168 research outputs found

    Formulation of a mmaA4 Gene Deletion Mutant of Mycobacterium bovis BCG in Cationic Liposomes Significantly Enhances Protection against Tuberculosis

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    A new vaccination strategy is urgently needed for improved control of the global tuberculosis (TB) epidemic. Using a mouse aerosol Mycobacterium tuberculosis challenge model, we investigated the protective efficacy of a mmaA4 gene deletion mutant of Mycobacterium bovis BCG (ΔmmaA4BCG) formulated in dimethyl dioctadecyl ammonium bromide (DDA) – D(+) trehalose 6,6 dibenenate (TDB) (DDA/TDB) adjuvant. In previous studies, deletion of the mmaA4 gene was shown to reduce the suppression of IL-12 production often seen after mycobacterial infections. While the non-adjuvanted ΔmmaA4BCG strain did not protect mice substantially better than conventional BCG against a tuberculous challenge in four protection experiments, the protective responses induced by the ΔmmaA4BCG vaccine formulated in DDA/TDB adjuvant was consistently increased relative to nonadjuvanted BCG controls. Furthermore, the ΔmmaA4BCG-DDA/TDB vaccine induced significantly higher frequencies of multifunctional (MFT) CD4 T cells expressing both IFNγ and TNFα (double positive) or IFNγ, TNFα and IL-2 (triple positive) than CD4 T cells derived from mice vaccinated with BCG. These MFT cells were characterized by having higher IFNγ and TNFα median fluorescence intensity (MFI) values than monofunctional CD4 T cells. Interestingly, both BCG/adjuvant and ΔmmaA4BCG/adjuvant formulations induced significantly higher frequencies of CD4 T cells expressing TNFα and IL-2 than nonadjuvanted BCG or ΔmmaA4BCG vaccines indicating that BCG/adjuvant mixtures may be more effective at inducing central memory T cells. Importantly, when either conventional BCG or the mutant were formulated in adjuvant and administered to SCID mice or immunocompromised mice depleted of IFNγ, significantly lower vaccine-derived mycobacterial CFU were detected relative to immunodeficient mice injected with non-adjuvanted BCG. Overall, these data suggest that immunization with the ΔmmaA4BCG/adjuvant formulation may be an effective, safe, and relatively inexpensive alternative to vaccination with conventional BCG

    Nut consumption and risk of atrial fibrillation in the Physicians' Health Study

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    <p>Abstract</p> <p>Background</p> <p>Atrial Fibrillation is highly prevalent in clinical practice affecting approximately 2.3 million people in USA and 4.5 million people in European Union. The aim of the study was to examine the association between nut consumption and incident atrial fibrillation.</p> <p>Methods</p> <p>Prospective cohort of 21,054 male participants of Physicians' Health Study I. Nut consumption was estimated using food frequency questionnaire and incident atrial fibrillation was ascertained through yearly follow-up questionnaires. Cox regression was used to estimate relative risks of atrial fibrillation.</p> <p>Results</p> <p>The average age was 54.6 ± 9.5 years (40.7-87.1). During a mean follow up of 20 years (median 24 years), 3,317 cases of atrial fibrillation occurred. The crude incidence rate was 7.6, 7.4, 8.2, 7.9, and 6.8 cases/1000 person-years for people reporting nut consumption of rarely/never, 1-3/month, 1/per week, 2-6/week, and ≥ 7/week, respectively. Multivariable adjusted hazard ratios (95% CI) for incident atrial fibrillation were 1.00 (ref), 1.00 (0.90-1.11), 1.09 (0.97-1.21), 1.07 (0.95-1.21), and 0.91 (0.70-1.17) for nut consumption from the lowest to the highest category of nut consumption (p for trend 0.26). No statistically significant association between nut consumption and atrial fibrillation was found when stratified by body mass index (BMI < 25 vs ≥ 25 kg/m<sup>2</sup>) or age (< 65 vs. ≥ 65 years).</p> <p>Conclusions</p> <p>Our data did not show an association between nut consumption and incident atrial fibrillation among US male physicians.</p

    A Diverse Group of Previously Unrecognized Human Rhinoviruses Are Common Causes of Respiratory Illnesses in Infants

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    Human rhinoviruses (HRVs) are the most prevalent human pathogens, and consist of 101 serotypes that are classified into groups A and B according to sequence variations. HRV infections cause a wide spectrum of clinical outcomes ranging from asymptomatic infection to severe lower respiratory symptoms. Defining the role of specific strains in various HRV illnesses has been difficult because traditional serology, which requires viral culture and neutralization tests using 101 serotype-specific antisera, is insensitive and laborious.To directly type HRVs in nasal secretions of infants with frequent respiratory illnesses, we developed a sensitive molecular typing assay based on phylogenetic comparisons of a 260-bp variable sequence in the 5' noncoding region with homologous sequences of the 101 known serotypes. Nasal samples from 26 infants were first tested with a multiplex PCR assay for respiratory viruses, and HRV was the most common virus found (108 of 181 samples). Typing was completed for 101 samples and 103 HRVs were identified. Surprisingly, 54 (52.4%) HRVs did not match any of the known serotypes and had 12-35% nucleotide divergence from the nearest reference HRVs. Of these novel viruses, 9 strains (17 HRVs) segregated from HRVA, HRVB and human enterovirus into a distinct genetic group ("C"). None of these new strains could be cultured in traditional cell lines.By molecular analysis, over 50% of HRV detected in sick infants were previously unrecognized strains, including 9 strains that may represent a new HRV group. These findings indicate that the number of HRV strains is considerably larger than the 101 serotypes identified with traditional diagnostic techniques, and provide evidence of a new HRV group

    Deficiency of Vasodilator-Stimulated Phosphoprotein (VASP) Increases Blood-Brain-Barrier Damage and Edema Formation after Ischemic Stroke in Mice

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    Background: Stroke-induced brain edema formation is a frequent cause of secondary infarct growth and deterioration of neurological function. The molecular mechanisms underlying edema formation after stroke are largely unknown. Vasodilator-stimulated phosphoprotein (VASP) is an important regulator of actin dynamics and stabilizes endothelial barriers through interaction with cell-cell contacts and focal adhesion sites. Hypoxia has been shown to foster vascular leakage by downregulation of VASP in vitro but the significance of VASP for regulating vascular permeability in the hypoxic brain in vivo awaits clarification. Methodology/Principal Findings: Focal cerebral ischemia was induced in Vasp2/2 mice and wild-type (WT) littermates by transient middle cerebral artery occlusion (tMCAO). Evan’s Blue tracer was applied to visualize the extent of blood-brainbarrier (BBB) damage. Brain edema formation and infarct volumes were calculated from 2,3,5-triphenyltetrazolium chloride (TTC)-stained brain slices. Both mouse groups were carefully controlled for anatomical and physiological parameters relevant for edema formation and stroke outcome. BBB damage (p,0.05) and edema volumes (1.7 mm360.5 mm3 versus 0.8 mm360.4 mm3; p,0.0001) were significantly enhanced in Vasp2/2 mice compared to controls on day 1 after tMCAO. This was accompanied by a significant increase in infarct size (56.1 mm3617.3 mm3 versus 39.3 mm3610.7 mm3, respectively; p,0.01) and a non significant trend (p.0.05) towards worse neurological outcomes. Conclusion: Our study identifies VASP as critical regulator of BBB maintenance during acute ischemic stroke. Therapeutic modulation of VASP or VASP-dependent signalling pathways could become a novel strategy to combat excessive edema formation in ischemic brain damage

    A Polymorphism in a Gene Encoding Perilipin 4 Is Associated with Height but not with Bone Measures in Individuals from the Framingham Osteoporosis Study

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    There is increasing interest in identifying new pathways and candidate genes that confer susceptibility to osteoporosis. There is evidence that adipogenesis and osteogenesis may be related, including a common bone marrow progenitor cell for both adipocytes and osteoblasts. Perilipin 1 (PLIN1) and Perilipin 4 (PLIN4) are members of the PATS family of genes and are involved in lipolysis of intracellular lipid deposits. A previous study reported gender-specific associations between one polymorphism of PLIN1 and bone mineral density (BMD) in a Japanese population. We hypothesized that polymorphisms in PLIN1 and PLIN4 would be associated with bone measures in adult Caucasian participants of the Framingham Osteoporosis Study (FOS). We genotyped 1,206 male and 1,445 female participants of the FOS for four single-nucleotide polymorphism (SNPs) in PLIN1 and seven SNPs in PLIN4 and tested for associations with measures of BMD, bone ultrasound, hip geometry, and height. We found several gender-specific significant associations with the measured traits. The association of PLIN4 SNP rs8887, G>A with height in females trended toward significance after simulation testing (adjusted P = 0.07) and remained significant after simulation testing in the combined-sex model (adjusted P = 0.033). In a large study sample of men and women, we found a significant association between one SNP in PLIN4 and height but not with bone traits, suggesting that PATS family genes are not important in the regulation of bone. Identification of genes that influence human height may lead to a better understanding of the processes involved in growth and development

    HER2-Mediated Internalization of Cytotoxic Agents in ERBB2 Amplified or Mutant Lung Cancers

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    Amplification and oncogenic mutations of ERBB2, the gene encoding the HER2 receptor tyrosine kinase, promote receptor hyperactivation and tumor growth. Here we demonstrate that HER2 ubiquitination and internalization, rather than its overexpression, are key mechanisms underlying endocytosis and consequent efficacy of the anti-HER2 antibody-drug conjugates (ADCs) ado-trastuzumab emtansine (T-DM1) and trastuzumab deruxtecan (T-DXd) in lung cancer cell lines and patient-derived xenograft models. These data translated into a 51% response rate in a clinical trial of T-DM1 in 49 patients with ERBB2/HER2-amplified or mutant lung cancers. We show that co-treatment with irreversible pan-HER inhibitors enhances receptor ubiquitination and consequent ADC internalization and efficacy. We also demonstrate that ADC switching to T-DXd, which harbors a different cytotoxic payload, achieves durable responses in a patient with lung cancer and corresponding xenograft model developing resistance to T-DM1. Our findings may help guide future clinical trials and expand the field of ADC as cancer therapy

    Clinical responses to EGFR-tyrosine kinase inhibitor retreatment in non-small cell lung cancer patients who benefited from prior effective gefitinib therapy: a retrospective analysis

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    <p>Abstract</p> <p>Background</p> <p>Gefitinib was the first epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) approved for the treatment of advanced non-small cell lung cancer (NSCLC). Few treatment options are available for NSCLC patients who have responded to gefitinib treatment and demonstrated tumor progression. The present study was conducted to evaluate the efficacy and toxicity of the 2<sup>nd </sup>EGFR-TKI administration.</p> <p>Methods</p> <p>We retrospectively analyzed 11 patients who had obtained a partial response (PR) or stable disease (SD) with gefitinib treatment and were re-treated with EGFR-TKI after failure of the initial gefitinib treatment.</p> <p>Results</p> <p>Three patients (27%) were treated with gefitinib as the 2<sup>nd </sup>EGFR-TKI, and 8 patients (73%) received erlotinib. Only one patient (9%) showed PR, 7 (64%) achieved SD, and 3 (27%) had progressive disease. The disease control rate was 73% (95% CI, 43% - 91%) and the median progression-free survival was 3.4 months (95% CI, 2 - 5.2). The median overall survival from the beginning of the 2<sup>nd </sup>EGFR-TKI and from diagnosis were 7.3 months (95% CI, 2.7 - 13) and 36.7 months (95% CI, 23.6 - 43.9), respectively. No statistical differences in PFS or OS were observed between gefitinib and erlotinib as the 2<sup>nd </sup>EGFR-TKI (PFS, P = 0.23 and OS, P = 0.052). The toxicities associated with the 2<sup>nd </sup>EGFR-TKI were generally acceptable and comparable to those observed for the initial gefitinib therapy.</p> <p>Conclusions</p> <p>Our results indicate that a 2<sup>nd </sup>EGFR-TKI treatment can be an effective treatment option for gefitinib responders.</p

    Clinical responses to EGFR-tyrosine kinase inhibitor retreatment in non-small cell lung cancer patients who benefited from prior effective gefitinib therapy: a retrospective analysis

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    <p>Abstract</p> <p>Background</p> <p>Gefitinib was the first epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) approved for the treatment of advanced non-small cell lung cancer (NSCLC). Few treatment options are available for NSCLC patients who have responded to gefitinib treatment and demonstrated tumor progression. The present study was conducted to evaluate the efficacy and toxicity of the 2<sup>nd </sup>EGFR-TKI administration.</p> <p>Methods</p> <p>We retrospectively analyzed 11 patients who had obtained a partial response (PR) or stable disease (SD) with gefitinib treatment and were re-treated with EGFR-TKI after failure of the initial gefitinib treatment.</p> <p>Results</p> <p>Three patients (27%) were treated with gefitinib as the 2<sup>nd </sup>EGFR-TKI, and 8 patients (73%) received erlotinib. Only one patient (9%) showed PR, 7 (64%) achieved SD, and 3 (27%) had progressive disease. The disease control rate was 73% (95% CI, 43% - 91%) and the median progression-free survival was 3.4 months (95% CI, 2 - 5.2). The median overall survival from the beginning of the 2<sup>nd </sup>EGFR-TKI and from diagnosis were 7.3 months (95% CI, 2.7 - 13) and 36.7 months (95% CI, 23.6 - 43.9), respectively. No statistical differences in PFS or OS were observed between gefitinib and erlotinib as the 2<sup>nd </sup>EGFR-TKI (PFS, P = 0.23 and OS, P = 0.052). The toxicities associated with the 2<sup>nd </sup>EGFR-TKI were generally acceptable and comparable to those observed for the initial gefitinib therapy.</p> <p>Conclusions</p> <p>Our results indicate that a 2<sup>nd </sup>EGFR-TKI treatment can be an effective treatment option for gefitinib responders.</p

    Topoisomerase II alpha gene copy loss has adverse prognostic significance in ERBB2-amplified breast cancer: a retrospective study of paraffin-embedded tumor specimens and medical charts

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    <p>Abstract</p> <p>Background</p> <p>Amplification of the <it>ERBB2 </it>(<it>Her-2/neu</it>) oncogene, which occurs in approximately 25% of breast carcinomas, is a known negative prognostic factor. Available data indicate that a variable number of nearby genes on chromosome 17q may be co-amplified or deleted, forming a continuous amplicon of variable size. In approximately 25% of these patients, the amplicon extends to the gene for <it>topoisomerase II alpha </it>(<it>TOP2A</it>), a target for anthracyclines. We sought to understand the significance of these associated genomic changes for breast cancer prognosis and predicting response to therapy.</p> <p>Methods and patients</p> <p>Archival tissue samples from 63 breast cancer patients with <it>ERBB2 </it>amplification, stages 0–IV, were previously analyzed with FISH probes for genes located near <it>ERBB2</it>. In the present study, the clinical outcome data were determined for all patients presenting at stages I–III for whom adequate clinical follow up was available.</p> <p>Results</p> <p>Four amplicon patterns (Classes) were identified. These were significantly associated with the clinical outcome, specifically, recurrence of breast cancer. The Amplicon class IV with deleted <it>TOP2A </it>had 67% (6/9) cases with recurrence, whereas the other three classes combined had only 12% (3/25) cases (p-value = 0.004) at the time of last follow-up. <it>TOP2A </it>deletion was also significantly associated with time to recurrence (p-value = 0.0002). After adjusting for age in Cox regression analysis, the association between <it>TOP2A </it>deletion and time to recurrence remains strongly significant (p-value = 0.002) whereas the association with survival is marginally significant (p-value = 0.06).</p> <p>Conclusion</p> <p><it>TOP2A </it>deletion is associated with poor prognosis in <it>ERBB2</it>-amplified breast carcinomas. Clarification of the mechanism of this association will require additional study.</p
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