication, and replication fidelity

The herpes simplex virus DNA polymerase catalytic subunit, which has intrinsic polymerase and 3'-5' exonuclease activities, contains sequence motifs that are homologous to those important for 3'-5' exonuclease activity in other polymerases. The role of one such motif, Exo III, was examined in this study. Mutated polymerases containing either a single tyrosine-to-histidine change at residue 577 or this change plus an aspartic acid-to-alanine at residue 581 in the Exo III motif exhibited defective or undetectable exonuclease activity, respectively, yet retained substantial polymerase activity. Despite the defects in exonuclease activity, the mutant polymerases were able to support viral replication in transient complementation assays, albeit inefficiently. Viruses replicated via the action of these mutant polymerases exhibited substantially increased frequencies of mutants resistant to ganciclovir. Furthermore, when the Exo III mutations were incorporated into the viral genome, the resulting mutant viruses displayed only modestly defect in replication in Vero cells and exhibited substantially increased mutation frequencies. The results suggest that herpes simplex virus can replicate despite severely impaired exonuclease activity and that the 3'-5' exonuclease contributes substantially to the fidelity of viral DNA replication.

Measuring and predicting surgeons' practice styles for breast cancer treatment in older women

BACKGROUND

Few measures exist to assess physicians' practice style, and there are few data on physicians' practice styles and patterns of care.

OBJECTIVES

To use clinical vignettes to measure surgeons' "propensity" for local treatments for early-stage breast cancer and to describe factors associated with propensity.

RESEARCH DESIGN AND SUBJECTS

A cross-sectional mailed survey with telephone follow-up of a random sample of 1,000 surgeons treating Medicare beneficiaries in fee-for-service settings.

MEASURES

Outcome measures include treatment propensity, self-reported practice, and actual treatment received by the surgeons' patients.

RESULTS

Propensities were significantly associated with actual treatment, controlling for covariates. Area Medicare fees were the strongest predictor of propensity, followed by region, attitudes, volume, and gender. For instance, after other factors were considered, surgeons practicing in areas with the highest breast-conserving surgery (BCS) fees were 8.61 (95% CI 2.26-32.73) times more likely to have a BCS propensity than surgeons in areas with the lowest fees. Surgeons with the strongest beliefs in patient participation in treatment decisions were nearly 6 times (95% CI 1.67-20.84) more likely to have a BCS propensity than surgeons with the lowest such beliefs, controlling for covariates. Male surgeons were also independently more likely to have a mastectomy propensity than female surgeons.

CONCLUSIONS

Surgeons' propensities explain some of the observed variations in breast cancer treatment patterns among older women. Standardized scenarios provide a practical method to measure practice style and could be used to evaluate physician contributions to shared decision making, practice patterns, costs and outcomes, and adherence to guidelines.

An increased risk of stroke among young schizophrenia patients

OBJECTIVE

This study sets out to estimate the risk of stroke developing among young schizophrenia patients during a five-year follow-up period after hospitalization for episodes of acute exacerbation.

METHODS

Hospitalized schizophrenia patients under 45 years of age were identified from the Taiwan National Health Insurance Research Database for the year 1998 (n=5001). Two age-matched cases were randomly selected for each schizophrenia patient from among patients who underwent appendectomies in the same year (n=10,002). Each individual patient was retrospectively followed up from 1998 until the end of 2003 to determine whether any had developed strokes. Cox proportional hazard regressions were carried out to compute the adjusted five-year survival rate.

RESULTS

A total of 219 patients (1.46%) developed strokes during the five-year follow-up period, with the attacks occurring among 2.46% of schizophrenia patients and 0.94% of the comparison cohort. Following adjustment for patients' demographic characteristics, select comorbid medical disorders and substance abuse, schizophrenia patients were found to be 2.02 times (p<0.001) more likely to develop strokes during the follow-up period than age-matched appendectomy patients. The adjusted hazard ratios of developing stroke for male and female schizophrenia patients were, respectively, 1.64 (p<0.001) and 2.87 (p<0.001) times greater than their counterparts in the comparison group.

CONCLUSIONS

As compared with the comparison group, young schizophrenia patients demonstrated a two-fold increased risk of developing stroke during the five-year period after hospitalization. The risk of developing stroke among schizophrenia patients was found to be much higher for females than males.

Chronic hepatitis C without anti-hepatitis C antibodies by second-generation assay. A clinicopathologic study and demonstration of the usefulness of a third-generation assay

To study the clinicopathologic features of hepatitis C viremic patients negative for hepatitis C antibodies (anti-HCV) by current second-generation assay, we categorized 139 consecutive histologically verified patients with chronic non-A, non-B hepatitis into three groups: 121 (87%) were positive for second-generation anti-HCV (group A); 10 (7%) were negative for second-generation anti-HCV but positive for HCV RNA (group B); and 8 (6%) were negative for both antibodies and viremia (group C). Six (60%) of group B patients could be, further detected by a new third-generation assay, but none of group C patients was third-generation anti-HCV-positive. The demographic features, mean peak serum alanine aminotransferase levels, HCV genotype distribution, and histologic changes were comparable among the three groups. The study indicates that most patients with chronic hepatitis C in Taiwan could be identified by current second-generation assay, and viremic but antibody seronegative patients were clinicopathologically similar to the seropositives. Most patients of the latter group could be diagnosed by a third-generation assay, indicating the usefulness of this assay.

The association between total serum isomers of per- and polyfluoroalkyl substances, lipid profiles, and the DNA oxidative/nitrative stress biomarkers in middle-aged Taiwanese adults

Per- and polyfluoroalkyl substances (PFAS) have been widely used in consumer products. In vitro and animal studies have demonstrated that exposure to perfluorooctanoic acid (PFOA) and/or perfluorooctane sulfonate (PFOS) increases oxidative/nitrative stress. Recent studies have also found that isomers of PFOA/PFOS may have unique biological effects on clinical parameters. However, the correlation between PFOA/PFOS isomers and markers of oxidative/nitrative stress has never been investigated in the general population. In the current study, 597 adult subjects (ages between 22 and 63 years old) were enrolled from a control group of a case-control study entitled "Work-related risk factors and coronary heart disease". We investigated the correlation between the serum isomers of PFOA/PFOS, lipid profiles, and the urine compounds 8-hydroxy-2-deoxyguanosine (8-OHdG) and 8-nitroguanine (8-NO2Gua) in these participants. There were 519 men and 78 women with a mean age of 45.8 years. Linear PFOA levels were positively correlated with serum low density lipoprotein cholesterol (LDL-C), small dense LDL, and triglyceride, and linear PFOS levels were positively correlated with LDL-C and HDL-C in multiple linear regression analyses. After controlling for potential confounders, the mean levels of 8-OHdG and 8-NO2Gua significantly increased across the quartiles of linear PFOS in multiple linear regression analyses. When both the 8-OHdG and 8-NO2Gua levels were above the 50th percentile, the odds ratio (OR) of higher levels of LDL-C (>75th percentile) with one unit increase in ln linear PFOS level was the highest (OR 3.15 (95% CI = 1.45-6.64), P = 0.003) in logistic regression models. In conclusion, serum linear PFOA/PFOS were correlated with lipid profiles, and linear PFOS was associated with urine oxidative/nitrative stress biomarkers. The positive correlation between linear PFOS and LDL-C was more marked when concentrations of urine oxidative/nitrative stress biomarkers were elevated. Further studies are needed to elucidate the causal relationships among PFAS isomers, lipid profiles, and oxidative/nitrative stress.

Economic evaluation of breast cancer treatment: considering the value of patient choice

PURPOSE

To use 5 years of primary data to compare the incremental cost-effectiveness of breast conservation and radiation versus mastectomy with the restriction of choice to a single therapy versus providing a choice of either therapy.

PATIENTS AND METHODS

We evaluated a random retrospective cohort of 2,517 Medicare beneficiaries treated for newly diagnosed stage I or II breast cancer from 1992 through 1994. The outcome measures were quality-adjusted life-years (QALYs) and 5-year medical costs. Risk and propensity score adjustments were used in the analysis.

RESULTS

A breast conservation and radiation regimen has significantly higher costs than mastectomy in the first year after surgery; the adjusted 5-year costs are $14,054 (95% confidence interval, $9,791 to $18,312) greater than those of mastectomy. The adjusted incremental cost-effectiveness ratio comparing breast conservation and radiation to mastectomy was $219,594 per QALY for the comparison of the two strategies. If the possibility of patient choice from maintaining the availability of multiple treatments versus restricting choice to mastectomy alone provides a quality-of-life gain of 0.031 QALYs, then the cost-effectiveness ratio of this choice option is $80,440 per QALY.

CONCLUSION

The current system of providing a choice between mastectomy and breast conservation surgery is economically attractive when the economic analysis includes the benefit of patient choice of treatment.

Sequelae of axillary lymph node dissection in older women with stage 1 and 2 breast carcinoma

BACKGROUND

There are few data on the long-term sequelae of axillary dissection among older breast carcinoma patients. We describe the impact of axillary dissection in a cohort of older women.

METHODS

A longitudinal cohort of 571 patients with Stage 1 and 2 breast carcinoma, 67 years and older, diagnosed between 1995 and 1997 from 29 hospitals in five regions, and followed for 2 years. Data were collected from patients and medical charts. The primary outcome was posttreatment quality of life. Generalized estimation equation longitudinal modeling was used to evaluate the outcome, controlling for baseline function, comorbidity, age, clinical status, and other factors.

RESULTS

Sixty percent of women reported arm problems at some time in the 2 years after surgery. The cumulative risk of having arm problems 2 years posttreatment was three times higher (95% confidence interval 1.94-4.67) for women who underwent axillary surgery compared with women without axillary surgery, controlling for covariates. The effects of having axillary dissection and arthritis were multiplicative 2 years postsurgery. Arm problems were, in turn, the primary determinate of lower physical and mental functioning (P = 0.0001 and 0.04, respectively), controlling for other factors. Undergoing axillary dissection did not lessen fears about recurrence.

CONCLUSIONS

Arm problems after axillary dissection have a consistent negative impact on quality of life, suggesting that the risks may outweigh the potential benefits in this population.

An exploratory instrumental variable analysis of the outcomes of localized breast cancer treatments in a medicare population

This study is motivated by the potential problem of using observational data to draw inferences about treatment outcomes when experimental data are not available. We compare two statistical approaches, ordinary least-squares (OLS) and instrumental variables (IV) regression analysis, to estimate the outcomes (three-year post-treatment survival) of three treatments for early stage breast cancer in elderly women: mastectomy (MST), breast conserving surgery with radiation therapy (BCSRT), and breast conserving surgery only (BCSO). The primary data source was Medicare claims for a national random sample of 2907 women (age 67 or older) with localized breast cancer who were treated between 1992 and 1994. Contrary to randomized clinical trial (RCT) results, analysis with the observational data found highly significant differences in survival among the three treatment alternatives: 79.2% survival for BCSO, 85.3% for MST, and 93.0% for BCSRT. Using OLS to control for the effects of observable characteristics narrowed the estimated survival rate differences, which remained statistically significant. In contrast, the IV analysis estimated survival rate differences that were not significantly different from 0. However, the IV-point estimates of the treatment effects were quantitatively larger than the OLS estimates, unstable, and not significantly different from the OLS results. In addition, both sets of estimates were in the same quantitative range as the RCT results.We conclude that unadjusted observational data on health outcomes of alternative treatments for localized breast cancer should not be used for cost-effectiveness studies. Our comparisons suggest that whether one places greater confidence in the OLS or the IV results depends on at least three factors: (1) the extent of observable health information that can be used as controls in OLS estimation, (2) the outcomes of statistical tests of the validity of the instrumental variable method, and (3) the similarity of the OLS and IV estimates. In this particular analysis, the OLS estimates appear to be preferable because of the instability of the IV estimates.

Left atrial emptying fraction predicts recurrence of atrial fibrillation after radiofrequency catheter ablation

Background

Compared with left atrial (LA) dimension, LA emptying fraction (LAEF) has received less emphasis as a predictor of atrial fibrillation (AF) recurrence after radiofrequency catheter ablation (RFCA). In addition, patients experiencing post-RFCA AF recurrence may respond to previously ineffective antiarrhythmic drugs (AADs). Classifying these patients into a third RFCA outcome category is recommended.

Objective

To identify predictors of RFCA outcome classified into three categories, and to build proportional odds logistic regression models for clinical applicability to predict AF recurrence.

Methods

Data were retrospectively collected from 483 consecutive patients with drug-refractory AF undergoing RFCA (328 men; age 58.4 ± 11.5 years; 383 paroxysmal). Patients were classified into 3 groups based on the last RFCA outcome: group 1, free from AF without AADs; group 2, free from AF with AADs; and group 3, recurrence of AADs-refractory atrial tachyarrhythmia.

Results

After a mean follow-up duration of 64.5 ± 43.2 months and mean ablation procedure number of 1.37 ± 0.68, the RFCA outcome showed 76.0%, 9.5% and 14.5% of patients in groups 1, 2, and 3, respectively. In multivariate analysis, LAEF was the most stable and important predictor of AF recurrence, followed by body mass index, stroke, AF duration, mitral regurgitation, and LA linear ablation. For patients undergoing repeat RFCA, LAEF was the only independent predictor (cutoffs: 43% and 35% for groups 1 and 3, respectively).

Conclusion

LAEF provides optimal prognostic information regarding the risk stratification of AF patients undergoing RFCA.

Mutations in the Exo III motif of the herpes simplex virus DNA polymerase gene can confer altered drug sensitivities

Two herpes simplex virus mutants containing mutated residues within the conserved Exo III motif of the polymerase gene were previously shown to be defective in 3'-5' exonuclease activity and exhibited extremely high mutation frequencies. In this study, we have shown that these mutants also exhibited higher resistance to phosphonoacetic acid and sensitivity to aphidicolin and all nucleoside analogs tested, including acyclovir and gangciclovir, compared to wild-type virus. Marker transfer experiments and sequencing analyses demonstrated that these altered phenotypes were the result of mutations within the Exo III motif. The data indicate that, aside from leading to exonuclease deficiency, mutations in the Exo III motif may also affect interaction of nucleoside triphosphates with the catalytic sites of polymerase activity.

Acceptability of diagnostic tests for breast cancer

PURPOSE

To assess the acceptability of new non-invasive breast cancer diagnostic tests intended to triage women in need of biopsy.

METHODS

Women who had abnormal screening tests and had been recommended to have a biopsy were invited to receive digital mammography, magnetic resonance imaging (MRI), and nuclear medicine evaluation (Tc-99m-sestamibi scanning) before biopsy. Participants completed a questionnaire about satisfaction and acceptability of the procedures. Satisfaction measured women's overall and test-specific satisfaction. Acceptability was measured by self-reported discomfort, embarrassment and women's preference in terms of willingness to pay to avoid a biopsy.

RESULTS

Women were satisfied with all of the potential diagnostic triage procedures. Most found the tests more comfortable than a routine mammogram (47, 50, and 66% undergoing MRI, digital mammography, and sestamibi scanning, respectively). Women who provided a response to willingness to pay questions (N = 43) were willing to pay an average of 611 dollars to have a test instead of a biopsy, if the test was as accurate as biopsy. The willingness to pay significantly decreased to 308 dollars if the test only had 95% accuracy. Those who had prior benign breast disease were less willing to pay for a test with 95% accuracy than those without this history.

CONCLUSION

Instead of immediate biopsy after an abnormal screening, these results suggest that women would find non-invasive triage tests acceptable, or preferable to biopsy if they were equally accurate or nearly equally accurate as a biopsy. New technologies to diagnose breast cancer should focus on decreasing discomfort as well as increasing test accuracy.

Effects of exonuclease activity and nucleotide selectivity of the herpes simplex virus DNA polymerase on the fidelity of DNA replication in vivo

A mutagenesis system was developed for the in vivo study of the fidelity of DNA replication mediated by wild-type herpes simplex virus type 1 (HSV-1) strain KOS and its polymerase (Pol) mutant derivatives PAAr5, Y7, and YD12. The pHOS1 shuttle plasmid, which contained the SupF mutagenesis marker gene and the HSV oris sequence, was used for analysis of the mutation frequency and the mutation spectrum. All three Pol mutants induced significant increases in the mutation frequencies of the target gene, despite the fact that PAAr5 was previously shown to have an antimutator phenotype by the thymidine kinase mutagenesis assay (J. D. Hall, D. M. Coen, B. L. Fisher, M. Weisslitz, S. Randall, R. E. Almy, P. Gelep, and P. A. Schaffer, Virology 132:26-37, 1984; C. B. C. Hwang and J.-H. Chen, Gene 152:191-193, 1995). Altered spectra of mutated target genes induced by these three mutants were also observed. The relative frequencies of both deletion and complex mutations found in mutants induced by exonuclease-proficient Pols were significantly higher than those induced by exonuclease-deficient Pols. On the other hand, the exonuclease-deficient Pols induced significant increases in the frequency of base substitutions, which comprised predominantly G. C-to-T. A transversions, as well as mutations at additional hot spots. These results suggest that the HSV-1 DNA Pol can incorporate purine-purine or pyrimidine-pyrimidine mispaired bases which may be preferentially proofread by its intrinsic exonuclease activity. Furthermore, the effects of the sequence context of the target gene and the assay method should also be considered carefully in any analysis of replication fidelity.

Analysis of the immunodominant antigens of Corynebacterium pseudotuberculosis

Antibodies to seven antigens in a whole cell lysate of Corynebacterium pseudotuberculosis ranging in molecular mass from 22 to 120 kilodaltons (kDa) were present in sera of 40 sheep and goats infected with C. pseudotuberculosis. Three antigens of about 120, 68, and 31.5 kDa in size were consistently detected with sera from all animals and twenty-two sera had antibodies to 64, 43, 40, and 22 kDa antigens. None of these antigens were detected by sera from 160 sheep in a C. pseudotuberculosis-free research flock. An NaCl extract of C. pseudotuberculosis cells contained one major protein of about 31.5 kDa and four minor proteins of 68, 64, 43, and 22 kDa in molecular mass as shown by Coomassie Blue staining. Immunoblot analysis demonstrated that the three immunodominant antigens identified in the whole cell extract were contained in the NaCl extract. The 31.5-kDa protein was purified from the NaCl extract by fast-protein liquid chromatography gel filtration to near homogeneity. The purified 31.5-kDa protein showed phospholipase D activity as indicated by synergistic hemolysis with Rhodococcus equi factors and sphingomyelinase activity. The 31.5-kDa protein reacted with antibodies in serum from a sheep naturally infected with C. pseudotuberculosis. This serum also had phospholipase D neutralizing activity. On the basis of its molecular mass, biological activity, N-terminal amino acid sequence analysis, and immunoreactivity, the 31.5-kDa protein was identified as the phospholipase D exotoxin of C. pseudotuberculosis.

Effect of antioxidant activity and functional properties of Chingshey purple sweet potato fermented milk by Lactobacillus acidophilus, L. delbrueckii subsp. lactis, and L. gasseri strains

In this study, individual selected lactic acid bacteria strains Lactobacillus acidophilus (LA), L. delbrueckii subsp. lactis (LDL), and L. gasseri (LGA) were grown in Chingshey purple sweet potato (CPSP) substrate/media. CPSP is rich in anthocyanin, which possesses antioxidant activity and in vitro cell assay. The antioxidant ability and functional properties of the fermented milk were examined. High-performance liquid chromatographic (HPLC) method was used to analyze the free amino acid, organic acids, and anthocyanin content. Total phenolic compounds, scavenging effects of 1,1-diphenyl-2-picyl-hydrazyl (DPPH) radicals, and scavenging effects of superoxide anion radicals were determined to evaluate the antioxidant ability of the samples. The cell proliferation of the fermented PSP milk was evaluated by 3-(4,5-dimethyldiazol-2-yl)-2,5 diphenyl Tetrazolium Bromide (MTT) assay. The result indicated that the antioxidant ability of the fermented CPSP milk through LA, LDL, and LGA strains was significantly higher than CPSP. The main anthocyanins present in the samples are cyanidin and delphinidin. MTT assay has revealed that incubation with both PSP and fermented CPSP milk prevented the cell death of macrophage-like RAW264.7 cells. The potential health benefit of fermented PSP milk through LA, LDL, and LGA strains makes the further application of CPSP in health food highly worthwhile.

PRACTICAL APPLICATION

(1) In our study, we have employed the γ-aminobutyric acid (GABA), organic acid contents, total phenol content, anthocyanins content, DPPH, oxygen radical absorbance capacity, superoxide dismutase activity assay, and cytotoxicity assay to assess the functional properties of fermented CPSP milk by different lactic acid bacteria. (2) Our results have revealed that the fermented CPSP milk samples possess high GABA concentrations, organic acid contents, anthocyanins contents, and antioxidant activity. This will provide potential opportunity to develop different functional food products from fermented CPSP milk. (3) The potential health benefit of fermented CPSP milk makes the further application of CPSP in health food highly worthwhile.

Medicare breast surgery fees and treatment received by older women with localized breast cancer

OBJECTIVE

To determine whether area-level Medicare physician fees for mastectomy and breast conserving surgery were associated with treatment received by Medicare beneficiaries with localized breast cancer and to compare these results with an earlier analysis conducted using small areas (three-digit zip codes) as the unit of observation.

DATA SOURCE

Medicare claims and physician survey data for a national sample of elderly (aged 67 or older) Medicare beneficiaries with localized breast cancer treated in 1994 (unweighted n = 1,787).

STUDY DESIGN

Multinomial logistic regression analysis was used to estimate a model of treatment received as a function of Medicare fees, controlling for other area economic factors, patient demographic and clinical characteristics, physician experience, and region.

PRINCIPAL FINDINGS

In 1994, average Medicare fees (adjusted for the effects of modifiers and procedure mix) for mastectomy (MST) and breast conserving surgery (BCS) were 904 dollars and 305 dollars, respectively. Holding other fees and factors fixed, a 10 percent increase in the BCS fee increased the odds of breast conserving surgery with radiation therapy relative to mastectomy to 1.34 (p = 0.02), while a 10 percent decrease in the MST fee increased the odds of breast conserving surgery with radiation therapy to 1.86 (p < 0.01).

CONCLUSIONS

Among older women with localized breast cancer, financial incentives appear to influence the use of mastectomy and breast conserving surgery with radiation therapy. This finding is consistent with the hypothesis that physicians are responsive to financial incentives when the alternative procedures have clinically equivalent outcomes and the patient's clinical condition does not dominate the treatment choice. We also find that the fee effects derived from this analysis of individual data with more precise measurement of both diagnosis and treatment are qualitatively similar to the results of the small-area analysis. This suggests that the earlier study was not severely affected by ecological bias or other data limitations inherent in Medicare claims data.

Urinary heavy metals, DNA methylation, and subclinical atherosclerosis

PURPOSE

Lead (Pb) or cadmium (Cd) exposure has been linked to atherosclerosis. Co-exposure of these two heavy metals often occurs in humans. Recent evidence has indicated a crucial role of DNA methylation in atherosclerosis, while Pb or Cd exposure has also been shown to alter DNA methylation. However, it is still unknown whether DNA methylation plays a role in the pathological mechanism of these two heavy metals in atherosclerosis.

APPROACH AND RESULTS

We enrolled 738 participants (12-30 years) to investigate the association among concentrations of urine Pb or Cd, the 5mdC/dG value (a global DNA methylation marker) and the carotid intima-media thickness (CIMT). When each heavy metal was modeled separately, the results showed urine Pb and Cd concentrations were positively associated with the 5mdC/dG value and CIMT, respectively. When the two heavy metals were analyzed in the same model, urinary Pb concentrations were positively associated with the 5mdC/dG value and CIMT, while urinary Cd concentrations were only positively associated with the CIMT. When Pb and Cd are simultaneously considered in the same logistic regression model, the odds ratios (OR) of thicker CIMT (greater than 75th percentile) with one unit increase in ln-Pb level was 1.67 (95% C.I. = 1.17-2.46, P = 0.005) when levels of 5mdC/dG were above 50th percentile, which is higher than 5mdC/dG bellow the 50th percentile (OR = 1.50 (95% C.I. = 0.96-2.35), P = 0.076). In structural equation model (SEM), Pb or Cd levels are directly associated with CIMT. Moreover, Pb or Cd had an indirect association with CIMT through the 5mdC/dG. When we considered Pb and Cd together, Pb levels had a direct association with CIMT and an indirect association with CIMT through the 5mdC/dG value, while Cd only had a direct association with CIMT.

CONCLUSIONS

Our findings imply that Pb and Cd exposure might be associated with subclinical atherosclerosis, and global DNA methylation might mediate Pb-associated subclinical atherosclerosis in this young population. Future effort is necessary to elucidate the causal relationship.

The influence of renal dialysis and hip fracture sites on the 10-year mortality of elderly hip fracture patients: A nationwide population-based observational study

Hip fractures in older people requiring dialysis are associated with high mortality. Our study primarily aimed to evaluate the specific burden of dialysis on the mortality rate following hip fracture. The secondary aim was to clarify the effect of the fracture site on mortality. A retrospective cohort study was conducted using Taiwan's National Health Insurance Research Database to analyze nationwide health data regarding dialysis and non-dialysis patients ≥65 years who sustained a first fragility-related hip fracture during the period from 2001 to 2005. Each dialysis hip fracture patient was age- and sex-matched to 5 non-dialysis hip fracture patients to construct the matched cohort. Survival status of patients was followed-up until death or the end of 2011. Survival analyses using multivariate Cox proportional hazards models and the Kaplan-Meier estimator were performed to compare between-group survival and impact of hip fracture sites on mortality. A total of 61,346 hip fracture patients were included nationwide. Among them, 997 dialysis hip fracture patients were identified and matched to 4985 non-dialysis hip fracture patients. Mortality events were 155, 188, 464, and 103 in the dialysis group, and 314, 382, 1505, and 284 in the non-dialysis group, with adjusted hazard ratios (associated 95% confidence intervals) of 2.58 (2.13-3.13), 2.95 (2.48-3.51), 2.84 (2.55-3.15), and 2.39 (1.94-2.93) at 0 to 3 months, 3 months to 1 year, 1 to 6 years, and 6 to 10 years after the fracture, respectively. In the non-dialysis group, survival was consistently better for patients who sustained femoral neck fractures compared to trochanteric fractures (0-10 years' log-rank test, P < .001). In the dialysis group, survival of patients with femoral neck fractures was better than that of patients with trochanteric fractures only within the first 6 years post-fracture (0-6 years' log-rank, P < .001). Dialysis was a significant risk factor of mortality in geriatric hip fracture patients. Survival outcome was better for non-dialysis patients with femoral neck fractures compared to those with trochanteric fractures throughout 10 years. However, the survival advantage of femoral neck fractures was limited to the first 6 years postinjury among dialysis patients.

A Novel Approach for Predicting Atrial Fibrillation Recurrence After Ablation Using Deep Convolutional Neural Networks by Assessing Left Atrial Curved M-Mode Speckle-Tracking Images

Aims: Curved M-mode images of global strain (GS) and strain rate (GSR) provide sufficiently detailed spatiotemporal information of deformation mechanics. This study investigated whether a deep convolutional neural network (CNN) could accurately classify these images in patients with atrial fibrillation (AF) who underwent radiofrequency catheter ablation (RFCA) with different outcomes.

Methods and Results: We retrospectively evaluated 606 consecutive patients who underwent RFCA for drug-refractory AF. Patients were divided into AF-free (n = 443) and AF-recurrent (n = 163) groups. Transthoracic echocardiography was performed within 24 h after RFCA. Left atrial curved M-mode speckle-tracking images were acquired from randomly selected 163 patients in AF-free group and 163 patients in AF-recurrent group as the dataset for deep CNN modeling. We used the ReLu activation function and repeatedly performed CNN model for 32 times to evaluate the stability of hyperparameters. Logistic regression models with the left atrial dimension, emptying fraction, and peak systolic GS as predictor variables were used for comparisons. Images from the apical 2-chamber (2-C) and 4-chamber (4-C) views had distinct features, leading to different CNN performance between settings; of them, the “4-C GS+4-C GSR” setting provided the highest performance index values. All four predictor variables used for logistic regression modeling were significant; however, none of them, individually or in any combined form, could outperform the optimal CNN model.

Conclusion: The novel approach using deep CNNs for learning features of left atrial curved M-mode speckle-tracking images seems to be optimal for classifying outcome status after AF ablation.

Dietary intake of soy and cruciferous vegetables and treatment-related symptoms in Chinese-American and non-Hispanic White breast cancer survivors

PURPOSE

This project was undertaken to examine the association between dietary intake of soy or cruciferous vegetables and breast cancer treatment-related symptoms among Chinese-American (CA) and Non-Hispanic White (NHW) breast cancer survivors.

METHODS

This cross-sectional study included 192 CA and 173 NHW female breast cancer survivors (stages 0-III, diagnosed between 2006 and 2012) recruited from two California cancer registries, who had completed primary treatment. Patient-reported data on treatment-related symptoms and potential covariates were collected via telephone interviews. Dietary data were ascertained by mailed questionnaires. The outcomes evaluated were menopausal symptoms (hot flashes, night sweats, vaginal dryness, vaginal discharge), joint problems, fatigue, hair thinning/loss, and memory problems. Associations between soy and cruciferous vegetables and symptoms were assessed using logistic regression. Analyses were further stratified by race/ethnicity and endocrine therapy usage (non-user, tamoxifen, aromatase inhibitors).

RESULTS

Soy food and cruciferous vegetable intake ranged from no intake to 431 and 865 g/day, respectively, and was higher in CA survivors. Higher soy food intake was associated with lower odds of menopausal symptoms (≥ 24.0 vs. 0 g/day, OR 0.51, 95% CI 0.25, 1.03), and fatigue (≥ 24.0 vs. 0 g/day, OR 0.43, 95% CI 0.22, 0.84). However, when stratified by race/ethnicity, associations were statistically significant in NHW survivors only. Compared with low intake, higher cruciferous vegetable intake was associated with lower odds of experiencing menopausal symptoms (≥ 70.8 vs. < 33.0 g/day, OR 0.50, 95% CI 0.25, 0.97) in the overall population.

CONCLUSIONS

In this population of breast cancer survivors, higher soy and cruciferous vegetable intake was associated with less treatment-related menopausal symptoms and fatigue.