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PubMed1999

Foods contributing to absolute intake and variance in intake of selected vitamins, minerals and dietary fiber in middle-aged Japanese.

Using 351 one-day weighted diet records, we selected foods providing vitamins, minerals and dietary fiber according to contribution analysis (CA) and multiple regression analysis (MRA). Vitamin C was supplied by various vegetables and fruits, and carotene was specifically derived from green-yellow vegetables based on MRA as well as CA. Vitamin A was provided by green-yellow vegetables, fruits, chicken egg and milk (whole) according to CA; whereas chicken liver and pork liver were major sources according to MRA. Vitamin E was mainly of vegetable origin as determined by CA, and largely of spinach, safflower oil and pumpkin as determined by MRA. Vitamin D was mainly derived from chicken egg, fish and mushroom based on CA, and particularly from fish based on MRA. Calcium was supplied by milk (whole), soy products and chicken egg as determined by CA; while milk, tofu and various small fishes were the main contributors to variance. Magnesium was provided by soy products, well-milled rice and spinach according to both analyses, and iron by chicken egg, spinach and soy products. Zinc was largely derived from well-milled rice, followed by chicken egg and milk (whole) as determined by CA, and copper was provided by well-milled rice, soy and wheat products. Dietary fiber was supplied by vegetable sources, whether water soluble or insoluble, based on both analytic methods.

Animals↗
PubMed2005

Single cell manipulation, analytics, and label-free protein detection in microfluidic devices for systems nanobiology.

Single cell analytics for proteomic analysis is considered a key method in the framework of systems nanobiology which allows a novel proteomics without being subjected to ensemble-averaging, cell-cycle, or cell-population effects. We are currently developing a single cell analytical method for protein fingerprinting combining a structured microfluidic device with latest optical laser technology for single cell manipulation (trapping and steering), free-solution electrophoretical protein separation, and (label-free) protein detection. In this paper we report on first results of this novel analytical device focusing on three main issues. First, single biological cells were trapped, injected, steered, and deposited by means of optical tweezers in a poly(dimethylsiloxane) microfluidic device and consecutively lysed with SDS at a predefined position. Second, separation and detection of fluorescent dyes, amino acids, and proteins were achieved with LIF detection in the visible (VIS) (488 nm) as well as in the deep UV (266 nm) spectral range for label-free, native protein detection. Minute concentrations of 100 fM injected fluorescein could be detected in the VIS and a first protein separation and label-free detection could be achieved in the UV spectral range. Third, first analytical experiments with single Sf9 insect cells (Spodoptera frugiperda) in a tailored microfluidic device exhibiting distinct electropherograms of a green fluorescent protein-construct proved the validity of the concept. Thus, the presented microfluidic concept allows novel and fascinating single cell experiments for systems nanobiology in the future.

Animals↗
PubMed2004

Quantitative imaging of lymphocyte membrane protein reorganization and signaling.

Changes in membrane protein localization are critical to establishing cell polarity and regulating cell signaling. Fluorescence microscopy of labeled proteins allows visualization of these changes, but quantitative analysis is needed to study this aspect of cell signaling in full mechanistic detail. We have developed a novel approach for quantitative assessment of membrane protein redistribution based on four-dimensional video microscopy of fluorescently labeled proteins. Our analytic system provides robust automated methods for cell surface reconstruction, cell shape tracking, cell-surface distance measurement, and cluster formation analysis. These methods permit statistical analyses and testing of mechanistic hypotheses regarding cell signaling. We have used this approach to measure antigen-dependent clustering of signaling molecules in CD4+ T lymphocytes, obtaining clustering velocities consistent with single-particle tracking data. Our system captures quantitative differences in clustering between signaling proteins with distinct biological functions. Our methods can be generalized to a range of cell-signaling phenomena and enable novel applications not feasible with single-particle studies, such as analysis of subcellular protein localization in live organ culture.

Algorithms↗
PubMed2000

World Cancer Research Fund/American Institute of Cancer Research 1997 recommendations: applicability to digestive tract cancer in Japan.

OBJECTIVES: This paper reviewed analytic epidemiological studies of the major Japanese digestive tract cancers, i.e. esophageal, stomach, colon and rectal. The applicability of the recommendations for prevention of these cancers by the World Cancer Research Fund/American Institute of Cancer Research (W&A) to Japan is considered. METHODS: Papers were searched by the MEDLINE for the period 1966 through 1997. Among them, 43 relevant papers including data from Japan were reviewed. RESULTS: Results for 11 lifestyle-related factors were considered. Cigarette smoking was a strong and consistent, thus, convincing, risk factor for esophageal cancer, and a possible risk factor for stomach and colorectal cancer. Excessive consumption of alcohol was a convincing risk factor for esophageal cancer, and a possible risk factor for stomach and colorectal cancer. Excessive salt intake was a risk factor supported by some strong evidence but inconsistent; therefore, it is a probable risk factor for stomach cancer and a possible risk factor for colorectal cancer. Low physical activity was a probable risk factor for colorectal cancer. On the other hand, sufficient intake of vegetables, including green-yellow vegetables, and fruits was regarded as a possible protective factor for these cancers. CONCLUSIONS: These observations were mostly consistent with those reported by W&A; therefore the recommendations by W&A for prevention of these cancers may be considered applicable to the current Japanese population.

Alcohol Drinking↗
PubMed2002

Fluorophor-linked immunosorbent assay: a time- and cost-saving method for the characterization of antibody fragments using a fusion protein of a single-chain antibody fragment and enhanced green fluorescent protein.

A novel assay, referred to as fluorophor-linked immunosorbent assay (FLISA), for the characterization of single-chain antibody fragments (scFvs) is described. The principle of the method is the fusion of an scFv to enhanced green fluorescent protein (EGFP). The scFv domain, which binds to the immobilized hapten, can be detected by measuring the fluorescence of the EGFP domain. The time-consuming binding of secondary antibodies and enzyme reaction, necessary for enzyme-linked immunosorbent assays (ELISAs) are not required. Consequently, the assay time of 1.5 h needed to complete the FLISA is much shorter than that of comparable ELISAs, which require about 5 h. This renders the FLISA suitable for applications where a short assay time is essential, such as screening of mutant libraries of scFvs in directed evolution experiments or monitoring of the amount of functionally expressed recombinant protein during production processes. In contrast to a comparable ELISA, the FLISA showed no saturation when determining the relative amount of functional scFv. The amount of the soluble fraction of cell extracts from Escherichia coli expressing the fusion protein and the normalized fluorescence signal showed a linear correlation with R(2)>0.99. The usefulness of a competitive FLISA for the detection of analytes is shown exemplarily by the detection of s-triazines with the s-triazine-specific scFv K411B.

Antibody Specificity↗
PubMed1981

Comparative efficiency of brilliant green, bismuth sulfite, Salmonella-Shigella, hektoen enteric, and xylose lysine desoxycholate agars for the recovery of Salmonella from foods: collaborative study.

The relative efficiency of brilliant green (BG), bismuth sulfite (BS), Salmonella-Shigella (SS), xylose lysine desoxycholate (XLD), and Hektoen enteric (HE) agars for the recovery of Salmonella from 5 foods was collaboratively studied in 11 laboratories. The analytical efficiency of various paired combinations of the 5 agars was statistically compared according to 3 parameters: (1) productivity or recovery of Salmonella, (2) rate of enumeration of cultures that were false positive for Salmonella, and (3) rate of enumeration of false-negative reactions. In descending order of productivity, the sequential ranking was BS, XLD, HE, BG, and SS agars. In ascending order, the rates of false-positive reactions based on a statistical analysis of paired agar combinations was HE, BS, BG and XLD (tie), and SS agars. Analogously, in ascending order, the sequence of false-negative reaction rates was BS, XLD, HE, BG, and SS agars. The combination of BS, XLD, and HE agars is more efficient for recovery of Salmonella from foods than is the present official combination of BG, BS, and SS agars. The revision of official final action method 46.054 to replace the combination of BG, BS, and SS agars with a combination of BS, XLD, and HE agars has been adopted official first action.

Agar↗
PubMed1999

Average optical performance of the human eye as a function of age in a normal population.

PURPOSE: To determine the average optical performance of the human eye, in terms of the modulation transfer function (MTF), as a function of age. METHODS: An apparatus was constructed to measure the ocular MTF, based on the recording of images of a green, 543-nm laser-point source after reflection in the retina and double pass through the ocular media. MTFs were computed from the average of three 4-second-exposure double-pass images recorded by a slow-scan, cooled charge-coupled device camera. The ocular MTF was measured for three artificial pupil diameters (3 mm, 4 mm, and 6 mm) with paralyzed accommodation under the best refractive correction in 20 subjects for each of three age categories: young subjects aged 20 to 30 years, middle-aged subjects aged 40 to 50 years, and older subjects aged 60 to 70 years. The selected subjects passed an ophthalmologic examination, excluding subjects with any form of ocular or retinal disease, spherical or cylindrical refractive errors exceeding 2 D, and corrected visual acuity lower than 1 (0.8 in the older age group). RESULTS: The average MTF was determined for each age group and pupil diameter. A two-parameter analytical expression was proposed to represent the average MTF in each age group for every pupil diameter. The ocular MTFs declined as age increased from young to older groups. The SD of the MTF results within age groups was lower than the differences between the mean for each group. CONCLUSIONS: The average optical performance of the human eye progressively declines with age. These MTF results can serve as a reference for determining mean ocular optics according to age.

Adult↗
PubMed2006

A novel analytical method for in vivo phosphate tracking.

Genetically-encoded fluorescence resonance energy transfer (FRET) sensors for phosphate (P(i)) (FLIPPi) were engineered by fusing a predicted Synechococcus phosphate-binding protein (PiBP) to eCFP and Venus. Purified fluorescent indicator protein for inorganic phosphate (FLIPPi), in which the fluorophores are attached to the same PiBP lobe, shows P(i)-dependent increases in FRET efficiency. FLIPPi affinity mutants cover P(i) changes over eight orders of magnitude. COS-7 cells co-expressing a low-affinity FLIPPi and a Na(+)/P(i) co-transporter exhibited FRET changes when perfused with 100 microM P(i), demonstrating concentrative P(i) uptake by PiT2. FLIPPi sensors are suitable for real-time monitoring of P(i) metabolism in living cells, providing a new tool for fluxomics, analysis of pathophysiology or changes of P(i) during cell migration.

Animals↗
PubMed2002

Planar near-field acoustical holography in a moving medium.

Near-field acoustical holography (NAH) is a well-established method to study acoustic radiation near a stationary sound source in a homogeneous, stationary medium. However, the current theory of NAH is not applicable to moving sound sources, such as automobiles and trains. In this paper, the inclusion of a moving medium (i.e., moving source and receiver) is introduced in the wave equation and a new set of equations for plannar NAH is developed. Equations are developed for the acoustic pressure, particle velocity, and intensity when mean flow is either parallel or perpendicular to the hologram plane. If the source and the measurement plane are moving at the same speed, the frequency Doppler effect is absent, but a wave number Doppler effect exists. This leads to errors when reconstructing the acoustic field both towards and away from the source using static NAH. To investigate these errors, a point source is studied analytically using planar NAH with flow in one direction. The effect of the medium moving parallel to the hologram plane is noted by a shift of the radiation circle in wave number space (k-space). A k-space Green's function and a k-space filter are developed that include the effects of the moving medium.

Journal Article↗
PubMed1985

Analysis of vaterite microspherolith deposits on a pure cholesterol gallstone by X-ray diffraction, X-ray microanalysis and infrared absorption techniques.

Minute globular concretions of light-green and light-brown colour were found as deposits in the pits at the rough surface of a pure cholesterol gallstone. They were analyzed by scanning electron microscopic, X-ray diffraction, X-ray microanalytical and infrared absorption spectrometric methods. In scanning electron microscopy, the concretions appeared as ovoid microspheroliths varying from 5 to 30 micron in size. The microspheroliths presented smooth and rough surfaces; the reason for these different types of surface remained unclear. X-ray diffraction and infrared absorption analysis revealed that the microspheroliths were mainly composed of vaterite and the host plate-like crystals were cholesterol. By energy-dispersive X-ray microanalysis, large quantities of calcium without significant quantities of phosphorus were detected in the microspheroliths. Calcium was absent in the plate-like crystals and could not be detected in the central part of the stone. In the pigmented periphery of the stone, some silicon and iron were found. The presence of calcite, aragonite and iron-containing pigment materials in the concretion is suggested. From the textural point of view, the analytical data strongly suggest that the stone-forming conditions suddenly changed from a cholesterol-favourable stasis condition to a condition favoring the deposition of calcium carbonate possible as the result of haemorrhage.

Absorption↗
PubMed2006

Continuous photobleaching in vesicles and living cells: a measure of diffusion and compartmentation.

We present a comprehensive and analytical treatment of continuous photobleaching in a compartment, under single photon excitation. In the very short time regime (t<0.1 ms), the diffusion does not play any role. After a transition (or short time regime), one enters in the long time regime (t>0.1-5 s), for which the diffusion and the photobleaching balance each other. In this long time regime, the diffusion is either fast (i.e., the photobleaching probability of a molecule diffusing through the laser beam is low) so that the photobleaching rate is independent of the diffusion constant and dependent only of the laser power, or the diffusion is slow (i.e., the photobleaching probability is high) and the photobleaching rate is mainly dependent on the diffusion constant. We illustrate our theory by using giant unilamellar vesicles ranging from approximately 10 to 100 microm in diameter, loaded with molecules of various diffusion constants (from 20 to 300 microm2/s) and various photobleaching cross sections, illuminated under laser powers between 3 and 100 microW. We also demonstrated that information about compartmentation can be obtained by this method in living cells expressing enhanced green fluorescent proteins or that were loaded with small FITC-dextrans. Our quantitative approach shows that molecules freely diffusing in a cellular compartment do experience a continuous photobleaching. We provide a generic theoretical framework that should be taken into account when studying, under confocal microscopy, molecular interactions, permeability, etc.

Biophysics↗
PubMed2006

Dual-color time-integrated fluorescence cumulant analysis.

We introduce dual-color time-integrated fluorescence cumulant analysis (TIFCA) to analyze fluorescence fluctuation spectroscopy data. Dual-color TIFCA utilizes the bivariate cumulants of the integrated fluorescent intensity from two detection channels to extract the brightness in each channel, the occupation number, and the diffusion time of fluorophores simultaneously. Detecting the fluorescence in two detector channels introduces the possibility of differentiating fluorophores based on their fluorescence spectrum. We derive an analytical expression for the bivariate factorial cumulants of photon counts for arbitrary sampling times. The statistical accuracy of each cumulant is described by its variance, which we calculate by the moments-of-moments technique. A method that takes nonideal detector effects such as dead-time and afterpulsing into account is developed and experimentally verified. We perform dual-color TIFCA analysis on simple dye solutions and a mixture of dyes to characterize the performance and accuracy of our theory. We demonstrate the robustness of dual-color TIFCA by measuring fluorescent proteins over a wide concentration range inside cells. Finally we demonstrate the sensitivity of dual-color TIFCA by resolving EGFP/EYFP binary mixtures in living cells with a single measurement.

Animals↗
PubMed2006

Green chemistry in urinalysis for trichloroethanol and trichloroacetic acid as markers of exposure to chlorinated hydrocarbon solvents.

The aim of the present study was to develop a method of urinalysis for trichloroacetic acid (TCA) and trichloroethanol (TCE), and therefore total trichloro-compounds (TTC) as the sum, with least use of hazardous chemicals, being green in that sense. After acid hydrolysis followed by dilution with an ethanol (EtOH)-methanol (MeOH)-water mixture, capillary gas-choromatography with an electron-capture detector can quantify TCA and TCE in the diluted hydrolyzate. Comparison studies showed that the results were identical among three methods, i.e., 1. the method developed in the present study, 2. a head-space GC with acid hydrolysis of conjugated TCE and methyl-esterification of TCA, and 3. traditional colorimetry with Fujiwara reaction. When applied to exposure-excretion analysis, the three methods gave results reproducible to each other. Over-all evaluation therefore was such that the method developed in the present study is as equally reliable as previously developed methods. It should be further noted that the procedures are very simple, with minimum use of occupationally or environmentally hazardous chemicals. In case the determination of only TCA is requested, it is possible to skip the hydrolysis step so that the treatment prior to the GC analysis is even simpler, i.e., just a 60-fold dilution of the urine sample with the EtOH-MeOH-water mixture. It was also demonstrated that correction of urinary analyte levels for urine density in terms of creatinine or specific gravity did not improve the correlation with the intensity of TRI exposure.

Biomarkers↗
PubMed1999

Purification and initial characterization of primate satellite chromatin.

Nucleoprotein hybridization, a method for the purification of specific DNA sequences as chromatin, was employed to fractionate primate centromeric alpha satellite chromatin as a first step in the identification and analysis of novel centromere-enriched proteins. In order to optimize the amount of material available for further study, cultured African green monkey cells were employed because satellite DNA represents approximately 25% of the genome. Two chromatin preparations were compared for the yield and total protein content of purified material. Regardless of the preparation, alpha satellite sequences were enriched to near purity. Since intact satellite chromatin is relatively refractile to the enzymatic digestion steps in the method, the total amount of solubilized material available for purification is rather low. In contrast, nuclei treated with acidic washes to extract histone H1 provided solubilized material enriched in satellite sequences. In addition, this material is more efficiently utilized in an affinity chromatography step. However, the extraction of many non-histones at low pH resulted in very low yields of protein in the purified fraction. Two-dimensional gel comparisons of proteins associated with H1-containing satellite chromatin after iodination of total chromatin proteins revealed a number of polypeptides enriched to varying degrees in the purified fraction. The electrophoretic mobilities of a few enriched polypeptides corresponded to previously identified heterochromatin-associated proteins while many others appear to be novel. The work presented validates nucleoprotein hybridization as a purification method for highly repeated sequences as chromatin in analytical amounts. The fact that a number of the enriched proteins are visible in stained gels of bulk chromatin proteins suggests that further biochemical analysis can be carried out on these polypeptides directly.

Animals↗
PubMed2004

[A study on the association between tea consumption and stroke].

OBJECTIVE: The aim of the study was to investigate the association between tea consumption and stroke. METHODS: A cross sectional study was conducted in autumn, 1998. The subjects were from 12 provinces in China. 15 groups of populations were selected by cluster randomized sampling and each group had about 1000 persons, aged from 35 to 60 years old. 14 212 subjects had complete data for analysis. Data regarding tea drinking would include drinking status, dose and type of teas. Logistic regression was used to analyze the association between tea consumption and stroke. RESULTS: There was a strong inverse correlation between tea drinking and stroke after adjusting other risk factors of stroke (P < 0.05). The odds ratio (OR) of stroke was 0.60 [95% confidence interval (CI): 0.42 - 0.85] for subjects who drank tea compared to those who did not. Increased amount of tea consumption per month was associated with decreased stroke prevalence. The association for tea consumption over 150 gram per month and stroke was statistically significant (P < 0.05) with an OR value of 0.56 (95% CI: 0.36 - 0.89). Analytical results indicated that the OR value was 0.24 (95% CI: 0.06 - 1.01) for black tea and other tea (P = 0.05). The OR value was 0.35 (95% CI: 0.18 - 0.72) for green tea (P < 0.01), and 0.75 (95% CI: 0.51 - 1.11) for jasmine tea (P > 0.05). CONCLUSION: Tea drinking was independently associated with prevalence of stroke which might play a role in the prevention of the disease.

Adult↗
PubMed2004

Bioeffects of low-frequency ultrasonic gene delivery and safety on cell membrane permeability control.

OBJECTIVE: To develop a novel method of ultrasonic naked gene delivery (UNGD); to examine the relationship between optimal parameters of ultrasound exposure and cell membrane permeability, enzymes, and free radicals; and to find optimal control parameters that were realizable, reliable, and noncytotoxic for use in gene therapy. METHODS: Suspensions of chicken, rabbit, and rat red blood cells and S180 cells were exposed to a calibrated ultrasonic field with different parameters in both the still and flowing states to obtain optimal parameters for UNGD. The optimal parameters then were used to implement UNGD. We examined morphologic characteristics, membrane permeability, enzymes, free radicals, naked gene expression efficiency, cell damage threshold, and cell viability by laser scanning confocal microscopy, fluorescent microscopy, flow cytometry, and spectrophotometry. RESULTS: Green fluorescent protein (GFP) as a reporter was delivered into S180 cells under the optimal parameters without cell damage or cytotoxicity. The transfection rate (mean +/- SD) was approximately 35.83% +/- 2.53% (n = 6) in viable cells, and cell viability was 90.17% +/- 1.47% (n = 6). The intensity of GFP expression with UNGD showed a higher fluorescent peak over both an adeno-associated virus vector-GFP group and a control group (P < .001). Additionally, malondialdehyde, hydroxyl free radicals, alkaline phosphatase, and acid phosphatase displayed an S-shaped growth model (r = 0.98 +/- 0.01) in response to permeability and morphologic alteration. CONCLUSIONS: Under optimal conditions, low-frequency ultrasound can safely deliver naked genes into cells without causing cell damage. The analytical results indicate that, except for subcavitation, free radical products are responsible for bioeffects in gene delivery. The constant E of energy deposition at 90% cell viability is the optimal control factor, and 80% viability represents the damage threshold. Optimal gene uptake by cells and safety depend on E. Constant E can be applied to control the gene delivery effect in combination with other parameters.

Animals↗
PubMedDate not supplied

Comparison of helium leak test and vacuum leak test using canned foods: collaborative study.

Two can leak tests were compared by 7 collaborators. In the helium leak test, pressurized helium is applied to the outside of the container, and a headspace gas sample from the can is then analyzed for the presence of helium. The vacuum test is described in the Bacteriological Analytical Manual. Ninety No. 303 cans of creamed-style corn, green beans, carrots, fruit cocktail, and whole-kernel corn were shipped in 3 groups. Two groups of 30 cans had 10 dented flat cans, 5 flat controls (nondented), 10 dented swollen cans, and 5 swollen control cans (nondented). The third group had 10 dented swollen cans and 5 swollen control cans. Of 600 cans analyzed, 37 (6.2%) were deleted from the analysis because results were not available for both tests. One laboratory was constrained by scheduling to analyze 15 of 45 swollen cans. The helium leak test found 12 (13%) positives of 92 nondented swollen cans. One pressurization test yielded 7 of those 12 positives. Of the 400 dented cans sent as possible leakers, the helium test found 267 positives, and the vacuum test found 181. Five of the 7 analysts had significantly (alpha = 0.05) higher percent positive helium results. One analyst found more leakers by the vacuum leak test. Both tests found fewer positives in the swollen dented cans than in the flat dented cans. After exposure to pressurized helium, all cans with greater than 8 psi headspace pressure were positive helium leakers. The method was adopted official first action.

Atmospheric Pressure↗
PubMedDate not supplied

Exposure to toxic waste sites: an investigative approach.

Improper dumping and storage of hazardous substances and whether these practices produce significant human exposure and health effects are growing concerns. A sequential approach has been used by the Centers for Disease Control and the Agency for Toxic Substances and Disease Registry in investigating potential exposure to and health effects resulting from environmental contamination with materials such as heavy metals, volatile organic compounds, and pesticide residues at sites throughout the United States. The strategy consists of four phases: site evaluation, pilot studies of exposure or health effects, analytic epidemiology studies, and public health surveillance. This approach offers a logical, phased strategy to use limited personnel and financial resources of local, State, national, or global health agency jurisdictions optimally in evaluating populations potentially exposed to hazardous materials in waste sites. Primarily, this approach is most helpful in identifying sites for etiologic studies and providing investigative leads to direct and focus these studies. The results of such studies provide information needed for making risk-management decisions to mitigate or eliminate human exposures and for developing interventions to prevent or minimize health problems resulting from exposures that already have occurred.

Centers for Disease Control and Prevention, U.S.↗