C.L. Hicks

Aluminum bioavailability from basic sodium aluminum phosphate, an approved food additive emulsifying agent, incorporated in cheese

Oral aluminum (Al) bioavailability from drinking water has been previously estimated, but there is little information on Al bioavailability from foods. It was suggested that oral Al bioavailability from drinking water is much greater than from foods. The objective was to further test this hypothesis. Oral Al bioavailability was determined in the rat from basic [26Al]-sodium aluminum phosphate (basic SALP) in a process cheese. Consumption of approximately 1g cheese containing 1.5% or 3% basic SALP resulted in oral Al bioavailability (F) of approximately 0.1% and 0.3%, respectively, and time to maximum serum 26Al concentration (Tmax) of 8-9h. These Al bioavailability results were intermediate to previously reported results from drinking water (F approximately 0.3%) and acidic-SALP incorporated into a biscuit (F approximately 0.1%), using the same methods. Considering the similar oral bioavailability of Al from food vs. water, and their contribution to the typical humans daily Al intake ( approximately 95% and 1.5%, respectively), these results suggest food contributes much more Al to systemic circulation, and potential Al body burden, than does drinking water. These results do not support the hypothesis that drinking water provides a disproportionate contribution to total Al absorbed from the gastrointestinal tract.

An Electron Microscope Study of the Axonemal Ultrastructure in Human Spermatozoa From Male Smokers and Nonsmokers

OBJECTIVE To investigate possible abnormalities or deterioration of the sperm axonemal ultrastructure in men who have smoked a large quantity of cigarettes (> 20 per day) for a prolonged period. DESIGN Semen specimens were collected by patients via masturbation; qualitative characteristics of the sperm were assessed and ultrastructural analysis of the sperm axoneme was performed using standard operating procedures for electron transmission microscopy. SETTING The Andrology Institute of Lexington, Lexington, Kentucky, and the Department of Histology and Embryology, University of Salonika, Greece (collaborative effort). PATIENT(S) Twenty-nine men (mean age +/- SD, 30.7 +/- 2.1 years) who smoked a mean (+/- SD) of 30.7 +/- 2.1 cigarettes per day for 10.7 +/- 0.7 years and 15 men who never smoked (mean age +/- SD, 30.4 +/- 2.2 years) participated in this study. MAIN OUTCOME MEASURE(S) Ultrastructural organization of the sperm axoneme in male smokers and nonsmokers. RESULT(S) Changes in the number and the arrangement of axonemal microtubules were noted in the smoker group when compared to the nonsmoker group. The incidence of axonemal abnormalities was higher in spermatozoa from smokers compared with that in spermatozoa from nonsmokers. CONCLUSION(S) Smoking a large quantity of cigarettes per day, under the conditions of the current study, severely affected the ultrastructure of the flagellum and, more specifically, it affected the axoneme of the human spermatozoon.

Effect of calcium and enzyme in cutting time prediction of coagulating goats’ milk using a light scattering sensor

An on-line fibre optic sensor measuring backscatter at 880 nm was used for predicting the cutting time of goats’ milk. A factorial design was utilised to test the kid rennet and enzyme from Mucor miehei at three levels of added CaCl2. A cutting time prediction equation using the diffuse reflectance parameter, Tmax; predicted the cutting time with a standard error of 0.55 min. Tmax and cutting time decreased with CaCl2 addition. Coagulation was faster for kid rennet. The sensor was found useful for comparing the activity of milk-clotting enzymes. r 2002 Elsevier Science Ltd. All rights reserved.

Synthesis of novel isoluminol probes and their use in rapid bacterial assays

Rapid assays for bacteria have been developed utilizing novel LysLysLys-isoluminol (14) and GluGlu-isoluminol (16) probes that have been derived from peptides which potentially mimic bacteriophage attachment protein binding regions. Compared to two conventional methods that are widely used, namely nucleic acid probes and polymerase chain reaction (PCR) assays, these types of probes may eventually have certain advantages, such as high sensitivity, and short preparation and assay time.

FIBER OPTIC SENSOR RESPONSE TO HIGH LEVELS OF FAT IN CREAM

A light backscatter technique using optical fibers to deliver and receive light was investigated for measuring the milkfat content of unhomogenized cream. Light backscatter through cream at wavelengths of 450 to 900 nm was measured for fiber separation distances from 2 to 6.5 mm and for cream containing 10 to ~40 weight percent (wt%) milkfat. Unhomogenized cream (~40 wt% milkfat) was mixed with skim milk (~0.05 wt% milkfat) to yield samples with five different milkfat levels. Three optical response models were tested for correlation with milkfat content: one using the light intensity measurement at a single separation distance, the second using the ratio of the light intensity at two distances, and a third using the light intensity as a function of separation distance based on the backscatter of light in a particulate solution. The calibration equations from all three methods were used to predict milkfat content in the evaluation samples with root mean square errors (RMSEs) of 1.5 to 2.0 wt%. Statistical analysis did not find a significant difference between the three methods. For simplicity, using the ratio of the intensities measured and two different separation distances is attractive for further sensor design.

Enhanced real-time optical detection of micron-sized particles in water using standing ultrasonic wave fields

The overall goal of the research was to develop a water quality monitoring system that simultaneously concentrates micron-size particles and bacterial cells in the nodal planes of a standing ultrasonic wave field and monitors the level of contamination using light transmission measurements. Ultrasonic concentration is an attractive method for in-line, continuous sensing since it has no moving parts and is not limited by a physical barrier, e.g., a filter, which may get plugged over time. The degree of concentration was evaluated over a range of initial particle concentration. Results showed that particle banding occurred within seconds of sonication - allowing for real-time analysis - and the degree of concentration increased with decreasing initial concentration of particles in the suspension. Concentration factors of 5 to 10 were achievable. Results from this study can be used in the design and fabrication of sensitive water quality monitoring systems that would permit real-time water quality analysis.