129 research outputs found

    Expression patterns of CEACAM5 and CEACAM6 in primary and metastatic cancers

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    BACKGROUND: Many breast, pancreatic, colonic and non-small-cell lung carcinoma lines express CEACAM6 (NCA-90) and CEACAM5 (carcinoembryonic antigen, CEA), and antibodies to both can affect tumor cell growth in vitro and in vivo. Here, we compare both antigens as a function of histological phenotype in breast, pancreatic, lung, ovarian, and prostatic cancers, including patient-matched normal, primary tumor, and metastatic breast and colonic cancer specimens. METHODS: Antigen expression was determined by immunohistochemistry (IHC) using tissue microarrays with MN-15 and MN-3 antibodies targeting the A1B1- and N-domains of CEACAM6, respectively, and the MN-14 antibody targeting the A3B3 domain of CEACAM5. IHC was performed using avidin-biotin-diaminobenzide staining. The average score ± SD (0 = negative/8 = highest) for each histotype was recorded. RESULTS: For all tumors, the amount of CEACAM6 expressed was greater than that of CEACAM5, and reflected tumor histotype. In breast tumors, CEACAM6 was highest in papillary > infiltrating ductal > lobular > phyllodes; in pancreatic tumors, moderately-differentiated > well-differentiated > poorly-differentiated tumors; mucinous ovarian adenocarcinomas had almost 3-fold more CEACAM6 than serous ovarian adenocarcinomas; lung adenocarcinomas > squamous tumors; and liver metastases of colonic carcinoma > primary tumors = lymph nodes metastases > normal intestine. However, CEACAM6 expression was similar in prostate cancer and normal tissues. The amount of CEACAM6 in metastatic colon tumors found in liver was higher than in many primary colon tumors. In contrast, CEACAM6 immunostaining of lymph node metastases from breast, colon, or lung tumors was similar to the primary tumor. CONCLUSION: CEACAM6 expression is elevated in many solid tumors, but variable as a function of histotype. Based on previous work demonstrating a role for CEACAM6 in tumor cell migration, invasion and adhesion, and formation of distant metastases (Blumenthal et al., Cancer Res 65: 8809–8817, 2005), it may be a promising target for antibody-based therapy

    Characterisation of heart failure with normal ejection fraction in a tertiary hospital in Nigeria

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    <p>Abstract</p> <p>Background</p> <p>The study aimed to determine the frequency and characteristics of heart failure with normal EF in a native African population with heart failure.</p> <p>Methods</p> <p>It was a hospital cohort study. Subjects were 177 consecutive individuals with heart failure and ninety apparently normal control subjects. All the subjects underwent transthoracic echocardiography. The group with heart failure was further subdivided into heart failure with normal EF (EF ≥ 50) (HFNEF) and heart failure with low EF(EF <50)(HFLEF).</p> <p>Results</p> <p>The subjects with heart failure have a mean age of 52.3 ± 16.64 years vs 52.1 ± 11.84 years in the control subjects; p = 0.914. Other baseline characteristics except blood pressure parameters and height were comparable between the group with heart failure and the control subjects. The frequency of HFNEF was 39.5%. Compared with the HFLEF group, the HFNEF group have a smaller left ventricular diameter (in diastole and systole): (5.2 ± 1.22 cm vs 6.2 ± 1.39 cm; p < 0.0001 and 3.6 ± 1.24 cm vs 5.4 ± 1.35 cm;p < 0.0001) respectively, a higher relative wall thickness and deceleration time of the early mitral inflow velocity: (0.4 ± 0.12 vs 0.3 ± 0.14 p < 0.0001 and 149.6 ± 72.35 vs 110.9 ± 63.40 p = 0.001) respectively.</p> <p>The two groups with heart failure differed significantly from the control subjects in virtually all echocardiographic measurements except aortic root diameter, LV posterior wall thickness(HFLEF), and late mitral inflow velocity(HFNEF). HFNEF accounted for 70(39.5%) of cases of heart failure in this study.</p> <p>Hypertension is the underlying cardiovascular disease in 134(75.7%) of the combined heart failure population, 58 (82.9%) of the subjects with HFNEF group and 76(71%) of the HFLEF group. Females accounted for 44 (62.9%) of the subjects with HFNEF against 42(39.3%) in the HFLEF group (p = 0.002).</p> <p>Conclusion</p> <p>The frequency of heart failure with normal EF in this native African cohort with heart failure is comparable with the frequency in other populations. These groups of patients are more likely female, hypertensive with concentric pattern of left ventricular hypertrophy.</p

    The Pentameric Vertex Proteins Are Necessary for the Icosahedral Carboxysome Shell to Function as a CO2 Leakage Barrier

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    BACKGROUND: Carboxysomes are polyhedral protein microcompartments found in many autotrophic bacteria; they encapsulate the CO(2) fixing enzyme, ribulose-1,5-bisphosphate carboxylase/oxygenase (RubisCO) within a thin protein shell and provide an environment that enhances the catalytic capabilities of the enzyme. Two types of shell protein constituents are common to carboxysomes and related microcompartments of heterotrophic bacteria, and the genes for these proteins are found in a large variety of bacteria. METHODOLOGY/PRINCIPAL FINDINGS: We have created a Halothiobacillus neapolitanus knockout mutant that does not produce the two paralogous CsoS4 proteins thought to occupy the vertices of the icosahedral carboxysomes and related microcompartments. Biochemical and ultrastructural analyses indicated that the mutant predominantly forms carboxysomes of normal appearance, in addition to some elongated microcompartments. Despite their normal shape, purified mutant carboxysomes are functionally impaired, although the activities of the encapsulated enzymes are not negatively affected. CONCLUSIONS/SIGNIFICANCE: In the absence of the CsoS4 proteins the carboxysome shell loses its limited permeability to CO(2) and is no longer able to provide the catalytic advantage RubisCO derives from microcompartmentalization. This study presents direct evidence that the diffusion barrier property of the carboxysome shell contributes significantly to the biological function of the carboxysome

    The Prometastatic Microenvironment of the Liver

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    The liver is a major metastasis-susceptible site and majority of patients with hepatic metastasis die from the disease in the absence of efficient treatments. The intrahepatic circulation and microvascular arrest of cancer cells trigger a local inflammatory reaction leading to cancer cell apoptosis and cytotoxicity via oxidative stress mediators (mainly nitric oxide and hydrogen peroxide) and hepatic natural killer cells. However, certain cancer cells that resist or even deactivate these anti-tumoral defense mechanisms still can adhere to endothelial cells of the hepatic microvasculature through proinflammatory cytokine-mediated mechanisms. During their temporary residence, some of these cancer cells ignore growth-inhibitory factors while respond to proliferation-stimulating factors released from tumor-activated hepatocytes and sinusoidal cells. This leads to avascular micrometastasis generation in periportal areas of hepatic lobules. Hepatocytes and myofibroblasts derived from portal tracts and activated hepatic stellate cells are next recruited into some of these avascular micrometastases. These create a private microenvironment that supports their development through the specific release of both proangiogenic factors and cancer cell invasion- and proliferation-stimulating factors. Moreover, both soluble factors from tumor-activated hepatocytes and myofibroblasts also contribute to the regulation of metastatic cancer cell genes. Therefore, the liver offers a prometastatic microenvironment to circulating cancer cells that supports metastasis development. The ability to resist anti-tumor hepatic defense and to take advantage of hepatic cell-derived factors are key phenotypic properties of liver-metastasizing cancer cells. Knowledge on hepatic metastasis regulation by microenvironment opens multiple opportunities for metastasis inhibition at both subclinical and advanced stages. In addition, together with metastasis-related gene profiles revealing the existence of liver metastasis potential in primary tumors, new biomarkers on the prometastatic microenvironment of the liver may be helpful for the individual assessment of hepatic metastasis risk in cancer patients

    Between-Population Outbreeding Affects Plant Defence

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    Between-population crosses may replenish genetic variation of populations, but may also result in outbreeding depression. Apart from direct effects on plant fitness, these outbreeding effects can also alter plant-herbivore interactions by influencing plant tolerance and resistance to herbivory. We investigated effects of experimental within- and between-population outbreeding on herbivore resistance, tolerance and plant fitness using plants from 13 to 19 Lychnis flos-cuculi populations. We found no evidence for outbreeding depression in resistance reflected by the amount of leaf area consumed. However, herbivore performance was greater when fed on plants from between-population compared to within-population crosses. This can reflect outbreeding depression in resistance and/or outbreeding effects on plant quality for the herbivores. The effects of type of cross on the relationship between herbivore damage and plant fitness varied among populations. This demonstrates how between-population outbreeding effects on tolerance range from outbreeding depression to outbreeding benefits among plant populations. Finally, herbivore damage strengthened the observed outbreeding effects on plant fitness in several populations. These results raise novel considerations on the impact of outbreeding on the joint evolution of resistance and tolerance, and on the evolution of multiple defence strategies

    Evidence for a Novel Marine Harmful Algal Bloom: Cyanotoxin (Microcystin) Transfer from Land to Sea Otters

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    “Super-blooms” of cyanobacteria that produce potent and environmentally persistent biotoxins (microcystins) are an emerging global health issue in freshwater habitats. Monitoring of the marine environment for secondary impacts has been minimal, although microcystin-contaminated freshwater is known to be entering marine ecosystems. Here we confirm deaths of marine mammals from microcystin intoxication and provide evidence implicating land-sea flow with trophic transfer through marine invertebrates as the most likely route of exposure. This hypothesis was evaluated through environmental detection of potential freshwater and marine microcystin sources, sea otter necropsy with biochemical analysis of tissues and evaluation of bioaccumulation of freshwater microcystins by marine invertebrates. Ocean discharge of freshwater microcystins was confirmed for three nutrient-impaired rivers flowing into the Monterey Bay National Marine Sanctuary, and microcystin concentrations up to 2,900 ppm (2.9 million ppb) were detected in a freshwater lake and downstream tributaries to within 1 km of the ocean. Deaths of 21 southern sea otters, a federally listed threatened species, were linked to microcystin intoxication. Finally, farmed and free-living marine clams, mussels and oysters of species that are often consumed by sea otters and humans exhibited significant biomagnification (to 107 times ambient water levels) and slow depuration of freshwater cyanotoxins, suggesting a potentially serious environmental and public health threat that extends from the lowest trophic levels of nutrient-impaired freshwater habitat to apex marine predators. Microcystin-poisoned sea otters were commonly recovered near river mouths and harbors and contaminated marine bivalves were implicated as the most likely source of this potent hepatotoxin for wild otters. This is the first report of deaths of marine mammals due to cyanotoxins and confirms the existence of a novel class of marine “harmful algal bloom” in the Pacific coastal environment; that of hepatotoxic shellfish poisoning (HSP), suggesting that animals and humans are at risk from microcystin poisoning when consuming shellfish harvested at the land-sea interface

    Testosterone Deficiency Accelerates Neuronal and Vascular Aging of SAMP8 Mice: Protective Role of eNOS and SIRT1

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    Oxidative stress and atherosclerosis-related vascular disorders are risk factors for cognitive decline with aging. In a small clinical study in men, testosterone improved cognitive function; however, it is unknown how testosterone ameliorates the pathogenesis of cognitive decline with aging. Here, we investigated whether the cognitive decline in senescence-accelerated mouse prone 8 (SAMP8), which exhibits cognitive impairment and hypogonadism, could be reversed by testosterone, and the mechanism by which testosterone inhibits cognitive decline. We found that treatment with testosterone ameliorated cognitive function and inhibited senescence of hippocampal vascular endothelial cells of SAMP8. Notably, SAMP8 showed enhancement of oxidative stress in the hippocampus. We observed that an NAD+-dependent deacetylase, SIRT1, played an important role in the protective effect of testosterone against oxidative stress-induced endothelial senescence. Testosterone increased eNOS activity and subsequently induced SIRT1 expression. SIRT1 inhibited endothelial senescence via up-regulation of eNOS. Finally, we showed, using co-culture system, that senescent endothelial cells promoted neuronal senescence through humoral factors. Our results suggest a critical role of testosterone and SIRT1 in the prevention of vascular and neuronal aging

    Research into the effect Of SGLT2 inhibition on left ventricular remodelling in patients with heart failure and diabetes mellitus (REFORM) trial rationale and design

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    Background Heart failure (HF) and diabetes (DM) are a lethal combination. The current armamentarium of anti-diabetic agents has been shown to be less efficacious and sometimes even harmful in diabetic patients with concomitant cardiovascular disease, especially HF. Sodium glucose linked co-transporter type 2 (SGLT2) inhibitors are a new class of anti-diabetic agent that has shown potentially beneficial cardiovascular effects such as pre-load and after load reduction through osmotic diuresis, blood pressure reduction, reduced arterial stiffness and weight loss. This has been supported by the recently published EMPA-REG trial which showed a striking 38 and 35 % reduction in cardiovascular death and HF hospitalisation respectively. Methods The REFORM trial is a novel, phase IV randomised, double blind, placebo controlled clinical trial that has been ongoing since March 2015. It is designed specifically to test the safety and efficacy of the SLGT2 inhibitor, dapagliflozin, on diabetic patients with known HF. We utilise cardiac-MRI, cardio-pulmonary exercise testing, body composition analysis and other tests to quantify the cardiovascular and systemic effects of dapagliflozin 10 mg once daily against standard of care over a 1 year observation period. The primary outcome is to detect the change in left ventricular (LV) end systolic and LV end diastolic volumes. The secondary outcome measures include LV ejection fraction, LV mass index, exercise tolerance, fluid status, quality of life measures and others. Conclusions This trial will be able to determine if SGLT2 inhibitor therapy produces potentially beneficial effects in patients with DM and HF, thereby replacing current medications as the drug of choice when treating patients with both DM and HF
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