Multistate outbreak of Salmonella Paratyphi B variant L(+) tartrate(+) and Salmonella Weltevreden infections linked to imported frozen raw tuna: USA, March-July 2015.

Foodborne non-typhoidal salmonellosis causes approximately 1 million illnesses annually in the USA. In April 2015, we investigated a multistate outbreak of 65 Salmonella Paratyphi B variant L(+) tartrate(+) infections associated with frozen raw tuna imported from Indonesia, which was consumed raw in sushi. Forty-six (92%) of 50 case-patients interviewed ate sushi during the week before illness onset, and 44 (98%) of 45 who specified ate sushi containing raw tuna. Two outbreak strains were isolated from the samples of frozen raw tuna. Traceback identified a single importer as a common source of tuna consumed by case-patients; this importer issued three voluntary recalls of tuna sourced from one Indonesian processor. Four Salmonella Weltevreden infections were also linked to this outbreak. Whole-genome sequencing was useful in establishing a link between Salmonella isolated from ill people and tuna. This outbreak highlights the continuing foodborne illness risk associated with raw seafood consumption, the importance of processing seafood in a manner that minimises contamination with pathogenic microorganisms and the continuing need to ensure imported foods are safe to eat. People at higher risk for foodborne illness should not consume undercooked animal products, such as raw seafood.

Multistate outbreak of Listeria monocytogenes infections linked to whole apples used in commercially produced, prepackaged caramel apples: United States, 2014-2015.

Whole apples have not been previously implicated in outbreaks of foodborne bacterial illness. We investigated a nationwide listeriosis outbreak associated with caramel apples. We defined an outbreak-associated case as an infection with one or both of two outbreak strains of Listeria monocytogenes highly related by whole-genome multilocus sequence typing (wgMLST) from 1 October 2014 to 1 February 2015. Single-interviewer open-ended interviews identified the source. Outbreak-associated cases were compared with non-outbreak-associated cases and traceback and environmental investigations were performed. We identified 35 outbreak-associated cases in 12 states; 34 (97%) were hospitalized and seven (20%) died. Outbreak-associated ill persons were more likely to have eaten commercially produced, prepackaged caramel apples (odds ratio 326·7, 95% confidence interval 32·2-3314). Environmental samples from the grower's packing facility and distribution-chain whole apples yielded isolates highly related to outbreak isolates by wgMLST. This outbreak highlights the importance of minimizing produce contamination with L. monocytogenes. Investigators should perform single-interviewer open-ended interviews when a food is not readily identified.

A new bivalent fluorescent fusion protein for differential Cu(II) and Zn(II) ion detection in aqueous solution.

Simple and easy to engineer metal-sensing molecules that are capable of differentiating metal ions and producing metal-specific signals are highly desirable. Metal ions affect the thermal stability of proteins by increasing or decreasing their resistance to unfolding. This work illustrates a new strategy for designing bivalent fluorescent fusion proteins capable of differentiating metal ions in solution through their distinct effects on a protein's thermal stability. A new dual purpose metal sensor was developed consisting of biotin protein ligase (BirA) from B. pseudomallei (Bp) fused to green fluorescent protein (GFP). When coupled with differential scanning fluorimetry of GFP-tagged proteins (DSF-GTP) for signal-transduction detection, Bp BirA-GFP yields distinct protein unfolding signatures with Zn(II) and Cu(II) ions in aqueous solutions. The limit of detection of the system is ∼1 µM for both metal species. The system can be used in a variety of high-throughput assay formats including for the screening of metal-binding proteins and chelators. Bp BirA-GFP has also the additional benefit of being useful in Cu(II) ion field-testing applications through simple visual observation of a temperature-dependent loss of fluorescence. Bp BirA-GFP is the first example of a 2protein-based dual purpose Cu(II) and Zn(II) ion sensor compatible with two different yet complementary signal-transduction detection systems.

Myelinated, synapsing cultures of murine spinal cord--validation as an in vitro model of the central nervous system.

Research in central nervous system (CNS) biology and pathology requires in vitro models, which, to recapitulate the CNS in vivo, must have extensive myelin and synapse formation under serum-free (defined) conditions. However, finding such a model has proven difficult. The technique described here produces dense cultures of myelinated axons, with abundant synapses and nodes of Ranvier, that are suitable for both morphological and biochemical analysis. Cellular and molecular events were easily visualised using conventional microscopy. Ultrastructurally, myelin sheaths were of the appropriate thickness relative to axonal diameter (G-ratio). Production of myelinated axons in these cultures was consistent and repeatable, as shown by statistical analysis of multiple experimental repeats. Myelinated axons were so abundant that from one litter of embryonic mice, myelin was produced in amounts sufficient for bulk biochemical analysis. This culture method was assessed for its ability to generate an in vitro model of the CNS that could be used for both neurobiological and neuropathological research. Myelin protein kinetics were investigated using a myelin fraction isolated from the cultures. This fraction was found to be superior, quantitatively and qualitatively, to the fraction recovered from standard cultures of dissociated oligodendrocytes, or from brain slices. The model was also used to investigate the roles of specific molecules in the pathogenesis of inflammatory CNS diseases. Using the defined conditions offered by this culture system, dose-specific, inhibitory effects of inflammatory cytokines on myelin formation were demonstrated, unequivocally. The method is technically quick, easy and reliable, and should have wide application to CNS research.

Diet and colon cancer: assessment of risk by fiber type and food source.

How fiber in the diet is related to the development of colon cancer was assessed in a population-based study conducted on 231 cases and 391 controls in Utah between 1979 and 1983. Crude fiber consistently decreased risk associated with colon cancer in both males [odds ratio (OR) = 0.4] and females (OR = 0.5). Dietary fiber, as analyzed by the method of A. S. Bitner, and neutral detergent fiber were not consistently related to colon cancer risk. Of the noncellulose polysaccharides examined, mannose and galactose were protective against cancers in the ascending colon in males (ORs = 0.5 and 0.3, respectively), whereas galactose and uronic acid were protective against cancers in the ascending colon in females (ORs = 0.5). Highest quartiles of intake of fruits and vegetables were also associated with a decreased risk of colon cancer in males (ORs = 0.3 and 0.6, respectively) and in females (ORs = 0.6 and 0.3, respectively) compared with lowest quartile of intake, whereas high intake of grains was not protective.

Energy intake: its relationship to colon cancer risk.

A case-control study was conducted to assess the role of diet in the etiology of colon cancer. Diet was measured by means of a comprehensive quantifiable food frequency history instrument in 246 cases and 484 controls drawn from the general population of Utah. Each subject's diet was described by major nutrient groups and total energy based on the nutritional content of foods reported. Cases reported higher daily food intake 5 years preceding diagnosis than controls [men, rate ratio (RR) = 2.5; women, RR = 3.6], as measured by total energy content of the diet. Higher risk of colon cancer with increasing energy intake was independent of stage of disease at diagnosis and obesity, as measured by body mass. Fat, protein, and carbohydrate intake all had elevated RRs but could not be assessed as risk factors independent of energy intake because of their strong correlations with total calories. Due to the higher energy intake of the cases, odds ratios for the daily intake of dietary fiber and vitamins A and C were also greater than 1. However, adjusting for caloric intake removed this effect, and dietary fiber showed a weak protective effect. Total energy intake must be evaluated before attempting to assign a causal role to any food or nutrient that may be postulated to play a role in colon cancer.

The need for comprehensive diet studies to assess the relation of lipids to cancer.

Dietary lipids have been linked by both basic research and epidemiological evidence to the etiology of some cancers. It is yet unclear which lipid(s) may be active in the carcinogenic process, but one promising hypothesis concerns the interaction of cholesterol metabolites, considered a risk factor for colon cancer, and dietary fiber which may have a protective role. A multidisciplinary case control study currently underway is investigating the relationship and possible mode of action of fiber and bile acids on colon cancer. The study has epidemiological, biochemical, and pharmacological components that have been designed to integrate data on the intake and fate of lipids, dietary fiber, and other nutritional parameters in colon cancer cases and matched controls and in animal models. Subcomponents of the study deal specifically with the characterization of dietary fiber constituents and their in vivo effect on lipid metabolism.

Water permeability of isolated muscle fibers of a marine crab.

This report deals with the diffusional and nondiffusional water fluxes of muscle fibers of the crab, Chionoecetes bairdi. Graphical analysis of the deuterium exchange indicates that two fiber compartments exist for water. The first, comprising about 60-70% of the fiber water, probably represents the sarcoplasm which is bounded externally by the plasma membrane. The second compartment might represent intracellular organelles. The ratio between the nondiffusional and diffusional fluxes is very much larger than that found earlier for erythrocytes and for the giant axon of the squid. A ratio of such size is unlikely to be caused by unstirred layers and more accurate determinations of the water flux must include study of the influence of the complex morphology of these muscle fibers.

Inhibition by hypertonic solutions of Ca-dependent electrogenesis in single crab muscle fibers.

This study describes the effect of hypertonic solutions on isolated muscle fibers of Callinectes danae. Solutions of twice normal tonicity (2.0 T) inhibit both the normal graded membrane responses and the spikes induced by procaine, tetraethylammonium, or barium. The inhibition is maintained throughout exposure to hypertonic solutions prepared by addition of impermeant solutes such as NaCl, sucrose, or Tris-propionate, but is reversible on their withdrawal. In the presence of permeant solutes such as glycerol or acetamide, the inhibition is transient. In both cases the onset of inhibition of the depolarizing Ca electrogenesis is correlated with shrinkage of the fiber. In the case of permeant solutes, the time course of recovery of the graded responses or the spikes follows the recovery of the fiber volume. Changes in the passive electrical characteristics of the fibers due to hypertonic solutions were unrelated to the blockade of membrane Ca activation. The current-voltage relationship in hypertonic sollution revealed no increase in depolarizing K activation. Inhibition of the graded membrane responses and spikes appears to be associated with depression of Ca conductance. Hypertonic solutions might affect the activation of Ca conductance through reduction of the electric field generated by fixed negative surface charges and/or morphological changes in the T tubules. Membrane depolarization elicited little or no tension in 2.0 T solutions while caffeine contracture (10 mM) with an ampliture of 76% of the maximal contractile ability could still be elicited. This indicates that direct effects of hypertonic solutions on the contractile apparatus were not responsible for loss of tension. The latter is attributed to the inhibition of the transmembrane Ca currents.

Electrophysiological properties of resting secretory membranes of lamellibranch mantles. Interaction between calcium and potassium.

This study concerns the effects of ions on the shell-secreting membrane of clam mantles. The average resting potentials were --47 mV for freshwater mantles and --60 mV for marine mantles. Elevation of potassium in the absence of chloride gave a maximal slope of depolarization equivalent to 59 mV for a 10-fold change in the marine form but much less in the freshwater form. In normal potassium, a 10-fold reduction in calcium produced a hyperpolarization of 6 mV for the freshwater mantle. Neither reduction nor elevation of calcium affected the potential of marine mantles in the presence of normal potassium, but a hyperpolarization of 8 mV occurred when calcium was deleted in a low-potassium medium. Elevated calcium reduced the depolarization induced by raised potassium in both species and resulted in an increased effective membrane resistance in marine mantles. Lowered calcium enhanced the hyperpolarization caused by reduction in potassium in freshwater mantles but not in the marine species. Replacement of chloride by large anions produced transient depolarization in both freshwater and marine mantles and resulted in a maintained increased effective membrane resistance in marine mantles. The effects of sodium and magnesium on the membrane potential were not significant in normal potassium. We conclude that the secretory membrane of freshwater and marine clam mantles is permeable mainly to potassium and chloride, and that responses of the membrane potential to calcium are mediated through its effect on the permeability to potassium.

Size and shape of enzymatically isolated ventricular myocytes from rats and cardiomyopathic hamsters.

Rod-shaped and branched ventricular myocytes from rats and cardiomyopathic hamsters (strain 53.58) were isolated enzymatically, and their widths and lengths were measured in physiological salt solutions containing normal levels of calcium (2.5 mmol). In rats of approximately 200 g body weight, the average myocyte width and length are 25 micron and 115 micron. The isolated cells are also classified according to shape with nearly 50% branched or otherwise irregular. Myocytes of the hearts of the 53.58 strain of cardiomyopathic hamsters at 7 months of age are significantly larger than control hamsters of the same age, indicating that cellular hypertrophy has occurred. Estimates of the number of cells in the ventricles indicate that there is a cell loss of nearly 13% in the myopathic heart. A consideration of the significance of wider and longer myocytes with undiminished myofibrillar mass lead to the conclusion that the decreased contractility displayed by the cardiomyopathic hamster heart must be due, at least in part, to functional defects in the myofibrillar apparatus, in the system of activation, or in cellular integration.

Colon cancer in a low-risk population.

Data are presented on colon mortality in Utah. For the years 1950 to 1969, the state population had 34% fewer deaths from colon cancer than the average United States population. Colon cancer incidence was also studied for the years 1966 to 1970, both for the state and for a large subgroup (Mormons) who abstain from tobacco and alcohol for religious reasons; the colon cancer incidence of Mormons was 37% below the United States average, and that of non-Mormons was 18% below the United States average. A preliminary dietary survey found little difference in meat, fat, and fiber consumption between the population of Utah and that of the United States as a whole.

Pharmacokinetics of FK506 after intravenous and oral administration in patients awaiting renal transplantation.

The authors examined the safety and pharmacokinetics of FK506, a new hepatically metabolized immunosuppressant, after single-dose intravenous (i.v.) infusion (20 micrograms.kg(-1) x 4 hours-1) and oral (80 micrograms/kg) administration in six nondialysis patients, aged 27 to 53 years, with chronic renal failure awaiting transplantation. A two-period, randomized, crossover study protocol was used with blood samples drawn for 72 hours after each dose and a washout period of 4 days. Whole-blood FK506 levels were determined using a standard, two-step, nonspecific enzyme immunoassay. There were no significant changes in vital signs, EKG, or complete laboratory test battery for any patient during the entire study period. No side effects were noted after i.v. or oral FK506 dosing. Mean +/- SD distribution half life was 0.9 +/- 0.2 hours, elimination half life (t1/2 beta) 33 +/- 8 hours, total body clearance (CL) 2.4 +/- 1.1 L/hour, and bioavailability 14 +/- 12%. There was no significant correlation between serum creatinine (Cr) and CL (r = 0.36) or between Cr and t1/2 beta (r = -0.30). It was found that FK506 is incompletely and erratically absorbed after oral administration and is rapidly distributed outside the blood compartment after IV dosing. An extended sampling period seems necessary to accurately characterize the slow elimination phase of FK506.

Bone-related mineral content of water samples collected on the Navajo reservation.

Although dairy food intake is low among the Navajo people, hip fracture rates are lower than in Caucasians. Genetic differences in bone density have been cited as the reasons for low fracture rates among Native Americans and other segments of the population. However, more detailed examination of mineral intakes suggests that environmental factors may provide part of the explanation for the lower fracture rates. Cultural practices such as the addition of ash to traditional foods and the high mineral content of water may provide much higher intakes of bone-related minerals than food intake surveys have previously reported. As part of a larger study to assess overall intake of minerals related to bone health and other conditions, water samples were collected from the Navajo reservation. Duplicates were collected at least one week apart from 53 sites including wells, springs, taps, and storage barrels and analyzed by atomic absorption and inductively coupled plasma spectrometry for a number of minerals. For average intakes of 2 l/day, water could provide up to 212 mg of calcium, 150 mg of magnesium and 8 mg of zinc. The combined contribution of mineral intakes provided by the addition of juniper ash to traditional foods, not genetic differences, may partially explain the lower fracture rates of the Navajo people. Further research in this area is required to confirm this hypothesis.

Zinc and copper in infant diets.

The diets of 59 healthy Utah infants were examined for nutritional adequacy. The analysis included zinc and copper intake calculated from new assays of zinc and copper in commercial baby foods and table foods obtained at local retail outlets. Group averages showed adequate dietary intake, with copper the limiting nutrient. Zinc-to-copper ratios were only slightly higher than suggested.

Health objectives for the nation: moving toward the 1990s.

The 1990 Objectives are an outgrowth of the 1979 Surgeon General's Report, Healthy People, which identified a set of five broad goals for improving the health of the American public through the decade of the 1980s. A year later, more than 500 health experts from the government and the private sector met to develop specific quantifiable objectives for each of the areas outlined in Healthy People. Fifteen topics, including improved nutrition, were used to formulate a framework for 227 objectives that give directions for a national program of health promotion and disease prevention. In 1980, the Public Health Service published the report Promoting Health/Preventing Disease: Objectives for the Nation. A mid-course review of the 1990 objectives has been conducted, and the results were published in 1986. In the nutrition area, it is apparent that some overall progress has been made, but data are insufficient to assess progress on several objectives, and others are unlikely of achievement by 1990. Ultimately, however, the success of the objectives depends on the recognition that they are national, not federal, goals that require commitment to their implementation by both the public and the private sector.

International food component data system.

The International Network of Food Data Systems planning conference recommends establishing nomenclature and a system of coding for use in INFOODS. The International Food Naming System would facilitate collection, tabulation, storing, and retrieval of information. The system consists of two files for each food: one describing the name in a standardized manner and another reporting chemical and biological data. The two files are linked by International Food Number (IFN). Food names consist of controlled terms called facets: origin, part, process, stage of maturity, and grade. Within each facet, such elements as genus, species, variety (scientific name) and generic name, breed or kind, and strain (English name) are defined. Elements are assigned numerical codes to facilitate sorting and storage. Carefully defined standard descriptions are used in each facet. Each descriptor is assigned an alphabetic code, an unlimited number allowing an open-ended flexible system. IFN may be incorporated into a computerized data management system and stored data searched and sorted for information retrieval on given parameters, e.g., country, state, laboratory, or kind of package. Data can be summarized to obtain averages, ranges, and standard deviations. Summarized data, linked with the International Food Names by the IFN, may be printed out in desired format.

An Index of Nutritional Quality for a balanced diet. New help for an old problem.

The Index of Nutritional Quality (INQ) is a method of quantitative and qualitative analysis of single foods, meals, and diets which has special significance in assessing clinical nutritional problems. The INQ is a ratio of the nutrient-to-calorie content of foods which may be calculated by computer and printed as bar graphs and tabular data. The number of nutrients and the nutrient standards used for analysis are flexible parameters which may be varied for each clinical situation. Illustrative examples include INQ analysis of simple foods, an institutional house diet, the diabetic Exchange list, and the diagnostic evaluation of the dietary intake of a hospitalized patient.

Impact of 'Mad Cow Disease' publicity on trends in meat and total vitamin A consumption in Geneva between 1993 and 2000.

BACKGROUND: In March 1996, revelations about the possible risk for humans of the 'mad cow disease' epidemic had a sudden impact on the diets of European populations. OBJECTIVE: To assess changes in meat and nutrient intakes in adults living in Geneva, Switzerland from 1993 to 2000. DESIGN: Independent annual cross-sectional surveys (4047 women and 4092 men total). MAIN OUTCOME MEASURE: Dietary habits assessed and compared to baseline (January 1993-April 1996) via validated semi-quantitative food-frequency questionnaire. RESULTS: Women beef abstainers increased from 8.9 to 14.9% in late 1996 (P<0.001) and 13.3% in 1997 (P<0.05); among meat consumers, in late 1996 meat/beef intakes declined -10/-12% (both P<0.05). From 1997 to 2000 most intake levels drifted back toward those at baseline, but chicken intakes were significantly (all P<0.05) greater each year (+19% in 2000 (P<0.001). Consistent but less dramatic changes were observed among men. From late 1996 until 2000, liver abstention was significantly (all P<0.05) greater (women from 60 to 78%; men from 61 to 73% in 2000; (both P<0.001). The only nutrient intakes that decreased significantly (all P<0.05) each year from 1997 through 2000 were retinol and total vitamin A women: -22% (P<0.001); -11% (P<0.05) respectively; men: -16% (P<0.001); -10% (P<0.05) respectively, in 2000). Total vitamin A intakes exceeded the dietary reference intake (DRI) for liver eaters (women 185%, men 153%), but were below the DRI for liver abstainers (women 83%; men 66%) in 2000. CONCLUSION: The decreases in beef and liver consumption since late 1996 led to the discovery of a long-term disparity in the retinol and total vitamin A intakes of liver eaters vs abstainers.

Acute corneal endothelial changes after laser in situ keratomileusis.

PURPOSE: To report the acute effects of laser in situ keratomileusis (LASIK) on the corneal endothelium. METHODS: Twenty eyes of 10 consecutive patients (mean age, 38.1 +/- 10.84 years) underwent bilateral simultaneous LASIK for myopic astigmatism (spherical equivalent ranging from -1.75 to -7.13 diopters) without any complications. Each eye was evaluated by slit-lamp biomicroscopy and noncontact specular microscopy preoperatively, within 15 minutes after LASIK and 1 day after surgery. Specular microscopy images were then analyzed to calculate endothelial cell density (ECD), coefficient of variation (CV) of cell size, and percentage of hexagonal cells. RESULTS: All corneas demonstrated marked alterations in endothelial cell morphology by slit-lamp biomicroscopy within 15 minutes after surgery that resolved by the first postoperative day. Central corneal endothelial analysis by noncontact specular microscopy confirmed pleomorphism with definite loss of hexagonality. Mean ECD was calculated to be 2,816.3 +/- 286.02 cells/mm(2) preoperatively, 2,750.85 +/- 327.95 cells/mm(2) on day 0 (p = 0.395), and 2,810.55 +/- 218.48 cells/mm(2) on day 1 (p = 0.461). Mean CV was 32.65 +/- 7.29 preoperatively, 34.4 +/- 6.19 on day 0 (p = 0.412), and 30.9 +/- 5.54 on day 1 (p = 0.067). Mean percentage of hexagonal cells was 63.35 +/- 10.76 preoperatively, 47.55 +/- 9.69 on day 0 (p = 0.000009), and 60 +/- 9.3 on day 1 (p = 0.00003). CONCLUSION: Qualitative and quantitative changes in endothelial cell morphology (i.e., decreased endothelial cell hexagonality) demonstrate that LASIK does induce an acute effect on the corneal endothelium that may represent transient endothelial cell edema.