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2.
Int J Surg Case Rep ; 105: 107975, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36940541

RESUMO

INTRODUCTION AND IMPORTANCE: Leiomyoma is the most common gynecologic tumor which may show atypical locations and degenerations. Cystic degeneration is said to be found in 4 % of all degenerations. Endometriosis, the presence of endometrial glands and stroma at extrauterine sites, is a common gynaecological condition seen in 10 % to 15 % of reproductive-age women usually being associated with various degrees of fertility problems. CASE PRESENTATION: 40 years old woman with P1L1A2, with secondary sub-fertility for 5 years, presented with chief complaints of dysmenorrhoea for 1 year initially around the menstrual cycle relieving with analgesics but later not limited to the menstrual cycle and pain not relieving with analgesics since 1 month. The patient underwent fertility-sparing laparoscopic removal avoiding a laparotomy and definitive hysterectomy. Manual morcellation was achieved. CLINICAL DISCUSSION: Cystic degeneration is rare in Leiomyoma although it is the more common gynaecological tumor in women and is associated with endometriosis probably due to retrograde menstruation. CONCLUSIONS: Laparoscopic removal of leiomyoma without laparotomy and definitive hysterectomy for a case of cystic endometriosis in a degenerated subserous myoma which to the best of our knowledge according to our search of articles on the relevant topic is the first reported case pertaining to the topic from Nepal.

3.
JCI Insight ; 8(7)2023 04 10.
Artigo em Inglês | MEDLINE | ID: mdl-36821369

RESUMO

Cholesterol-25-hydroxylase (CH25H), the biosynthetic enzyme for 25-hydroxycholesterol (25HC), is most highly expressed in the lung, but its role in lung biology is poorly defined. Recently, we reported that Ch25h is induced in monocyte-derived macrophages recruited to the airspace during resolution of lung inflammation and that 25HC promotes liver X receptor-dependent (LXR-dependent) clearance of apoptotic neutrophils by these cells. Ch25h and 25HC are, however, also robustly induced by lung-resident cells during the early hours of lung inflammation, suggesting additional cellular sources and targets. Here, using Ch25h-/- mice and exogenous 25HC in lung injury models, we provide evidence that 25HC sustains proinflammatory cytokines in the airspace and augments lung injury, at least in part, by inducing LXR-independent endoplasmic reticulum stress and endothelial leak. Suggesting an autocrine effect in endothelium, inhaled LPS upregulates pulmonary endothelial Ch25h, and non-hematopoietic Ch25h deletion is sufficient to confer lung protection. In patients with acute respiratory distress syndrome, airspace 25HC and alveolar macrophage CH25H were associated with markers of microvascular leak, endothelial activation, endoplasmic reticulum stress, inflammation, and clinical severity. Taken together, our findings suggest that 25HC deriving from and acting on different cell types in the lung communicates distinct, temporal LXR-independent and -dependent signals to regulate inflammatory homeostasis.


Assuntos
Lesão Pulmonar Aguda , Hidroxicolesteróis , Animais , Camundongos , Hidroxicolesteróis/metabolismo , Hidroxicolesteróis/farmacologia , Macrófagos Alveolares/metabolismo , Lesão Pulmonar Aguda/induzido quimicamente
4.
Int J Neurosci ; 133(10): 1120-1123, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35369847

RESUMO

Background: Transverse myelitis (TM) is a rare, acquired neuro-immunological spinal cord disorder that occurs with rapid onset of motor weakness, sensory deficits with bowel and bladder dysfunction. Patients being treated with immune checkpoint inhibitors (ICIs) for advanced malignancy have a known higher propensity of developing neuro immune complications. With the advent of COVID-19 pandemic there have been reported cases of TM with COVID-19 immunization. The reported infrequency of TM with both of the aforementioned causes makes delineation of the etiology challenging.Methods: We present a patient with metastatic small cell lung cancer (SCLC) on maintenance Atezolizumab immunotherapy who developed longitudinal extensive transverse myelitis (LETM) after administration of second dose of COVID-19 mRNA vaccine one day prior to presenting symptoms of acute paralysis of the lower extremity, sensory loss from chest down with overflow incontinence. A clinical diagnosis of myelopathy was supported by MRI of the spine illustrating enhancing lesions from C7-T7 concerning for LETM.Results: A 5-day course of pulsed methylprednisolone followed by therapeutic plasma exchange for 3 days resulted in only minimal improvement in the neurologic exam with increased strength in his lower extremities while the sensory level remained unchanged.Conclusions: This case demonstrates the complication and symptomatology of TM in the setting of anti-PD-L1 monoclonal antibody with coincidental COVID-19 mRNA vaccine administration. The causal relationship between the vaccine and LETM is difficult to establish. However, the presence of a known inciting factor hints at a possible exaggeration of the existing neuro-inflammatory process.


Assuntos
COVID-19 , Mielite Transversa , Doenças da Medula Espinal , Humanos , Mielite Transversa/induzido quimicamente , Mielite Transversa/terapia , Vacinas contra COVID-19/efeitos adversos , Pandemias , COVID-19/complicações , Imunização/efeitos adversos
5.
Food Chem (Oxf) ; 4: 100079, 2022 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-35415672

RESUMO

Over the past decade, the gut microbiome has been linked to several diseases including gastrointestinal diseases, cancer, immune disorder and metabolic syndrome. Shifts in the gut bacterial population affect the overall metabolic health status leading towards obesity and Type II diabetes mellitus. Secondary metabolites secreted by the gut microbiome interact with various host-sensing signalling pathways and are responsible for functional modulation of immune resident cells in metabolic tissues (Blüher, 2019). Of these, short- chain fatty acids (SCFAs) i.e., acetate, propionate and butyrate have been significantly correlated with the disposition of diabetes and metabolic disorder. The altered gut microbial population depletes the intestinal barrier causing entry of LPS into circulation and towards metabolic tissues triggering pro-inflammatory responses. As butyrate has been known to maintain intestinal integrity, we aimed to assess the apparent effect of externally given sodium butyrate [NaB] on immuno-metabolic profiling of adipose tissue, and its association with metabolic and inflammatory status of adipose tissue. To assess this, we put groups of C57BL/6 mice i.e., Control fed with a regular chow diet and another group that was fed on a high fat diet (HFD, 60%) for 8 weeks. Following this, the HFD group were further subdivided into two groups one fed with HFD and the other with HFD + NaB (5%w/w) for another 8 weeks. Body composition, weight gain, body adiposity and biochemical parameters were assessed. NaB fed group showed an improved metabolic profile compared to HFD fed group. Administration of NaB also improved glucose tolerance capacity and insulin sensitivity as determined by IPGTT and ITT profiles. Earlier reports have shown gut leakage and increased LPS in circulation is the primary cause of setting up inflammation at the tissue level. Our studies exhibited that, NaB increased the expression of tight junction proteins of intestinal linings and thereby enhanced intestinal barrier integrity. The FITC dextran permeability assay further confirmed this enhanced intestinal barrier integrity. We assessed the quantitative and relative population of different types of resident immune cells from a stromal vascular fraction of adipose tissue. Flow cytometry studies revealed significantly increased M2 (CD206+ ) macrophages and Tregs (CD25+ ) relative to the M1 macrophage population and CD4+ T cells respectively in NaB treated mice, suggesting its potential role in alleviating the inflammatory profile. In a nutshell, taken together better glucose tolerance, better gut health, reduced inflammatory adipose tissue immune cells, suggest potential beneficial role of sodium butyrate in alleviating overall inflammation and metabolic dysfunction associated with obesity.

6.
Cureus ; 14(2): e22590, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35355549

RESUMO

The objective is to describe a rare case of lumbar lipomyelomeningocele presenting as progressive urinary incontinence. Lipomyelomeningocele is a type of closed spinal dysraphism typically presenting as a lipomatous mass contiguous with a neural defect above the gluteal crease. Tethered cord syndrome is defined as symptoms and signs caused by excessive spinal cord tension from an abnormally low conus medullaris, with an abnormally thick filum terminale attached to the lower sacral region. A 19-year-old male with no remarkable medical history presented with low back pain and urinary incontinence for the past one year. On physical exam patient had normal motor strength, sensory testing to all modalities was intact. The rectal tone was normal, and no saddle anesthesia was noted. MRI lumbar spine revealed lumbar lipomyelomeningocele with associated tethered cord syndrome. The patient underwent tethered cord release surgery with lipoma excision. Pathology of the soft tissue showed fibrovascular tissue and mature adipose tissue consistent with lipoma. The majority of cases of tethered cord syndrome are related to spinal dysraphism, a rare pediatric syndrome. It is potentially treatable if caught early, and MRI can help with an accurate diagnosis of the condition. Older adults are more likely to present with urological and neurological complaints. Surgical un-tethering is indicated in patients with progressive symptoms. In our case, the only presenting symptom was urinary incontinence, and the neurological exam was normal other than lower lumbar paraspinal tenderness.

7.
Cureus ; 13(5): e14867, 2021 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-34113504

RESUMO

Introduction Alternative medicine during treatment is often used to make the quality of life (QoL) better. Women with early-stage breast cancer, particularly the ones who possess lower QoL, are more prone to opt for complementary medicine. This study aims to explore the effects exerted by intravenous vitamin C (IVC) on symptoms and adverse events associated with breast cancer treatment. Methods This single-center, parallel-group, single-blind interventional study was conducted in the oncology ward of a tertiary care hospital in Pakistan. For this study, after informed consent was taken, breast cancer patients with Union for International Cancer Control stages IIA to IIIb were included in the study. Three hundred and fifty (n = 350) patients were randomized into two groups at a ratio of 1:1. Study group was randomized to receive 25 grams per week of IVC at a rate of 15 grams per hour for four weeks in addition to their current standard treatment, and the control group received placebo (normal saline drip with label removed) in addition to their current standard treatment. Results In patients who had received IVC, there was a significant decrease in the mean severity score after 28 days for the following symptoms: nausea (2.65 ± 0.62 vs. 2.59 ± 0.68; p-value: 0.0003), loss of appetite (2.26 ± 0.51 vs. 2.11 ± 0.52; p-value: 0.007), tumor pain (2.22 ± 0.45 vs. 1.99 ± 0.40, p-value: <0.0001), fatigue (3.11 ± 0.32 vs. 2.87 ± 0.29; p-value: <0.0001), and insomnia (2.59 ± 0.35 vs. 2.32 ± 0.36, p-value: <0.0001). Conclusion Our study showed improvement in the mean severity score of nausea, fatigue, tumor pain, loss of appetite, and fatigue. More studies are also needed to assess the long-term effects of IVC in the cancer management. This shall help incorporate the use of IVC in standard practice to make the journey of cancer management comfortable for the patients.

8.
Nat Immunol ; 22(3): 312-321, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33510463

RESUMO

Mitochondrial abnormalities have been noted in lupus, but the causes and consequences remain obscure. Autophagy-related genes ATG5, ATG7 and IRGM have been previously implicated in autoimmune disease. We reasoned that failure to clear defective mitochondria via mitophagy might be a foundational driver in autoimmunity by licensing mitochondrial DNA-dependent induction of type I interferon. Here, we show that mice lacking the GTPase IRGM1 (IRGM homolog) exhibited a type I interferonopathy with autoimmune features. Irgm1 deletion impaired the execution of mitophagy with cell-specific consequences. In fibroblasts, mitochondrial DNA soiling of the cytosol induced cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING)-dependent type I interferon, whereas in macrophages, lysosomal Toll-like receptor 7 was activated. In vivo, Irgm1-/- tissues exhibited mosaic dependency upon nucleic acid receptors. Whereas salivary and lacrimal gland autoimmune pathology was abolished and lung pathology was attenuated by cGAS and STING deletion, pancreatic pathology remained unchanged. These findings reveal fundamental connections between mitochondrial quality control and tissue-selective autoimmune disease.


Assuntos
Doenças Autoimunes/metabolismo , Autoimunidade , Fibroblastos/metabolismo , Proteínas de Ligação ao GTP/metabolismo , Mitocôndrias/metabolismo , Mitofagia , Animais , Doenças Autoimunes/genética , Doenças Autoimunes/imunologia , Doenças Autoimunes/patologia , Células Cultivadas , Fibroblastos/imunologia , Fibroblastos/patologia , Proteínas de Ligação ao GTP/deficiência , Proteínas de Ligação ao GTP/genética , Regulação da Expressão Gênica , Macrófagos/imunologia , Macrófagos/metabolismo , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/metabolismo , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos Endogâmicos C57BL , Mitocôndrias/genética , Mitocôndrias/imunologia , Mitocôndrias/patologia , Nucleotidiltransferases/genética , Nucleotidiltransferases/metabolismo , Transdução de Sinais , Receptor 7 Toll-Like/genética , Receptor 7 Toll-Like/metabolismo
9.
Mult Scler Relat Disord ; 48: 102699, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33373797

RESUMO

BACKGROUND: Tumefactive MS is a rare variant of multiple sclerosis that poses a diagnostic and a therapeutic challenge due to its close resemblance to central nervous neoplasms on MRI. TMS is defined as acute large >2 cm, tumour like demyelinating lesion in the CNS that may occur with surrounding edema, mass effect and ring enhancement. Some of the known mimickers are CNS lymphoma, metastasis, primary brain tumour such as glioblastoma, brain abscesses. The prevalence of TMS is estimated to be 1-3/1000 cases. There are also reported cases of drug induced TMS cases especially with fingolimod and natalizumab therapy. We report the occurrence of tumefactive MS at our institution. METHODS: We retrospectively reviewed the chart of the patients with multiple sclerosis including initial visits, hospitalizations, clinic follow up notes and collected data on demographic, ethnicity, presenting signs and symptoms, imaging modalities, cerebrospinal fluid analysis results, disease progression. After reviewing the charts, we isolated the patients with tumefactive multiple sclerosis from the group and summarized the cases. Four of these patients were managed with Glatiramer acetate, 2 on dimethyl fumarate and 1 on beta interferon with 0-2 clinical flare ups on subsequent years. RESULTS: Out of 323 patients reviewed with multiple sclerosis or possible multiple sclerosis, 7 carried a diagnosis of tumefactive MS. The age range of these patients were 19 to 62 years old with 4 females and 3 males. Five patients were Caucasian and 2 were Hispanic. Out of seven patients, 6 were newly diagnosed MS following biopsy of the lesion. The histological findings in 3 patients who underwent biopsy demonstrated include reactive gliosis and inflammatory cells predominantly macrophages and lymphocytes while 1 patient showed hypercellular brain tissue with perineuronal satellosis. CONCLUSION: Tumefactive MS remains a challenging disease to diagnosis and often times requires a biopsy for definitive diagnosis or to exclude neoplasms, other inflammatory conditions such as neurosarcoidosis. The demographic of the patients in this case series is no different than patients with relapsing remitting multiple sclerosis (RRMS). However, based on our experience, the patients with TMS do respond to disease modifying agents such as Glatiramer acetate and Dimethyl fumarate with similar progression as of RRMS.


Assuntos
Esclerose Múltipla Recidivante-Remitente , Esclerose Múltipla , Adulto , Feminino , Cloridrato de Fingolimode/uso terapêutico , Acetato de Glatiramer , Humanos , Masculino , Pessoa de Meia-Idade , Esclerose Múltipla/diagnóstico por imagem , Esclerose Múltipla/tratamento farmacológico , Estudos Retrospectivos , Adulto Jovem
10.
Neurooncol Pract ; 7(6): 583-588, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33312673

RESUMO

Patients with primary brain tumors often experience seizures, which can be the presenting symptom or occur for the first time at any point along the illness trajectory. In addition to causing morbidity, seizures negatively affect independence and quality of life in other ways, for example, by leading to loss of driving privileges. Long-term therapy with antiepileptic drugs (AEDs) is the standard of care in brain tumor patients with seizures, but the role of prophylactic AEDs in seizure-naive patients remains controversial. In this article, experts in the field discuss the issues of AED efficacy and toxicity, and explain their differing recommendations for routine use of prophylactic AEDs.

11.
Neuro Oncol ; 22(11): 1708-1709, 2020 11 26.
Artigo em Inglês | MEDLINE | ID: mdl-32722769
12.
Am J Physiol Gastrointest Liver Physiol ; 316(1): G95-G105, 2019 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-30335469

RESUMO

Crohn's disease (CD) is a chronic inflammatory gastrointestinal disorder. Genetic association studies have implicated dysregulated autophagy in CD. Among risk loci identified are a promoter single nucleotide polymorphism (SNP)( rs13361189 ) and two intragenic SNPs ( rs9637876 , rs10065172 ) in immunity-related GTPase family M ( IRGM) a gene that encodes a protein of the autophagy initiation complex. All three SNPs have been proposed to modify IRGM expression, but reports have been divergent and largely derived from cell lines. Here, analyzing RNA-Sequencing data of human tissues from the Genotype-Tissue Expression Project, we found that rs13361189 minor allele carriers had reduced IRGM expression in whole blood and terminal ileum, and upregulation in ileum of ZNF300P1, a locus adjacent to IRGM on chromosome 5q33.1 that encodes a long noncoding RNA. Whole blood and ileum from minor allele carriers had altered expression of multiple additional genes that have previously been linked to colitis and/or autophagy. Notable among these was an increase in ileum of LTF (lactoferrin), an established fecal inflammatory biomarker of CD, and in whole blood of TNF, a key cytokine in CD pathogenesis. Last, we confirmed that risk alleles at all three loci associated with increased risk for CD but not ulcerative colitis in a case-control study. Taken together, our findings suggest that genetically encoded IRGM deficiency may predispose to CD through dysregulation of inflammatory gene networks. Gene expression profiling of disease target tissues in genetically susceptible populations is a promising strategy for revealing new leads for the study of molecular pathogenesis and, potentially, for precision medicine. NEW & NOTEWORTHY Single nucleotide polymorphisms in immunity-related GTPase family M ( IRGM), a gene that encodes an autophagy initiation protein, have been linked epidemiologically to increased risk for Crohn's disease (CD). Here, we show for the first time that subjects with risk alleles at two such loci, rs13361189 and rs10065172 , have reduced IRGM expression in whole blood and terminal ileum, as well as dysregulated expression of a wide array of additional genes that regulate inflammation and autophagy.


Assuntos
Autofagia/genética , Colite Ulcerativa/genética , Doença de Crohn/genética , Proteínas de Ligação ao GTP/genética , Predisposição Genética para Doença , Estudos de Casos e Controles , Expressão Gênica/genética , Regulação da Expressão Gênica/genética , Estudos de Associação Genética , Humanos , Risco
13.
J Neurol Sci ; 390: 156-161, 2018 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-29801878

RESUMO

PURPOSE: The purpose of this paper is to describe the venous anatomy of the insula using conventional MR brain imaging and confocal reconstructions in cases with glioma induced venous dilatation (venous gliography). METHODS: Routine clinical MRI brain scans that included thin cut (1.5-2 mm) post contrast T1 weighted imaging were retrospectively reviewed to assess the insular venous anatomy in 19 cases (11 males and 8 females) with insular gliomas. Reconstruction techniques (Anatom-e and Osirix) were used to improve understanding of the venous anatomy. RESULTS: We identified the following insular and peri-insular veins on MRI: the superficial middle cerebral vein (SMCV), peri-insular sulcus vein, vein of the anterior limiting sulcus, the precentral, central, and posterior sulcus veins of the insula, the communicating veins and deep MCV. CONCLUSIONS: We concluded that venous anatomy of insula is complicated and is often overlooked by radiologists on MR brain imaging. Use of confocal imaging in different planes helped us to identify the superficial and deep middle cerebral veins and their relationship to the insula. The understanding of the insular venous architecture is also useful to distinguish these vessels from insular arteries. This knowledge may be helpful for presurgical planning prior to insular glioma resection.


Assuntos
Córtex Cerebral/irrigação sanguínea , Córtex Cerebral/diagnóstico por imagem , Veias Cerebrais/diagnóstico por imagem , Imageamento por Ressonância Magnética , Adulto , Idoso , Variação Biológica Individual , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/cirurgia , Córtex Cerebral/anatomia & histologia , Córtex Cerebral/patologia , Veias Cerebrais/anatomia & histologia , Veias Cerebrais/patologia , Feminino , Glioma/diagnóstico por imagem , Glioma/patologia , Glioma/cirurgia , Humanos , Hiperemia/diagnóstico por imagem , Hiperemia/patologia , Processamento de Imagem Assistida por Computador , Masculino , Microscopia Confocal , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto Jovem
14.
J Biol Chem ; 291(37): 19651-60, 2016 09 09.
Artigo em Inglês | MEDLINE | ID: mdl-27471270

RESUMO

MicroRNAs (miRNAs) are short non-coding RNAs that regulate gene expression by promoting degradation and/or repressing translation of specific target mRNAs. Several miRNAs have been identified that regulate the amplitude of the innate immune response by directly targeting Toll-like receptor (TLR) pathway members and/or cytokines. miR-33a and miR-33b (the latter present in primates but absent in rodents and lower species) are located in introns of the sterol regulatory element-binding protein (SREBP)-encoding genes and control cholesterol/lipid homeostasis in concert with their host gene products. These miRNAs regulate macrophage cholesterol by targeting the lipid efflux transporters ATP binding cassette (ABC)A1 and ABCG1. We and others have previously reported that Abca1(-/-) and Abcg1(-/-) macrophages have increased TLR proinflammatory responses due to augmented lipid raft cholesterol. Given this, we hypothesized that miR-33 would augment TLR signaling in macrophages via a raft cholesterol-dependent mechanism. Herein, we report that multiple TLR ligands down-regulate miR-33 in murine macrophages. In the case of lipopolysaccharide, this is a delayed, Toll/interleukin-1 receptor (TIR) domain-containing adapter-inducing interferon-ß-dependent response that also down-regulates Srebf-2, the host gene for miR-33. miR-33 augments macrophage lipid rafts and enhances proinflammatory cytokine induction and NF-κB activation by LPS. This occurs through an ABCA1- and ABCG1-dependent mechanism and is reversible by interventions upon raft cholesterol and by ABC transporter-inducing liver X receptor agonists. Taken together, these findings extend the purview of miR-33, identifying it as an indirect regulator of innate immunity that mediates bidirectional cross-talk between lipid homeostasis and inflammation.


Assuntos
Transportador 1 de Cassete de Ligação de ATP/imunologia , Membro 1 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/imunologia , Imunidade Inata , Macrófagos/imunologia , Microdomínios da Membrana/imunologia , MicroRNAs/imunologia , Transportador 1 de Cassete de Ligação de ATP/genética , Membro 1 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/genética , Animais , Microdomínios da Membrana/genética , Camundongos , Camundongos Knockout , MicroRNAs/genética , Células RAW 264.7 , Proteína de Ligação a Elemento Regulador de Esterol 2/genética , Proteína de Ligação a Elemento Regulador de Esterol 2/imunologia
15.
Sci Rep ; 6: 22972, 2016 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-27026501

RESUMO

Streptococcus pneumoniae produces pneumolysin toxin as a key virulence factor against host cells. Pneumolysin is a cholesterol-dependent cytolysin (CDC) toxin that forms lytic pores in host membranes and mediates pneumococcal disease pathogenesis by modulating inflammatory responses. Here, we show that pneumolysin, which is released during bacterial lysis, induces DNA double strand breaks (DSBs), as indicated by ataxia telangiectasia mutated (ATM)-mediated H2AX phosphorylation (γH2AX). Pneumolysin-induced γH2AX foci recruit mediator of DNA damage checkpoint 1 (MDC1) and p53 binding protein 1 (53BP1), to sites of DSBs. Importantly, results show that toxin-induced DNA damage precedes cell cycle arrest and causes apoptosis when DNA-dependent protein kinase (DNA-PK)-mediated non-homologous end joining is inhibited. Further, we observe that cells that were undergoing DNA replication harbored DSBs in greater frequency during pneumolysin treatment. This observation raises the possibility that DSBs might be arising as a result of replication fork breakdown. Additionally, neutralizing the oligomerization domain of pneumolysin with monoclonal antibody suppresses DNA damage and also cell cycle arrest, indicating that pneumolysin oligomerization is important for causing DNA damage. Taken together, this study reveals a previously unidentified ability of pneumolysin to induce cytotoxicity via DNA damage, with implications in the pathophysiology of S. pneumoniae infection.


Assuntos
Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Quebras de DNA de Cadeia Dupla/efeitos dos fármacos , Dano ao DNA , Estreptolisinas/farmacologia , Células A549 , Proteínas Adaptadoras de Transdução de Sinal , Proteínas Mutadas de Ataxia Telangiectasia/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/farmacologia , Western Blotting , Proteínas de Ciclo Celular , Proteína Quinase Ativada por DNA/metabolismo , Histonas/metabolismo , Humanos , Microscopia Confocal , Proteínas Nucleares/metabolismo , Fosforilação/efeitos dos fármacos , Proteínas Recombinantes/farmacologia , Streptococcus pneumoniae/metabolismo , Estreptolisinas/genética , Transativadores/metabolismo , Proteína 1 de Ligação à Proteína Supressora de Tumor p53/metabolismo
16.
Proc Natl Acad Sci U S A ; 112(26): E3421-30, 2015 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-26080406

RESUMO

Streptococcus pneumoniae is a leading cause of pneumonia and one of the most common causes of death globally. The impact of S. pneumoniae on host molecular processes that lead to detrimental pulmonary consequences is not fully understood. Here, we show that S. pneumoniae induces toxic DNA double-strand breaks (DSBs) in human alveolar epithelial cells, as indicated by ataxia telangiectasia mutated kinase (ATM)-dependent phosphorylation of histone H2AX and colocalization with p53-binding protein (53BP1). Furthermore, results show that DNA damage occurs in a bacterial contact-independent fashion and that Streptococcus pyruvate oxidase (SpxB), which enables synthesis of H2O2, plays a critical role in inducing DSBs. The extent of DNA damage correlates with the extent of apoptosis, and DNA damage precedes apoptosis, which is consistent with the time required for execution of apoptosis. Furthermore, addition of catalase, which neutralizes H2O2, greatly suppresses S. pneumoniae-induced DNA damage and apoptosis. Importantly, S. pneumoniae induces DSBs in the lungs of animals with acute pneumonia, and H2O2 production by S. pneumoniae in vivo contributes to its genotoxicity and virulence. One of the major DSBs repair pathways is nonhomologous end joining for which Ku70/80 is essential for repair. We find that deficiency of Ku80 causes an increase in the levels of DSBs and apoptosis, underscoring the importance of DNA repair in preventing S. pneumoniae-induced genotoxicity. Taken together, this study shows that S. pneumoniae-induced damage to the host cell genome exacerbates its toxicity and pathogenesis, making DNA repair a potentially important susceptibility factor in people who suffer from pneumonia.


Assuntos
Apoptose , Dano ao DNA , Peróxido de Hidrogênio/metabolismo , Alvéolos Pulmonares/metabolismo , Streptococcus pneumoniae/metabolismo , Animais , Reparo do DNA , Células Epiteliais/patologia , Feminino , Camundongos , Camundongos Endogâmicos BALB C , Alvéolos Pulmonares/citologia , Streptococcus pneumoniae/patogenicidade , Virulência
17.
Lasers Med Sci ; 28(2): 579-87, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22581389

RESUMO

Impurity-free, controlled synthesis of iron oxide nanoparticle, in ultrapure water and chitosan, using laser ablation technique and its application for type II diabetes management through oral delivery of insulin-loaded iron oxide-chitosan nanocomposite is presented. The purity of the nanoparticle is monitored by laser-induced breakdown spectroscopy technique. The synthesized iron oxide nanoparticle was characterized by UV/Vis absorption spectroscopy, and morphological study was performed by scanning electron microscope. The intensity of absorption peak and wavelength corresponding to peak of the nanoparticle prepared in water and chitosan is dependent on the laser energy used for ablation purpose. Red shift in the absorption peak wavelength was observed by increasing laser energy. In addition to red shift, an increase in intensity of absorption peak was also seen when ablating laser energy was increased. The appearance of a weak peak around 295 nm was observed in iron oxide-chitosan nanocomposite. The spherical shape of the nanoparticle synthesized at the lower laser energy has gradually changed to triangular and irregular shaped structures as ablating laser energy was increased. The spherical nanoparticles loaded with insulin were used for oral delivery for diabetic management. The iron oxide-chitosan nanocomposite loaded with insulin has resulted in reduction in blood glucose level in mild diabetic, subdiabetic, and severely diabetic rats; more than 51 % reduction in blood glucose level, compared to the control group, has been achieved in the present work.


Assuntos
Diabetes Mellitus Experimental/tratamento farmacológico , Compostos Férricos/síntese química , Insulina/administração & dosagem , Nanopartículas Metálicas/administração & dosagem , Nanopartículas Metálicas/química , Animais , Glicemia/metabolismo , Técnicas de Química Sintética , Quitosana/química , Coloides/química , Feminino , Compostos Férricos/administração & dosagem , Terapia a Laser , Masculino , Ratos , Ratos Wistar , Espectrofotometria Ultravioleta
18.
Tsitol Genet ; 44(6): 9-14, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-21250546

RESUMO

Mutation breeding has been used for improving oligogenic and polygenic characters, disease resistance and quantitative characters including yielding ability. The cytological stability of maize inbred lines is an important consideration in view of their extensive use in genetics and plant breeding research. Investigation in Zea mays L. confirms that the migration of chromosomes is a real event that cannot be misunderstood as an artifact produced by fixation or mechanical injuries. During present investigation, we found that out of six inbred lines of Zea mays L. viz. CM-135, CM-136, CM-137, CM-138, CM-142 and CM-213 at various treatment doses of gamma irradiations viz. 200, 400 and 600 Gy, some of the plants of inbred line CM- 138 at 200 Gy dose displayed characteristic cytoplasmic connections during all the stages of meiosis. Four plants from this treatment set were found to be engaged in a rare phenomenon reported as "Cytomixis". It elucidates that in inbred of Zea mays L., induced cytomixis through gamma rays treatment may be considered to be a possible source of production of aneuploid and polyploid gametes. This phenomenon may have several applications in Zea mays L. improvement in the sense of diversity and ever yield potential.


Assuntos
Variação Genética , Meiose , Seleção Genética , Zea mays/crescimento & desenvolvimento , Cromossomos de Plantas , Relação Dose-Resposta à Radiação , Raios gama , Doses de Radiação , Zea mays/genética , Zea mays/efeitos da radiação
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