Expression and purification of the recombinant ConBr (Canavalia brasiliensis lectin) produced in Escherichia coli cells

ConBr, a D-glucose/D-mannose-specific lectin from Canavalia brasiliensis seeds, was produced in Escherichia coli from a (c)DNA clone subcloned to pET15b expression vector. The recombinant lectin (rConBr) was purified by one-step immobilized metal-affinity chromatography using an amino-terminal hexahistidine tag. By SDS-PAGE and Western blot, rConBr was highly pure with an apparent molecular mass of 37 kDa. N-terminal sequence analysis revealed a single sequence, confirming the identity of the expressed protein as the pre-pro-ConBr.     

Omega-3 Fatty Acid Deficiency in Infants before Birth Identified Using a Randomized Trial of Maternal DHA Supplementation in Pregnancy

Background

DHA is accumulated in the central nervous system (CNS) before birth and is involved in early developmental processes, such as neurite outgrowth and gene expression.

Objective

To determine whether fetal DHA insufficiency occurs and constrains CNS development in term gestation infants.

Design

A risk reduction model using a randomized prospective study of term gestation single birth healthy infants born to women (n = 270) given a placebo or 400 mg/day DHA from 16 wk gestation to delivery. Fetal DHA deficiency sufficient to constrain CNS development was assessed based on increased risk that infants in the placebo group would not achieve neurodevelopment scores in the top quartile of all infants in the study.

Results

Infants in the placebo group were at increased risk of lower language development assessed as words understood (OR 3.22, CL 1.49–6.94, P = 0.002) and produced (OR 2.61, CL 1.22–5.58, P = 0.01) at 14 mo, and words understood (OR 2.77, CL 1.23–6.28, P = 0.03) and sentences produced (OR 2.60, CL 1.15–5.89, P = 0.02) at 18 mo using the McArthur Communicative Developmental Inventory; receptive (OR 2.23, CL 1.08–4.60, P = 0.02) and expressive language (OR 1.89, CL 0.94–3.83, P = 0.05) at 18 mo using the Bayley Scales of Infant Development III; and visual acuity (OR 2.69, CL 1.10–6.54, P = 0.03) at 2 mo.

Trial Registration

ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT00620672","term_id":"NCT00620672"}}NCT00620672     

Morphometry,Bite-Force,and Paleobiology of the Late Miocene Caiman Purussaurus brasiliensis

Purussaurus brasiliensis thrived in the northwestern portion of South America during the Late Miocene. Although substantial material has been recovered since its early discovery, this fossil crocodilian can still be considered as very poorly understood. In the present work, we used regression equations based on modern crocodilians to present novel details about the morphometry, bite-force and paleobiology of this species. According to our results, an adult Purussaurus brasiliensis was estimated to reach around 12.5 m in length, weighing around 8.4 metric tons, with a mean daily food intake of 40.6 kg. It was capable of generating sustained bite forces of 69,000 N (around 7 metric tons-force). The extreme size and strength reached by this animal seems to have allowed it to include a wide range of prey in its diet, making it a top predator in its ecosystem. As an adult, it would have preyed upon large to very large vertebrates, and, being unmatched by any other carnivore, it avoided competition. The evolution of a large body size granted P. brasiliensis many advantages, but it may also have led to its vulnerability. The constantly changing environment on a large geological scale may have reduced its long-term survival, favoring smaller species more resilient to ecological shifts.     

An insertion within the factor IX gene: hemophilia BEl Salvador.

A patient with moderate to severe hemophilia B has been found to have a large insertion within his factor IX gene. The site of insertion is located in a DNA segment of approximately 0.8 kb between exon IV and an EcoRI site within intron D. The size of the DNA insertion is approximately 6 kb, and it contains at least two TaqI sites, two EcoRI sites, and one HindIII site. The insert probably originates from outside the FIX gene and does not represent an internal duplication. We propose that this abnormal FIX gene be called FIX El Salvador in recognition of the birthplace of the patient.     

Glycine Betaine Enhances Growth of Nitrogen-Fixing Bacteria <Emphasis Type="Italic">Gluconacetobacter diazotrophicus</Emphasis> PAL5 Under Saline Stress Conditions

In this study, the effect of glycine betaine as osmoprotectant compound for Gluconacetobacter diazotrophicus PAL5 was evaluated by kinetic growth parameters. Batch fermentation assays were performed employing media supplemented with different sodium chloride concentrations to simulate saline stress conditions. Salt concentrations of 50–300 mM led to decreased cell concentrations, while the maximum specific growth rates and cell productivities were reduced at concentrations above 100-mM NaCl. Salt inhibition was mainly observed in media with 200- and 300-mM NaCl, in which drastic changes in cell morphology were also noted. The addition of glycine betaine to the media showed to be efficient to counteract the salt inhibitory effect by increasing some fermentation parameters. However, the osmoprotectant was not able to revert the polymorphism promoted by higher salt concentrations.