54 research outputs found

    Polysaccharopeptides derived from Coriolus versicolor potentiate the S-phase specific cytotoxicity of Camptothecin (CPT) on human leukemia HL-60 cells

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    <p>Abstract</p> <p>Background</p> <p>Polysaccharopeptide (PSP) from <it>Coriolus versicolor </it>(<it>Yunzhi</it>) is used as a supplementary cancer treatment in Asia. The present study aims to investigate whether PSP pre-treatment can increase the response of the human leukemia HL-60 cells to apoptosis induction by Camptothecin (CPT).</p> <p>Methods</p> <p>We used bivariate bromodeoxyuridine/propidium iodide (BrdUrd/PI) flow cytometry analysis to measure the relative movement (RM) of the BrdUrd positively labeled cells and DNA synthesis time (Ts) on the HL-60 cell line. We used annexin V/PI flow cytometry analysis to quantify the viable, necrotic and apoptotic cells. The expression of cyclin E and cyclin B1 was determined with annexin V/PI flow cytometry and western blotting. Human peripheral blood mononuclear cells were used to test the cytotoxicity of PSP and CPT.</p> <p>Results</p> <p>PSP reduced cellular proliferation; inhibited cells progression through both S and G<sub>2 </sub>phase, reduced <sup>3</sup>H-thymidine uptake and prolonged DNA synthesis time (Ts) in HL-60 cells. PSP-pretreated cells enhanced the cytotoxicity of CPT. The sensitivity of cells to the cytotoxic effects of CPT was seen to be the highest in the S-phase and to a small extent of the G<sub>2 </sub>phase of the cell cycle. On the other hand, no cell death (measured by annexin V/PI) was evident with the normal human peripheral blood mononuclear cells with treatment of either PSP or CPT.</p> <p>Conclusion</p> <p>The present study shows that PSP increases the sensitization of the HL-60 cells to undergo effective apoptotic cell death induced by CPT. The pattern of sensitivity of cancer cells is similar to that of HL-60 cells. PSP rapidly arrests and/or kills cells in S-phase and did not interfere with the anticancer action of CPT. PSP is a potential adjuvant to treat human leukemia as rapidly proliferating tumors is characterized by a high proportion of S-phase cells.</p

    Antibiotics increase gut metabolism and antioxidant proteins and decrease acute phase response and necrotizing enterocolitis in preterm neonates

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    BACKGROUND: The appropriate use of antibiotics for preterm infants, which are highly susceptible to develop necrotizing enterocolitis (NEC), is not clear. While antibiotic therapy is commonly used in neonates with NEC symptoms and sepsis, it remains unknown how antibiotics may affect the intestine and NEC sensitivity. We hypothesized that broad-spectrum antibiotics, given immediately after preterm birth, would reduce NEC sensitivity and support intestinal protective mechanisms. METHODOLOGY/PRINCIPAL FINDINGS: Preterm pigs were treated with antibiotics for 5 d (oral and systemic doses of gentamycin, ampicillin and metrodinazole; AB group) and compared with untreated pigs. Only the untreated pigs showed evidence of NEC lesions and reduced digestive function, as indicated by lowered villus height and activity of brush border enzymes. In addition, 53 intestinal and 22 plasma proteins differed in expression between AB and untreated pigs. AB treatment increased the abundance of intestinal proteins related to carbohydrate and protein metabolism, actin filaments, iron homeostasis and antioxidants. Further, heat shock proteins and the complement system were affected suggesting that all these proteins were involved in the colonization-dependent early onset of NEC. In plasma, acute phase proteins (haptoglobin, complement proteins) decreased, while albumin, cleaved C3, ficolin and transferrin increased. CONCLUSIONS/SIGNIFICANCE: Depressed bacterial colonization following AB treatment increases mucosal integrity and reduces bacteria-associated inflammatory responses in preterm neonates. The plasma proteins C3, ficolin, and transferrin are potential biomarkers of the colonization-dependent NEC progression in preterm neonates

    Robust estimation of bacterial cell count from optical density

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    Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals &lt;1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

    Finishing the euchromatic sequence of the human genome

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    The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

    Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

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    Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

    The effect of E. coli endotoxin on the metabolic responses of Wistar rats

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    Escherichia coli endotoxin is a potent stimulator of IL-1 and cachetin/TNF production from macrophages. Both IL-1 and cachetin/TNF have been implicated in muscle protein loss, acute phase protein synthesis, fever, depressed serum zinc, and elevate serum corticosterone concentration. The source of mobilized amino acids during infection and inflamation is believed to come from muscle proteolysis. Data presented in this thesis clearly indicated that the relative contribution to the negative N balance by skin and bone should not be neglected. The reduction in fractional rates of protein synthesis measured by injection of flooding doses of [3H]-phenylalanine in the endotoxin was in the order of skin (abdomen) &gt; bone &gt; muscle. These also run parallel with the reduction of protein content. Total liver protein synthesised per day in the endotoxin-treated animals was increased. Some preparations of E. coli endotoxin (phenol and TCA extract) (ED) are hypothermic and enhanced greater reduction in food intake and body weight loss; while the butanol extracts endotoxin (ES) caused fever, produced less anorexia and body weight loss. The reason for these differences is not clear but may be due to the production of potent shock mediator, cachetin/TNF and/or stimulation on the sympatho-adrenal nervous sytem. The latter action may be modulated by protaglandins since indomethacin prevented ED-induced hypothermia. Administration of the β-adrengeric blocker propranolol, blunted the ES-induced hyperthermia and delayed the recovery of ED-induced hypothermia. The contribution of heat from non-thermogenesis in brown adipose tissue is unimportant in the production of fever since the binding of [^3H]-GDP to BAT mitochondria in both hyperthermic and hypothermic animals did not differ from that of the saline-treated animals. The present investigation suggests the existence of the diurnal variation in the body temperature responses to endotoxin. Both ES and ED produced hypothermia. Furthermore, reversed the lighting cycles (6pm-6am) (RL) affected : serum zinc, corticosterone, except for tissue protein loss. Both ES and ED produced hypothermia in the RL-adopted rats. The production and actions of IL-1 and cachectin/TNF may be affected by dietary fatty acids concentration and composition. Feeding rats with diets either enriched with or supplemented by 30g/kg, 90g/kg and 200g/kg of hydrogenated coconut oil (HCO); or by the 9og/Kg fish oil (FO) abolished most of the metabolic responses to ED injection. Both HCO and FO could influence the response via a reduction in prostaglandins and leukotrienes by reducing the formation of arachidonic acid (AA) precursor of eicosanoids. Fatty acids composition analysis from the PC fraction of the spleen showed a decreased amount of AA in the order of FO &gt; HCO &gt; CO. Pretreatment with the cycloxygenase inhibitor, indomethacin blocked body weight loss, prevented protein loss from peripheral tissues, and affected the elevation of serum corticosterone; whereas the lipoxygenase inhibitor AA861 inhibited ED-induced hypozincemia, and muscle cathepsin B activity. Total liver protein was unaffected by inhibitors, nor HCO or FO feeding. T ese data suggested that many of the endotoxin-induced metabolic changes are controlled by metabolites of AA, and that the acute-phase proteins synthesis by the liver is independent on eicosanoids production. Dietary fats manipulation moderated the metabolic responses to E. coli endotoxin through both pathways. (D74421/87)</p

    Polysaccharopeptide enhances the anticancer activity of doxorubicin and etoposide on human breast cancer cells ZR-75-30

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    In search of natural bioactive microbial compounds with adjuvant properties, we have previously showed that the polysaccharopeptide (PSP), isolated from Chinese medicinal mushroom Coriolus versicolor, was able to enhance the cytotoxicity of certain S-phase targeted-drugs on human leukemic HL-60 cells via some cell-cycle and apoptotic-dependent pathways. The present study aimed to investigate whether the synergism of mechanisms of PSP with certain chemotherapeutic drugs also applies to human breast cancer. PSP treatment enhanced the cytotoxicity of doxorubicin (Doxo), etoposide (VP-16) but not cytarabine (Ara-C). Bivariate bromodeoxyuridine (BrdUrd)/DNA flow cytometry analysis estimated a longer DNA synthesis time (Ts) for the PSP treated cancerous cells suggesting that PSP enhanced the apoptotic effect of Doxo and VP-16 via creating an S-phase trap in the human breast cancer cell line ZR-75-30. The participation of PSP in the apoptotic machinery of the chemotherapeutic agents was further supported by a reduced ratio of protein expression of Bcl-xL/Bax of the cancer cells. This study provides further insight into the synergistic mechanisms of PSP and supports the hypothesis that the anticancer potentials of PSP is not limited to leukemia but may also be used as an adjuvant therapy for breast cancers
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