672 research outputs found
ENDOCRINE AND AMINO-ACID REGULATION OF LIVER MACROAUTOPHAGY AND PROTEOLYTIC FUNCTION
Endocrine and amino acid regulation of liver macroautophagy and proteolytic function. Am, J. Physiol. 266 (Gastrointest. Liver Physiol. 29): G118-G122, 1994.-Regulation of liver macroautophagy and protein degradation by hormones and direct regulatory amino acids were studied in male 2-mo-old Sprague-Dawley albino rats with the use of the antilipolytic agent 3,5'-dimethylpyrazole (DMP; 12 mg/kg body wt ip) as a stimulatory agent. Injection of DMP decreased glutamine plasma levels and glutamine release from the perfused liver. Autophagic vacuoles were observed in the pericanalicular area of liver cells after 30 min. Levels and release of other regulatory amino acids did not exhibit any significant decrease but subsequently increased. Intraperitoneal administration of glutamine inhibited the proteolytic response. In conclusion, these studies demonstrate that in vivo induction and control of liver macroautophagy and protein degradation by the physiological mechanism (i.e., by shortage of nutrients) involve unbalanced and asynchronous changes in the levels of selected direct regulatory amino acids (i.e., a decrease in glutamine and a subsequent increase in leucine and tyrosine levels)
aberrant inos signaling is under genetic control in rodent liver cancer and potentially prognostic for the human disease
Mounting evidence underlines the role of inducible nitric oxidesynthase (iNOS) in hepatocellular carcinoma (HCC) develop-ment, but its functional interactions with pathways involved inHCC progression remain uninvestigated. Here, we analyzed inpreneoplastic and neoplastic livers from Fisher 344 and BrownNorway rats, possessing different genetic predisposition to HCC,in transforming growth factor-a (TGF-a) and c-Myc–TGF-atransgenic mice, characterized by different susceptibility toHCC, and in human HCC: (i) iNOS function and interactionswith nuclear factor-kB (NF-kB) and Ha-RAS/extracellularsignal-regulated kinase (ERK) during hepatocarcinogenesis;(ii) influence of genetic predisposition to liver cancer on thesepathways and role of these cascades in determining a susceptibleor resistant phenotype and (iii) iNOS prognostic value in humanHCC. We found progressive iNos induction in rat and mouse liverlesions, always at higher levels in the most aggressive models rep-resented by HCC of rats genetically susceptible to hepatocarcino-genesis and c-Myc–TGF-a transgenic mice. iNOS, inhibitor of kBkinase/NF-kB and RAS/ERK upregulation was significantly higherin HCC with poorer prognosis (as defined by patients' survivallength) and positively correlated with tumor proliferation, genomicinstability and microvascularization and negatively with apoptosis.Suppression of iNOS signaling by aminoguanidine led to decreasedHCC growth and NF-kB and RAS/ERK expression and increasedapoptosis both in vivo and in vitro. Conversely, block of NF-kBsignaling by sulfasalazine or short interfering RNA (siRNA) orERK signaling by UO126 caused iNOS downregulation in HCCcell lines. These findings indicate that iNOS cross talk with NF-kB and Ha-RAS/ERK cascades influences HCC growth and prog-nosis, suggesting that key component of iNOS signaling could rep-resent important therapeutic targets for human HCC.IntroductionHepatocellular carcinoma (HCC) is one of the most frequent anddeadliest human cancers worldwide. Current therapies do not improvesignificantly the prognosis of patients with unresectable HCC (1,2).This emphasizes the need to investigate the molecular mechanismsresponsible for HCC development to identify new targets for earlydiagnosis, chemoprevention and treatment.Numerous genes regulating susceptibility to HCC and controllinggrowth, progression and redifferentiation of preneoplastic and neo-plastic lesions have been mapped in rodents (3). Decrease in growthability and/or marked redifferentiation of preneoplastic lesion char-acterizes rodent strains resistant to hepatocarcinogenesis (3,4). Con-sequently, studies on the mechanisms underlying the acquisition ofa phenotype susceptible/resistantto hepatocarcinogenesis in rodentstrains, carrying preneoplastic lesions differently prone to progressto HCC, may lead to the discovery of prognostic markers and ther-apeutic targets for the human disease. Dysplastic nodules and HCCinduced in susceptible Fisher 344 (F344) rats show upregulation ofc-Myc, Cyclin D1, E and A and E2f1 genes, increased cyclinD1–Cdk4, cyclin E–Cdk2 and E2f1–Dp1 complexes and retinoblas-toma protein (pRb) hyperphosphorylation (4–6). These changes areabsent or less pronounced in liver lesions from resistant Brown Norway(BN) rats, where a block of
Near-infrared spectroscopy estimation of combined skeletal muscle oxidative capacity and O2 diffusion capacity in humans
The final steps of the O2 cascade during exercise depend on the product of the microvascular-tointramyocyte PO2 difference and muscle O2 diffusing capacity (DmO2). Non-invasive methods to determine DmO2 in humans are currently unavailable. Muscle oxygen uptake (mVO2) recovery rate constant (k), measured by near-infrared spectroscopy (NIRS) using intermittent arterial occlusions, is associated with muscle oxidative capacity in vivo. We reasoned that k would be limited by DmO2 when muscle oxygenation is low (kLOW), and hypothesized that: i) k in well-oxygenated muscle (kHIGH) is associated with maximal O2 flux in fiber bundles; and ii) Δk (kHIGH-kLOW) is associated with capillary density (CD). Vastus lateralis k was measured in 12 participants using NIRS after moderate exercise. The timing and duration of arterial occlusions were manipulated to maintain tissue saturation index (TSI) within a 10% range either below (LOW) or above (HIGH) half-maximal desaturation, assessed during sustained arterial occlusion. Maximal O2 flux in phosphorylating state was 37.7±10.6 pmol·s−1·mg−1 (~5.8 ml·min−1·100g−1). CD ranged 348 to 586 mm-2. kHIGH was greater than kLOW (3.15±0.45 vs 1.56±0.79 min-1, p\u3c0.001). Maximal O2 flux was correlated with kHIGH (r=0.80, p=0.002) but not kLOW (r=-0.10, p=0.755). Δk ranged -0.26 to -2.55 min-1, and correlated with CD (r=- 0.68, p=0.015). mVO2 k reflects muscle oxidative capacity only in well-oxygenated muscle. Δk, the difference in k between well- and poorly-oxygenated muscle, was associated with CD, a mediator of DmO2. Assessment of muscle k and Δk using NIRS provides a non-invasive window on muscle oxidative and O2 diffusing capacity
Confocal Laser Scanning Microscopy for Detection of Schistosoma mansoni Eggs in the Gut of Mice
Background: The gold standard for diagnosing Schistosoma mansoni infections is the detection of eggs from stool or biopsy specimens. The viability of collected eggs can be tested by the miracidium hatching procedure. Direct detection methods are often limited in patients with light or early infections, whereas serological tests and PCR methods fail to differentiate between an inactive and persistent infection and between schistosomal species. Recently, confocal laser scanning microscopy (CLSM) has been introduced as a diagnostic tool in several fields of medicine. In this study we evaluated CLSM for the detection of viable eggs of S. mansoni directly within the gut of infected mice. Methodology/Principal Findings: The confocal laser scanning microscope used in this study is based on the Heidelberg Retina Tomograph II scanning laser system in combination with the Rostock Cornea Module (image modality 1) or a rigid endoscope (image modality 2). Colon sections of five infected mice were examined with image modalities 1 and 2 for schistosomal eggs. Afterwards a biopsy specimen was taken from each colon section and examined by bright-field microscopy. Visualised eggs were counted and classified in terms of viability status. Conclusions/Significance: We were able to show that CLSM visualises eggs directly within the gut and permits discrimination of schistosomal species and determination of egg viability. Thus, CLSM may be a suitable non-invasive too
Bortezomib-dexamethasone as maintenance therapy or early retreatment at biochemical relapse versus observation in relapsed/refractory multiple myeloma patients: a randomized phase II study
Quantum numbers of the state and orbital angular momentum in its decay
Angular correlations in decays, with , and , are used to measure
orbital angular momentum contributions and to determine the value of
the meson. The data correspond to an integrated luminosity of 3.0
fb of proton-proton collisions collected with the LHCb detector. This
determination, for the first time performed without assuming a value for the
orbital angular momentum, confirms the quantum numbers to be .
The is found to decay predominantly through S wave and an upper limit
of at C.L. is set on the fraction of D wave.Comment: 16 pages, 4 figure
Phase 1/2 study of weekly carfilzomib, cyclophosphamide, dexamethasone in newly diagnosed transplant-ineligible myeloma
This multicentre, open-label phase 1/2 trial determined safety and efficacy of weekly carfilzomib plus cyclophosphamide-dexamethasone (wKCyd) in newly diagnosed multiple myeloma (NDMM) patients aged ≥65 years or transplant ineligible. Patients received wKCyd for up to nine 28-day cycles, followed by maintenance with carfilzomib until progression/intolerance. The phase 1 portion used a 3+3 dose-escalation scheme to determine the maximum tolerated dose of weekly carfilzomib: 12 patients received wKCyd with carfilzomib doses of 45, 56 and 70 mg/m 2. The recommended phase 2 dose was established at 70 mg/m 2 and 54 patients (phase 1 and 2) received weekly carfilzomib 70 mg/m 2: 85% of them achieved ≥partial response (PR), 66% ≥very good PR, 30%≥near-complete response (CR) and 15% CR. Responses improved in 40 patients who started maintenance: 98% achieved ≥PR, including 29% CR and 10% stringent CR. After a median follow-up of 18 months, the 2-year progression-free survival and overall survival rates were 53.2% and 81%, respectively. The most frequent grade 3-5 toxicities were neutropenia (22%) and cardiopulmonary adverse events (9%). This is the first study of weekly carfilzomib plus an alkylating agent in elderly patients with NDMM. wKCyd was effective, with an acceptable risk/benefit ratio, and thus can be a valid option in this setting
The central region of the msp gene of Treponema denticola has sequence heterogeneity among clinical samples, obtained from patients with periodontitis
<p>Abstract</p> <p>Background</p> <p><it>Treponema denticola </it>is an oral spirochete involved in the pathogenesis and progression of periodontal disease. Of its virulence factors, the major surface protein (MSP) plays a role in the interaction between the treponeme and host. To understand the possible evolution of this protein, we analyzed the sequence of the <it>msp </it>gene in 17 <it>T. denticola </it>positive clinical samples.</p> <p>Methods</p> <p>Nucleotide and amino acid sequence of MSP have been determined by PCR amplification and sequencing in seventeen <it>T. denticola </it>clinical specimens to evaluate the genetic variability and the philogenetic relationship of the <it>T. denticola msp </it>gene among the different amplified sequence of positive samples. In silico antigenic analysis was performed on each MSP sequences to determined possible antigenic variation.</p> <p>Results</p> <p>The <it>msp </it>sequences showed two highly conserved 5' and 3' ends and a central region that varies substantially. Phylogenetic analysis categorized the 17 specimens into 2 principal groups, suggesting a low rate of evolutionary variability and an elevated degree of conservation of <it>msp </it>in clinically derived genetic material. Analysis of the predicted antigenic variability between isolates, demonstrated that the major differences lay between amino acids 200 and 300.</p> <p>Conclusion</p> <p>These findings showed for the first time, the nucleotide and amino acids variation of the <it>msp </it>gene in infecting <it>T. denticola</it>, <it>in vivo</it>. This data suggested that the antigenic variability found in to the MSP molecule, may be an important factor involved in immune evasion by <it>T. denticola</it>.</p
Thaptomys Thomas 1915 (Rodentia, Sigmodontinae, Akodontini) with karyotypes 2n = 50, FN = 48, and 2n = 52, FN = 52: Two monophyletic lineages recovered by molecular phylogeny
A novel karyotype with 2n = 50, FN = 48, was described for specimens of Thaptomys collected at Una, State of Bahia, Brazil, which are morphologically indistinguishable from Thaptomys nigrita, 2n = 52, FN = 52, found in other localities. It was hence proposed that the 2n = 50 karyotype could belong to a distinct species, cryptic of Thaptomys nigrita, once chromosomal rearrangements observed, along with the geographic distance, might represent a reproductive barrier between both forms. Phylogenetic analyses using maximum parsimony and maximum likelihood based on partial cytochrome b sequences with 1077 bp were performed, attempting to establish the relationships among the individuals with distinct karyotypes along the geographic distribution of the genus; the sample comprised 18 karyotyped specimens of Thaptomys, encompassing 15 haplotypes, from eight different localities of the Atlantic Rainforest. The intra-generic relationships corroborated the distinct diploid numbers, once both phylogenetic reconstructions recovered two monophyletic lineages, a northeastern clade grouping the 2n = 50 and a southeastern clade with three subclades, grouping the 2n = 52 karyotype. The sequence divergence observed between their individuals ranged from 1.9% to 3.5%
Imatinib Treatment Induces CD5+ B Lymphocytes and IgM Natural Antibodies with Anti-Leukemic Reactivity in Patients with Chronic Myelogenous Leukemia
Imatinib mesylate is a first line treatment of Chronic Myelogenous Leukemia and of a rare form of gastrointestinal stromal cancer, where the response to the drug is also linked to the immune system activation with production of antineoplastic cytokines. In this study, forty patients in the chronic phase of disease, treated with imatinib mesylate, were analyzed. Bone marrow aspirates were drawn at diagnosis, after 3, 6, 12, 18 months for haematological, cytofluorimetric, cytogenetic, biomolecular evaluation and cytokine measurement. Responder and non responder patients were defined according to the European LeukemiaNet recommendations. In responder patients (n = 32), the percentage of bone marrow CD20+CD5+sIgM+ lymphocytes, and the plasma levels of IgM, were significantly higher, at 3 months and up to 9 months, than in non responders. These IgM reacted with O-linked sugars expressed by leukemic cells and could induce tumor cell apoptosis. In responeìder patients the stromal-derived factor-1 and the B-lymphocyte-activating factor of the tumor necrosis factor family significantly raised in the bone marrow after imatinib administration, together with the bone morphogenetic proteins-2 and −7. All patients with high number of CD20+CD5+sIgM+ cells and high stromal-derived factor-1 and B lymphocyte activating factor levels, underwent complete cytogenetic and/or molecular remission by 12 months. We propose that CD20+CD5+sIgM+ lymphocytes producing anti-carbohydrate antibodies with anti-tumor activity, might contribute to the response to imatinib treatment. As in multivariate analysis bone marrow CD20+CD5+sIgM+ cells and stromal-derived factor-1 and B-lymphocyte-activating factor levels were significantly related to cytogenetical and molecular changes, they might contribute to the definition of the pharmacological response
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