Regulation of growth by the trehalose pathway: Relationship to temperature and sucrose

Carbon signaling can override carbon supply in the regulation of growth. At least some of this regulation is imparted by the sugar signal trehalose 6-phosphate (T6P) through the protein kinase, SnRK1. This signaling pathway regulates biosynthetic processes involved in growth under optimal growing conditions. Recently, using a seedling system we showed that under sub-optimal conditions, such as cold, carbon signaling by T6P/ SnRK1 enables recovery of growth following relief of the stress. The T6P/ SnRK1 mechanism thus could be selected as a means of improving low temperature tolerance. High-throughput automated Fv/Fm measurements provide a potential means to screen for T6P/ SnRK1, and here we confirm through measurements of Fv/Fm in rosettes that T6P promotes low temperature tolerance and recovery during cold to warm transfer. Further, to better understand the coordination between sugars, trehalose pathway, and temperature-dependent growth, we examine the interrelationship between sugars, trehalose phosphate synthase (TPS), and trehalose phosphate phosphatase (TPP) gene expression and T6P content in seedlings. Sucrose, particularly when fed exogenously, correlated well with TPS1 and TPPB gene expression, suggesting that these enzymes are involved in maintaining carbon flux through the pathway in relation to sucrose supply. However, when sucrose accumulated to higher levels under low temperature and low N, TPS1 and TPPB expression were less directly related to sucrose; other factors may also contribute to regulation of TPS1 and TPPB expression under these conditions. TPPA expression was not related to sucrose content and all genes were not well correlated with endogenous glucose. Our work has implications for understanding acclimation to sink-limited growth conditions such as low temperature and for screening cold-tolerant genotypes with altered T6P/ SnRK1 signaling.     

Changing Mortality Profile among HIV-Infected Patients in Rio de Janeiro,Brazil: Shifting from AIDS to Non-AIDS Related Conditions in the HAART Era

Introduction

We describe temporal trends in the mortality rates and factors associated with AIDS and non-AIDS related mortality at the Evandro Chagas Clinical Research Institute (IPEC), Oswaldo Cruz Foundation (FIOCRUZ).

Methods

Adult patients enrolling from 1986 through 2009 with a minimum follow up of 60 days were included. Vital status was exhaustively checked using patients’ medical charts, through active contact with individuals and family members and by linkage with the Rio de Janeiro Mortality database using a previously validated algorithm. The CoDe protocol was used to establish the cause of death. Extended Cox proportional hazards models were used for multivariate modeling.

Results

A total of 3530 individuals met the inclusion criteria, out of which 868 (24.6%) deceased; median follow up per patient was 3.9 years (interquartile range 1.7–9.2 years). The dramatic decrease in the overall mortality rates was driven by AIDS-related causes that decreased from 9.19 deaths/100PYs n 1986–1991 to 1.35/100PYs in 2007–2009. Non-AIDS related mortality rates remained stable overtime, at around 1 death/100PYs. Immunodeficiency significantly increased the hazard of both AIDS-related and non-AIDS-related causes of death, while HAART use was strongly associated with a lower hazard of death from either cause.

Conclusions

Our results confirm the remarkable decrease in AIDS-related mortality as the HIV epidemic evolved and alerts to the conditions not traditionally related to HIV/AIDS which are now becoming more frequent, needing careful monitoring.     

Serum Metalloproteinases 2 and 9 as Predictors of Gait Status,Pressure Ulcer and Mortality after Hip Fracture

Introduction

The aim of this study is to evaluate the serum activity of metalloproteinases (MMPs) -2 and -9 as predictors of pressure ulcer (PU), gait status and mortality 6 months after hip fracture.

Methods

Eighty-seven patients over the age of 65 admitted to the orthopedic unit from January to December 2010 with hip fracture were prospectively evaluated. Upon admission, patient demographic information, including age, gender and concomitant diseases, was recorded. Blood samples were taken for analysis of MMP -2 and -9 activity by gel zymography and for biochemical examination within the first 72 hours of the patient’s admission, after clinical stabilization. The fracture pattern (neck, trochanteric or subtrochanteric), time from admission to surgery, surgery duration and length of hospital stay were also recorded.

Results

Two patients were excluded due to the presence of pathological fractures (related to cancer), and three patients were excluded due to the presence of PU before admission. Eighty-two patients, with a mean age of 80.4 ± 7.3 years, were included in the analysis. Among these patients, 75.6% were female, 59.8% had PU, and 13.4% died 6 months after hip fracture. All patients underwent hip fracture repair. In a univariate analysis, there were no differences in serum MMP activity between hip fracture patients with or without PU. In addition, the multiple logistic regression analysis models, which were adjusted by age, gender, length of hospital stay and C-reactive protein, showed that the pro-MMP-9 complexed with neutrophil gelatinase-associated lipocalin form (130 kDa) was associated with gait status recovery 6 months after hip fracture.

Conclusions

In conclusion, serum pro-MMP-9 is a predictor of gait status recovery 6 months after hip fracture.     

FAS/FASL Expression Profile as a Prognostic Marker in Squamous Cell Carcinoma of the Oral Cavity

FAS/FASL altered expression may cause tumor protecting immunomodulation, with a direct impact on patient prognosis. FAS expression was studied in 60 squamous cell carcinomas of the oral cavity. FAS expression did not show a significant association with tumor histopathological characteristics, but was significantly associated with lymph node positivity. FAS expression was significantly associated with disease specific death and negative FAS expression was an independent risk factor, increasing risk 4 times when compared to positive expression. When FAS and FASL expression results were combined, we were able to define high, intermediate and low risk profiles. Disease-free and disease-specific survival were significantly correlated with FAS/FASL expression profiles. The high risk category was an independent marker for earlier disease relapse and disease-specific death, with approximately 4- and 6-fold increased risk, respectively, when compared to the low risk profile. Risk profiles based on FAS/FASL expression showed that high risk was significantly associated with increased disease relapse and death, as well as shorter disease-free or disease-specific survival. This categorization, added to patient clinical data, may facilitate the choice of therapy, minimizing treatment failure and increasing disease control.     

Evidence of a landlocked reproducing population of the marine pejerrey Odontesthes argentinensis (Actinopterygii; Atherinopsidae)

In South America, the order Atheriniformes includes the monophyletic genus Odontesthes with 20 species that inhabit freshwater, estuarine and coastal environments. Pejerrey Odontesthes argentinensis is widely distributed in coastal and estuarine areas of the Atlantic Ocean and is known to foray into estuaries of river systems, particularly in conditions of elevated salinity. However, to our knowledge, a landlocked self-sustaining population has never been recorded. In this study, we examined the pejerrey population of Salada de Pedro Luro Lake (south-east of Buenos Aires Province, Argentina) to clarify its taxonomic identity. An integrative taxonomic analysis based on traditional meristic, landmark-based morphometrics and genetic techniques suggests that the Salada de Pedro Luro pejerrey population represents a novel case of physiological and morphological adaptation of a marine pejerrey species to a landlocked environment and emphasises the environmental plasticity of this group of fishes.     

Fish biodiversity of Saint Peter and Saint Paulʼs Archipelago,Mid-Atlantic Ridge,Brazil: new records and a species database

Saint Peter and Saint Paul's Archipelago (SPSPA), one of the smallest and most isolated island groups in the world, is situated on the Mid-Atlantic Ridge, between Brazil and the African continent. SPSPA has low species richness and high endemism; nonetheless, the diversity of fishes from deep habitats (>30 m depth) had not been previously studied in detail. Several expeditions conducted between 2009 and 2018 explored the shallow and deep reefs of SPSPA using scuba, closed-circuit rebreathers, manned submersibles, baited remote underwater stereo-videos (stereo-BRUV) and fishing between 0 and 1050 m depth. These expeditions yielded 41 new records of fishes for SPSPA: 9 in open waters, 9 in shallow waters (0–30 m), 8 in mesophotic ecosystems (30–150 m) and 15 in deeper reefs (>150 m). Combined with literature records of adult pelagic, shallow and deep-reef species, as well as larvae, the database of the fish biodiversity for SPSPA currently comprises 225 species (169 recorded as adult fishes and 79 as larvae, with 23 species found in both stages). Most of them (112) are pelagic, 86 are reef-associated species and 27 are deep-water specialists. Species accumulation curves show that the number of fish species has not yet reached an asymptote. Whereas the number of species recorded in SPSPA is similar to that in other oceanic islands in the Atlantic Ocean, the proportion of shorefishes is relatively lower, and the endemism level is the third highest in the Atlantic. Twenty-nine species are listed as threatened with extinction. Observations confirm the paucity of top predators on shallow rocky reefs of the island, despite the presence of several pelagic shark species around SPSPA. Because all of the endemic species are reef associated, it is argued that the new marine-protected areas created by the Brazilian government do not ensure the protection and recovery of SPSPA's biodiversity because they allow exploitation of the most vulnerable species around the archipelago itself. This study suggests a ban on reef fish exploitation inside an area delimited by the 1000 m isobath around the islands (where all known endemics are concentrated) as the main conservation strategy to be included in the SPSPA management plan being prepared by the Brazilian government.     

Selenium improves photosynthesis and induces ultrastructural changes but does not alleviate cadmium-stress damages in tomato plants

Protoplasma - The application of Se to plants growing under Cd contamination may become an alternative strategy to minimize Cd damage. However, there is no specific information available regarding...