Metabolic Profiles in Ovine Carotid Arteries with Developmental Maturation and Long-Term Hypoxia

Background

Long-term hypoxia (LTH) is an important stressor related to health and disease during development. At different time points from fetus to adult, we are exposed to hypoxic stress because of placental insufficiency, high-altitude residence, smoking, chronic anemia, pulmonary, and heart disorders, as well as cancers. Intrauterine hypoxia can lead to fetal growth restriction and long-term sequelae such as cognitive impairments, hypertension, cardiovascular disorders, diabetes, and schizophrenia. Similarly, prolonged hypoxic exposure during adult life can lead to acute mountain sickness, chronic fatigue, chronic headache, cognitive impairment, acute cerebral and/or pulmonary edema, and death.

Aim

LTH also can lead to alteration in metabolites such as fumarate, 2-oxoglutarate, malate, and lactate, which are linked to epigenetic regulation of gene expression. Importantly, during the intrauterine life, a fetus is under a relative hypoxic environment, as compared to newborn or adult. Thus, the changes in gene expression with development from fetus to newborn to adult may be as a consequence of underlying changes in the metabolic profile because of the hypoxic environment along with developmental maturation. To examine this possibility, we examined the metabolic profile in carotid arteries from near-term fetus, newborn, and adult sheep in both normoxic and long-term hypoxic acclimatized groups.

Results

Our results demonstrate that LTH differentially regulated glucose metabolism, mitochondrial metabolism, nicotinamide cofactor metabolism, oxidative stress and antioxidants, membrane lipid hydrolysis, and free fatty acid metabolism, each of which may play a role in genetic-epigenetic regulation.     

Routine Clinical-Pathologic Correlation of Pigmented Skin Tumors Can Influence Patient Management

Background

Several studies have demonstrated the benefit of integrating clinical with pathologic information, to obtain a confident diagnosis for melanocytic tumors. However, all those studies were conducted retrospectively and no data are currently available about the role of a clinical-pathologic correlation approach on a daily basis in clinical practice.

Aim of the Study

In our study, we evaluated the impact of a routine clinical-pathologic correlation approach for difficult skin tumors seen over 3 years in a tertiary referral center.

Results

Interestingly, a re-appraisal was requested for 158 out of 2015 (7.7%) excised lesions because clinical-pathologic correlation was missing. Of note, in 0.6% of them (13 out of 2045) the first histologic diagnosis was revised in the light of clinical information that assisted the Pathologist to re-evaluate the histopathologic findings that might be bland or inconspicuous per se.

Conclusion

In conclusion, our study demonstrated that an integrated approach involving clinicians and pathologists allows improving management of selected patients by shifting from a simply disease-focused management (melanoma versus nevus) to a patient-centered approach.     

Effect of Oxidation on the Structure of Human Low- and High-Density Lipoproteins

This work presents a controlled study of low-density lipoprotein (LDL) and high-density lipoprotein (HDL) structural changes due to in vitro oxidation with copper ions. The changes were studied by small-angle x-ray scattering (SAXS) and dynamic light scattering (DLS) techniques in the case of LDL and by SAXS, DLS, and Z-scan (ZS) techniques in the case of HDL. SAXS data were analyzed with a to our knowledge new deconvolution method. This method provides the electron density profile of the samples directly from the intensity scattering of the monomers. Results show that LDL particles oxidized for 18 h show significant structural changes when compared to nonoxidized particles. Changes were observed in the electrical density profile, in size polydispersity, and in the degree of flexibility of the APO-B protein on the particle. HDL optical results obtained with the ZS technique showed a decrease of the amplitude of the nonlinear optical signal as a function of oxidation time. In contrast to LDL results reported in the literature, the HDL ZS signal does not lead to a complete loss of nonlinear optical signal after 18 h of copper oxidation. Also, the SAXS results did not indicate significant structural changes due to oxidation of HDL particles, and DLS results showed that a small number of oligomers formed in the sample oxidized for 18 h. All experimental results for the HDL samples indicate that this lipoprotein is more resistant to the oxidation process than are LDL particles.     

Curcumin derivatives as new ligands of Aβ peptides

Curcumin derivatives with high chemical stability, improved solubility and carrying a functionalized appendage for the linkage to other entities, have been synthesized in a straightforward manner. All compounds retained Curcumin ability to bind Aβ peptide oligomers without inducing their aggregation. Moreover all Curcumin derivatives were able to stain very efficiently Aβ deposits.     

Sulfated polysaccharides from marine sponges: conspicuous distribution among different cell types and involvement on formation of in vitro cell aggregates

Marine sponges (Porifera) display an ancestral type of cell-cell adhesion, based on carbohydrate-carbohydrate interaction. The aim of the present work was to investigate further details of this adhesion by using, as a model, the in vitro aggregation of dissociated sponge cells. Our results showed the participation of sulfated polysaccharides in this cell-cell interaction, as based on the following observations: (1) a variety of sponge cells contained similar sulfated polysaccharides as surface-associated molecules and as intracellular inclusions; (2) ³⁵S-sulfate metabolic labeling of dissociated sponge cells revealed that the majority (two thirds) of the total sulfated polysaccharide occurred as a cell-surface-associated molecule; (3) the aggregation process of dissociated sponge cells demanded the active de novo synthesis of sulfated polysaccharides, which ceased as cell aggregation reached a plateau; (4) the typical well-organized aggregates of sponge cells, known as primmorphs, contained three cell types showing sulfated polysaccharides on their cell surface; (5) collagen fibrils were also produced by the primmorphs in order to fill the extracellular spaces of their inner portion and the external layer surrounding their entire surface. Our data have thus clarified the relevance of sulfated polysaccharides in this system of in vitro sponge cell aggregation. The molecular basis of this system has practical relevance, since the culture of sponge cells is necessary for the production of molecules with biotechnological applications.     

Cologastric fistula with a foreign body in a patient with Crohn's disease

Although the medical management of fistulizing Crohn's disease is improving, a subset of patients does not respond to maximal medical therapy and is referred for surgical consultation. We report a case of Crohn's colitis with an ingested foreign body resulting in a cologastric fistula. The patient underwent segmental colectomy and takedown of the cologastric fistula. At the time of laparotomy, the foreign body was found in the fistulous colonic segment. The presence of an ingested foreign body likely contributed to a rare fistula that was refractory to medical management.     

New miRNA labeling method for bead-based quantification

Background  

microRNAs (miRNAs) are small single-stranded non-coding RNAs that act as crucial regulators of gene expression. Different methods have been developed for miRNA expression profiling in order to better understand gene regulation in normal and pathological conditions. miRNAs expression values obtained from large scale methodologies such as microarrays still need a validation step with alternative technologies.     

Fasting and differential chemotherapy protection in patients

Chronic calorie restriction has been known for decades to prevent or retard cancer growth, but its weight-loss effect and the potential problems associated with combining it with chemotherapy have prevented its clinical application. Based on the discovery in model organisms that short term starvation (STS or fasting) causes a rapid switch of cells to a protected mode, we described a fasting-based intervention that causes remarkable changes in the levels of glucose, IGF-I and many other proteins and molecules and is capable of protecting mammalian cells and mice from various toxins, including chemotherapy. Because oncogenes prevent the cellular switch to this stress resistance mode, starvation for 48 hours or longer protects normal yeast and mammalian cells and mice but not cancer cells from chemotherapy, an effect we termed Differential Stress Resistance (DSR). In a recent article, ten patients who fasted in combination with chemotherapy, reported that fasting was not only feasible and safe but caused a reduction in a wide range of side effects accompanied by an apparently normal and possibly augmented chemotherapy efficacy. Together with the remarkable results observed in animals, these data provide preliminary evidence in support of the human application of this fundamental biogerontology finding, particularly for terminal patients receiving chemotherapy. Here we briefly discuss the basic, pre-clinical and clinical studies on fasting and cancer therapy.Key words: fasting, cancer, chemotherapy, calorie restriction, stress resistanceAfter decades of slow progress in the identification of treatments effective on a wide range of malignancies, cancer treatment is now turning to personalized therapies based in part on pharmacogenomics. By contrast, aging research is moving in the opposite direction by searching for common ways to prevent, postpone and treat a wide range of age-related diseases, based on the modulation of genetic pathways that are conserved from yeast to mammals.¹ In fact, it may be a solid evolutionary and comparative biology-foundation, which makes this ambitious goal of biogerontologists a realistic or at least a promising one. On the other hand, the progress of biogerontology is viewed by many clinicians as too fundamental and far from translational applications. In most cases, it is not clear how aging research will be translated into FDA approved drugs or treatments that have effects that are superior to those already available or being developed. For example, it is not clear how the long-term 20–30% reduction in calorie intake (dietary restriction, DR) that we and many others before us have shown to be effective in extending the life span of model organisms will make humans live longer or healthier.^1–3 Furthermore, despite the fact that long-term DR was confirmed to reduce cancer and cardiovascular disease in monkeys⁴ and to be effective in preventing obesity, type 2 diabetes, inflammation, hypertension and atherosclerosis, as indicated by the early results in humans studies,⁵ it is highly unlikely to be adopted in its more extreme and effective version by even a small portion of the population. For example, the 20 to 40% chronic reduction in daily calorie intake shown to be effective in retarding cancer growth in mice would not be feasible for cancer therapy for multiple reasons: (1) the effects of chronic DR in patients with a clinically evident tumor is expected to delay but not stop the progression of the disease^6–8 and this delay may only occur for a portion of the malignancies,⁹ (2) although weight loss and cachexia in the early stages of treatment are less prevalent than commonly thought,^10–12 the ∼15% loss of BMI and ∼30% long-term loss of body fat caused by a moderate (20%) calorie restriction¹³ may be tolerated by only a very small portion of cancer patients receiving treatment, (3) Because this long-term restriction is accompanied by delayed wound healing and immunologic impairment in rodents,^1,14,15 it is not clear what risks it may impose on cancer patients receiving treatment.¹⁶ Our studies of DSR, which were triggered by our fundamental findings that switching yeast cells to water protected them against a wide range of toxins, started as a way to address these concerns but also as an attempt to achieve a much more potent therapeutic effect than that achieved by DR.^17,18 Because starvation-induced protection can increase many fold when combined with modulation of pro-aging pathways and since it is in principle blocked by the expression of any oncogene, it has the potential to provide a method to allow common chemotherapy to selectively kill cancer cells, independently of the type of cancer.^19–21 The DSR experiments in mammals were also based on our hypothesis that stress resistance and aging regulatory pathways were conserved from yeast to mammals.We found that fasting for 48 or more hours or in vitro starvation conditions that mimic fasting protected mice and/or normal cells but not cancer cells from various chemotherapy drugs and other deleterious agents.²¹ This effect was shown to depend in part on the reduction of circulating IGF-I and glucose levels.^21,22 Although a differential regulation of cell division in normal and cancer cells^23,24 is likely to contribute to DSR, much of it appears to be dependent on protective systems which are normally maintained in an inactive or low activity state even in non-dividing cells.^1,25 In fact, in non-dividing yeast and mice, deficiencies in glucose or IGF-I signaling that match those observed after starvation promote resistance to doxorubicin, a chemotherapy drug that specifically targets muscle cells in the heart.^21,22As expected, many clinicians were skeptical of our hypothesis that cancer treatment could be improved not by a “magic bullet” but by a “not so magic DSR shield” as underlined by Leonard Saltz, an oncologist at Memorial Sloan-Kettering Cancer Center: “Would I be enthusiastic about enrolling my patients in a trial where they''re asked not to eat for 2.5 days? No.”²⁶ However, ten oncologists did allow their patients, suffering from malignancies ranging from stage II breast cancer to stage IV esophageal, prostate and lung malignancies to undergo a 48–140 hours pre-chemotherapy and a 5–56 hours post chemotherapy water-only fast. The six patients who received chemotherapy with or without fasting reported a reduction in fatigue, weakness and gastrointestinal side effects while fasting²⁷ (Fig. 1). A trend for a reduction of many additional side effects was also reported by the group of patients who always fasted before chemotherapy.²⁷ In those patients whose cancer progression was assessed, chemotherapy was effective and in some cases it was highly effective.²⁷ A clinical trial sponsored by the V-Foundation for Cancer Research, aimed at testing the safety and efficacy of a 24 hour fast in combination with chemotherapy, is in its safety stage. Because it was originally limited to patients diagnosed with bladder cancer the clinical trial progressed slowly. However, its recent expansion to include patients receiving platinum-based chemotherapy (breast, ovarian, lung cancer), is expected to expedite it. Conclusive results for the effect of a 3–4 day fast on chemotherapy-dependent side effects and possibly therapeutic index are not expected to become available for several years. Even if a more modest effect than the 1,000-fold differential protection against oxidative stress and chemotherapy observed in normal and cancer-like yeast cells was achieved in humans, this method could result in long-term survival for many patients with metastatic cancers, particularly those in which malignant cells have not acquired multidrug resistance.Open in a separate windowFigure 1Average self-reported severity of symptoms in patients that have received chemotherapy with or without fasting.