Antimicrobial interventions to reduce Salmonella and Campylobacter populations and improve shelf life of quail carcasses

Quail (Coturnix japonica) is processed and marketed as fresh meat, with limited shelf life. The objective of this study was to evaluate the efficacy of antimicrobial interventions during slaughter on reducing Salmonella and Campylobacter contamination and to determine the microbiological shelf life of quail during refrigerated (4°C) storage. Three antimicrobials, peracetic acid (400 ppm; PAA), Citrilow (pH 1.2), and Cecure (cetylpyridinium chloride [CPC], 450 ppm), along with a water and no-treatment control were evaluated. Quail carcasses (n = 75) were inoculated with a cocktail of nalidixic acid–resistant Salmonella Typhimurium and gentamicin-resistant Campylobacter coli. After 30 min of attachment time, quail carcasses were submerged in each antimicrobial solution for 20 s with air agitation. Noninoculated quail carcasses (n = 25) were similarly treated, packaged, and stored under refrigeration (4°C). Aerobic plate counts (APC), psychrotroph counts (PC), Enterobacteriaceae counts (ENT), total coliform counts (TCC), and Escherichia coli counts on quail carcasses were determined on 1, 4, 7, and 10 d. Salmonella and Campylobacter populations were determined by plating on Petrifilm APC supplemented with 200-ppm nalidixic acid and Campy Cefex agar supplemented with 200-ppm gentamycin, respectively. No significant reductions in (P > 0.01 log cfu/mL) in APC, PC, ENT, TCC, and E. coli counts were observed on carcasses submerged in water. However, treatments with PAA, Citrilow, and CPC significantly reduced (P ≤ 0.05) Salmonella and Campylobacter coli contamination. Citrilow showed greater (P ≤ 0.05) reduction in Salmonella and Campylobacter population (1.90 and 3.82 log cfu/mL reduction, respectively) to PAA and CPC. Greater (P ≤ 0.05) reductions in APC, PC, ENT, TCC, and E. coli counts (2.22, 1.26, 1.47, 1.52, and 1.59 log cfu/mL, respectively) were obtained with the application of CPC. Application of antimicrobial interventions resulted in a reduction in Campylobacter and Salmonella, APC, PC, and ENT populations after treatments (day 0) and throughout the storage period (day 10). Use of antimicrobial interventions after slaughter can improve the microbiological safety and shelf life of quail.

Racial Differences in Physical and Mental Health: Socio-economic Status, Stress and Discrimination

This article examines the extent to which racial differences in socio-economic status (SES), social class and acute and chronic indicators of perceived discrimination, as well as general measures of stress can account for black-white differences in self-reported measures of physical and mental health. The observed racial differences in health were markedly reduced when adjusted for education and especially income. However, both perceived discrimination and more traditional measures of stress are related to health and play an incremental role in accounting for differences between the races in health status. These findings underscore the need for research efforts to identify the complex ways in which economic and non-economic forms of discrimination relate to each other and combine with socio-economic position and other risk factors and resources to affect health.

The impact of lesion in-painting and registration methods on voxel-based morphometry in detecting regional cerebral gray matter atrophy in multiple sclerosis

BACKGROUND AND PURPOSE

VBM has been widely used to study GM atrophy in MS. MS lesions lead to segmentation and registration errors that may affect the reliability of VBM results. Improved segmentation and registration have been demonstrated by WM LI before segmentation. DARTEL appears to improve registration versus the USM. Our aim was to compare the performance of VBM-DARTEL versus VBM-USM and the effect of LI in the regional analysis of GM atrophy in MS.

MATERIALS AND METHODS

3T T1 MR imaging scans were acquired from 26 patients with RRMS and 28 age-matched NC. LI replaced WM lesions with normal-appearing WM intensities before image segmentation. VBM analysis was performed in SPM8 by using DARTEL and USM with and without LI, allowing the comparison of 4 VBM methods (DARTEL + LI, DARTEL - LI, USM + LI, and USM - LI). Accuracy of VBM was assessed by using NMI, CC, and a simulation analysis.

RESULTS

Overall, DARTEL + LI yielded the most accurate GM maps among the 4 methods (highest NMI and CC, P < .001). DARTEL + LI showed significant GM loss in the bilateral thalami and caudate nuclei in patients with RRMS versus NC. The other 3 methods overestimated the number of regions of GM loss in RRMS versus NC. LI improved the accuracy of both VBM methods. Simulated data suggested the accuracy of the results provided from patient MR imaging analysis.

CONCLUSIONS

We introduce a pipeline that shows promise in limiting segmentation and registration errors in VBM analysis in MS.

The relationship between socioeconomic position and depression among a US nationally representative sample of African Americans

PURPOSE

Findings from previous studies have not revealed significant, inverse relationships between socioeconomic position (SEP) and depression among African Americans. This study examined the relationship between multiple indicators of SEP and Major Depressive Episode (MDE) among African Americans.

METHODS

Data were drawn from the National Survey of American Life main interview and re-interview. MDE, at both 12 month and lifetime intervals, was assessed using the World Mental Health version of the Composite International Diagnostic Interview. Logistic regression models were adjusted for demographics.

RESULTS

For 12-month MDE, household income and unemployment predicted greater odds of MDE among African American men, while there was an inverse relationship between education and 12-month MDE. Only unemployment was significantly associated with lifetime MDE among African American men. For African American women, a significant inverse relationship between household income and 12-month MDE was observed.

CONCLUSIONS

Findings garnered from this study indicate that it is important to consider multiple measures of SEP in the prediction of depression among African Americans, and that the pattern of association between SEP and depression varies according to sex. Considering the paucity of studies that have explored the relationship between SEP and depression, additional research is needed to more firmly establish the relationship between SEP and depression. It is also important to consider stressors that may affect the relationship between SEP and depression among African Americans.

The associations between socio-economic status and major depressive disorder among Blacks, Latinos, Asians and non-Hispanic Whites: findings from the Collaborative Psychiatric Epidemiology Studies

BACKGROUND

This study examined whether there were associations between individual measures of socio-economic status (SES) and the 12-month prevalence of major depressive disorder (MDD) in representative samples of Blacks, Latinos, Asians and Whites in the USA.

METHOD

The data used were from the Collaborative Psychiatric Epidemiology Studies (CPES).

RESULTS

There was an association between household income and MDD among Whites. However, the association was not statistically significant. Statistically significant associations were present between educational attainment and MDD among Whites. Among both Whites and Latinos, being out of the labor force was significantly associated with MDD. In analyses by nativity, being out of the labor force was significantly associated with MDD among US-born and foreign-born Latinos.

CONCLUSIONS

Significant associations between various measures of SES and MDD were consistently observed among White and, in some cases, Latino populations. Future studies should continue to examine sociopsychological factors related to SES that increase the risk of MDD among people from racial-ethnic communities.

Magnetization transfer ratio abnormalities reflect clinically relevant grey matter damage in multiple sclerosis

BACKGROUND

In multiple sclerosis, grey matter (GM) damage appears more clinically relevant than either white matter damage or lesion load.

OBJECTIVE

We investigated if normal-appearing white matter (NAWM) and grey matter tissue changes assessed by magnetization transfer ratio were associated with long-term disability.

METHODS

Sixty-nine people were assessed 20 years after presentation with a clinically isolated syndrome (CIS) [28 still CIS, 31 relapsing-remitting multiple sclerosis, 10 secondary progressive multiple sclerosis], along with 19 healthy subjects. Mean magnetization transfer ratio, peak height (PH) and peak location of the normalized magnetization transfer ratio histograms were determined in NAWM and grey matter, as well as, white matter and GM Fraction (GMF) and T(2)-weighted lesion load.

RESULTS

Median expanded disability status scale for multiple sclerosis patients was 2.5 (range 1-8). GM-PH, and less so, NAWM mean and peak location, were lower in multiple sclerosis patients (P = 0.009) versus controls, relapsing-remitting multiple sclerosis versus CIS (P = 0.008) and secondary progressive multiple sclerosis versus relapsing-remitting multiple sclerosis (P = 0.002). GM-PH (as well as GMF) correlated with expanded disability status scale (r(s) = -0.49; P = 0.001) and multiple sclerosis functional score (r(s) = 0.51; P = 0.001). GM-PH independently predicted disability with similar strength to the associations of GMF with clinical measures.

CONCLUSION

Grey matter damage was related to long-term disability in multiple sclerosis cohort with a relatively low median expanded disability status scale. Markers of intrinsic grey matter damage (magnetization transfer ratio) and tissue loss offer clinically relevant information in multiple sclerosis.

Upper dose thresholds for radiation-induced adaptive response against cancer in high-dose-exposed, cancer-prone, radiation-sensitive Trp53 heterozygous mice

Trp53 heterozygous mice are radiation-sensitive and cancer-prone. Groups of 7-8-week-old female Trp53 heterozygous mice were exposed to 4 Gy of 60Co gamma radiation at high (0.5 Gy/min) or low (0.5 mGy/min) dose rate. Other groups received 10 or 100 mGy at low dose rate 24 h prior to the 4-Gy dose. Tumor frequency and latency were measured over the animals' life span. Exposure to 10 mGy prior to 4 Gy resulted in a small (approximately 5%) but significant life-span regain and increased latency (approximately 9%) for all malignant tumors taken together, but 100 mGy further reduced life span slightly (approximately 7%). Latency responses were tumor type-specific. The prior 10-mGy exposure resulted in a small (approximately 7%) regain in latency for lymphomas but no change in latency for spinal osteosarcomas. Increasing the adapting dose to 100 mGy eliminated the increase in lymphoma latency and further reduced life span (approximately 8%). A 10-mGy dose prior to 4 Gy at low dose rate had no effects. Adapting exposures had no significant effect on tumor frequency. We conclude that a single low dose induced a small protective response in vivo in Trp53+/- mice, reducing the carcinogenic effects of a subsequent large, high-dose-rate exposure by increasing tumor latency. The upper dose threshold at which low-dose protective effects gave way to detrimental effects was tumor type-specific, as found previously for spontaneous tumors in these same cancer-prone mice (Radiat. Res. 159, 320-327, 2003). However, the upper dose thresholds appear to be lower (below 100 mGy) for radiation-induced tumors than for the same tumors appearing spontaneously.

Low doses of radiation increase the latency of spontaneous lymphomas and spinal osteosarcomas in cancer-prone, radiation-sensitive Trp53 heterozygous mice

Mice heterozygous for Trp53 are radiation-sensitive and cancer-prone, spontaneously developing a variety of cancer types. Osteosarcomas in the spine lead to paralysis, while lymphomas lead rapidly to death, distinct events that provide objective measures of latency. The effects of a single low-dose (10 or 100 mGy), low-dose-rate (0.5 mGy/min) (60)Co gamma irradiation on lymphoma or spinal osteosarcoma frequency and latency, defined as time of death or of onset of paralysis, respectively, were examined. Compared to spontaneous lymphomas or to spinal osteosarcomas leading to paralysis in unexposed mice, an exposure of 7-8-week-old Trp53(+/-) mice to 10 or 100 mGy had no significant effect on tumor frequency, indicating no effect on tumor initiation. All tumors are therefore assumed to be of spontaneous origin. However, a 10-mGy exposure reduced the risk of both lymphomas and spinal osteosarcomas by significantly increasing tumor latency, indicating that the main in vivo effect of a low-dose exposure is a reduction in the rate at which spontaneously initiated cells progress to malignancy. The effect of this adaptive response persisted for the entire life span of all the animals that developed these tumors. Exposure to 100 mGy delayed lymphoma latency longer than the 10-mGy exposure. However, the 100-mGy dose increased spinal osteosarcoma risk by decreasing overall latency compared to unexposed control mice. That result suggested that this higher dose was in a transition zone between reduced and increased risk, but that the dose at which the transition occurs varies with the tumor type.

Uranium and uranium decay series radionuclide dynamics in bone of rats following chronic uranium ore dust inhalation

The accumulation and release of uranium and some uranium decay chain radionuclides were measured in the bones of rats that had been chronically exposed to inhaled uranium ore dust during the first half (approximately) of their natural adult lifespan. Endochondral bone (femur, tibia, humerus, radius, and ulna), membrane bone (skull roofing bones) and muscle of Sprague-Dawley rats (n = 55) that died at various times up to 65 weeks after the end of chronic inhalation of uranium ore dust aerosol (4.2 h d(-1) for 65 wk) and from age matched controls (n = 10), were analyzed for uranium, 230Th, 226Ra, 210Pb, and 210Po. Overall, during the period of dust inhalation, the nuclides accumulated in the above order of decreasing concentration in dry bone. However, the results demonstrate that there was some differential accumulation of uranium and uranium decay series radionuclides in muscle and two bone types of rats during the chronic inhalation period. The data also show that the bone levels of some, but not all, radionuclides decreased significantly with time after inhalation ceased. Lung uranium concentration at the time of death was a highly significant covariant for temporal changes in the levels of some radionuclides in both endochondral bone and membrane bone, indicating that lung remained a major source of these isotopes for accumulation in these bone types after ore dust inhalation had ceased. For some isotopes, the two bone types behaved differently during the dust inhalation period, and differently again after the dust inhalation ceased. The relative behavior of one bone type compared to the other for a particular isotope during the dust inhalation period did not predict the relative behavior after dust inhalation ceased. However, a faster accumulation of one bone type compared to the other for a particular isotope during the dust inhalation period predicted a faster decrease after dust inhalation ended.

Diagnosis of metachronous contralateral breast cancer

The purpose of this study was to compare the characteristics of primary breast cancers (PBCs) and metachronous contralateral breast cancers (MCBCs). Between 1984 and 1996, 236 women treated with curative intent for PBC who developed a MCBC >6 months after initial diagnosis (without previous evidence of distant metastases) were retrospectively evaluated for clinical and pathologic characteristics and method of diagnosis of their tumors. There were more noninvasive cancers among the MCBCs than the PBCs (11.4% and 5.1%, respectively, p < 0.02). Among the invasive cancers, the mean size of the MCBCs was smaller than the PBCs (1.94 versus 2.55 cm, p < 0.001). MCBCs were more likely than PBCs to be mammographically detected (46.2% versus 19.9%, p < 0.001). Tumor size was correlated with the method of diagnosis. The mean tumor size was 1.39, 2.02, and 2.69 cm for mammogram-, physician-, and patient-detected tumors, respectively. Among patients having axillary lymph node dissections, mammogram- and physician-detected tumors were less likely to have lymph node metastases than patient-detected tumors (22.0% versus 41.2%, p < 0.005). Regular follow-up of breast cancer patients diagnoses MCBCs when they are smaller and less likely to have nodal metastases than PBCs mainly because of early mammographic detection.

Neighborhood disadvantage, stress, and drug use among adults

This paper explores the relationships among neighborhood disadvantage, stress, and the likelihood of drug use in a sample of adults (N = 1,101). Using the 1995 Detroit Area Study in conjunction with tract-level data from the 1990 census, we find a positive relationship between neighborhood disadvantage and drug use, and this relationship remains statistically significant net of controls for individual-level socioeconomic status. Neighborhood disadvantage is moderately associated with drug related behaviors, indirectly through increased social stressors and higher levels of psychological distress among residents of disadvantaged neighborhoods. A residual effect of neighborhood disadvantage remains, net of a large number of socially relevant controls. Finally, results from interactive models suggest that the relationship between neighborhood disadvantage and drug use is most pronounced among individuals with lower incomes.

The contribution of hope to the quality of life among aging African Americans: 1980-1992

This study examined age differences between 1979-80 and 1992 in the quality of life of African Americans using panel data from the National Survey of Black Americans. Of particular interest was the role of the hope dimension of personal efficacy in accounting for variance in general well-being, beyond that contributed by social demographic and economic indicators. Hierarchical regression analyses revealed that hope and family satisfaction in 1980 consistently accounted for significant amounts of variance in general life satisfaction in the 1992 fourth wave of data among all three cohorts. For older respondents, increased frequency of contact with friends and family help were the most important contributors to high satisfaction. Across waves in all age cohorts family satisfaction and contact with friends were most important in contributing to life satisfaction. Implications for further research on well-being among African Americans were discussed.

Health system costs of metastatic breast cancer

To assess the costs of treating patients with incurable breast cancer, all health system costs during the interval from diagnosis of first recurrence or metastasis until death for 75 female subjects randomly selected from those known to have died of breast cancer in British Columbia, Canada between July 1, 1995 and December 31, 1996, were identified. Costs were determined from several databases within the British Columbia (BC) Ministry of Health, as well as from BC Cancer Agency patient charts. The mean total cost to the health system was CDN $36,474.33 (95% confidence interval $29,752-$43,196) per subject. The mean costs were highest for the youngest age group and lowest for the middle age group, but these only differed by $2,300. Inpatient costs accounted for the greatest proportion of the total, over 50% in all age groups. This data may be valuable in assessing the cost-effectiveness of interventions that are known to affect mortality due to breast cancer.

Race/ethnicity and the 2000 census: recommendations for African American and other black populations in the United States

This commentary considers the implications of the assessment of racial/ethnic status for monitoring the health of African Americans and other Black populations in the United States. It argues that because racial disparities in health and other social indicators persist undiminished, the continued assessment of race is essential. However, efforts must be made to ensure that racial data are of the highest quality. This will require uniform assessment of racial status that includes identifiers for subgroups of the Black population. Research also indicates that the health of multiracial persons varies by maternal race. Thus, efforts to monitor multiracial status should assess the race of both parents. More attention should also be given to analysis and interpretation of racial data and to the collection of additional data that capture characteristics linked to race (such as socioeconomic factors and racism) that may adversely affect health.

A decision analysis of the effect of avoiding axillary lymph node dissection in low risk women with invasive breast carcinoma

BACKGROUND

Evidence that avoiding axillary lymph node dissection (AxD) strikes an appropriate balance between morbidity and recurrence risk in patients with invasive breast carcinoma generally is anecdotal and without a formally quantified basis. The current study presents a decision analysis of the difference in 5-year disease free survival (DFS) rate between treatment scenarios with and without routine AxD.

METHODS

To derive quantitative estimates of the effect of avoiding AxD on 5-year DFS, the authors examined outcomes for women undergoing 2 treatment scenarios: AxD or no AxD with adjuvant therapy decisions based on risk factors in the primary tumor. Eligible patients belonged to 2 lymph node metastases risk groups: low (patients without palpable lymph nodes and lymphatic or vascular invasion [LVI] negative tumors < or = 0.5 cm in greatest dimension) and moderate (patients with mammographically detected, LVI negative tumors, between 0.6-2.0 cm in greatest dimension or patients with palpable LVI negative tumors between 0.6-1.0 cm in greatest dimension with nonpalpable lymph nodes). Along with observed data regarding treatment and recurrence, the authors employed estimates of the efficacy of chemotherapy, tamoxifen, and regional radiation therapy derived from published randomized trials to estimate the 5-year DFS rate for treatment scenarios with and without AxD.

RESULTS

Patients in the low risk group had a 5% risk of lymph node metastases. In these women, eliminating AxD and treating no patients with chemotherapy and/or tamoxifen resulted in a < 1% decrease in the 5-year DFS rate. Patients in the moderate risk group had a 10% risk of lymph node metastases. Eliminating AxD and treating only those women with Grade 3 tumors > 1 cm in greatest dimension with chemotherapy and/or tamoxifen resulted in a 1.8% decrease in the 5-year DFS rate. However, if all patients in this group were treated with chemotherapy and/or tamoxifen and no AxD, the 5-year DFS rate increased by 2.7%.

CONCLUSIONS

In patients with a low risk of lymph node metastases, it was estimated that eliminating AxD may result in only minimal changes in the estimated 5-year DFS rate.

Effect of time interval between breast-conserving surgery and radiation therapy on ipsilateral breast recurrence

PURPOSE

To examine the effect of the time interval (interval) between breast-conserving surgery (BCS) and the start of radiation therapy (RT) on the subsequent risk of ipsilateral breast cancer recurrence (IBR).

METHODS AND MATERIALS

We reviewed interval and a number of prognostic and treatment factors among 1,962 women treated with BCS and RT for invasive breast cancer diagnosed between January 1, 1989 and December 31, 1993 in British Columbia, Canada. Subjects were female, less than 90 years old at diagnosis, not treated with chemotherapy, not stage T4 or M1, and had survived more than 30 days from diagnosis. The cumulative incidence of IBR was estimated in four interval groups: 0-5, 6-8, 9-12, and 13+ weeks. Only 23 women had an interval of greater than 20 weeks between BCS and start of RT. To assess whether an imbalance of prognostic and treatment factors could be obscuring real differences between the interval groups, Cox proportional hazards regression analyses were conducted.

RESULTS

Median follow-up was 71 months. The crude incidence of IBR for the entire sample was 3.9%. The cumulative incidence of IBR in the 6-8, 9-12, and 13+ week groups was not statistically significantly different from the cumulative incidence of IBR in the 0-5 week group. Multivariate analyses demonstrated that patients not using tamoxifen p = 0.027) and those with grade 3 histology (p = 0.003) were more likely to recur in the breast. Interval between BCS and RT was not a statistically significant predictor of breast recurrence when entered into a model incorporating tamoxifen use and tumor grade (0-5 vs. 6-8 weeks, p = 0.872; 0-5 vs. 9-12 weeks, p = 0.665; 0-5 vs. 13+ weeks, p = 0.573).

CONCLUSIONS

We found no univariate or multivariate difference in ipsilateral breast cancer recurrence between intervals of 0 to 20 weeks from breast conserving surgery to start of radiation therapy, in a population-based, low risk group of women not receiving adjuvant chemotherapy, after controlling for other factors important in predicting ipsilateral breast cancer recurrence.

Psychiatric diagnosis of African Americans: diagnostic divergence in clinician-structured and semistructured interviewing conditions

This study is a primary data collection that varied patient race and diagnosis and used two diagnostic interviewing conditions: one clinician-structured (phase one) and the other a semi-structured diagnostic instrument (phase two). Four basic research questions are addressed: What is the relationship between race and the hospital diagnosis? How is race related to diagnosis in both research interviewing conditions? Why does diagnostic concordance between the hospital diagnosis and the research diagnosis vary by research interviewing condition? Is diagnostic concordance between the hospital and research diagnosis influenced by patient race? A total of 291 patients completed an interview during phase one, while 665 patients completed an interview during phase two. Blacks were more likely to receive a hospital diagnosis of schizophrenia and less likely to be diagnosed with mood disorder. Patient race was similarly related to the research diagnoses produced in the clinician-structured research condition (phase one). Although less pronounced, a higher percentage of African Americans than whites received a diagnosis of schizophrenia using the semi-structured DSM-III-R Symptom Checklist (phase two). The black-white distribution for mood disorders showed that whites were more likely than blacks to be diagnosed with mood disorder.

The adaptive response modifies latency for radiation-induced myeloid leukemia in CBA/H mice

We have investigated the effect of the adaptive response on acute myeloid leukemia (AML) induced in CBA/Harwell mice by a chronic radiation exposure. Groups of mice irradiated with a total dose of 1. 0 Gy at two different chronic dose rates (0.5, 0.004 Gy/h) had similar frequencies of AML. Compared to control animals that did not develop AML, irradiation at either of these dose rates did not change the longevity of the mice that did not die of leukemia. The survival rates of irradiated mice that did develop leukemia in the two groups were not different from each other, indicating that the dose rates produced similar responses and therefore were both chronic exposures. We then tested the ability of a chronic 10-cGy (0. 5 Gy/h) exposure to ionizing radiation, mild hyperthermia (40.5 degrees C whole-body, 60 min) or treatment with interleukin-1 (1500 U i.p.) to induce an adaptive response and modify the frequency or latency of AML which resulted from a subsequent (24 h later) 1.0-Gy (0.5 Gy/h) chronic radiation exposure. The frequency of radiation-induced leukemia was not changed in mice given any of the three adapting treatments 24 h prior to the chronic 1.0-Gy dose that induced leukemia. However, the latent period for development of AML was significantly increased by both the prior low radiation dose and mild hyperthermia treatment. Injection of interleukin-1, in contrast, may have reduced the latent period. Similar to the single 1.0-Gy chronic exposure alone, none of the adapting treatments prior to that exposure influenced the survival of animals that did not develop AML. These results indicate that an earlier exposure to a small adapting dose of radiation or to a mild heat stress can influence secondary steps in radiation-induced carcinogenesis.

Inhaled uranium ore dust and lung cancer risk in rats

Using a nose-only inhalation system, male Sprague-Dawley rats were exposed 4.2 h d(-1), 5 days per week for 65 weeks to one of two concentrations of natural uranium ore dust aerosol (44% U, 50 mg m(-3) and 19 mg m(-3)) without significant radon content. After inhalation exposure ceased, the rats were allowed to live for their natural lifetime. Lung uranium burdens, measured at the time of death of each animal, declined exponentially after dust inhalation ceased, and the rate of decline was independent of the initial lung burden. Lymph node specific burdens ranged from 1 to 60 fold greater than the specific lung burden in the same animal. No lymph node tumors were observed. The frequency of primary malignant lung tumors was 0.016, 0.175 and 0.328 and primary non-malignant lung tumors 0.016, 0.135 and 0.131 in the control, low and high aerosol exposed groups, respectively. There was no difference in tumor latency between the groups. Absorbed dose to the lung was calculated for each animal in the study. The average doses for all the animals exposed to the low and high dust aerosol concentrations were 0.87 Gy and 1.64 Gy respectively, resulting in an average risk of malignant lung tumors of about 0.20 tumors per animal per Gy in both groups. The frequency of primary lung tumors was also calculated as a function of dose increment for both exposed groups individually and combined. The data indicate that, in spite of the above result, lung tumor frequency was not directly proportional to dose. However, when malignant lung tumor frequency was calculated as a function of dose rate (as measured by the lung burden at the end of dust inhalation) a direct linear relationship was seen (p < 0.01) suggesting dose rate may be a more important determinant of lung cancer risk than dose. Conversely, non-malignant lung tumors were significantly correlated with low lung burdens (p = 0.01). We conclude that chronic inhalation of natural uranium ore dust alone in rats creates a risk of primary malignant and non-malignant lung tumor formation and that malignant tumor risk was not directly proportional to dose, but was directly proportional to dose rate.

Prediction of axillary lymph node involvement of women with invasive breast carcinoma: a multivariate analysis

BACKGROUND

The increasing use of systemic therapy for women with lymph node negative breast carcinoma and earlier stage of disease at mammographic detection raises questions regarding the need for routine axillary lymph node dissection. Predictive modeling for lymph node involvement may be one way to reduce the need for axillary lymph node dissection and its morbidity.

METHODS

A multivariate analysis of 12 factors predictive of axillary lymph node involvement was conducted in a population-based cohort of 4312 women with invasive breast carcinoma diagnosed between January 1, 1993 and December 31, 1996.

RESULTS

Clinical palpability, lymphatic or vascular invasion, lesion size, margin status, histology, and patient age were independent predictors of axillary lymph node involvement. The model correctly identified lymph node status in 76.6% of cases. Model accuracy and fit were equally high when applied to randomly selected halves of the study subjects. Approximately 32.0% of the patients in the study sample (1363/4312) were identified as having an extremely high (91%; n = 1102) or low (10%; n = 261) risk of lymph node involvement. In a second analysis, a clinically useable, three-variable model identified a very low risk group of patients (n = 147) with a 4.8% risk of lymph node metastasis and a high risk group of patients (n = 1008) with a 74.2% risk of lymph node metastasis. Greater than 90% of subjects in the high risk group received adjuvant systemic therapy even if they were lymph node negative pathologically.

CONCLUSIONS

A clinically useable, three-variable model employing tumor and lymph node palpability, size, and lymphatic or vascular invasion can identify women with invasive breast carcinoma in whom axillary lymph node dissection is very unlikely to alter recommendations regarding adjuvant systemic therapy.

Perceived race-based discrimination, employment status, and job stress in a national sample of black women: implications for health outcomes

Previous research has not systematically examined the relationship of perceived race-based discriminations to labor force participation or job related stresses-problems experienced by Black women. The present study investigated the relative contributions of perceived race-based discriminations and sociodemographic characteristics to employment status and job stress in a national probability sample (the National Survey of Black Americans; J. S. Jackson, 1991) of Black women in the United States. Logit and polychotomous logistic regression analyses revealed that Black women's current employment status was best explained by sociodemographic measures. In contrast, the combination of perceived discrimination and sociodemographics differentially affects patterns of employment status and perceived job stress in the work environment of Black women. Implications of these findings for the health of African American women are discussed.

Aggressiveness of colon carcinoma in blacks and whites. National Cancer Institute Black/White Cancer Survival Study Group

Black patients with colon cancer in the Black/White Cancer Survival Study were found to have a poorer survival than white patients. More advanced-stage disease at diagnosis was the primary determinant, accounting for 60% of the excess mortality. After adjusting for stage, factors such as poverty, other socioeconomic conditions, and treatment did not further explain the remaining survival deficit. This study examined the aggressiveness of colon tumors in blacks and whites to explore its role in the racial survival differences. Tumor characteristics of 703 cases of newly diagnosed invasive colon adenocarcinoma were centrally evaluated by a gastrointestinal pathologist, blinded in regard to the age, race, and sex of the patients. Blacks were less likely to have poorly differentiated (grade 3) tumors [odds ratio (OR), 0.44; 95% confidence interval, 0.22-0.88] and lymphoid reaction (OR, 0.49; 95% confidence interval, 0.26-0.90) when compared with whites. These black/white (B/W) differences remained statistically significant after adjusting for age, sex, metropolitan area, summary stage, socioeconomic status, body mass index, and health care access and utilization. In addition, blacks were less likely to have high-grade (grade 3) nuclear atypia, mitotic activity, and tubule formation, although these ORs did not reach a statistical significance level of 0.05. Similar B/W differences were observed for patients with advanced disease but not with early stage. Comparison by anatomical subsite showed that blacks had statistically significantly better differentiated tumors for cancers of the proximal and transverse colon but not for the distal. No racial differences were found for blood vessel and lymphatic invasion, necrosis, fibrosis, and mucinous type of histology. The findings, therefore, are the opposite of those hypothesized. After adjusting for stage, more aggressive tumor characteristics do not explain the adverse survival differential in blacks. This suggests that there may be racial differences in environmental exposure, and that the intensity and mode of delivery of carcinogen insult as well as host susceptibility may differ by race and anatomical subsite. Future studies should explore the B/W differences in tumor biology using molecular markers that precede the conventional histological parameters evaluated here.

Recruitment and retention of African American patients for clinical research: an exploration of response rates in an urban psychiatric hospital

The issues related to recruiting African American psychiatric inpatients are discussed in the context of a study on the influence of ethnicity on psychiatric diagnosis. Ethnically diverse psychiatric residents interviewed 960 Black and White inpatients in 2 urban psychiatric hospitals. Despite the obstacles cited in the literature about recruiting and retaining African Americans into research, 78% of this sample were African American. In addition, interview completion and refusal rates did not differ by patient ethnicity. Results suggest that matching interviewer and patient ethnicity did not influence African Americans' likelihood of participating in or of refusing an interview. This article summarizes a number of guidelines that others may find useful in conducting clinical research with African Americans, ranging from the formation of academic-public liaisons to interviewer training.

Recruitment and retention of African American patients for clinical research: an exploration of response rates in an urban psychiatric hospital

The issues related to recruiting African American psychiatric inpatients are discussed in the context of a study on the influence of ethnicity on psychiatric diagnosis. Ethnically diverse psychiatric residents interviewed 960 Black and White inpatients in 2 urban psychiatric hospitals. Despite the obstacles cited in the literature about recruiting and retaining African Americans into research, 78% of this sample were African American. In addition, interview completion and refusal rates did not differ by patient ethnicity. Results suggest that matching interviewer and patient ethnicity did not influence African Americans' likelihood of participating in or of refusing an interview. This article summarizes a number of guidelines that others may find useful in conducting clinical research with African Americans, ranging from the formation of academic-public liaisons to interviewer training.

Vital status in the National Panel Survey of Black Americans: a test of the National Death Index among African Americans

To test the specificity of the National Death Index (NDI), information was submitted on 157 randomly selected respondents from the National Panel Survey of Black Americans (NPSBA) who were known to be living as of 1992. Information also was submitted for 153 known deceased respondents from the panel survey to test the sensitivity of the NDI. The NDI was very sensitive; however, specificity was somewhat less impressive. Although we found the NDI/NPSBA match to be highly accurate, there was a nontrivial number of false positives.

Perceived race-based discrimination, employment status, and job stress in a national sample of black women: implications for health outcomes

Previous research has not systematically examined the relationship of perceived race-based discriminations to labor force participation or job related stresses-problems experienced by Black women. The present study investigated the relative contributions of perceived race-based discriminations and sociodemographic characteristics to employment status and job stress in a national probability sample (the National Survey of Black Americans; J. S. Jackson, 1991) of Black women in the United States. Logit and polychotomous logistic regression analyses revealed that Black women's current employment status was best explained by sociodemographic measures. In contrast, the combination of perceived discrimination and sociodemographics differentially affects patterns of employment status and perceived job stress in the work environment of Black women. Implications of these findings for the health of African American women are discussed.

Relative biological effectiveness of tritium for induction of myeloid leukemia in CBA/H mice

To help resolve uncertainties as to the most appropriate weighting factor for tritium beta rays, a large experiment was carried out to measure the relative biological effectiveness (RBE) of tritiated water compared to X rays for the induction of myeloid leukemia in male mice of the CBA/H strain. The study was designed to estimate the lifetime incidence of myeloid leukemia in seven groups of about 750 mice each; radiation exposures were approximately 0, 1, 2 and 3 Gy both for tritiated water and for X rays. The lifetime incidence of leukemia in these mice increased from 0.13% in the control group to 6-8% in groups exposed to higher radiation doses. The results were fitted to various equations relating leukemia incidence to radiation dose, using both the raw data and data corrected for cumulative mouse-days at risk. The calculated RBE values for tritium beta rays compared to X rays ranged from 1.0 +/- 0.5 to 1.3 +/- 0.3. A best estimate of the RBE for this experiment was about 1.2 +/- 0.3. A wR value of 1 would thus appear to be more appropriate than a wR of 2 for tritium beta rays.

The relationship between social ties and survival among black and white breast cancer patients. National Cancer Institute Black/White Cancer Survival Study Group

The relationship between social ties, stage of disease, and survival was analyzed in a population-based sample of 525 black and 486 white women with newly diagnosed breast cancer. There were significant differences between the two race groups in reported social ties. Using logistic regression to adjust for the effects of age, race, study area, education, and the presence of symptoms, there was little or no evidence for an association between individual network measures of social ties and stage of disease. However, a summary measure of social networks was found to be associated modestly with late stage disease, attributable in part to significantly more advanced disease among black, but not white, women reporting few friends and relatives [relative risk (RR) = 1.8; 95% confidence interval (CI) = 1.1-3.0]. With adjustments for differences in stage of disease and other covariates, and with the use of Cox proportional hazards modeling to estimate hazard ratios, the absence of close ties and perceived sources of emotional support were associated significantly with an increased breast cancer death rate. White women in the lowest quartile of reported close friends and relatives had twice the breast cancer death rate of white women in the highest quartile (RR = 2.1; 95% CI = 1.1-4.4). Notably, both black and white women reporting few sources of emotional support had a higher death rate from their disease during the 5-year period of follow-up (RR = 1.8; 95% CI = 1.3-2.5).(ABSTRACT TRUNCATED AT 250 WORDS)

AIDS survey methodology with black Americans

Unique substantive and methodological issues are involved in conducting survey research on sexual and HIV risk related behaviors among Americans of African descent. Problem conceptualization, sampling, design of instruments, mode of data collection, interviewer/respondent characteristics, community resistance, and data analysis and interpretation are discussed. The lack of survey research on sensitive health issues is noted. Possible methods for addressing these issues are drawn from the experiences of the authors in conducting national research on the general and at risk Black community populations. It is concluded that attention to these issues can substantially improve the quality of research on AIDS related behaviors on Black communities. Finally, it is suggested that behavioral theories and sophisticated methodological and analytic approaches, sensitive to the special cultural dimensions of racial/ethnic life in the United States, would contribute substantially to the scientific armamentarium needed to successfully meet the challenge of the AIDS epidemic.

Age differences in productive activities

Age differences in productive contributions through both paid and unpaid work are examined in commensurate terms. Data are from a nationwide household survey of 3,617 adults age 25 and older conducted in 1986. Older Americans participate in many unpaid productive activities at levels that are comparable to those reached by middle-aged and younger Americans; these activities include volunteer work in organizations, informal help to others, maintenance and repair of their home and possessions, and housework. Relatively few older Americans spend any time participating in paid work and unpaid rearing of children. Largely because of the cessation of paid work and child care, older Americans spend less time overall in productive activities. Women and men spend about equal time in productive activities, but women spend more of it in unpaid work and less of it in paid work. The difficulties with using paid work as the major indicator for describing productivity across the life span are discussed.

Hypertension in blacks: psychosocial and biological perspectives

The extraordinarily high rate of hypertension in blacks remains a significant public health issue in most industrialized societies. Research has focused on the investigation of racial differences in biological, nutritional, behavioural and psychological, and social factors in an effort to identify the causes of this high morbidity rate. Thus far, research suggests important racial differences in renal functioning, particularly in sodium metabolism and plasma renin activity, as well as potassium intake and sodium:potassium ratio. Behavioral factors such as anger-coping style and John Henryism, and social factors such as socioeconomic status, socioecological stress, social support, urban-rural residence, and family interaction patterns have also been identified as potential contributors. Finally, emerging research paradigms such as laboratory stress reactivity and 24-h ambulatory monitoring of blood pressure may provide promising leads about the interaction between these effects and hypertension in black populations.

The influence of racial factors on psychiatric diagnosis: a review and suggestions for research

Research on race and diagnosis initially focused on black-white differences in depression and schizophrenia. Statistics showing a higher treated prevalence of schizophrenia and a lower prevalence of depression for blacks seemed to support the claim that blacks did not suffer from depression. Others argued, however, that clinicians were misdiagnosing depression in blacks. This article reviews empirical studies of racial differences in individual symptoms and summarizes the evidence on misdiagnosis. It argues that more attention must be paid to resolving two contradictory assumptions made by researchers working in the area of race and diagnostic inference: (1) blacks and whites exhibit symptomatology similarly but diagnosticians mistakenly assume that they are different; (2) blacks and whites display psychopathology in different ways but diagnosticians are unaware of or insensitive to such cultural differences. The article concludes with suggested research directions and a discussion of critical research issues.

Barriers to medical care among adult blacks: what happens to the uninsured?

This article examines perceived barriers to the utilization of medical care among the uninsured in a national sample of adult (18 years and older) black Americans. Uninsured respondents were more likely to feel that it was difficult for them to receive medical care, and that they needed more care than they were obtaining. The uninsured in comparison with insured respondents were less likely to utilize private, office-based physicians. Insurance coverage, however, made no difference in hospital emergency room use for health care. The results suggest that the lack of health insurance places large numbers of blacks at a severe disadvantage in obtaining needed health care.

Uninsured risk groups in a national survey of black Americans

Comprehensive data on risk groups within the black population are lacking because of the small number of black Americans usually sampled in national health surveys. Health policy, planning, and service delivery can be substantially improved by having data that reveal the specific health concerns of blacks within these different risk groups. This paper describes the demographic characteristics of the uninsured in a national sample of adult (18 years and older) black Americans. The poor, farmers, unemployed, young (18 to 25 years) and pre-retired (55 to 64 years) were the most likely to be uninsured. Persons living in the South and in rural locations were also more likely to be uninsured than blacks in the North and in urban areas. Implications for health policy and health care delivery are discussed.

Aged blacks' choices for an informal helper network

Research on the support networks of impaired elderly adults suggests that membership in sociodemographic subgroups influences use of specific informal helpers. This study explored the relationships of sociodemographic, health, and family factors to informal helper choice among a nationally representative sample (N = 581) of older (55 years and above) blacks (National Survey of Black Americans). Nine categories of helpers were examined: spouse, son, daughter, father, mother, brother, sister, friend, and neighbor. Logistic regression analyses revealed that marital status is important in selecting the categories of sister, friend, and neighbor. Presence of children decreased the likelihood that siblings and friends would be chosen. Perceived family closeness facilitated the selection of siblings but inhibited the choice of friends. Regional differences suggest a greater likelihood of selecting the categories of sister, friend, and neighbor among Southern residents.

Size and composition of the informal helper networks of elderly blacks

Research on the informal support networks of older persons recognizes that network size and composition (i.e., family vs. nonkin) may have important consequences for care. Factors that determine these aspects of networks among older blacks, however, have not been explored systematically. The present study examined the relationship of a group of sociodemographic, health, family, and availability factors to the size and composition of the informal support network. The data were taken from the National Survey of Black Americans and constitute a nationally representative sample (N = 581) of older blacks (55 years and older). The results for several of the sociodemographic factors (i.e., sex and marital status) are consistent with previous work. Regional differences in network dimensions, however, suggest new areas of inquiry. The findings underscore the importance of availability and family factors in support relationships and the relative ineffectiveness of health factors as predictors of network size and composition.

The use of informal and formal help: four patterns of illness behavior in the black community

Most studies of professional help use among black Americans fail to describe this group's relationship to blacks experiencing distress but not requesting professional help, and generally ignore the salience of informal social support processes. A more comprehensive understanding of black help-seeking behavior would come from an approach which describes both the users and nonusers of formal helping services, and examines the benefits derived from the interpersonal relationships that comprise black friend- and kin-based networks. These analyses focused on four patterns of informal and formal help use in the National Survey of Black Americans. The findings indicated that most people use informal help only, or they use informal and professional help together. In addition, gender, age, income, and problem-type were significantly related to the different patterns of illness behavior. The implications of these findings for help seeking in the black community were discussed.

Stress, coping, and Black mental health: preliminary findings from a national study

Despite the fact that blacks are disproportionately exposed to social conditions considered to be antecedents of psychiatric disorder, epidemiologic studies have not conclusively demonstrated that blacks exhibit higher rates of mental illness than whites. The present paper employed a research approach which considered not only rates of psychological distress, but also the stressors that blacks face and the various coping strategies used to adapt to those stressors. The data were obtained from the National Survey of Black Americans, the first study of a national probability sample of the adult black population. The information on mental health and coping was collected within the context of a single stressful personal problem. The analysis indicates that prayer was an extremely important coping response used by blacks especially among those making less than $10,000, above the age of 55 and women. The informal social network was used quite extensively as a means of coping with problems. This was true for all sociodemographic groups studied. The young (18-34) were less likely than those age 35 and above to seek professional help, while women were more likely than men to seek formal assistance. Income was not related to professional help seeking. With respect to the use of specific professional help sources, hospital emergency rooms, private physicians and ministers were used most frequently. The implications of these findings for research on black mental health and primary prevention are discussed.

Stress, coping, and Black mental health: preliminary findings from a national study

Despite the fact that blacks are disproportionately exposed to social conditions considered to be antecedents of psychiatric disorder, epidemiologic studies have not conclusively demonstrated that blacks exhibit higher rates of mental illness than whites. The present paper employed a research approach which considered not only rates of psychological distress, but also the stressors that blacks face and the various coping strategies used to adapt to those stressors. The data were obtained from the National Survey of Black Americans, the first study of a national probability sample of the adult black population. The information on mental health and coping was collected within the context of a single stressful personal problem. The analysis indicates that prayer was an extremely important coping response used by blacks especially among those making less than $10,000, above the age of 55 and women. The informal social network was used quite extensively as a means of coping with problems. This was true for all sociodemographic groups studied. The young (18-34) were less likely than those age 35 and above to seek professional help, while women were more likely than men to seek formal assistance. Income was not related to professional help seeking. With respect to the use of specific professional help sources, hospital emergency rooms, private physicians and ministers were used most frequently. The implications of these findings for research on black mental health and primary prevention are discussed.