Vitamin D and progression of carotid intima-media thickness in HIV-positive Canadians.

OBJECTIVES: Based on a growing body of evidence implicating low vitamin D status in the development of cardiovascular disease (CVD), we hypothesized that in Canadian HIV-positive adults, low 25-hydroxyvitamin D (25(OH)D) concentration would be associated with increased subclinical vascular disease progression. METHODS: We prospectively studied the relationship between baseline 25(OH)D and subsequent progression of carotid intima-media thickness (CIMT) between 2002 and 2011, in the Canadian HIV Vascular Study using stored blood specimens. RESULTS: Of the 128 participants, 89.1% were men, the mean age (standard deviation [SD]) was 46.5 (8.2) years, 93.8% were white, and 36.7% were current smokers. Mean (SD) annual CIMT follow-up was 5.9 (1.8) years (maximum 8.5 years), providing approximately 750 patient-years of follow-up. Mean (SD) CIMT progression was 0.027 (0.030) mm/year. Mean (SD) 25(OH)D was 95.0 (46.9) nmol/L. Only 13.3% of participants were vitamin D deficient (25(OH)D < 50 nmol/L), whereas 61.7% had a 25(OH)D exceeding the sufficiency threshold (75 nmol/L). Vitamin D quartiles were inversely associated with body mass index (BMI) (P = 0.034), total cholesterol to high-density lipoprotein (HDL) cholesterol ratio (P = 0.001) and parathyroid hormone concentration (P = 0.003), but not efavirenz exposure (P = 0.141). In linear regression analyses, baseline 25(OH)D as a continuous variable was inversely associated with CIMT progression in univariable (P < 0.001) and multivariable (P < 0.001) models. CONCLUSIONS: Baseline 25(OH)D was associated with CIMT progression in this relatively vitamin D replete, predominately white and male, Canadian HIV-positive population. Future research needs to establish causality as this may warrant more targeted screening or supplementation.

Laser scanning system for real-time mapping of fiber formations in meat analogues.

High moisture extrusion has been used to produce vegetable meat analogues that resemble real animal meat and can provide significant health benefits. Since visual and textural properties are key factors for consumer acceptance, assessing fiber formation in the extruded products is important for quality control purpose. Recently, we developed a nondestructive photon migration method to quantify fiber formation in meat analogues. In this study, we implemented this technique in a real-time optical scanning system. This system can scan the entire sample area in real-time and provide 2-dimensional maps to visualize the degree of fiber formation and fiber orientation in the sample. The new system has a potential to provide a fast, nondestructive means for online monitoring of the fiber formation in meat analogues.

Puffing of okara/rice blends using a rice cake machine.

Okara is the insoluble byproduct of soymilk and tofu manufactures. It is cheap, high in nutrients, and possesses great potential to be applied to functional human foods. In this study, a puffed okara/rice cake product was developed with blends of okara pellets and parboiled rice. Consumer preference and acceptance tests were conducted for the product. Okara pellets were prepared by grinding the strands obtained from extruding a mixture of dried okara and rice flour (3:2, w/w) with a twin-screw extruder. Okara pellets and parboiled rice were blended in 4 ratios, 90:10, 70:30, 40:60, and 0:100 (w/w), and tempered to 14% and 17% moisture. The blends were puffed at 221, 232, and 243 degrees C for 4, 5, or 6 s. The okara/rice cakes were evaluated for specific volume (SPV), texture, color, and percent weight loss after tumbling. Overall, the decrease in okara content and increase in moisture, heating temperature and time led to greater specific volume (SPV) and hardness, lighter color, and lower percent weight loss after tumbling. The consumer tests indicated that the okara/rice cake containing 70% okara pellets was preferred and the 90% one was liked the least. The possible drivers of liking for the puffed okara/rice cakes could be the okara content, hardness, SPV, bright color, and percent weight loss after tumbling.

Bacterial inactivation using a low-temperature atmospheric plasma brush sustained with argon gas.

This study investigated the bacterial inactivation/sterilization effects of a new atmospheric plasma source, which is a brush-shaped argon glow discharge created under 1 atm pressure. Such an atmospheric plasma brush requires extremely low power of less than 20 W to operate; and therefore is essentially a low-temperature discharge as confirmed by gas-phase temperature measurements. Two bacteria, Escherichia coli (E. coli) and Micrococcus luteus (M. luteus), seeded in various media were subjected to plasma treatment and their survivability was examined. It was found that such argon atmospheric plasma brush is very effective in destruction of the bacteria cells. With nutrient broth and standard methods agar as supporting media, a cell reduction in a level of 6 orders of magnitude was observed for E. coli within 3-4 min plasma treatment. A similar level of cell reduction was also observed for M. luteus in the two media with 2 or 3 min plasma treatment. The plasma treatment effects on the bacteria cell structures were also examined using scanning electron microscopy and the cell structure damages due to the plasma exposure were observed on both bacteria. The possible sterilization mechanism of the argon plasmas is also discussed in this article.

Comparison of graphite, aluminum, and TransHab shielding material characteristics in a high-energy neutron field.

Space radiation transport models clearly show that low atomic weight materials provide a better shielding protection for interplanetary human missions than high atomic weight materials. These model studies have concentrated on shielding properties against charged particles. A light-weight, inflatable habitat module called TransHab was built and shown to provide adequate protection against micrometeoroid impacts and good shielding properties against charged particle radiation in the International Space Station orbits. An experiment using a tissue equivalent proportional counter, to study the changes in dose and lineal energy spectra with graphite, aluminum, and a TransHab build-up as shielding, was carried out at the Los Alamos Nuclear Science Center neutron facility. It is a continuation of a previous study using regolith and doped polyethylene materials. This paper describes the results and their comparison with the previous study.

Alterations in dose and lineal energy spectra under different shieldings in the Los Alamos high-energy neutron field.

Nuclear interactions of space radiation with shielding materials result in alterations in dose and lineal energy spectra that depend on the specific elemental composition, density and thickness of the material. The shielding characteristics of materials have been studied using charged-particle beams and radiation transport models by examining the risk reduction using the conventional dose-equivalent approach. Secondary neutrons contribute a significant fraction of the total radiation exposure in space. An experiment to study the changes in dose and lineal energy spectra by shielding materials was carried out at the Los Alamos Nuclear Science Center neutron facility. In the energy range of about 2 to 200 MeV, this neutron spectrum is similar in shape within a factor of about 2 to the spectrum expected in the International Space Station habitable modules. It is shown that with a shielding thickness of about 5 g cm(-2), the conventional radiation risk increases, in some cases by as much as a factor of 2, but decreases with thicknesses of about of 20 g cm(-2). This suggests that care must be taken in evaluating the shielding effectiveness of a given material by including both the charged-particle and neutron components of space radiation.

Counts of Six Types of Bacteria on Lamb Carcasses Dipped or Sprayed with Acetic Acid at 25° or 55°C and Stored Vacuum Packaged at 0°C.

This study evaluates the sanitizing effectiveness of applying, by spraying or dipping, 1.5 or 3.0% acetic acid at either 25°C or 55°C to freshly slaughtered lamb carcasses. After vacuum packaging and during extended storage at 0°C, samples were examined for microbial populations. Each treatment reduced counts significantly compared with counts of untreated controls. Numbers of gram negative bacteria and lactobacilli were affected significantly by the temperature of acid solutions. Other variables caused insignificant differences in the amounts that counts were reduced by sanitization. Overall, dipping in 3% acetic acid at 55°C was the most effective treatment.

Evaluation of Swab and Tissue Excision Methods for Recovering Microorganisms from Washed and Sanitized Beef Carcasses 1, 2.

Samples taken from dressed beef carcasses by swabbing surfaces or excising tissues were plated to produce counts of aerobic bacteria, Enterobacteriaceae , and Escherichia coli . Counts were compared to determine efficiencies of the two sampling methods. Excised tissues produced much higher counts than did swabs, especially when washed and sanitized carcasses were sampled. Percentages recovered by swabbing appeared to be influenced by characteristics of the area sampled on the carcass. Numbers of Enterobacteriaceae and E. coli recovered by swabbing washed and sanitized carcasses were usually too few to be countable, whereas excision usually produced countable plates. The excision sampling method permitted differentiation among treatment effects of washing and sanitizing.

A Simple Qualitative Method for Detecting Cleanliness of Food Contact Surfaces.

Two tests were developed for detecting protein on food contact surfaces. Wetted swabs rubbed over surfaces on which 3 µg of protein was dried became visibly blue when reacted with Folin's test reagents. Wetted Chemstrips, available to test for protein in urine, became visibly colored on rubbing on surfaces with 0.25 µg of protein. Sensitivity of the tests varied with type of protein.

Removal of Animal Fat From Food Grade Belting as Affected by Pressure and Temperature of Sprayed Water.

This study was designed to determine the extent of removal of pork, beef and chicken fat from food grade belting with water when temperature and pressure were the experimental variables. For pork fat, no significant difference was observed between water temperature of 40 and 55°C, whereas at 25°C less fat (P<0.05) was removed regardless of pressure. Significantly more beef fat was removed at 40°C and the intermediate pressure than at 40°C and either the higher or lower pressure. For chicken fat, pressure was the only significant variable, with no interaction between pressure and temperature. The higher the pressure, the more chicken fat was removed. Overall, temperature was a more important variable than pressure. The data imply that temperature of the washing solution should be above the melting point of the type of fat to be removed.

Simple, Accurate Method for Evaluating the Amount of Fat and Protein Residue on a Food Contact Surface 1, 2.

The objective of this research was to evaluate a method for quantitatively removing pork fat and blood plasma from different food contact surfaces - glass, stainless steel, plastic and food grade belting. Two studies were conducted. In the first study, a mass balance procedure was used to determine whether the developed method could remove virtually all the fat or protein placed on stainless steel and glass. In the second study, a gravimetric method was used to verify that the amount of fat on test strips could be harvested and quantified as residue. A recovery rate of from 98% or 100% was achieved for the different types of food contact surfaces.

Inexpensive Device for CIP Cleaning of the Inside of a Beef Carcass Spray Chamber 1, 2.

An automated device for spray-type cleaning-in-place of a beef carcass washer constructed of linear polyethylene was evaluated by microbiological tests. Swabbing of seams at the welded joints, followed by plating of the swab rinse solution, disclosed that cleaning reduced counts by more than 99%. The average number of microorganisms recovered from seams after cleaning was 80/cm2. However, it was necessary also to manually clean certain joints weekly. Flat surfaces were quite adequately cleaned according to results of tests with RODAC plates. With RODAC plates, numbers of yeasts and molds recovered on potato dextrose acid agar were better indicators of sanitary condition than numbers of coliforms on violet red bile agar or numbers of staphylococci on Baird-Parker agar.