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Generally, revision rhinoplasty cases require the use of stiff grafts to restore the lost support. However, the majority of patients indicated for revision surgery present with a lack of a bony cartilaginous framework of the septum, especially after previous septoplasty. Thus, surgeons are compelled to harvest costal cartilage. At the same time, rib graft harvesting is associated with additional trauma and a risk of serious complications. Being ENT surgeons, we often resect a part of the lateral wall of the inferior nasal meatus during the extended endoscopic approach to the maxillary sinus. We supposed that this bone plate could be used as a donor site for rhinoplasty graft harvesting. The aim of our study was a radiological assessment of the feasibility and limits of using the inferior meatus lateral wall (IMLW) as a donor site for rhinoplasty bone graft.A retrospective evaluation of 100 CT scans of sinuses was conducted. Further measurements of the IMLW were performed: average length and width (28.06 ± 4.03 mm and 19.73 ± 3.08 mm, respectively), thickness (0.62 ± 0.21 mm), and average deviation from the sagittal plane (17.7 ± 9.53 degrees). According to the obtained measurements, the described donor site is appropriate for harvesting nice straight bony fragments.The IMLW bone graft was used in four revision rhinoplasty cases. There were no postoperative complications. During the long-term follow-up, patients reported significant improvement in aesthetics, function, and social aspects according to Rhinoplasty Outcome Evaluation. Thus, the described technique is an easy and safe method for bone harvesting for revision rhinoplasty. Our first experience demonstrated the convenience and stability of IMLW grafts for revision rhinoplasty during the follow-up period of up to 2 years.
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Deviated nose correction is one of the most challenging procedures in rhinoplasty. Recent studies proposed effectiveness of preservation techniques even for patients with crooked nose deformity, although the long-term results are still controversial. Obviously, only addressing the blocking points is not enough to achieve stable midline position in crooked nose. To ensure consistent long-term results, we proposed a unilateral suturing of the bony pyramid along with unilateral resection of the excessive bone along the lateral osteotomy line. The first results of described surgical technique have proven its simplicity, reliability, and high efficiency both in primary and in revision surgeries. LEVEL OF EVIDENCE V: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .
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Scaly-tailed squirrels, the most poorly known group of gliding mammals, hold the record for variety of remarkable integument peculiarities. One of the most striking of these features is the scales on the tail, which apparently allow them to reduce energy costs when positioning themselves on a tree trunk. No less interesting is a peculiar spur that supports the flying membrane: the unciform element ('spur'). Despite the peculiarity of such elements, their nature has not yet been studied. Using anatomical, histological methods and scanning electron microscopy we studied the structure of the skin and its derivatives in five of the six species from both genera of extant gliding scaly-tailed squirrels (Anomaluridae, Rodentia): Idiurus macrotis, Idiurus zenkeri, Anomalurus beecrofti, Anomalurus pusillus and Anomalurus derbianus. In addition to the common mammalian skin structures, such as hair, vibrissae, sebaceous glands, meibomian glands of eyelids and eccrine sweat glands of the palmar and plantar pads, these animals have unique species-specific skin derivatives (the tail scaly organ and its specific glands, vibrissae of the withers, patagium and its hair brush) that play a significant role in their adaptation to gliding and to their environment in general. The structure of the elbow spur is also described and hypotheses on its evolutionary origin from the tendon of the triceps muscle are presented.
Assuntos
Adaptação Fisiológica/fisiologia , Tegumento Comum/anatomia & histologia , Locomoção/fisiologia , Roedores/anatomia & histologia , Animais , Tegumento Comum/fisiologia , Roedores/fisiologia , Especificidade da EspécieRESUMO
Studying the phenomenon of cellular senescence has been hindered by the lack of senescence-specific markers. As such, detection of proteins informally associated with senescence accompanies the use of senescence-associated ß-galactosidase as a collection of semiselective markers to monitor the presence of senescent cells. To identify novel biomarkers of senescence, we immunized BALB/c mice with senescent mouse lung fibroblasts and screened for antibodies that recognized senescence-associated cell-surface antigens by FACS analysis and a newly developed cell-based ELISA. The majority of antibodies that we isolated, cloned, and sequenced belonged to the IgM isotype of the innate immune system. In-depth characterization of one of these monoclonal, polyreactive natural antibodies, the IgM clone 9H4, revealed its ability to recognize the intermediate filament vimentin. By using 9H4, we observed that senescent primary human fibroblasts express vimentin on their cell surface, and MS analysis revealed a posttranslational modification on cysteine 328 (C328) by the oxidative adduct malondialdehyde (MDA). Moreover, elevated levels of secreted MDA-modified vimentin were detected in the plasma of aged senescence-accelerated mouse prone 8 mice, which are known to have deregulated reactive oxygen species metabolism and accelerated aging. Based on these findings, we hypothesize that humoral innate immunity may recognize senescent cells by the presence of membrane-bound MDA-vimentin, presumably as part of a senescence eradication mechanism that may become impaired with age and result in senescent cell accumulation.
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Anticorpos/metabolismo , Membrana Celular/metabolismo , Senescência Celular/fisiologia , Vimentina/metabolismo , Animais , Biomarcadores/metabolismo , Células Cultivadas , Feminino , Fibroblastos/metabolismo , Imunidade Humoral/fisiologia , Imunidade Inata/fisiologia , Imunoglobulina M/metabolismo , Filamentos Intermediários/metabolismo , Malondialdeído/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Espécies Reativas de Oxigênio/metabolismo , beta-Galactosidase/metabolismoRESUMO
Efficient diagnostic approaches to detect coronary artery disease (CAD) in elderly patients are necessary to ensure optimal and timely treatment. The population of suspected CAD patients older than 70 years is especially vulnerable and constantly growing. Finding the optimal diagnostic approach is challenging due to certain features of this population, such as high prevalence of comorbidities, existing contraindications to exercise tests or cognitive decline, which hinders correct assessment of the patient's situation. Moreover, some symptoms of CAD can have variable significance in the elderly compared to younger adult groups. In this review, we present current recommendations of the United States (US) and European cardiologists' associations and discuss their applicability for diagnostics in the elderly population. Exercise electrocardiogram (ECG) and exercise stress echocardiography (SE) tests are not feasible for a substantial proportion of elderly patients. Coronary computed tomography angiography (CTA) appears to be an attractive alternative for such patients, but is not universally applicable; for instance, it is problematic in patients with significant calcification of the vessels. Moreover, more studies are needed to compare the results delivered by CTA to those of other diagnostic methods. Future efforts should be focused on comparative studies to better understand the limits and advantages of different diagnostic methods and their combinations. It is possible that some of the currently used diagnostic criteria could be improved to better accommodate the needs of the elderly population.
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Angiografia Coronária/métodos , Doença da Artéria Coronariana/diagnóstico , Eletrocardiografia/métodos , Teste de Esforço/métodos , Idoso , Idoso de 80 Anos ou mais , Comorbidade , Feminino , Humanos , Masculino , Guias de Prática Clínica como Assunto , Estados UnidosRESUMO
Mycoplasmas are bacteria lacking the cell wall, which is the major characteristic of this taxonomic class (Mollicutes). Among bacteria, mycoplasmas possess the smallest genome known for free-living organisms. This feature limits the autonomy of bacteria and makes them increasingly susceptible to changes in the host organism. Many mycoplasmas themselves cause pathological changes in the host organism, often complicated by immune disorders. Infection with certain strains of mycoplasma results in the activation of the nuclear factor kappa-light-chain-enhancer of activated B cells, which is the major mediator of the inflammatory response. Furthermore, mycoplasmas can inhibit p53-mediated checkpoint control of cell cycle and apoptosis. Collectively, these properties indicate that mycoplasmas might act as cancer-promoting factors. In this review, we summarize the information known to date on the role of mycoplasmas in the regulation of the host immune response and their functional interactions with p53.
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Infecções por Mycoplasma/genética , Mycoplasma/patogenicidade , NF-kappa B/genética , Proteína Supressora de Tumor p53/genética , Apoptose/genética , Apoptose/imunologia , Divisão Celular/genética , Interações Hospedeiro-Patógeno/genética , Interações Hospedeiro-Patógeno/imunologia , Humanos , Ativação Linfocitária/genética , Ativação Linfocitária/imunologia , Mycoplasma/genética , Mycoplasma/imunologia , Infecções por Mycoplasma/imunologia , Infecções por Mycoplasma/microbiologia , Transdução de Sinais , Fator de Transcrição RelA/genética , Fator de Transcrição RelA/imunologiaRESUMO
This study demonstrated that extracellular membrane vesicles are involved with the development of resistance to fluoroquinolones by mycoplasmas (class Mollicutes). This study assessed the differences in susceptibility to ciprofloxacin among strains of Acholeplasma laidlawii PG8. The mechanisms of mycoplasma resistance to antibiotics may be associated with a mutation in a gene related to the target of quinolones, which could modulate the vesiculation level. A. laidlawii extracellular vesicles mediated the export of the nucleotide sequences of the antibiotic target gene as well as the traffic of ciprofloxacin. These results may facilitate the development of effective approaches to control mycoplasma infections, as well as the contamination of cell cultures and vaccine preparations.
Assuntos
Acholeplasma laidlawii/efeitos dos fármacos , Adaptação Fisiológica , Antibacterianos/farmacologia , Ciprofloxacina/farmacologia , Genes Bacterianos , Mutação , Acholeplasma laidlawii/genética , Acholeplasma laidlawii/fisiologia , Sequência de Aminoácidos , Antibacterianos/farmacocinética , Sequência de Bases , Transporte Biológico , Ciprofloxacina/farmacocinética , DNA Topoisomerase IV/química , DNA Topoisomerase IV/genética , DNA Bacteriano , Testes de Sensibilidade Microbiana , Microscopia de Força Atômica , Microscopia Eletrônica de Transmissão , Dados de Sequência Molecular , Homologia de Sequência de Aminoácidos , Homologia de Sequência do Ácido NucleicoRESUMO
Endoscopic repair of large nasal septal perforation (SP) remains a rather challenging procedure. The presented modification of vascularized flap, which is supplied with branches of posterior septal artery, has proven to be convenient and effective in closure of SPs larger than 2 cm. Laryngoscope, 134:3485-3488, 2024.
Assuntos
Endoscopia , Perfuração do Septo Nasal , Septo Nasal , Retalhos Cirúrgicos , Humanos , Perfuração do Septo Nasal/cirurgia , Retalhos Cirúrgicos/transplante , Retalhos Cirúrgicos/irrigação sanguínea , Endoscopia/métodos , Septo Nasal/cirurgia , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Resultado do Tratamento , Artérias/cirurgia , Artérias/lesõesRESUMO
For the first time, the phytopathogenicity of extracellular vesicles of Acholeplasma laidlawii PG8 (a ubiquitous mycoplasma that is one of the five common species of cell culture contaminants and is a causative agent for phytomycoplasmoses) in Oryza sativa L. plants was studied. Data on the ability of extracellular vesicles of Acholeplasma laidlawii PG8 to penetrate from the nutrient medium into overground parts of Oryza sativa L. through the root system and to cause alterations in ultrastructural organization of the plants were presented. As a result of the analysis of ultrathin leaf sections of plants grown in medium with A. laidlawii PG8 vesicles, we detected significant changes in tissue ultrastructure characteristic to oxidative stress in plants as well as their cultivation along with bacterial cells. The presence of nucleotide sequences of some mycoplasma genes within extracellular vesicles of Acholeplasma laidlawii PG8 allowed a possibility to use PCR (with the following sequencing) to perform differential detection of cells and bacterial vesicles in samples under study. The obtained data may suggest the ability of extracellular vesicles of the mycoplasma to display in plants the features of infection from the viewpoint of virulence criteria--invasivity, infectivity--and toxigenicity--and to favor to bacterial phytopathogenicity.
Assuntos
Acholeplasma laidlawii/genética , Acholeplasma laidlawii/patogenicidade , Organelas/metabolismo , Doenças das Plantas/microbiologia , Acholeplasma laidlawii/citologia , Meios de Cultura , Di-Hidrolipoil-Lisina-Resíduo Acetiltransferase/genética , Genes Fúngicos , Interações Hospedeiro-Patógeno , Organelas/genética , Oryza/microbiologia , Estresse Oxidativo , Doenças das Plantas/genética , Folhas de Planta/microbiologia , Folhas de Planta/ultraestrutura , Raízes de Plantas/microbiologia , Polirribonucleotídeo Nucleotidiltransferase/genética , RNA Ribossômico 16S , RNA Ribossômico 23SRESUMO
Extracellular vesicle production is believed to be a ubiquitous process in bacteria, but the data on such a process in Mollicutes are absent. We report the isolation of ultramicroforms - extracellular vesicles from supernatants of Acholeplasma laidlawii PG8 (ubiquitous mycoplasma; the main contaminant of cell culture). Considering sizes, morphology, and ultrastructural organization, the ultramicroforms of A. laidlawii PG8 are similar to membrane vesicles of Gram-positive and Gram-negative bacteria. We demonstrate that A. laidlawii PG8 vesicles contain genetic material and proteins, and are mutagenic to lymphocytes of human peripheral blood. We show that Mycoplasma gallisepticum S6, the other mycoplasma, also produce similar structures, which suggests that shedding of the vesicles might be the common phenomenon in Mollicutes. We found that the action of stress conditions results in the intensive formation of ultramicroforms in mycoplasmas. The role of vesicular formation in mycoplasmas remains to be studied.
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Acholeplasma laidlawii/fisiologia , Vesículas Transportadoras/química , Vesículas Transportadoras/ultraestrutura , Acholeplasma laidlawii/genética , Acholeplasma laidlawii/ultraestrutura , Transporte Biológico , Células Cultivadas , Dano ao DNA , Espaço Extracelular , Humanos , Linfócitos/microbiologia , Testes de Mutagenicidade , Mycoplasma gallisepticum/genética , Mycoplasma gallisepticum/fisiologia , Mycoplasma gallisepticum/ultraestrutura , Estresse FisiológicoRESUMO
Representatives of the Mollicutes class are the smallest, wall-less bacteria capable of independent reproduction. They are widespread in nature, most are commensals, and some are pathogens of humans, animals and plants. They are also the main contaminants of cell cultures and vaccine preparations. Despite limited biosynthetic capabilities, they are highly adaptable and capable of surviving under various stress and extreme conditions, including antimicrobial selective pressure. This review describes current understanding of antibiotic resistance (ABR) mechanisms in Mollicutes. Protective mechanisms in these bacteria include point mutations, which may include non-target genes, and unique gene exchange mechanisms, contributing to transfer of ABR genes. Better understanding of the mechanisms of emergence and dissemination of ABR in Mollicutes is crucial to control these hypermutable bacteria and prevent the occurrence of highly ABR strains.
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Antibacterianos/farmacologia , Farmacorresistência Bacteriana/genética , Transferência Genética Horizontal , Tenericutes/efeitos dos fármacos , Animais , Genes Bacterianos , Humanos , Mutação , Tenericutes/genéticaRESUMO
Gliomas are the most common primary tumours of the central nervous system, with nearly 15,000 diagnosed annually in the United States and a lethality approaching 80% within the first year of glioblastoma diagnosis. The marked induction of angiogenesis in glioblastomas suggests that it is a necessary part of malignant progression; however, the precise molecular mechanisms underlying the regulation of brain tumour growth and angiogenesis remain unresolved. Here we report that a candidate tumour suppressor gene, ING4, is involved in regulating brain tumour growth and angiogenesis. Expression of ING4 is significantly reduced in gliomas as compared with normal human brain tissue, and the extent of reduction correlates with the progression from lower to higher grades of tumours. In mice, xenografts of human glioblastoma U87MG, which has decreased expression of ING4, grow significantly faster and have higher vascular volume fractions than control tumours. We show that ING4 physically interacts with p65 (RelA) subunit of nuclear factor NF-kappaB, and that ING4 regulates brain tumour angiogenesis through transcriptional repression of NF-kappaB-responsive genes. These results indicate that ING4 has an important role in brain tumour pathogenesis.
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Neoplasias Encefálicas/irrigação sanguínea , Neoplasias Encefálicas/patologia , Neovascularização Patológica , Proteínas Supressoras de Tumor/metabolismo , Animais , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Proteínas de Ciclo Celular , Divisão Celular , Linhagem Celular Tumoral , Ciclo-Oxigenase 2 , Progressão da Doença , Regulação para Baixo , Regulação Neoplásica da Expressão Gênica , Glioblastoma/irrigação sanguínea , Glioblastoma/genética , Glioblastoma/metabolismo , Glioblastoma/patologia , Proteínas de Homeodomínio , Humanos , Interleucina-6/genética , Interleucina-8/genética , Isoenzimas/genética , Proteínas de Membrana , Camundongos , Camundongos SCID , NF-kappa B/metabolismo , Transplante de Neoplasias , Prostaglandina-Endoperóxido Sintases/genética , Ligação Proteica , Fator de Transcrição RelA , Proteínas Supressoras de Tumor/genéticaRESUMO
This article reports on a study of some characteristics of DNA extracted from the vegetative and viable, but nonculturable (VBNC), cells of two mycoplasma species (Acholeplasma laidlawii PG8 and Mycoplasma hominis PG37) using atomic force microscopy (AFM). DNA images were obtained by operating the AFM microscope in the tapping mode. It was found that DNA from the VBNC forms of M. hominis PG37 has decreased sizes (height: 0.177 +/- 0.026 nm vs. 0.391 +/- 0.041 nm for the vegetative forms, and width: 1.92 +/- 0.099 vs. 2.17 +/- 0.156 nm for the vegetative forms) in comparison to DNA from the vegetative forms of the mycoplasma. In the case of DNA from the A. laidlawii PG8 VBNC forms, we detected a decrease in width (1.506 +/- 0.076 nm vs. 1.898 +/- 0.117 nm for the vegetative forms), but an increase in height (0.641 +/- 0.068 nm vs. 0.255 +/- 0.010 nm for the vegetative forms) of the molecule. Analyzing the obtained results, one can speculate on some similarities in the physical-chemical properties of DNA from M. hominis PG37 and M. gallisepticum S6. In turn, this implies some general mechanisms of adaptation to a severe environment.
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Acholeplasma laidlawii/genética , DNA Bacteriano/isolamento & purificação , Mycoplasma hominis/genética , Microscopia de Força AtômicaRESUMO
To elucidate the regularities of adaptation of the representatives of class Mollicutes to antimicrobials and to identify the promising targets for eradication of mycoplasma infections and contaminations the comparative analysis of the molecular basis of bacterial resistance to antibiotics of different classes is needed. Previously, we presented the data on the whole-genome sequences of Acholeplasma laidlawii strains with different susceptibility to ciprofloxacin (GenBank: LXYB00000000.1), tetracycline (GenBank: NELO00000000.2) and melittin (GenBank: NELN00000000.2) as well as the data on cell and extracellular vesicle proteomes of melittin-resistant A. laidlawii strain [1]. The lists of extracellular vesicle proteins secreted by A. laidlawii strains with the increased resistance to ciprofloxacin (PG8R10) and tetracycline (PG8RTet) are presented here. The vesicle proteome profiles were obtained by 1D SDS-PAGE and liquid chromatography-mass spectrometry.
RESUMO
Acholeplasma laidlawii is widespread hypermutable bacteria (class Mollicutes) capable of infecting humans, animals, plants, which is the main contaminant of cell cultures and vaccine preparations. The mechanisms of the development of antimicrobial resistance of this bacterium are associated with the secretion of extracellular vesicles, which can mediate the lateral transfer of antibiotic resistance determinants. We compared the genome profiles of ciprofloxacin-resistant A.laidlawii strains PG8r1 (MIC 10 µg/ml) and PG8r3 (MIC 10 µg/ml) selected under different in vitro conditions - when ciprofloxacin-sensitive (MIC 0.5 µg/ml) A.laidlawii PG8B strain was cultured at increasing concentrations of ciprofloxacin in a broth medium alone, and with vesicles derived from the ciprofloxacin-resistant (MIC 20 µg/ml) A.laidlawii PG8R10c-2 strain, respectively. Genome profiles of PG8c-3 (obtained from a single colony of the strain PG8B) and PG8R10c-2 were analyzed too. Patterns of the quinolone target genes (gyrA, gyrB, parE, parC) containing in extracellular vesicles of PG8c-3, PG8R10c-2, PG8r1 and PG8r3 were determined. Genome sequencing was performed on the NextSeq Illumina platform. Search and annotation of single nucleotide polymorphisms were performed using Samtools and SnpEff, respectively. We also compared cellular proteomes of PG8c-3, PG8r1 and PG8r3. The cellular proteome profiles of the A. laidlawii strains were determined by two-dimensional gel electrophoresis and MALDI-TOF/TOF MS. This work presents data on single nucleotide polymorphisms (SNPs) found in the genomes of the ciprofloxacin-resistant strains selected under different in vitro conditions and proteins that were differentially expressed in the cells of ciprofloxacin-resistant strains selected under different conditions in vitro.
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Mycoplasmas are the smallest free-living organisms. Reduced sizes of their genomes put constraints on the ability of these bacteria to live autonomously and make them highly dependent on the nutrients produced by host cells. Importantly, at the organism level, mycoplasmal infections may cause pathological changes to the host, including cancer and severe immunological reactions. At the molecular level, mycoplasmas often activate the NF-κB (nuclear factor kappa-light-chain-enhancer of activated B cells) inflammatory response and concomitantly inhibit the p53-mediated response, which normally triggers the cell cycle and apoptosis. Thus, mycoplasmal infections may be considered as cancer-associated factors. At the same time, mycoplasmas through their membrane lipoproteins (LAMPs) along with lipoprotein derivatives (lipopeptide MALP-2, macrophage-activating lipopeptide-2) are able to modulate anti-inflammatory responses via nuclear translocation and activation of the Nrf2 (nuclear factor-E2-related anti-inflammatory transcription factor 2). Thus, interactions between mycoplasmas and host cells are multifaceted and depend on the cellular context. In this review, we summarize the current information on the role of mycoplasmas in affecting the host's intracellular signaling mediated by the interactions between transcriptional factors p53, Nrf2, and NF-κB. A better understanding of the mechanisms underlying pathologic processes associated with reprogramming eukaryotic cells that arise during the mycoplasma-host cell interaction should facilitate the development of new therapeutic approaches to treat oncogenic and inflammatory processes.
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BACKGROUND: Exercise capacity is well known to be an important prognostic factor in patients with cardiovascular disease and among healthy persons. AIM: To determine if there are any differences between the peak exercise response during exercise treadmill testing with the individualized ramp protocol and the modified Bruce protocol in elderly patients. MATERIALS AND METHODS: The study included 40 patients (both male and female), aged 70 years and older, who had not had a baseline history of the confirmed coronary artery disease or heart failure diagnoses. All patients underwent exercise treadmill testing using modified Bruce protocol and individualized ramp protocol for 2 consecutive days. Peak heart rate, peak systolic and diastolic blood pressure, peak pressure-rate double product, exercise duration, and peak metabolic equivalents were recorded in both tests. Perceived level of exertion was evaluated using the Borg 10-point scale. RESULTS: The average duration of exercise was longer for the ramp protocol than for the modified Bruce protocol. When the modified Bruce protocol was used, patients achieved a lower workload than they did in using the ramp protocol. The rating of perceived exertion using the revised Borg scale (0 to 10) was 5.6±1.4 for the ramp protocol and 8.7±1.4 for the modified Bruce protocol, which indicates that the patients found the ramp protocol easier. CONCLUSION: In elderly patients the individualized ramp treadmill protocol allows to achieve the optimal test duration with higher degrees of workload and greater patient comfort during the test more often than does the modified Bruce protocol.
Assuntos
Pressão Sanguínea , Teste de Esforço/métodos , Tolerância ao Exercício , Frequência Cardíaca , Consumo de Oxigênio , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Equivalente Metabólico , Esforço FísicoRESUMO
The mechanistic target of rapamycin (mTOR) is a PI3K-related kinase that regulates cell growth, proliferation and survival in response to the availability of energy sources and growth factors. Cancer development and progression is often associated with constitutive activation of the mTOR pathway, thus justifying mTOR inhibition as a promising approach to cancer treatment and prevention. However, development of previous rapamycin analogues has been complicated by their induction of adverse side effects and variable efficacy. Since mTOR pathway regulation involves multiple feedback mechanisms that may be differentially activated depending on the degree of mTOR inhibition, we investigated whether rapamycin dosing could be adjusted to achieve chemopreventive efficacy without side effects. Thus, we tested the efficacy of two doses of a novel, highly bioavailable nanoformulation of rapamycin, Rapatar, in a mouse prostate cancer model (male mice with prostate epithelium-specific Pten-knockout). We found that the highest efficacy was achieved by the lowest dose of Rapatar used in the study. While both doses tested were equally effective in suppressing proliferation of prostate epithelial cells, higher dose resulted in activation of feedback circuits that reduced the drug's tumor preventive efficacy. These results demonstrate that low doses of highly bioavailable mTOR inhibitor, Rapatar, may provide safe and effective cancer prevention.
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Adipose tissue is recognized as a major source of systemic inflammation with age, driving age-related tissue dysfunction and pathogenesis. Macrophages (Mφ) are central to these changes yet adipose tissue Mφ (ATMs) from aged mice remain poorly characterized. To identify biomarkers underlying changes in aged adipose tissue, we performed an unbiased RNA-seq analysis of ATMs from young (8-week-old) and healthy aged (80-week-old) mice. One of the genes identified, V-set immunoglobulin-domain-containing 4 (VSIG4/CRIg), encodes a Mφ-associated complement receptor and B7 family-related immune checkpoint protein. Here, we demonstrate that Vsig4 expression is highly upregulated with age in perigonadal white adipose tissue (gWAT) in two mouse strains (inbred C57BL/6J and outbred NIH Swiss) independent of gender. The accumulation of VSIG4 was mainly attributed to a fourfold increase in the proportion of VSIG4+ ATMs (13%-52%). In a longitudinal study, VSIG4 expression in gWAT showed a strong correlation with age within a cohort of male and female mice and correlated strongly with physiological frailty index (PFI, a multi-parameter assessment of health) in male mice. Our results indicate that VSIG4 is a novel biomarker of aged murine ATMs. VSIG4 expression was also found to be elevated in other aging tissues (e.g., thymus) and was strongly induced in tumor-adjacent stroma in cases of spontaneous and xenograft lung cancer models. VSIG4 expression was recently associated with cancer and several inflammatory diseases with diagnostic and prognostic potential in both mice and humans. Further investigation is required to determine whether VSIG4-positive Mφ contribute to immunosenescence and/or systemic age-related deficits.
Assuntos
Tecido Adiposo Branco/metabolismo , Receptores de Complemento/metabolismo , Envelhecimento/metabolismo , Animais , Biomarcadores/metabolismo , Feminino , Macrófagos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BLRESUMO
Effective treatment of some types of cancer can be achieved by modulating cell lineage-specific rather than tumor-specific targets. We conducted a systematic search for novel agents selectively toxic to cells of hematopoietic origin. Chemical library screenings followed by hit-to-lead optimization identified OT-82, a small molecule with strong efficacy against hematopoietic malignancies including acute myeloblastic and lymphoblastic adult and pediatric leukemias, erythroleukemia, multiple myeloma, and Burkitt's lymphoma in vitro and in mouse xenograft models. OT-82 was also more toxic towards patients-derived leukemic cells versus healthy bone marrow-derived hematopoietic precursors. OT-82 was shown to induce cell death by inhibiting nicotinamide phosphoribosyltransferase (NAMPT), the rate-limiting enzyme in the salvage pathway of NAD synthesis. In mice, optimization of OT-82 dosing and dietary niacin further expanded the compound's therapeutic index. In toxicological studies conducted in mice and nonhuman primates, OT-82 showed no cardiac, neurological or retinal toxicities observed with other NAMPT inhibitors and had no effect on mouse aging or longevity. Hematopoietic and lymphoid organs were identified as the primary targets for dose limiting toxicity of OT-82 in both species. These results reveal strong dependence of neoplastic cells of hematopoietic origin on NAMPT and introduce OT-82 as a promising candidate for the treatment of hematological malignancies.