Relationships between the expression of hepatocyte nuclear factors and factors essential for lipoprotein production in a human mesenchymal stem cell line, UE7T-13.

To clarify the mechanisms regulating lipoprotein production by hepatocyte nuclear factors (HNFs), we generated four kinds of transfectants in human bone marrow mesenchymal stem cells: UE7T-13, stably expressing FOXA2 (also known as HNF3ß), HNF4α, HNF1α or co-expressing HNF4α, and HNF1α (HNF4α/HNF1α). In HNF4α/HNF1α transfectants, cellular contents of triglycerides (TG) and cholesterol were markedly higher than in UE7T-13 cells and comparable to those in human hepatoma HepG2 cells. However, TG and cholesterol, which are secreted from cells as components of lipoproteins, were hardly detected in the medium for any of the transfectants. ApoB100 and MTP, which are essential for the formation and secretion of lipoproteins, were undetectable and detected at low levels, respectively, in HNF4α/HNF1α transfectants. We suggest that enforced co-expression of HNF4α and HNF1α is effective for cellular lipid accumulation, while additional factors are probably required for lipoprotein formation and secretion.

Canonical discriminant analysis of cadmium content levels in unpolished rice using a portable near-infrared spectrometer.

Near-infrared analysis (NIRA) was applied to discriminate and determine the cadmium content levels of unpolished rice using canonical discriminant analysis (CDA). The overall correct classification rate was 85.2% for 318 NIR spectra, repeated three times for 106 samples. After a further improvement through decreased misclassification rates, NIRA could be useful as a rapid, nondestructive and convenient analytical method for primary screening and detecting of cadmium-polluted rice.

A near infrared spectroscopic discrimination of noodle flours using a principal-component analysis coupled with chemical information.

Using a portable near infrared (NIR) spectrometer, we discriminated flours for making Japanese noodles (Soba), not only relying on a statistical and mathematical approach, but also on a chemical interpretation of the NIR spectra. In original NIR spectra, the particle-size difference, which results in an undesired systematic variation, was extracted and interpreted as the first-principal component factor by a principal-component analysis. The discrimination of flour materials cannot be satisfied by this factor. However, after a standardized treatment for the original spectra, the particle-size effects were eliminated; alternatively, differences in the chemical contents were extracted as principal-component factors. Using these factors, flour material discrimination was achieved much better. This study suggests a novel idea of utilizing the wavelength contribution ratio spectra for interpreting the factors extracted from the principal-component analysis for the NIR spectra. This report also describes the relationship between the NIR spectra and the chemical-analysis data.

Taste of milk from inflamed breasts of breastfeeding mothers with mastitis evaluated using a taste sensor.

BACKGROUND: The refusal of infants to suckle from a breast that is inflamed with mastitis suggests that the taste of the milk has changed. However, the taste of milk from a breast with mastitis has never been empirically determined. The present study compares the taste of milk from breastfeeding mothers with or without mastitis and identifies specific changes in the taste of milk from mothers with mastitis. SUBJECTS AND METHODS: The intensity of four basic tastes (sourness, saltiness, bitterness, and umami) of breastmilk from 24 healthy mothers at 3-5 days and at 2-3, 4-5, and 8-10 weeks postpartum and from 14 mothers with mastitis was determined objectively using a taste sensor. The intensity of each basic taste and the concentrations of main taste substances in milk were compared between the inflamed breasts and the normal breasts of control mothers or the contralateral asymptomatic breast of mothers with unilateral mastitis. RESULTS: The transition from colostrum to mature milk was accompanied by changes in the taste of the milk, such as decreased saltiness and umami and increased bitterness and sourness. Umami and saltiness increased in milk from inflamed breasts. Contents of sodium, glutamate, and guanosine monophosphate increased in milk from inflamed breasts. CONCLUSIONS: Tastes that were specifically associated with inflamed breasts appeared to include an increase in umami and saltiness, which might have resulted from an increased content in factors associated with umami and sodium.

Refolding and activation of human prorenin expressed in Escherichia coli: application of recombinant human renin for inhibitor screening.

Human prorenin was expressed in Escherichia coli as a fusion protein of thioredoxin. The chimeric protein, which accumulated insoluble inclusion bodies, was solubilized in 4 M guanidine-HCl and refolded by an arginine-detergent buffer system and by systematic dialysis. The refolded fusion prorenin was activated by trypsin. The antiserum against human kidney renin specifically inhibited the recombinant human renin activity. Using the recombinant human renin, we screened its inhibitory activity in fermented soybean paste (miso) and demonstrated that miso contained renin inhibitory activity derived from soybean. The IC(50) values for soybean and steamed soybean extracts were determined to be 1.9 and 1.6 mg/ml, respectively. This is the first demonstration of renin inhibitory activity in miso and soybean.