Significant Decrease In Survival Research Articles

Do laboratory species protect endangered species? Interspecies variation in responses to 17β-estradiol, a model endocrine active compound.

Although the effects of estrogens on model laboratory species are well documented, their utility as surrogates for other species, including those listed as endangered, are less clear. Traditionally, conservation policies are evaluated based on model organism responses but are intended to protect all species in an environment. We tested the hypothesis that the endangered Rio Grande silvery minnow (Hybognathus amarus) is more vulnerable to endocrine disruption-as assessed through its larval predator-escape performance, survival, juvenile sex ratios, and whole-body vitellogenin concentration-than the commonly used toxicological model species fathead minnow (Pimephales promelas) and the bluegill sunfish (Lepomis macrochirus). Fish were exposed concurrently for 21 days to the model endocrine active compound (EAC) 17ß-estradiol (E2) at 10 ng E2/L and 30 ng E2/L in a flow-through system using reconstituted water that simulated the physicochemical conditions of the Middle Rio Grande in New Mexico, USA. No significant differences were observed between the fathead and silvery minnow in larval predator-escape response or juvenile sex ratio. Rio Grande silvery minnow survival decreased significantly at day 14 compared with the other two species; by day 21, both cyprinid species (silvery minnow and fathead minnow) exhibited a significant decrease in survival compared with bluegill sunfish, a member of the family Centrarchidae. Male Rio Grande silvery minnow showed a significant increase in whole-body vitellogenin concentration in the 10 ng/L treatment, whereas fathead minnow and bluegill sunfish showed no significant increases in vitellogenin concentrations across treatments. Our study showed response differences to estrogen exposures between the two cyprinid species and further divergence in responses between the families Cyprinidae and Centrarchidae. These results suggest that commonly used laboratory model organisms may be less sensitive to EACs than the endangered Rio Grande silvery minnow. However, this study supports the continued use of surrogate species for the beneficial implementation of water-quality regulations for the protection of threatened and endangered species if phylogenetic relationships are taken into consideration.

Assessment of selenium toxicity on the life cycle of Caenorhabditis elegans.

Selenium (Se) is a growing problem of global concern. Se can cause adverse effects on reproductive systems, which have been linked to declines in animal populations. The soil nematode Caenorhabditis elegans (C. elegans) is a ubiquitous soil organism that is increasingly utilized as a model organism in aquatic and soil toxicology. In the present study, the experimental data for individual body length, survival rate, brood size, and hatching rate were used to evaluate the possible effects of selenite [Se(IV)] on C. elegans. A stage-classified matrix model was applied to the experimental data to provide information on the population dynamics of C. elegans and to assess the Se(IV)-affected asymptotic population growth rate. Estimates of the survival probability showed significant decreases in survival at all stages when C. elegans was exposed to Se(IV). The growth probability of C. elegans in the L1 stage showed the most significant decline, from 0.11 h(-1) (for the control) to 0.04 h(-1) [for exposure to 3 mM Se(IV)]. These results showed that Se(IV) has a profound impact on C. elegans population dynamics. The asymptotic population growth rate (λ) was found to range from 1.00 to 0.64 h(-1) for increasing Se(IV) concentrations, implying a potential risk of population decrease for C. elegans exposure to a Se(IV)-contaminated environment. Our study shows how a mechanistic view based on the Se(IV) effects on the soil nematode C. elegans can promote a life cycle toxicity assessment. An important implication of this analysis is that mathematical models can be used to produce a population stage structure, to give clarity to the analysis of the key population-level endpoint (the asymptotic population growth rate) of population dynamics, and to evaluate the influences for the response of other species to environmental Se. These models sequentially provide candidate environmental criteria for the evaluation of the population impact of Se.

Do Locking Screws Work in Plates Bent at Holes?

To assess whether plate bending at a hole significantly changes the biomechanical properties of a locked screw. Coronal plane bends of 5-, 15-, or 45-degree angles were placed in 3.5-mm locking compression plates with the apex at a locking hole. An additional 45-degree angle test group was created in which a threaded screw head insert was placed before bending. Ten plates were tested in each group and compared with nonbent controls in a stepwise cyclic loading protocol. Statistically significant differences in protocol survival were shown between the control group and the 15-degree angle (P = 0.006) and 45-degree angle (P = 0.0007) groups. An apparent decrease in protocol survival in the 5-degree angle group did not reach statistical significance (P = 0.17). The average number of cycles survived was significantly different between the control group and the 15-degree angle (P = 0.027) and 45-degree angle (P = 0.0002) groups. The mean cycles to failure for the 5-degree angle group was 16% lower than for controls but did not reach statistical significance (P = 0.37). The test group bent to an angle of 45 degrees after placement of a threaded screw head insert showed no difference in protocol survival or in mean number of cycles survived compared with the regular 45-degree angle group. Bending of a 3.5-mm locking compression plate by more than 5 degrees at a locking hole results in a statistically significant decrease in survival of the corresponding locked screw. This effect cannot be prevented by the placement of a threaded screw head insert before bending.

Invasive adenoma and pituitary carcinoma: a SEER database analysis

Invasive pituitary adenomas and pituitary carcinomas are clinically indistinguishable until identification of metastases. Optimal management and survival outcomes for both are not clearly defined. The purpose of this study is to use the Surveillance, Epidemiology, and End Results (SEER) database to report patterns of care and compare survival outcomes in a large series of patients with invasive adenomas or pituitary carcinomas. One hundred seventeen patients diagnosed between 1973 and 2008 with pituitary adenomas/adenocarcinomas were included. Eighty-three invasive adenomas and seven pituitary carcinomas were analyzed for survival outcomes. Analyzed prognostic factors included age, sex, race, histology, tumor extent, and treatment. A significant decrease in survival was observed among carcinomas compared to invasive adenomas at 1, 2, and 5 years (p = 0.047, 0.001, and 0.009). Only non-white race, male gender, and age ≥65 were significant negative prognostic factors for invasive adenomas (p = 0.013, 0.033, and <0.001, respectively). There was no survival advantage to radiation therapy in treating adenomas at 5, 10, 20, or 30 years (p = 0.778, 0.960, 0.236, and 0.971). In conclusion, pituitary carcinoma patients exhibit worse overall survival than invasive adenoma patients. This highlights the need for improved diagnostic methods for the sellar phase to allow for potentially more aggressive treatment approaches.

Toxicity and transfer of metal oxide nanoparticles from microalgae to sea urchin larvae

Nanoparticles (NPs) contained in commercial products are released and enter into the aquatic ecosystem, posing serious possible risks to the environment and affecting the food chain. Therefore, investigating the potential toxicity of NPs on aquatic organisms has become an important issue. This study assessed the toxicity and trophic transfer of metal oxide NPs from marine microalgae (Cricosphaera elongata) to the larvae of the sea urchin Paracentrotus lividus. Larvae (24 h old) were fed on 2000 cell mL−1 48 h of microalgae contaminated with 5 mg L−1 of several metal oxide NPs (SiO2, SnO2, CeO2, Fe3O4) for 15 days. Larval viability and development were monitored from the 4-arm stage to the 8-arm pluteus stage. A significant decrease in survival was observed in larvae fed with microalgae exposed to SiO2 and CeO2 NPs. Abnormal development, characterised by skeletal degeneration and altered rudiment growth, was observed in all larvae fed with contaminated NP algae. Our findings revealed that SiO2 and CeO2 NPs exerted a toxic effect in the trophic interaction analysed, by reducing sea urchin larval viability, and all metal oxide NPs induced toxicological effects. In conclusion, metal oxide NPs may enter the food chain and become bioavailable for marine organisms, affecting their development.

Age-specific cerebral perfusion pressure thresholds and survival in children and adolescents with severe traumatic brain injury*.

Evidence-based traumatic brain injury guidelines support cerebral perfusion pressure thresholds for adults at a class 2 level, but evidence is lacking in younger patients. The purpose of this study is to identify the impact of age-specific cerebral perfusion pressure thresholds on short-term survival among patients with severe traumatic brain injury. Institutional review board-approved, prospective, observational cohort study. Level I or II trauma centers in New York State. Data on all patients with a postresuscitation Glasgow Coma Score less than 9 were added in the Brain Trauma Foundation prospective New York State TBI-trac database. We calculated the survival rates and relative risks of mortality for patients with severe traumatic brain injury based on predefined age-specific cerebral perfusion pressure thresholds. A higher threshold and a lower threshold were defined for each age group: 60 and 50 mm Hg for 12 years old or older, 50 and 35 mm Hg for 6-11 years, and 40 and 30 mm Hg for 0-5 years. Patients were stratified into age groups of 0-11, 12-17, and 18 years old or older. Three exclusive groups of CPP-L (events below low cerebral perfusion pressure threshold), CPP-B (events between high and low cerebral perfusion pressure thresholds), and CPP-H (events above high cerebral perfusion pressure threshold) were defined. As an internal control, we evaluated the associations between cerebral perfusion pressure events and events of hypotension and elevated intracranial pressure. Survival was significantly higher in 0-11 and 18 years old or older age groups for patients with CPP-H events compared with those with CPP-L events. There was a significant decrease in survival with prolonged exposure to CPP-B events for the 0-11 and 18 years old and older age groups when compared with the patients with CPP-H events (p = 0.0001 and p = 0.042, respectively). There was also a significant decrease in survival with prolonged exposure to CPP-L events in all age groups compared with the patients with CPP-H events (p< 0.0001 for 0- to 11-yr olds, p = 0.0240 for 12- to 17-yr olds, and p < 0.0001 for 18-yr old and older age groups). The 12- to 17-year olds had a significantly higher likelihood of survival compared with adults with prolonged exposure to CPP-L events (< 50 mm Hg). CPP-L events were significantly related to systemic hypotension for the 12- to 17-year-old group (p = 0.004) and the 18-year-old and older group (p < 0.0001). CPP-B events were significantly related to systemic hypotension in the 0- to 11-year-old group (p = 0.014). CPP-B and CPP-L events were significantly related to elevated intracranial pressure in all age groups. Our data provide new evidence that cerebral perfusion pressure targets should be age specific. Furthermore, cerebral perfusion pressure goals above 50 or 60 mm Hg in adults, above 50 mm Hg in 6- to 17-year olds, and above 40 mm Hg in 0- to 5-year olds seem to be appropriate targets for treatment-based studies. Systemic hypotension had an inconsistent relationship to events of low cerebral perfusion pressure, whereas elevated intracranial pressure was significantly related to all low cerebral perfusion pressure events across all age groups. This may impart a clinically important difference in care, highlighting the necessity of controlling intracranial pressure at all times, while targeting systolic blood pressure in specific instances.

Genetic and environmental factors associated with laboratory rearing affect survival and assortative mating but not overall mating success in Anopheles gambiae sensu stricto.

Anopheles gambiae sensu stricto, the main vector of malaria in Africa, is characterized by its vast geographical range and complex population structure. Assortative mating amongst the reproductively isolated cryptic forms that co-occur in many areas poses unique challenges for programs aiming to decrease malaria incidence via the release of sterile or genetically-modified mosquitoes. Importantly, whether laboratory-rearing affects the ability of An. gambiae individuals of a given cryptic taxa to successfully mate with individuals of their own form in field conditions is still unknown and yet crucial for mosquito-releases. Here, the independent effects of genetic and environmental factors associated with laboratory rearing on male and female survival, mating success and assortative mating were evaluated in the Mopti form of An. gambiae over 2010 and 2011. In semi-field enclosures experiments and despite strong variation between years, the overall survival and mating success of male and female progeny from a laboratory strain was not found to be significantly lower than those of the progeny of field females from the same population. Adult progeny from field-caught females reared at the larval stage in the laboratory and from laboratory females reared outdoors exhibited a significant decrease in survival but not in mating success. Importantly, laboratory individuals reared as larvae indoors were unable to mate assortatively as adults, whilst field progeny reared either outdoors or in the laboratory, as well as laboratory progeny reared outdoors all mated significantly assortatively. These results highlight the importance of genetic and environment interactions for the development of An. gambiae's full mating behavioral repertoire and the challenges this creates for mosquito rearing and release-based control strategies.

Assessing the Impact of a Sacral Resection on Morbidity and Survival After Extended Radical Surgery for Locally Recurrent Rectal Cancer

To describe the experience of sacrectomy with extended radical resection in the treatment of locally recurrent rectal cancer. Resections of the bony pelvis, especially the sacrum, are becoming more common as part of extended radical exenterations for patients with recurrent rectal cancer. However, sacrectomy has been shown to carry a significant decrease in survival. Morbidity rates have been associated with the level of the sacrectomy (ie, >S3 junction). An analysis was conducted using prospective data from patients with recurrent rectal cancer who underwent pelvic exenteration involving sacrectomy from July 1998 until June 2011. The impact of the proximal level of sacrectomy [low (≤S3) vs high (≥S2-S3 disc)] was compared. Of 240 exenteration patients, 79 underwent sacrectomy, with 49 for recurrent rectal cancer. An R0 margin was achieved in 36 (74%) patients. Achievement of clear operative margins (R0) conferred a large and significant benefit for disease-free survival compared with R1 and R2 resections (median 45 months vs 19 and 8 months, respectively; P = 0.045). Complications were reported in 40 (82%) patients, with major and minor complications in 19 (39%) and 38 (78%) patients, respectively. The proximal level of the sacrectomy (high vs low) did not significantly impair the ability to achieve a clear margin and was not associated with an increase in major or minor complications. This large, single-center series has demonstrated that extended pelvic exenteration involving sacrectomy has excellent R0 margins and survival rates for recurrent rectal cancer. A high sacrectomy has comparable results with a more distal abdominosacral resection.

Size-Dependent Effects of Micro Polystyrene Particles in the Marine Copepod Tigriopus japonicus

We investigated the effects of three sizes of polystyrene (PS) microbeads (0.05, 0.5, and 6-μm diameter) on the survival, development, and fecundity of the copepod Tigriopus japonicus using acute and chronic toxicity tests. T. japonicus ingested and egested all three sizes of PS beads used and exhibited no selective feeding when phytoplankton were added. The copepods (nauplius and adult females) survived all sizes of PS beads and the various concentrations tested in the acute toxicity test for 96 h. In the two-generation chronic toxicity test, 0.05-μm PS beads at a concentration greater than 12.5 μg/mL caused the mortality of nauplii and copepodites in the F0 generation and even triggered mortality at a concentration of 1.25 μg/mL in the next generation. In the 0.5-μm PS bead treatment, despite there being no significant effect on the F0 generation, the highest concentration (25 μg/mL) induced a significant decrease in survival compared with the control population in the F1 generation. The 6-μm PS beads did not affect the survival of T. japonicus over two generations. The 0.5- and 6-μm PS beads caused a significant decrease in fecundity at all concentrations. These results suggest that microplastics such as micro- or nanosized PS beads may have negative impacts on marine copepods.

Effect of a high-protein diet on development of heart failure in response to pressure overload

Heart failure treatment guidelines provide no recommendations regarding the intake of protein, though it has been proposed that increasing protein intake may result in clinical improvement. High-protein intake might improve protein synthesis and cell function, and prevent deterioration in mitochondrial and left ventricular function. We assessed the effects of a high-protein diet on the development of heart failure characterized by cardiac hypertrophy, impaired mitochondrial oxidative metabolism and contractile dysfunction induced by transverse aortic constriction in rats. A standard diet with 18% of energy intake from protein was compared with a high-protein diet (30% of energy intake). First, we evaluated the effects of protein intake on the development of heart failure during 14 weeks of aortic constriction, and found similar cardiac hypertrophy, contractile dysfunction, ventricular dilation, and decreased cardiac mitochondrial oxidative capacity with both 18% and 30% protein. We then assessed more advanced heart failure, with 22 weeks of aortic constriction. We again saw no difference in cardiac mass, left ventricular volume, mitochondrial oxidative capacity or resistance to permeability transition between the 18% and 30% protein diets. There was a modest but significant decrease in survival with heart failure with the 30% protein diet compared with 18% protein (p < 0.003). In conclusion, consumption of a high-protein diet did not affect cardiac mass, left ventricular volumes or ejection fraction, or myocardial mitochondrial oxidative capacity in rats with pressure overload induced heart failure, but significantly decreased survival.

Protein kinase Cα suppresses Kras-mediated lung tumor formation through activation of a p38 MAPK-TGFβ signaling axis

Protein kinase C alpha (PKCα) can activate both pro- and anti-tumorigenic signaling depending upon cellular context. Here, we investigated the role of PKCα in lung tumorigenesis in vivo. Gene expression data sets revealed that primary human non-small lung cancers (NSCLC) express significantly decreased PKCα levels, indicating that loss of PKCα expression is a recurrent event in NSCLC. We evaluated the functional relevance of PKCα loss during lung tumorigenesis in three murine lung adenocarcinoma models (LSL-Kras, LA2-Kras and urethane exposure). Genetic deletion of PKCα resulted in a significant increase in lung tumor number, size, burden and grade, bypass of oncogene-induced senescence, progression from adenoma to carcinoma and a significant decrease in survival in vivo. The tumor promoting effect of PKCα loss was reflected in enhanced Kras-mediated expansion of bronchio-alveolar stem cells (BASCs), putative tumor-initiating cells, both in vitro and in vivo. LSL-Kras/Prkca(-/-) mice exhibited a decrease in phospho-p38 MAPK in BASCs in vitro and in tumors in vivo, and treatment of LSL-Kras BASCs with a p38 inhibitor resulted in increased colony size indistinguishable from that observed in LSL-Kras/Prkca(-/-) BASCs. In addition, LSL-Kras/Prkca(-/-) BASCs exhibited a modest but reproducible increase in TGFβ1 mRNA, and addition of exogenous TGFβ1 to LSL-Kras BASCs results in enhanced growth similar to untreated BASCs from LSL-Kras/Prkca(-/-) mice. Conversely, a TGFβR1 inhibitor reversed the effects of PKCα loss in LSL-Kras/Prkca(-/-) BASCs. Finally, we identified the inhibitors of DNA binding (Id) Id1-3 and the Wilm's Tumor 1 as potential downstream targets of PKCα-dependent tumor suppressor activity in vitro and in vivo. We conclude that PKCα suppresses tumor initiation and progression, at least in part, through a PKCα-p38MAPK-TGFβ signaling axis that regulates tumor cell proliferation and Kras-induced senescence. Our results provide the first direct evidence that PKCα exhibits tumor suppressor activity in the lung in vivo.

Prolonged Mechanical Ventilation in Lung Transplant Recipients: Predictive Factors and Outcomes

Purpose Prolonged mechanical ventilation (PMV) and consequently longer ICU stays after lung transplantation (LTx), are serious complications but prognosis at medium and long term are not yet know. Our objectives were to identify patients requiring > 21 days of MV after the operation and the predictive factors of PMV, and to evaluate the impact of VMP on survival and functional outcomes at one post-transplant. Methods and Materials Observational retrospective analysis of data relating to 82 consecutive lung transplantation performed at the University Hospital of Marseille from January 2008 to May 2011, for which recipient’ survival was over 21 days. Donors’ and patients’ preoperative, intra operative and postoperative data were recorded. Results 34 recipients met our criteria of PMV and 48 patients did not met them (control group). None factor related to the characteristics of the donor and the recipient at the presurgical evaluation was predictive of PMV. Multivariable regression analysis retained the risk of lung volume reduction (OR 11.874, 95% CI: 1,16-121, 44, p = 0.04), and use of postoperative ECMO within 48 hours (OR 6695, 95% CI: 1,46-30, 75, p = 0.015). By freeing from context, only lung volume reduction stayed a predictive factor of PMV. A significant decrease in survival at 1, 2 and 3 years was observed in PMV patients compared to controls (73.5%, 61.2%, 51% vs. 85.4%, 82.5%, 77.9 %). Compared to controls, in patients who required PMV, lung function at 1 year was significantly impaired with a lowest value of FEV 1 (1681 ± 919 ml vs . 2625 ± 1132 ml, p = 0.001), FVC (2288 ± 1076 ml vs 3450 ± 1176 ml, p = 0.001), LTC (2288 ± 1076ml vs 3450 ± 1176 ml, p: 0.000). and PaO 2 (75.4 ± 10.4 mmHg vs. 85.7 ± 9.5 mmHg, p = 0.001). Conclusions Lung volume reduction appears to be a predictive factor for PMV after LTx. Patients who required PMV have a significantly decreased survival and a poorer lung function than controls at 1 year post-transplant.

The IL-6/GP130 signaling pathway in myeloid cells modulates the inflammatory response during sepsis

Background and Aim: Ascites and its bacterial infection (SBP) is a frequent and dangerous complication in patients suffering from liver cirrhosis. After bacterial peritonitis, the mobilization of the regulatory myeloid cells is a major requirement to prevent sepsis. Current research on inflammatory pathways has shown that GP130 in hepatocytes is essential in the modulation of inflammation. Therefore, we investigated the contribution of the GP130 pathway for the skewing of macrophage towards the regulatory M2 phenotype in a model of peritonitis. Methods: Depletion of GP130 in hematopoietic cell-deficient mice was achieved by bone marrow transplantation (BMC) using MxCre GP130loxp/loxp GFP (cre- BMC-WT; cre+ BMC-KO) as donors into WT as recipients. Subsequently, the recipients underwent cecal ligation and puncture (CLP) – a model of bacterial peritonitis. Additionally, bone marrow derived macrophages (BMDM) generated from BMC-WT and BMC-KO mice were stimulated with LPS, LPS/IFNγ, IL-4, IL-10/IL-4 or medium. Results: Clinical signs of sepsis such as lethargy, piloerection, tremors and respiratory distress associated with a significant decrease in survival and increased organ damage – liver, kidney and spleen – were more severely manifested in BMC-KO mice after CLP. Moreover, BMC-KO mice exhibited a pronounced pro-inflammatory response assessed by the expression of iNOS and IL-12. Concomitantly, TNFα, IL-12 and IL-6 levels in the peritoneal lavage fluid were significantly elevated in the BMC-KO mice. Next, we sought to determine the general role of GP130 in macrophage polarization. Thus, we generated BMDM from BMC-WT and BMC-KO mice and stimulated them with LPS, LPS/IFNγ, IL-4 or medium. Our data clearly showed (a) reduced expression of Arginase I and MMR after IL-4 stimulation and; (b) defective IL-6 response after stimulation with LPS/IFNγ. The anti-inflammatory phenotype, associated with a reduction of IL-4Rα, was rescued by the exogenous addition of IL-10 in vivo and in vitro. Conclusion: These data identify IL-6/GP130 signaling pathway as a critical component in myeloid lineage of immune cells for host survival and control of inflammation and infection during bacterial peritonitis. The IL-6/GP130 signaling cascade is required for the maintenance of the cytokine responses by regulating the activation of M1 macrophages during bacterial peritonitis and sepsis.

Severe Traumatic Brain Injury and Controlled Hemorrhage in Rats

Treatment of combined traumatic brain injury and hypovolemic shock poses a particular challenge due to the possible conflicting consequences. While restoring diminished volume is the treatment goal for hypovolemia, maintaining and adequate cerebral perfusion pressure and avoidance of secondary damage remain a treatment goal for the injured brain. Various treatment modalities have been proposed, but the optimal resuscitation fluid and goals have not yet been clearly defined. In this study, we investigate the physiological and neurological outcomes in a rat model of combined traumatic brain injury and hypovolemic shock, submitted to treatment with varying amounts of fresh blood. Forty-eight male Lewis rats were divided into control and treatment groups. Traumatic brain injury was inflicted by a free-falling rod on the exposed cranium. Hypovolemia was induced by controlled hemorrhage of 30% blood volume. Treatment groups were treated by fresh whole blood with varying volumes, reaching resuscitation goals of a mean arterial blood pressure (MAP) of 80, 100, and 120 mmHg at 15 min. Mean arterial blood pressure was assessed at 60 min and neurological outcomes and mortality in the subsequent 48 h. At 60 min, MAP was highest for the group resuscitated most aggressively. Neurological outcomes and mortality inversely correlated with the aggressiveness of resuscitation. In this study, we find that mild resuscitation with goals of restoring MAP to 80 mmHg (which is lower than baseline) provided best results when considering hemodynamic stability, survival, and neurological outcomes. An aggressive resuscitation may be detrimental, inducing processes that eventually cause a significant decrease in survival.

First Discovery of Two Polyketide Synthase Genes for Mitorubrinic Acid and Mitorubrinol Yellow Pigment Biosynthesis and Implications in Virulence of Penicillium marneffei

BackgroundThe genome of P. marneffei, the most important thermal dimorphic fungus causing respiratory, skin and systemic mycosis in China and Southeast Asia, possesses 23 polyketide synthase (PKS) genes and 2 polyketide synthase nonribosomal peptide synthase hybrid (PKS-NRPS) genes, which is of high diversity compared to other thermal dimorphic pathogenic fungi. We hypothesized that the yellow pigment in the mold form of P. marneffei could also be synthesized by one or more PKS genes.Methodology/Principal FindingsAll 23 PKS and 2 PKS-NRPS genes of P. marneffei were systematically knocked down. A loss of the yellow pigment was observed in the mold form of the pks11 knockdown, pks12 knockdown and pks11pks12 double knockdown mutants. Sequence analysis showed that PKS11 and PKS12 are fungal non-reducing PKSs. Ultra high performance liquid chromatography-photodiode array detector/electrospray ionization-quadruple time of flight-mass spectrometry (MS) and MS/MS analysis of the culture filtrates of wild type P. marneffei and the pks11 knockdown, pks12 knockdown and pks11pks12 double knockdown mutants showed that the yellow pigment is composed of mitorubrinic acid and mitorubrinol. The survival of mice challenged with the pks11 knockdown, pks12 knockdown and pks11pks12 double knockdown mutants was significantly better than those challenged with wild type P. marneffei (P<0.05). There was also statistically significant decrease in survival of pks11 knockdown, pks12 knockdown and pks11pks12 double knockdown mutants compared to wild type P. marneffei in both J774 and THP1 macrophages (P<0.05).Conclusions/SignificanceThe yellow pigment of the mold form of P. marneffei is composed of mitorubrinol and mitorubrinic acid. This represents the first discovery of PKS genes responsible for mitorubrinol and mitorubrinic acid biosynthesis. pks12 and pks11 are probably responsible for sequential use in the biosynthesis of mitorubrinol and mitorubrinic acid. Mitorubrinol and mitorubrinic acid are virulence factors of P. marneffei by improving its intracellular survival in macrophages.

Activation of AKT by hypoxia: a potential target for hypoxic tumors of the head and neck

BackgroundOnly a minority of cancer patients benefits from the combination of EGFR-inhibition and radiotherapy in head and neck squamous cell carcinoma (HNSCC). A potential resistance mechanism is activation of EGFR and/or downstream pathways by stimuli in the microenvironment. The aim of this study was to find molecular targets induced by the microenvironment by determining the in vitro and in vivo expression of proteins of the EGFR-signaling network in 6 HNSCC lines. As hypoxia is an important microenvironmental parameter associated with poor outcome in solid tumors after radiotherapy, we investigated the relationship with hypoxia in vitro and in vivo.MethodsSix human HNSCC cell lines were both cultured as cell lines (in vitro) and grown as xenograft tumors (in vivo). Expression levels were determined via western blot analysis and localization of markers was assessed via immunofluorescent staining. To determine the effect of hypoxia and pAKT-inhibition on cell survival, cells were incubated at 0.5% O2 and treated with MK-2206.ResultsWe observed strong in vitro-in vivo correlations for EGFR, pEGFR and HER2 (rs=0.77, p=0.10, rs=0.89, p=0.03) and rs=0.93, p=0.02, respectively), but not for pAKT, pERK1/2 or pSTAT3 (all rs<0.55 and p>0.30). In vivo, pAKT expression was present in hypoxic cells and pAKT and hypoxia were significantly correlated (rs=0.51, p=0.04). We confirmed in vitro that hypoxia induces activation of AKT. Further, pAKT-inhibition via MK-2206 caused a significant decrease in survival in hypoxic cells (p<0.01), but not in normoxic cells.ConclusionsThese data suggest that (p)EGFR and HER2 expression is mostly determined by intrinsic features of the tumor cell, while the activation of downstream kinases is highly influenced by the tumor microenvironment. We show that hypoxia induces activation of AKT both in vitro and in vivo, and that hypoxic cells can be specifically targeted by pAKT-inhibition. Targeting pAKT is thus a potential way to overcome therapy resistance induced by hypoxia and improve patient outcome.

Detailed Pathologic Characteristics of the Primary Colorectal Tumor Independently Predict Outcome after Hepatectomy for Metastases

Outcome after hepatic resection for colorectal cancer liver metastases (CRLM) is heterogeneous and accurate predictors of survival are lacking. This study analyzes the prognostic relevance of pathologic details of the primary colorectal tumor in patients undergoing hepatic resection for CRLM. Retrospective review of a prospective database identified patients who underwent resection for CRLM. Clinicopathological variables were investigated and their association with outcome was analyzed. From 1997-2007, 1,004 patients underwent hepatic resection for CRLM. The median follow-up was 59 months with a 5-year survival of 47%. Univariate analysis identified nine factors associated with poor survival; three of these related to the primary tumor: lymphovascular invasion (LVI, p<0.0001), perineural invasion (p=0.005), and degree of regional lymph node involvement (N0 vs. N1 vs. N2, p<0.0001). Multivariate analysis identified seven factors associated with poor survival, two of which related to the primary tumor: LVI (hazard ratio (HR) 1.3, 95% confidence interval (CI) 1.06-1.64, p=0.01) and degree of regional lymph node involvement [N1 (HR 1.3, 95% CI 1.04-1.69, p=0.02) vs. N2 (HR 1.7, 95% CI 1.27-2.21, p<0.0005)]. A significant decrease in survival along the spectrum of patients ranging from LVI negative/N0 to LVI positive/N2 was present. Patients who were LVI-positive/N2 had a median survival of 40 months compared with 74 months for patients who were LVI-negative/NO (p<0.0001). Histopathologic details of the primary colorectal tumor, particularly LVI and the detailed assessment of the degree of lymph node involvement, are strong predictors of survival. Future biomarker studies should consider exploring factors related to the primary colorectal tumor.

Monoclonal Antibody Therapy of Pancreatic Cancer With Cetuximab

Pancreatic cancer is a devastating disease, with a median survival of around 6 months for patients with stage IV disease. The epidermal growth factor receptor (EGFR, or HER1) belongs to the erbB receptor tyrosine kinase family. HER1-mediated cell signaling has been shown to play a major role in promoting tumor proliferation, angiogenesis, metastasis, and evasion of apoptosis. Over-expression of HER1 is observed in multiple human malignancies, including colorectal, lung, breast and pancreatic cancers. In pancreatic carcinoma, over-expression of HER1 is observed in greater than 70% of patients and is associated with a poor prognosis and a significant decrease in survival. Cetuximab (Erbitux) is a chimeric monoclonal antibody (mAb) that binds to the extracellular domain of the HER1 molecule preventing ligand binding and promoting internalization and subsequent degradation of the HER1 receptor. Cetuximab has shown anti-tumor activity either alone or in combination with other agents and is currently FDA approved for use in both squamous cell carcinoma of the head and neck (SCCHN) and colorectal carcinoma. Research efforts continue to elucidate a possible role for cetuximab in the treatment of pancreatic cancer. Despite promising preclinical work, phase II and phase III clinical trials have failed to consistently show efficacy of cetuximab treatment in advanced pancreatic cancer either alone or in combination with cytotoxic agents. Alternative approaches to HER1 blockade and mAbs including immune modulation with cytokines might be necessary in order to improve the efficacy of mAbs in pancreatic cancer therapy.

Cadmium toxicity assessment in juveniles of the Austral South America amphipod Hyalella curvispina

Hyalella curvispina is representative of zoobenthic communities in Austral South America. It is taxonomically close to Hyalella azteca and abundant in fresh water bodies of the pampasic region of Argentina. It is usually used as test organism in ecotoxicological studies at a regional level, and there is a strong concern to increase the knowledge of both their biology and their sensitivity to different toxic agents. The aim of the present work was to assess the effects of cadmium on H. curvispina juveniles exposed to concentrations expected in the water bodies of the distribution area of the species. Survival, growth and cadmium body burden were evaluated in aqueous and solid matrices under fixed experimental conditions. Animals were exposed in ten-day static toxicity bioassays to 2.5, 5.25 and 11.25μg Cd/L for the aqueous-phase bioassays, and to 0.85, 2.8 and 5.6mg Cd/Kg dry sediment for the solid-phase bioassays. In water only assays, the animals exposed to 11.25μg Cd/L showed a significant decrease in survival and growth. In the sediment bioassays, no effect was observed on survival, and weight was significantly reduced at the highest concentration. Cadmium uptake was concentration dependent for both assay matrices and one order of magnitude higher in the aqueous medium than in the solid matrix. Results indicate that juveniles of H. curvispina are sensitive to cadmium concentrations expected in their environment and thus confirm their importance as test organisms for ecotoxicity assessment in water bodies within the distribution area of the species.

The impact of mechanical ventilation time before initiation of extracorporeal life support on survival in pediatric respiratory failure

To evaluate the relationship between duration of mechanical ventilation before the initiation of extracorporeal life support and the survival rate in children with respiratory failure. Extracorporeal life support has been used as a rescue therapy for >30 yrs in children with severe respiratory failure. Previous studies suggest patients who received >7-10 days of mechanical ventilation were not acceptable extracorporeal life support candidates as a result of irreversible lung damage. A retrospective review encompassing the past 10 yrs of the International Extracorporeal Life Support Organization Registry (January 1, 1999, to December 31, 2008). Extracorporeal Life Support Organization Registry database. A total of 1325 children (≥ 30 days and ≤ 18 yrs) met inclusion criteria. None. The following pre-extracorporeal life support variables were identified as independently and significantly related to the chance of survival: 1) >14 days of ventilation vs. 0-7 days was adverse (odds ratio, 0.32; p < .001); 2) the presence of a cardiac arrest was adverse (odds ratio, 0.56; p = .001); 3) pH per 0.1-unit increase was protective (odds ratio, 1.15; p < .001); 4) oxygenation index, per 10-unit increase was adverse (odds ratio, 0.95; p = .002); and 5) any diagnosis other than sepsis was related to a more favorable outcome. Patients requiring >7-10 or >10-14 days of pre-extracorporeal life support ventilation did not have a statistically significant decrease in survival as compared with patients who received 0-7 days. There was a clear relationship between the number of mechanical ventilation days before the initiation of extracorporeal life support and survival. However; there was no statistically significant decrease in survival until >14 days of pre-extracorporeal life support ventilation was reached regardless of underlying diagnosis. We found no evidence to suggest that prolonged mechanical ventilation should be considered as a contraindication to extracorporeal life support in children with respiratory failure before 14 days.