Evolution of a minimal cell.

Possessing only essential genes, a minimal cell can reveal mechanisms and processes that are critical for the persistence and stability of life1,2. Here we report on how an engineered minimal cell3,4 contends with the forces of evolution compared with the Mycoplasma mycoides non-minimal cell from which it was synthetically derived. Mutation rates were the highest among all reported bacteria, but were not affected by genome minimization. Genome streamlining was costly, leading to a decrease in fitness of greater than 50%, but this deficit was regained during 2,000 generations of evolution. Despite selection acting on distinct genetic targets, increases in the maximum growth rate of the synthetic cells were comparable. Moreover, when performance was assessed by relative fitness, the minimal cell evolved 39% faster than the non-minimal cell. The only apparent constraint involved the evolution of cell size. The size of the non-minimal cell increased by 80%, whereas the minimal cell remained the same. This pattern reflected epistatic effects of mutations in ftsZ, which encodes a tubulin-homologue protein that regulates cell division and morphology5,6. Our findings demonstrate that natural selection can rapidly increase the fitness of one of the simplest autonomously growing organisms. Understanding how species with small genomes overcome evolutionary challenges provides critical insights into the persistence of host-associated endosymbionts, the stability of streamlined chassis for biotechnology and the targeted refinement of synthetically engineered cells2,7-9.

Phase Angle Reflects Loss of Functionality in Older Women.

OBJECTIVE: This study verified if the phase angle (PA) formed by the resistance (R) and reactance (Xc) obtained from bioimpedance (BIA) might be a useful tool to identify functionality. DESIGN AND PARTICIPANTS: It was conducted a cross-sectional study with 152 women ≥ 65 years old from the community. MEASUREMENTS: weight, height, body mass index (BMI), calf circumference (CC), hand grip strength (HGS), gait speed (GS), fat free mass (FFM), body fat (BF), PA with R and Xc from the BIA were measured. Spearman's and Pearson's correlations and the odds ratio (OR) were performed using the IBM SPSS software version 22.0. RESULTS: Sixty-four percent (n=98) women are with PA below the reference. Negative moderate significant correlation was found between PA and age (r =- 0.440*; p<0.001). Moderate significant correlation was observed between PA and GS (r = 0.484**; p<0.001). Weak significant correlation was found between PA and HGS (r = 0.177*; p = 0.029). Odds ratio (OR) demonstrated that individuals with PA above the mean value have 4.77 times more chances of having increased GS (confidence interval 2.40-9.48; 95%). Women aged below the mean value have 4.02 times more chances of having higher PA (confidence interval 2.02-7.99; 95%). Younger aged women showed 4.02 times more chances of having higher PA (confidence interval 2.02-7.99; 95%). CONCLUSIONS: Phase angle can be associated with functional tests, such as gait speed and hand grip strength, in older women.

Protein families, natural history and biotechnological aspects of spider silk.

Spiders are exceptionally diverse and abundant organisms in terrestrial ecosystems and their evolutionary success is certainly related to their capacity to produce different types of silks during their life cycle, making a specialized use on each of them. Presenting particularly tandemly arranged amino acid repeats, silk proteins (spidroins) have mechanical properties superior to most synthetic or natural high-performance fibers, which makes them very promising for biotechnology industry, with putative applications in the production of new biomaterials. During the evolution of spider species, complex behaviors of web production and usage have been coupled with anatomical specialization of spinning glands. Spiders retaining ancestral characters, such as the ones belonging to the Mygalomorph group, present simpler sorts of webs used mainly to build burrows and egg sacs, and their silks are produced by globular undifferentiated spinning glands. In contrast, Araneomorphae spiders have a complex spinning apparatus, presenting up to seven morphologically distinct glands, capable to produce a more complex set of silk polymers with different degrees of rigidness and elasticity associated with distinct behaviors. Aiming to provide a discussion involving a number of spider silks' biological aspects, in this review we present descriptions of members from each family of spidroin identified from five spider species of the Brazilian biodiversity, and an evolutionary study of them in correlation with the anatomical specialization of glands and spider's spinning behaviors. Due to the biotechnological importance of spider silks for the production of new biomaterials, we also discuss about the new possible technical and biomedical applications of spider silks and the current status of it.

Inflammatory response in a rat model of gastroschisis is associated with an increase of NF-kappaB

Babies with gastroschisis have high morbidity, which is associated with inflammatory bowel injury caused by exposure to amniotic fluid. The objective of this study was to identify components of the inflammatory response in the intestine and liver in an experimental model of gastroschisis in rats. The model was surgically created at 18.5 days of gestation. The fetuses were exposed through a hysterotomy and an incision at the right of the umbilicus was made, exposing the fetal bowel. Then, the fetus was placed back into the uterus until term. The bowel in this model had macro- and microscopic characteristics similar to those observed in gastroschisis. The study was conducted on three groups of 20 fetuses each: gastroschisis, control, and sham fetuses. Fetal body, intestine and liver weights and intestine length were measured. IL-1â, IL-6, IL-10, TNF-á, IFN-ã and NF-kappaB levels were assessed by ELISA. Data were analyzed statistically by ANOVA followed by the Tukey post-test. Gastroschisis fetuses had a decreased intestine length (means ± SD, 125 ± 25 vs 216 ± 13.9; P < 0.005) and increased intestine weight (0.29 ± 0.05 vs 0.24 ± 0.04; P < 0.005). Intestine length correlated with liver weight only in gastroschisis fetuses (Pearson’s correlation coefficient, r = 0.518, P = 0.019). There were no significant differences in the concentrations of IL-1â, TNF-á or IFN-ã in the intestine, whereas the concentration of NF-kappaB was increased in both the intestine and liver of fetuses with gastroschisis. These results show that the inflammatory response in the liver and intestine of the rat model of gastroschisis is accompanied by an increase in the amount of NF-kappaB in the intestine and liver.

Inflammatory response in a rat model of gastroschisis is associated with an increase of NF-kappaB.

Babies with gastroschisis have high morbidity, which is associated with inflammatory bowel injury caused by exposure to amniotic fluid. The objective of this study was to identify components of the inflammatory response in the intestine and liver in an experimental model of gastroschisis in rats. The model was surgically created at 18.5 days of gestation. The fetuses were exposed through a hysterotomy and an incision at the right of the umbilicus was made, exposing the fetal bowel. Then, the fetus was placed back into the uterus until term. The bowel in this model had macro- and microscopic characteristics similar to those observed in gastroschisis. The study was conducted on three groups of 20 fetuses each: gastroschisis, control, and sham fetuses. Fetal body, intestine and liver weights and intestine length were measured. IL-1beta, IL-6, IL-10, TNF-alpha, IFN-gamma and NF-kappaB levels were assessed by ELISA. Data were analyzed statistically by ANOVA followed by the Tukey post-test. Gastroschisis fetuses had a decreased intestine length (means +/- SD, 125 +/- 25 vs 216 +/- 13.9; P < 0.005) and increased intestine weight (0.29 +/- 0.05 vs 0.24 +/- 0.04; P < 0.005). Intestine length correlated with liver weight only in gastroschisis fetuses (Pearson's correlation coefficient, r = 0.518, P = 0.019). There were no significant differences in the concentrations of IL-1beta, TNF-alpha or IFN-gamma in the intestine, whereas the concentration of NF-kappaB was increased in both the intestine and liver of fetuses with gastroschisis. These results show that the inflammatory response in the liver and intestine of the rat model of gastroschisis is accompanied by an increase in the amount of NF-kappaB in the intestine and liver.

Spidroins from the Brazilian spider Nephilengys cruentata (Araneae: Nephilidae).

Spiders produce up to six different kinds of silk, each one for a specific biological function. Spider silks are also known for their unique mechanical properties. The possibility of producing new materials with similar properties motivated research on these silk proteins (spidroins). Using expression sequence tags, we identified four spidroins produced by major ampullate, minor ampullate, flagelliform and tubuliform silk glands from the Brazilian spider Nephilengys cruentata (Araneae: Nephilidae). The new protein sequences showed substantial similarity to other spidroins previously described, with high content of alanine and glycine due to the presence of the highly repetitive motifs (polyAla, (GA)n, (GGX)n, (GPGGX)n). Similarities among sequences were also observed between the different spidroins with the exception of tubuliform spidroin, which presents a unique complex amino acid sequence with high amounts of serine and low amounts of glycine.

[Choledochal cyst: a 10-year experience] / Cisto de colédoco: experiência de 10 anos.

BACKGROUND: Choledochal cyst is a rare abnormality usually found in infancy and childhood and mainly in females. Outcome depends on early diagnosis, complete resection of the cyst and proper hepaticoenterostomy.OBJECTIVE: The aim of this paper is to evaluate the outcome of 18 patients operated in ten years. METHODS: Retrospective chart review. RESULTS AND DISCUSSION: Age ranged between 20 days and 13 years (mean 3 years). Fifteen (83%) were female and 03 (17%) male. Signs presented included 15 (83%) with jaundice, 11 (61%) with dark urine, 10(55%) with pale colored stools, 09 (50%) with abdominal pain and palpable mass in only 02(11%). Ultrasonography identified the cyst in 14 (77%) patients. Endoscopic retrograde cholangio-pancreatography demonstrated a long common duct in three of four cases. Anatomical types were: 09 type I, 01 type II, 07 type IV and 01 type V. Except for one patient who had a type V cyst, all patients underwent cyst resection plus Roux-en-Y hepaticojejunostomy. There were two (11%) early postoperative deaths related to deterioration of liver function. Thirteen (86%) of the 15 patients available to follow-up were symptom-free without late complications at a mean period of three years, and two (14%) patients developed chronic pancreatitis.

[Mammary-coronary anastomosis: a new technique of approach through the brachial route for angiographic study and angioplasty]. / Anastomose mamária-coronária: nova técnica de abordagem por via braquial para estudo angiográfico e angioplastia.

PURPOSE: A new technique of mammary artery catheterization, by a brachial artery approach, utilizing a pre-molded conventional Sones catheter is described. METHODS: In a series of 300 patients, 308 procedures were performed. Three hundred internal mammary-coronary anastomosis were studied. In eight cases angioplasty were performed, five in the anterior descending artery and three in the internal mammary artery itself, with recanalization of one of the three cases. The approach was through the brachial artery homolateral to the anastomosed mammary artery. After the conventional coronarographic and bypass studies were performed, the catheter was withdrawn and pre-molded, forming a closed loop of approximately 10 mm in its distal extremity. The loop was introduced through the arteriotomy reaching the origin of the vertebral artery. The internal mammary artery was then catheterized utilizing rotation and traction movements. In the percutaneous transluminal coronary angioplasty (PTCA) procedures, the Sones catheter was replaced by a Myler right coronary catheter with a 260 cm metallic wire. RESULTS: In the 308 procedures, the internal mammary artery was catheterized in 305 instances (99.03%). In the remaining three cases selective catheterization of the internal mammary artery was not possible. In these three cases there was extreme tortuosity of the subclavian artery. The only complication observed in this series was thrombosis of the brachial artery in two cases (90.65%). In the eight patients submitted to PTCA the existing lesions were successfully dilated. CONCLUSION: Catheterization of the internal mammary artery through a brachial approach utilizing a pre-molded Sones catheter was an efficient procedure, with low incidence of complications. This approach could be the elective technique in the services that habitually utilize the brachial artery approach. It could be also an alternative for those utilizing the Judkins technique, whenever the internal mammary artery catheterization is impossible due to the anatomic characteristics of the patient.