Short communication: Carora cattle show high variability in alpha(s1)-casein.

The objective of this study was to analyze the genetic variability of milk proteins of the Carora, a shorthorned Bos taurus cattle breed in Venezuela and in other Southern American countries that is primarily used for milk production. A total of 184 individual milk samples were collected from Carora cattle in 5 herds in Venezuela. The milk protein genes alpha(s1)-casein (CN) (CSN1S1), beta-CN (CSN2), kappa-CN (CSN3), and beta-lactoglobulin (LGB) were typed at the protein level by isoelectrofocusing. It was necessary to further analyze CSN1S1 at the DNA level by a PCR-based method to distinguish CSN1S1*G from B. Increased variation was found in particular at the CSN1S1 gene, where 4 variants were identified. The predominant variant was CSN1S1*B (frequency = 0.8). The second most common CSN1S1 variant was CSN1S1*G (0.101), followed by CSN1S1*C (0.082). Moreover, a new isoelectrofocusing pattern was identified, which may result from a novel CSN1S1 variant, named CSN1S1*I, migrating at an intermediate position between CSN1S1*B and CSN1S1*C. Six cows carried the variant at the heterozygous condition. For the other loci, predominance of CSN2*A2 (0.764), CSN3*B (0.609), and LGB*B (0.592) was observed. Haplotype frequencies (AF) at the CSN1S1-CSN2-CSN3 complex were also estimated by taking association into account. Only 7 haplotypes showed AF values >0.05, accounting for a cumulative frequency of 0.944. The predominant haplotype was B-A2-B (frequency = 0.418), followed by B-A2-A (0.213). The occurrence of the G variant is at a rather high frequency, which is of interest for selection within the Carora breed because of the negative association of this variant with the synthesis of the specific protein. From a cheese-making point of view, this variant is associated with improved milk-clotting parameters but is negatively associated with cheese ripening. Thus, milk protein typing should be routinely carried out in the breed, with particular emphasis on using a DNA test to detect the CSN1S*G variant. The CSN1S*G allele is likely to have descended from the Brown Swiss, which contributed to the Carora breed and also carries this allele.

Development of a single nucleotide polymorphism genotyping microarray platform for the identification of bovine milk protein genetic polymorphisms.

The objective of this study was to develop and validate a fast method for typing the main mutations of bovine milk protein genes by using microarray technology. An approach based on the ligation detection reaction (LDR) and a universal array (UA) was used. Polymorphisms in both the coding and noncoding sequences of alpha(S1)-casein, beta-casein, kappa-casein, and beta-lactoglobulin genes were considered because of their well-known effects on milk composition and cheese production. A total of 22 polymorphic sites, corresponding to 21 different variants, were included in the diagnostic microarray. First, a multiplex PCR was developed to amplify all the DNA target sequences simultaneously. Second, the LDR-UA assay was implemented. The method was validated by analyzing 100 Italian Friesian DNA samples, which were also genotyped by conventional methods both at the protein level by means of milk isoelectrofocusing and at the molecular level using PCR-RFLP and PCR-single strand conformation polymorphism techniques. The genotypes obtained using the LDR-UA approach were in full agreement with those obtained by the conventional analyses. An important result of the LDR-UA assay was a more accurate genotyping of the different milk protein alleles than was found with conventional typing methods. At the kappa-casein gene, in fact, 4 samples were heterozygous (3 reference samples and 1 validation sample) for an allele coding for Thr(136) and Ala(148). This variant, which can be considered as the wild type of the genus Bos, is not usually identifiable by the conventional typing methods used. The multiplex PCR-LDR-UA approach developed provides for an accurate, inexpensive, and high-throughput assay that does not exhibit false positive or false negative signals, thus making it highly suitable for animal genotyping.

Comparative assessment of continuum-scale models of bimolecular reactive transport in porous media under pre-asymptotic conditions.

We compare the ability of various continuum-scale models to reproduce the key features of a transport setting associated with a bimolecular reaction taking place in the fluid phase and numerically simulated at the pore-scale level in a disordered porous medium. We start by considering a continuum-scale formulation which results from formal upscaling of this reactive transport process by means of volume averaging. The resulting (upscaled) continuum-scale system of equations includes nonlocal integro-differential terms and the effective parameters embedded in the model are quantified directly through computed pore-scale fluid velocity and pore space geometry attributes. The results obtained through this predictive model formulation are then compared against those provided by available effective continuum models which require calibration through parameter estimation. Our analysis considers two models recently proposed in the literature which are designed to embed incomplete mixing arising from the presence of fast reactions under advection-dominated transport conditions. We show that best estimates of the parameters of these two models heavily depend on the type of data employed for model calibration. Our upscaled nonlocal formulation enables us to reproduce most of the critical features observed through pore-scale simulation without any model calibration. As such, our results clearly show that embedding into a continuum-scale model the information content associated with pore-scale geometrical features and fluid velocity yields improved interpretation of typically available continuum-scale transport observations.

Pepsinogen Group I radioimmunoassay and total serum pepsinogen colorimetric determination: a comparative study in normal subjects and in peptic ulcer patients.

Pepsinogens, proteolytic enzymes produced by peptic cells of the stomach and discharged into the gastric lumen as well as into the blood have been divided into two groups: PG-I, originating from chief cells, and PG-II, mainly from antrum peptic cells. Both total serum pepsinogen (s-Pg) and PG-I have been separately reported as being significantly increased in gastric (GU) and duodenal ulcer (DU) patients and related to maximal acid output. In order to ascertain the relationship between s-Pg measured by means of the colorimetric Uete method, and PG-I determined by RIA method, these were assayed in 72 control subjects, 35 GU and 95 DU patients. s-Pg was found to be significantly increased both in GU and DU patients in comparison with control subjects. Likewise PG-I was significantly enhanced in GU and DU patients as compared with controls. A significant direct correlation between s-Pg and PG-I was found in all the subjects studied (r = 0.732).

Chemical and pharmacological investigations of constituents of Eleutherine bulbosa (Miller) Urb. (Iridaceae).

Eleutherin and eleutherol extracted from bulbs of Eleutherine bulbosa (Miller) Urb. (Iridaceae), collected in the Amazonian jungle and grown in Italy, were tested for biological properties. The extraction procedure and the results of antibacterial, cytotoxicity, and pharmacological assays are reported. Eleutherin has a weak and transient effect of decreasing the prothrombin time (in vivo in rats) and a weak antibacterial activity on Bacillus subtilis (in vitro).

A new look at the measurement and interpretation of enzyme assays.

Some methodological problems in clinical enzymology, including instability of enzymes in the incubation mixture and requirements for optimal reaction conditions, are highlighted. The importance of a knowledge of fundamental enzyme biochemistry and physiology as the basis for their diagnostic application is stressed, and the different behaviour of some hepatic enzymes--namely, GOT, GPT, gamma-GT, and OCT, in various pathological conditions is traced back to their characteristic biochemical and physiological properties. In the field of urinary enzymes a knowledge of the ideal requirements for the enzyme investigation of the various renal functions and of the properties of potentially valuable enzymes permits a critical selection of the really useful ones.

Lipid bound sialic acid in cancer patients.

Serum lipid-bound sialic acid (LSA) was measured with a recently described procedure in 108 healthy subjects and in 138 patients with a variety of solid tumors and hematologic malignancies. At the time of serum sampling, 128 patients had active disease and 10 patients had no evidence of disease. LSA was elevated in 104 of 128 (81.2%) patients with active disease, while carcinoembryonic antigen, analyzed in 74, was elevated only in 21 (28.4%) (P less than 0.05). Sensitivity of the serum LSA test ranged from 66% for breast and gastrointestinal cancer to 92% for lung cancer. In patients with lung cancer, ovarian cancer or Hodgkin's disease, LSA was correlated with the extent of disease and it also proved to be useful in following the course of disease. Our preliminary data indicate that this test can be used as a monitor of tumor burden.

In vitro and in vivo behaviour of narciclasine released from matrices based on poly (2-hydroxyethyl methacrylate).

Narciclasine (1,2,3,7-tetrahydroxy-8,9-methylendioxy-1,2,3,4-tetrahydrophena ntridone) is a natural substance with strong antimitotic effects on cells and potential antitumor activity. Its release form a hydrogel matrix was studied with the purpose of avoiding the concentration spikes of the parenteral administration. The matrix prepared by gamma ray polymerization of a mixture of 2-hydroxyethyl methacrylate (85%) and trimethylolpropane trimethacrylate (15%) was found to release narciclasine for several days, according to a diffusion controlled mechanism. In agreement with its antimitotic effect, narciclasine inhibited the growth rate of healthy mice, when the drug-loaded matrix was introduced subcutaneously. Antitumor effect was observed in an experimental model of Erlich ascitic tumor when low amounts of tumor cells were inoculated. No effect was observed at high concentrations of inoculum or towards solid tumors (Sarcoma 180). This behaviour was related to the rapid clearance of narciclasine from the body which prevented the reaching of sufficient therapeutical concentrations. A pharmacokinetic investigation carried out by an original method of assay demonstrated that narciclasine was accumulated in significant amounts in the kidney only and eliminated in urine with a half time of less than 20 min.