The pre-Columbian dog from Arica,Chile

Burials and mummies of dogs from the Arica, Chile, area are described. It is concluded that these dogs were brought to this area 2500 years ago by shepherds from the highlands and are still present, relatively unchanged.     

NH resonances of Ribonuclease S-peptide in aqueous solution. Low temperature n.m.r. study

A detailed study of the NH resonances of Ribonuclease-S-peptide (1-19 N-terminal fragment of Ribonuclease A) has been carried out in H2O, pH 3.0, in the temperature range 1-31 degrees, and ionic strength 0-1 M. Individual assignments of all NH amide signals have been achieved by means of extensive double resonance experiments. The folding of S-peptide at low temperature has been monitored by examination of the several NH resonance parameters: first, the nonlinearity of chemical shift vs. temperature plots; second, the selective broadening observed for signals assigned to residues 3-13; and third, the decrease of 3JHNCH coupling constants belonging to this region of the polypeptide chain. All these results are in agreement with the formation of a folded structure at low temperature, which is similar to the one found for the S-peptide in the RNase S crystal.     

The oxidation of cyclothionine by D-aspartate oxidase

Cyclothionine was found to be a substrate for bovine kidney D-Aspartate oxidase. The substrate, prepared chemically as a mixture of the possible stereoisomers, exhibits an inhibition at elevated concentrations. Compounds structurally related to cyclothionine, like TMDA and alpha-alpha'-iminodipropionic acid, have also been assayed with the enzyme.     

Effect of parturition on serum glycerol and non-esterified fatty acids in obese and normal weight women

Serum glycerol and NEFA content variations are examined before and after labor in obese and normal weighing women (35 subjects). Blood glycerol and NEFA are shown to increase before delivery. Glycerol values are shown to drop to normal immediately after delivery, while NEFA values diminish to a lesser extent. Statistical analysis shown that blood glycerol increase could be pregnancy-dependent in both normal weighing and obese women, but that NEFA increase could be pregnancy-dependent in normal weighing women only. Obesity increases blood glycerol and NEFA concentration considerably, thus masking the effects of pregnancy.     

Cloning and sequencing of a full length cDNA coding for human retinol-binding protein.

We have isolated and sequenced a cDNA clone coding for human Retinol Binding Protein. The sequence indicates that Retinol Binding Protein is synthesized as a single polypeptide chain precursor which is then matured to the secreted protein by removal of a leader peptide. Southern and Northern blot analysis suggest that the gene is present in one or few copies per haploid genome and is transcribed in a single mRNA species.     

Dose dependent inhibition of B-16 melanoma growth in vivo by a synthetic analogue of PGE2

Daily intratumor administration of 16,16-dimethyl-PGE2-methyl ester in two different dosages inhibited tumor growth in C57Bl/6J mice bearing subcutaneous B-16 melanomas. The larger dose (20 microgram/day/mouse) produced a 68% decrease in tumor volume, a 69% decrease in tumor weight and a 60% decrease in the number of cells in mitotic phase. The smaller dose (10microgram/day/mouse) was one fifth less effective than the 20microgram dose but produced similar changes. Histological examination of tumors revealed no significant differences either in the inflammatory cell population or the amount of necrosis in the control and di-M-PGE2-treated tumors.     

Associations between retinol-binding protein 4 and cardiometabolic risk factors and subclinical atherosclerosis in recently postmenopausal women: Cross-sectional analyses from the KEEPS Study

ABSTRACT: BACKGROUND: The published literature regarding the relationships between retinol-binding protein 4 (RBP4) and cardiometabolic risk factors and subclinical atherosclerosis is conflicting, likely due, in part, to limitations of frequently used RBP4 assays. Prior large studies have not utilized the gold-standard Western Blot analysis of RBP4 levels. METHODS: Full-length serum RBP4 levels were measured by Western Blot in 709 postmenopausal women screened for the Kronos Early Estrogen Prevention Study. Cross-sectional analyses related RBP4 levels to cardiometabolic risk factors, carotid artery intima-media thickness (CIMT), and coronary artery calcification (CAC). RESULTS: The mean age of women was 52.9 (+/- 2.6) years, and the median RBP4 level was 49.0 (interquartile range 36.9-61.5) ug/mL. Higher RBP4 levels were weakly associated with higher triglycerides (age, race, and smoking-adjusted partial Spearman correlation coefficient= 0.10; P=0.01), but were unrelated to blood pressure, cholesterol, C-reactive protein, glucose, insulin, and CIMT levels (all partial Spearman correlation coefficients [less than or equal to]0.06, P>0.05). Results suggested a curvilinear association between RBP4 levels and CAC, with women in the bottom and upper quartiles of RBP4 having higher odds of CAC (odds ratio [95% confidence interval] 2.10 [1.07-4.09], 2.00 [1.02-3.92], 1.64 [0.82-3.27] for the 1st, 3rd, and 4th RBP4 quartiles vs. the 2nd quartile). However, a squared RBP4 term in regression modeling was non-significant (P=0.10). CONCLUSIONS: In these healthy, recently postmenopausal women, higher RBP4 levels were weakly associated with elevations in triglycerides and with CAC, but not with other risk factors or CIMT. These data using the gold standard of RBP4 methodology only weakly support the possibility that perturbations in RBP4 homeostasis may be an additional risk factor for subclinical coronary atherosclerosis. Trial Registration: ClinicalTrials.gov number NCT00154180.     

Comparison of three fungal laccases from Rigidoporus lignosus and Pleurotus ostreatus: correlation between conformation changes and catalytic activity

The conformation changes in solution of three fungal laccases in different environmental conditions were examined by circular dichroism (CD) and electron paramagnetic resonance (EPR) spectroscopy. CD measurements indicate that the secondary structure of proteins depends slightly on the pH or ionic strength, though the presence of salt could interfere in the molecular recognition process between substrates and enzymes. The enzymes, however, are highly destabilized by prolonged exposure to low pH or high temperature. The observed unfolding of the proteins coincides with their inactivation and, in some cases, with precipitation. On the other hand, these conditions do not determine the disruption of the geometric arrangement of their metal centres, and this fact suggests that these centres represent the more stable core of the proteins.