Repository Planning, Design, and Engineering: Part II-Equipment and Costing.

Part II of this article discusses and provides guidance on the equipment and systems necessary to operate a repository. The various types of storage equipment and monitoring and support systems are presented in detail. While the material focuses on the large repository, the requirements for a small-scale startup are also presented. Cost estimates and a cost model for establishing a repository are presented. The cost model presents an expected range of acquisition costs for the large capital items in developing a repository. A range of 5,000-7,000 ft(2) constructed has been assumed, with 50 frozen storage units, to reflect a successful operation with growth potential. No design or engineering costs, permit or regulatory costs, or smaller items such as the computers, software, furniture, phones, and barcode readers required for operations have been included.

Repository Planning, Design, and Engineering: Part I--Infrastructure.

This is a two-part review describing the planning, engineering, and design considerations for building a new repository for biological and environmental samples. Part I addresses the physical infrastructure requirements for a repository; Part II will cover equipment and costing. Planning for construction of a new repository is a complex process requiring comprehensive preplanning and adherence to many regulatory and safety requirements. Guidance and a planning timeline are provided for many of the physical aspects and large capital acquisition costs for the expansion of an existing repository, or the creation of a new repository facility, using an available unoccupied building such as a former warehouse. This article provides a comprehensive set of information about every aspect of repository construction and operation to be considered in the planning process, and also addresses all aspects of designing and constructing a new repository in an existing structure. The engineering and design parameters for the repository are discussed in detail.

Quality management of biorepositories.

Biomedical investigators require high quality human tissue to support their research; thus, an important aspect of the provision of tissues by biorepositories is the assurance of high quality and consistency of processing specimens. This is best accomplished by a quality management system (QMS). This article describes the basis of a QMS program designed to aid biorepositories that want to improve their operations. In 1983, the UAB Tissue Collection and Biobanking Facility (TCBF) introduced a QMS program focused on providing solid tissues to support a wide range of research; this QMS included a quality control examination of the specific specimens provided for research. Similarly, the Division of Laboratory Sciences at the Centers for Disease Control and Prevention (CDC) introduced a QMS program for their laboratory analyses, focused primarily on bodily fluids. The authors of this article bring together the experience of the QMS programs at these two sites to facilitate the development or improvement of quality management systems of a wide range of biorepositories.

Homocysteine and vitamin B(12) concentrations and mortality rates in type 2 diabetes.

OBJECTIVE: To assess the role of homocysteine as a risk factor for mortality in diabetic subjects. METHODS: Homocysteine, vitamin B(12), and folate concentrations were measured in stored sera of 396 diabetic Pima Indians aged > or = 40 years when examined between 1982 and 1985. Vital status was assessed through 2001. RESULTS AND CONCLUSIONS: Over a median follow-up of 15.7 years, there were 221 deaths-76 were due to cardiovascular disease (CVD), 36 to diabetes/nephropathy and 34 to infections. Homocysteine was positively associated with mortality from all causes (hazard rate ratio (HRR) for highest versus lowest tertile of homocysteine = 1.70, 95% confidence interval (CI) 1.18-2.46), from diabetes/nephropathy (HRR = 2.39, 95% CI 0.94-6.11) and from infectious diseases (HRR = 3.39, 95% CI 1.19-9.70), but not from CVD (HRR = 1.16, 95% CI 0.62-2.17) after adjustment for age, sex and diabetes duration. Homocysteine correlated with serum creatinine (r = 0.50), and the relationships with mortality rates were not significant after adjustment for creatinine. Vitamin B(12) was positively associated with all-cause mortality (HRR for 100 pg/mL difference adjusted for age, sex and diabetes duration = 1.15, 95% CI 1.08-1.22) and death from diabetes/nephropathy (HRR = 1.27, 95% CI 1.10-1.46). The association between homocysteine and mortality in type 2 diabetes is not causal, but is confounded by renal disease in Pima Indians.

Biochemical indicators of B vitamin status in the US population after folic acid fortification: results from the National Health and Nutrition Examination Survey 1999-2000.

BACKGROUND: Mandatory folic acid fortification of cereal-grain products was introduced in the United States in 1998 to decrease the risk that women will have children with neural tube defects. OBJECTIVE: The objective was to determine the effect of folic acid fortification on concentrations of serum and red blood cell (RBC) folate, serum vitamin B-12, and plasma total homocysteine (tHcy) and methylmalonic acid (MMA) in the US population. DESIGN: Blood was collected from a nationally representative sample of approximately 7300 participants aged > or = 3 y in the National Health and Nutrition Examination Survey (NHANES) during 1999-2000 and was analyzed for these B vitamin-status indicators. The results were compared with findings from the prefortification survey NHANES III (1988-1994). RESULTS: The reference ranges (5th-95th percentiles) were 13.1-74.3 nmol/L for serum folate, 347-1167 nmol/L for RBC folate, and 179-738 pmol/L for serum vitamin B-12. For plasma tHcy and MMA, the reference ranges for serum vitamin B-12-replete participants with normal serum creatinine concentrations were 3.2-10.7 mumol/L and 60-210 nmol/L, respectively. The prevalence of low serum folate concentrations (<6.8 nmol/L) decreased from 16% before to 0.5% after fortification. In elderly persons, the prevalence of high serum folate concentrations (>45.3 nmol/L) increased from 7% before to 38% after fortification; 3% had marginally low serum vitamin B-12 concentrations (<148 pmol/L) and 7% had elevated plasma MMA concentrations (>370 nmol/L). Seventy-eight percent of the US population had plasma tHcy concentrations <9 micromol/L. CONCLUSIONS: Every segment of the US population appears to benefit from folic acid fortification. Continued monitoring of B vitamin concentrations in the US population is warranted.

Hematological and iron-related analytes--reference data for persons aged 1 year and over: United States, 1988-94.

OBJECTIVES: This report presents national estimates of hematologic and iron-related analytes for persons 1 year of age and over, by age, sex, and race/ethnicity. METHODS: The analysis is based on data from the third National Health and Nutrition Examination Survey (NHANES III) (1988-94), which was designed to provide information on the health and nutritional status of the civilian noninstitutionalized U.S. population. The sample used for these analyses included the 26,372 participants who had laboratory tests. RESULTS: This report provides mean, standard error of the mean, median, and percentile laboratory values for the U.S. population, 1988-94, for hematological and iron-related analytes. In addition, percentage distributions are provided. CONCLUSIONS: Data on hematological and iron analytes provide reference values for clinical and longitudinal comparisons.

Selenium and colorectal adenoma: results of a pooled analysis.

BACKGROUND: Secondary analyses of data from a large randomized clinical trial have suggested that intake of the trace element selenium reduces risk of colorectal neoplasia, but epidemiologic studies have not shown a consistent protective association. METHODS: We conducted a combined analysis of data from three randomized trials--the Wheat Bran Fiber Trial, the Polyp Prevention Trial, and the Polyp Prevention Study--which tested the effects of various nutritional interventions for colorectal adenoma prevention among participants who recently had an adenoma removed during colonoscopy. Selenium concentrations were measured from blood specimens from a total of 1763 trial participants, and quartiles of baseline selenium were established from the pooled data. To estimate the association between baseline selenium and colorectal adenoma risk, odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using logistic regression modeling. All statistical tests were two-sided. RESULTS: Individual study results among participants whose blood selenium concentrations were in the highest versus the lowest quartile varied in magnitude (Polyp Prevention Trial: OR = 0.67, 95% CI = 0.43 to 1.05; P(trend) = .21; Wheat Bran Fiber Trial: OR = 0.66, 95% CI = 0.40 to 1.10; P(trend) = .13, and Polyp Prevention Study: OR = 0.57, 95% CI = 0.34 to 0.95, P(trend) = .04). Analyses of the pooled data showed that individuals whose blood selenium values were in the highest quartile (median = 150 ng/mL) had statistically significantly lower odds of developing a new adenoma compared with those in the lowest quartile (OR = 0.66, 95% CI = 0.50 to 0.87; P(trend) = .006). CONCLUSIONS: The inverse association between higher blood selenium concentration and adenoma risk supports previous findings indicating that higher selenium status may be related to decreased risk of colorectal cancer.

Prospective study of serum selenium concentrations and esophageal and gastric cardia cancer, heart disease, stroke, and total death.

BACKGROUND: We previously reported an inverse association between prediagnostic serum selenium concentrations and the risk of esophageal squamous cell carcinoma (ESCC) and gastric cardia cancer (GCC) but not gastric noncardia cancer (GNCC) in a nested study from the Nutrition Intervention Trial in Linxian, China. OBJECTIVE: We examined the relation between baseline serum selenium and the subsequent risk of death from ESCC, GCC, GNCC, heart disease (HD), stroke, and total death over 15 y of follow-up (1986-2001). DESIGN: We measured baseline serum selenium concentrations in 1103 subjects randomly selected from a larger trial cohort. We identified 516 deaths during the 15-y follow up, including 75 from ESCC, 36 from GCC, 116 from HD, and 167 from stroke. Relative risks (RRs) and 95% CIs were estimated by using Cox proportional hazards regression models. Reported RRs estimated the change in risk conferred by a 25% increase in serum selenium relative to the population distribution. All estimates were adjusted for sex, age, smoking, drinking, and serum cholesterol. RESULTS: We found significant inverse associations between baseline serum selenium and death from ESCC (RR: 0.83; 95% CI: 0.71, 0.98) and GCC (0.75; 0.59, 0.95). Trends toward inverse associations were noted for death from HD (0.89; 0.78, 1.01; P = 0.07), but no association was noted for total death (0.96; 0.90, 1.02) or stroke (0.99; 0.88, 1.11). CONCLUSION: Population-wide selenium supplementation in the region of China with low serum selenium and high incidences of ESCC and GCC merits serious consideration.

Determination of folate vitamers in human serum by stable-isotope-dilution tandem mass spectrometry and comparison with radioassay and microbiologic assay.

BACKGROUND: Current clinical methods for folate give different results and cannot measure the various forms of folate. We developed an isotope-dilution tandem mass spectrometric method coupled to liquid chromatography (LC/MS/MS) as a candidate reference method for 5-methyltetrahydrofolic acid (5MeTHF), 5-formyltetrahydrofolic acid (5FoTHF), and folic acid (FA) in human serum. METHODS: We quantitatively isolated folates from 275 microL of serum with a phenyl solid-phase extraction cartridge, then detected and quantified them in stabilized serum extracts by positive-ion electrospray ionization LC/MS/MS. We used an isocratic mobile phase of acetic acid in organic solvent on a C(8) analytical column. (13)C-labeled folates were used as internal standards. RESULTS: Limits of detection in serum were 0.13 (5MeTHF), 0.05 (5FoTHF), and 0.07 (FA) nmol/L. Within- and between-run imprecision (CV) was <7% for 5MeTHF and <10% for 5FoTHF at concentrations >0.5 nmol/L, and <10% for FA at concentrations >2.0 nmol/L. Total folate (TFOL) concentrations determined by competitive protein binding radioassay were approximately 9% lower than results obtained with LC/MS/MS. The microbiologic assay gave approximately 15% higher TFOL results with FA calibrator and no difference with 5MeTHF calibrator. The mean (SD) [range] TFOL in 42 sera was 35.5 (17.8) [6.5-75.6] nmol/L. Thirty-two samples with TFOL <50 nmol/L had, on average, 93.3% 5MeTHF, 2.3% FA, and 4.4% 5FoTHF. Ten samples with TFOL >50 nmol/L had, on average, 81.7% 5MeTHF, 15.7% FA, and 2.5% 5FoTHF. CONCLUSIONS: This stable-isotope-dilution LC/MS/MS method can quantify 5MeTHF, 5FoTHF, and FA in serum. Currently used clinical assays agree with this candidate reference method.

Prospective study of serum vitamin E levels and esophageal and gastric cancers.

Participants in the General Population Trial, a randomized nutrition intervention trial in Linxian, China, who received a combination of selenium, beta-carotene, and vitamin E supplements, had statistically significantly lower cancer mortality rates than those who did not receive the supplements. In the current study, we used a case-cohort design to examine the association between pre-trial serum vitamin E levels and the risks of developing esophageal and gastric cancers during the trial. We measured serum alpha- and gamma-tocopherol and cholesterol levels in 1072 case patients with incident esophageal squamous cell carcinoma (ESCC), gastric cardia cancer (GCC), or gastric noncardia cancer (GNCC) and in 1053 control subjects. The relative risks for comparisons of the highest to the lowest quartiles of serum alpha-tocopherol were 0.63 (95% confidence interval [CI] = 0.44 to 0.91) for ESCC, 0.84 (95% CI = 0.55 to 1.26) for GCC, and 2.05 (95% CI = 0.89 to 4.75) for GNCC. Serum gamma-tocopherol level was not associated with the incidence of any of these cancers. Our findings provide support for the role of alpha-tocopherol in the etiology of upper gastrointestinal cancers.

HFE genotype and transferrin saturation in the United States.

PURPOSE: Examine the penetrance (defined by high transferrin saturation [TS]) of C282Y and H63D in the U.S. population. METHODS: 5171 participants from the Third National Health and Nutrition Examination Survey, 1992 to 1994. RESULTS: 77.1% (95% confidence interval [CI], 2.3, 95.1) of men and 51.9% (95% CI, 0, 84.2) of women with C282Y homozygosity had high TS. The associations of H63D homozygosity with high TS were stronger in people aged 50 years or older than in younger persons. Among Mexican-Americans, simple H63D heterozygosity was associated with high TS. CONCLUSIONS: The associations between HFE genotype and high TS may vary by sex, age, and ethnic group.

Erythrocyte protoporphyrin or hemoglobin: which is a better screening test for iron deficiency in children and women?

BACKGROUND: Hemoglobin and erythrocyte protoporphyrin (EP) tests are commonly used to screen for iron deficiency. However, little research has been done to systematically evaluate the sensitivity and specificity of these 2 tests. OBJECTIVE: The objective of this study was to evaluate the sensitivity and specificity of hemoglobin and EP measurements in predicting iron deficiency in preschool children and in women of childbearing age. DESIGN: We examined data from the third National Health and Nutrition Examination Survey (n = 2613 children aged 1-5 y and n = 5175 nonpregnant women aged 15-49 y). Children or women with blood lead >or= 10 microg/dL were excluded from this study. We used the receiver operating characteristic (ROC) curve to characterize the sensitivity and specificity of hemoglobin and EP measurements in screening for iron deficiency, defined as having abnormal values for >or= 2 of the following 3 indexes: mean cell volume, transferrin saturation, and serum ferritin. RESULTS: The ROC performance of EP was consistently better than that of hemoglobin for detecting iron deficiency in preschool children. However, in nonpregnant women, we found no significant difference between EP and hemoglobin in ROC performance for detecting iron deficiency. We observed the same results when we stratified the analyses by sex and race of the children and by race of the women. CONCLUSIONS: For children aged 1-5 y, EP is a better screening tool for iron deficiency than is hemoglobin. However, for nonpregnant women, EP and hemoglobin have similar sensitivity and specificity for predicting iron deficiency.

Serum selenium levels in the US population: Third National Health and Nutrition Examination Survey, 1988-1994.

The published literature on serum selenium levels in the US population describes studies on small samples that may not be representative of the US population. This analysis provides the first nationally representative serum selenium levels in the US population by age group, sex, race-ethnicity, poverty income ratio (PIR), geographic region, and urban status. The Third National Health and Nutrition Examination Survey (NHANES III) is a national population-based cross-sectional survey with an in-person interview and serum selenium measurements. For the 18,597 persons for whom serum selenium values wereavailable in NHANES III, the mean concentration was 1.58 nmol/L and the median concentration was 1.56 nmol/L. Mean serum selenium levels differed by age group, sex, race ethnicity, PIR, and geographic region. The US population has slight differences in serum selenium levels by demographic factors.

Hyperhomocysteinemia and vitamin B-12 deficiency in elderly using Title IIIc nutrition services.

BACKGROUND: The effect of the folate food fortification program on the prevalence of hyperhomocysteinemia in the older population with coexisting vitamin B-12 deficiency is not known. OBJECTIVE: The objective was to determine the prevalence of hyperhomocysteinemia and vitamin B-12 deficiency in elderly who were using Title IIIc nutrition services, after folate food fortification in the United States. DESIGN: Demographic, nutritional, cognitive, routine diagnostic, and serum methylmalonic acid (MMA) and total homocysteine (tHcy) tests were performed in a convenience sample of 103 elderly enrolled in nutrition service programs in rural northeast Georgia. A subgroup (n = 27) was treated with vitamin B-12, 2.5 mg, and a multivitamin with 400 micro g folic acid, 2 mg vitamin B-6, and 27 mg ferrous fumarate. RESULTS: The total cohort included 103 participants (+/- SD age: 76.4 +/- 8.1; 80% female; 68% white, 32% African American). Vitamin B-12 deficiency (serum vitamin B-12 < 258 pmol/L and MMA > 271 nmol/L) was present in 23%. Mean serum folate was high, 39.3 nmol/L, and no subject had serum folate < 6.8 nmol/L. Mean tHcy was 17.6 +/- 7.2 micro mol/L in vitamin B-12-deficient subjects and 10.8 +/- 3.6 micro mol/L in those who were nondeficient. Determinants of high tHcy were vitamin B-12 deficiency, high serum creatinine, and low red blood cell folate. Those with vitamin B-12 deficiency were more likely to have poor cognition (58% compared with 20%, P < 0.001) and anemia (38% compared with 18%, P = 0.042). High-dose oral B-12 therapy lowered mean MMA and tHcy by 49% and 32%, respectively. CONCLUSION: Vitamin B-12 deficiency was prevalent and was associated with poor cognition, anemia, and hyperhomocysteinemia.

Blood folate levels on the Texas-Mexico border.

The Texas-Mexico border population has a high prevalence of neural tube defects (NTDs). In 1998, in an effort to reduce the risk of NTD-affected pregnancies, the US Food and Drug Administration mandated folic acid fortification of enriched grain products. Since then, the median serum folate and red blood cell (RBC) folate levels of US women aged 15 through 44 years has risen. During 1995 through 2000, serum and RBC folate levels of 170 Mexican American women residing on the Texas-Mexico border who had delivered live, normal infants within the previous 3 months were tested. The median serum folate levels rose 46%, and RBC folate levels rose 44%. The increase suggests that food fortification may be affecting folate levels among populations with economic and cultural barriers to consuming fortified foods. However, more data are needed before we can assess the impact of food fortification on NTD rates on the border.

Hypovitaminosis D prevalence and determinants among African American and white women of reproductive age: third National Health and Nutrition Examination Survey, 1988-1994.

BACKGROUND: Recent reports of rickets among African American children drew attention to the vitamin D status of these infants and their mothers. African American women are at higher risk of vitamin D deficiency than are white women, but few studies have examined determinants of hypovitaminosis D in this population. OBJECTIVE: We examined the prevalence and determinants of hypovitaminosis D among African American and white women of reproductive age. DESIGN: We examined 1546 African American women and 1426 white women aged 15-49 y who were not pregnant and who participated in the third National Health and Nutrition Examination Survey (1988-1994). Hypovitaminosis D was defined as a serum 25-hydroxyvitamin D concentration < or =37.5 nmol/L. Multiple logistic regression was used to examine the independent association of dietary, demographic, and behavioral determinants of hypovitaminosis D. RESULTS: The prevalence of hypovitaminosis D was 42.4 +/- 3.1% ( +/- SE) among African Americans and 4.2 +/- 0.7% among whites. Among African Americans, hypovitaminosis D was independently associated with consumption of milk or breakfast cereal <3 times/wk, no use of vitamin D supplements, season, urban residence, low body mass index, and no use of oral contraceptives. Even among 243 African Americans who consumed the adequate intake of vitamin D from supplements (200 IU/d), 28.2 +/- 2.7% had hypovitaminosis D. CONCLUSIONS: The high prevalence of hypovitaminosis D among African American women warrants further examination of vitamin D recommendations for these women. The determinants of hypovitaminosis D among women should be considered when these women are advised on dietary intake and supplement use.

Serum TSH, T(4), and thyroid antibodies in the United States population (1988 to 1994): National Health and Nutrition Examination Survey (NHANES III).

NHANES III measured serum TSH, total serum T(4), antithyroperoxidase (TPOAb), and antithyroglobulin (TgAb) antibodies from a sample of 17,353 people aged > or =12 yr representing the geographic and ethnic distribution of the U.S. population. These data provide a reference for other studies of these analytes in the U.S. For the 16,533 people who did not report thyroid disease, goiter, or taking thyroid medications (disease-free population), we determined mean concentrations of TSH, T(4), TgAb, and TPOAb. A reference population of 13,344 people was selected from the disease-free population by excluding, in addition, those who were pregnant, taking androgens or estrogens, who had thyroid antibodies, or biochemical hypothyroidism or hyperthyroidism. The influence of demographics on TSH, T(4), and antibodies was examined. Hypothyroidism was found in 4.6% of the U.S. population (0.3% clinical and 4.3% subclinical) and hyperthyroidism in 1.3% (0.5% clinical and 0.7% subclinical). (Subclinical hypothyroidism is used in this paper to mean mild hypothyroidism, the term now preferred by the American Thyroid Association for the laboratory findings described.) For the disease-free population, mean serum TSH was 1.50 (95% confidence interval, 1.46-1.54) mIU/liter, was higher in females than males, and higher in white non-Hispanics (whites) [1.57 (1.52-1.62) mIU/liter] than black non-Hispanics (blacks) [1.18 (1.14-1.21) mIU/liter] (P < 0.001) or Mexican Americans [1.43 (1.40-1.46) mIU/liter] (P < 0.001). TgAb were positive in 10.4 +/- 0.5% and TPOAb, in 11.3 +/- 0.4%; positive antibodies were more prevalent in women than men, increased with age, and TPOAb were less prevalent in blacks (4.5 +/- 0.3%) than in whites (12.3 +/- 0.5%) (P < 0.001). TPOAb were significantly associated with hypo or hyperthyroidism, but TgAb were not. Using the reference population, geometric mean TSH was 1.40 +/- 0.02 mIU/liter and increased with age, and was significantly lower in blacks (1.18 +/- 0.02 mIU/liter) than whites (1.45 +/- 0.02 mIU/liter) (P < 0.001) and Mexican Americans (1.37 +/- 0.02 mIU/liter) (P < 0.001). Arithmetic mean total T(4) was 112.3 +/- 0.7 nmol/liter in the disease-free population and was consistently higher among Mexican Americans in all populations. In the reference population, mean total T(4) in Mexican Americans was (116.3 +/- 0.7 nmol/liter), significantly higher than whites (110.0 +/- 0.8 nmol/liter) or blacks (109.4 +/- 0.8 nmol/liter) (P < 0.0001). The difference persisted in all age groups. In summary, TSH and the prevalence of antithyroid antibodies are greater in females, increase with age, and are greater in whites and Mexican Americans than in blacks. TgAb alone in the absence of TPOAb is not significantly associated with thyroid disease. The lower prevalence of thyroid antibodies and lower TSH concentrations in blacks need more research to relate these findings to clinical status. A large proportion of the U.S. population unknowingly have laboratory evidence of thyroid disease, which supports the usefulness of screening for early detection.

Serum carotenoid concentrations and their reproducibility in children in Belize

Suggestions that carotenoid-containing foods are beneficial in maintaining health have led to several studies of circulating carotenoid concentrations of adults. Because few data are available for children, we report serum carotenoid concentrations of 493 children in Belize. Carotenoid concentrations were determined as part of a survey of vitamin A status of children, most between 65 and 89 mo of age. Reproducibility was tested by collecting a second blood samples 2 wk after the first collection from a subset of children (n = 23) who consumed their habiitual diet with no treatment during the interim. Predominant serum carotenoids were lutein/zeaxanthin and beta-carotene, which accounted for 26 percent and 24 percent of median total carotenoids, respectively. The three provitamin A carotenoids, alpha- and beta-carotene and beta-cryptoaxnthin, constituted 51 percent od median total carotenoid concentrations. Partial correlations of each carotenoid with fasting retinol concentrations indicated that beta-carotene had the highest correlation. Concordance correlation coefficients (rc) for fasting carotenoid concentrati9ons determined 2 wk apart were > or = 0.89 for lycopene, beta-cryptoxanthin, and alpha- and beta-catotene. The rc for lutein/zeaxanthin and total carotenoids was lower, 0.59 and 0.68, respectively, because of higher lutein/zeaxanthin concentrations at the second sampling than at the first. The reproducibility of the concentrations suggest both that individuals have characteristic profiles and that serum carotenoid concentrations can be measured randomly over > or =2 wk without significant bias. (au)