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1.
Breast Cancer Res Treat ; 204(1): 151-158, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38062336

ABSTRACT

PURPOSE: Breast cancer patients referred to genetic counseling often undergo genetic testing with broad panels that include both breast cancer susceptibility genes as well as genes more specific for extramammary sites. As a result, patients are often incidentally found to have germline mutations in genes that are not necessarily related to breast cancer risk. One such gene is MUTYH. To understand the role MUTYH may play in breast cancer, the clinicopathological features of patients with monoallelic MUTYH germline mutation and breast cancer were examined. METHODS: The clinicopathological characteristics of the breast cancers from patients with monoallelic MUTYH mutation were compared to breast cancer patients with other germline mutations in known breast cancer susceptibility genes, including ATM, BRCA1/2, CHEK2, and PALB2. The breast cancer patients who received genetic counseling but tested negative for the aforementioned gene mutations were used as a control group. RESULTS: Histologic characteristics of the breast cancers arising in monoallelic MUTYH mutation carriers had significantly larger tumor size, higher tumor grade, and more high-risk biomarker profiles (i.e., Her2-positive and triple-negative) than breast cancer patients with susceptibility genes, except for BRCA1. MUTYH mutation carriers also showed a trend of more frequent intratumoral divergency in terms of tumor grade and biomarker profiles. CONCLUSION: Although germline monoallelic MUTYH mutation is not thought to confer a meaningfully increased risk of breast cancer development, it may contribute to pathological aggressiveness and diversity of breast cancers when they sporadically arise in MUTYH carriers.


Subject(s)
Breast Neoplasms , Female , Humans , Biomarkers , BRCA1 Protein/genetics , BRCA2 Protein/genetics , Breast Neoplasms/genetics , Breast Neoplasms/pathology , Genetic Predisposition to Disease , Germ-Line Mutation , Mutation
2.
Front Pediatr ; 11: 1279673, 2023.
Article in English | MEDLINE | ID: mdl-38027307

ABSTRACT

Objectives: The aims of this study were to report the audiological characteristics of children with congenital unilateral hearing loss (UHL), examine the age at which the first reliable behavioural audiograms can be obtained, and investigate hearing changes from diagnosis at birth to the first reliable behavioural audiogram. Method: This study included a sample of 91 children who were diagnosed with UHL via newborn hearing screening and had reliable behavioural audiograms before 7 years of age. Information about diagnosis, audiological characteristics and etiology were extracted from clinical reports. Regression analysis was used to explore the potential reasons influencing the age at which first reliable behavioural audiograms were obtained. Correlation and ANOVA analyses were conducted to examine changes in hearing at octave frequencies between 0.5 and 4 kHz. The proportions of hearing loss change, as well as the clinical characteristics of children with and without progressive hearing loss, were described according to two adopted definitions: Definition 1: criterion (1): a decrease in 10 dB or greater at two or more adjacent frequencies between 0.5 and 4 kHz, or criterion (2): a decrease in 15 dB or greater at one octave frequency in the same frequency range. Definition 2: a change of ≥20 dB in the average of pure-tone thresholds at 0.5, 1, and 2 kHz. Results: The study revealed that 48 children (52.7% of the sample of 91 children) had their first reliable behavioural audiogram by 3 years of age. The mean age at the first reliable behavioural audiogram was 3.0 years (SD 1.4; IQR: 1.8, 4.1). We found a significant association between children's behaviour and the presence or absence of ongoing middle ear issues in relation to the delay in obtaining a reliable behavioural audiogram. When comparing the hearing thresholds at diagnosis with the first reliable behavioural audiogram across different frequencies, it was observed that the majority of children experienced deterioration rather than improvement in the initial impaired ear at each frequency. Notably, there were more instances of hearing changes (either deterioration or improvement), in the 500 Hz and 1,000 Hz frequency ranges compared to the 2,000 Hz and 4,000 Hz ranges. Seventy-eight percent (n = 71) of children had hearing deterioration between the diagnosis and the first behavioural audiogram at one or more frequencies between 0.5 and 4 kHz, with a high proportion of them (52 out of the 71, 73.2%) developing severe to profound hearing loss. When using the averaged three frequency thresholds (i.e., definition 2), only 26.4% of children (n = 24) in the sample were identified as having hearing deterioration. Applying definition 2 therefore underestimates the proportion of children that experienced hearing changes. The study also reported diverse characteristics of children with or without hearing deterioration. Conclusion: The finding that 78% of children diagnosed with UHL at birth had a decrease in hearing loss between the hearing levels at first diagnosis and their first behavioural audiogram highlights the importance of monitoring hearing threshold levels after diagnosis, so that appropriate intervention can be implemented in a timely manner. For clinical management, deterioration of 15 dB at one or more frequencies that does not recover warrants action.

3.
Opt Lett ; 48(21): 5587-5590, 2023 Nov 01.
Article in English | MEDLINE | ID: mdl-37910709

ABSTRACT

We report on a proof-of-concept snapshot imaging spectrometer developed using an array of optical fibers fabricated with 2-photon polymerization (2PP). The dense input array maps to an output array with engineered void spaces for spectral information. Previously, the development and fabrication of custom fiber arrays for imaging spectrometers have been a complex, time-consuming, and costly process, requiring a semi-manual assembly of commercial components. This work applies an automatic development process based on 2PP additive manufacturing with the Nanoscribe GmbH Quantum X system. The technique allows printing of arbitrary optical quality structures with submicron resolution with less than 5 nm roughness, enabling small core fibers/integrated arrays. Specifically, we developed an array prototype of 40 × 80 with 6-micron pitch at the input and 80-micron pitch at the output. The air-clad fibers had a core diameter of 5 µm. Fabricated optical fiber arrays were incorporated into a prism-based imaging spectrometer system with 48 spectral channels to demonstrate multi-spectral imaging. Imaging of a USAF target and color printed letter C as well as spectral comparisons to a commercial spectrometer were used to validate the performance of the system. These results clearly demonstrate the functionality and potential applications of the 3D-printed fiber-based snapshot imaging spectrometer.

4.
Cancers (Basel) ; 15(19)2023 Oct 09.
Article in English | MEDLINE | ID: mdl-37835599

ABSTRACT

Low response rates in immune check-point blockade (ICB)-treated head and neck squamous cell carcinoma (HNSCC) drive a critical need for robust, clinically validated predictive biomarkers. Our group previously showed that stress keratin 17 (CK17) suppresses macrophage-mediated CXCL9/CXCL10 chemokine signaling involved in attracting activated CD8+ T cells into tumors, correlating with decreased response rate to pembrolizumab-based therapy in a pilot cohort of ICB-treated HNSCC (n = 26). Here, we performed an expanded analysis of the predictive value of CK17 in ICB-treated HNSCC according to the REMARK criteria and investigated the gene expression profiles associated with high CK17 expression. Pretreatment samples from pembrolizumab-treated HNSCC patients were stained via immunohistochemistry using a CK17 monoclonal antibody (n = 48) and subjected to spatial transcriptomic profiling (n = 8). Our findings were validated in an independent retrospective cohort (n = 22). CK17 RNA expression in pembrolizumab-treated patients with various cancer types was investigated for predictive significance. Of the 48 patients (60% male, median age of 61.5 years), 21 (44%) were CK17 high, and 27 (56%) were CK17 low. A total of 17 patients (35%, 77% CK17 low) had disease control, while 31 patients (65%, 45% CK17 low) had progressive disease. High CK17 expression was associated with a lack of disease control (p = 0.037), shorter time to treatment failure (p = 0.025), and progression-free survival (PFS, p = 0.004), but not overall survival (OS, p = 0.06). A high CK17 expression was associated with lack of disease control in an independent validation cohort (p = 0.011). PD-L1 expression did not correlate with CK17 expression or clinical outcome. CK17 RNA expression was predictive of PFS and OS in 552 pembrolizumab-treated cancer patients. Our findings indicate that high CK17 expression may predict resistance to ICB in HNSCC patients and beyond.

5.
Opt Express ; 31(16): 26323-26334, 2023 Jul 31.
Article in English | MEDLINE | ID: mdl-37710495

ABSTRACT

Advances in 2-photon lithography have enabled in-lab production of sub-micron resolution and millimeter scale 3D optical components. The potential complex geometries are well suited to rapid prototyping and production of waveguide structures, interconnects, and waveguide directional couplers, furthering future development and miniaturization of waveguide-based imaging technologies. System alignment is inherent to the 2-photon process, obviating the need for manual assembly and allowing precise micron scale waveguide geometries not possible in traditional fused fiber coupler fabrication. Here we present the use of 2-photon lithography for direct printing of multi-mode waveguide couplers with air cladding and single mode waveguide couplers with uncured liquid photoresin cladding. Experimental results show reproducible coupling which can be modified by selected design parameters.

6.
Nutrients ; 14(24)2022 Dec 09.
Article in English | MEDLINE | ID: mdl-36558410

ABSTRACT

The pathophysiological process of intracerebral hemorrhage (ICH) is very complex, involving various mechanisms such as apoptosis, oxidative stress and inflammation. As one of the key factors, the inflammatory response is responsible for the pathological process of acute brain injury and is associated with the prognosis of patients. Abnormal or dysregulated inflammatory responses after ICH can aggravate cell damage in the injured brain tissue. The NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome is a multiprotein complex distributed in the cytosol, which can be triggered by multiple signals. The NLRP3 inflammasome is activated after ICH, thus promoting neuroinflammation and aggravating brain edema. In addition, there is evidence that the gut microbiota is crucial in the activation of the NLRP3 inflammasome. The gut microbiota plays a key role in a variety of CNS disorders. Changes in the diversity and species of the gut microbiota affect neuroinflammation through the activation of the NLRP3 inflammasome and the release of inflammatory cytokines. In turn, the gut microbiota composition can be influenced by the activation of the NLRP3 inflammasome. Thereby, the regulation of the microbe-gut-brain axis via the NLRP3 inflammasome may serve as a novel idea for protecting against secondary brain injury (SBI) in ICH patients. Here, we review the recent evidence on the functions of the NLRP3 inflammasome and the gut microbiota in ICH, as well as their interactions, during the pathological process of ICH.


Subject(s)
Brain Injuries , Gastrointestinal Microbiome , Humans , Inflammasomes , NLR Family, Pyrin Domain-Containing 3 Protein , Neuroinflammatory Diseases , Cerebral Hemorrhage
7.
Opt Express ; 30(7): 10614-10632, 2022 Mar 28.
Article in English | MEDLINE | ID: mdl-35473024

ABSTRACT

A field-ready, fiber-based high spatial sampling snapshot imaging spectrometer was developed for applications such as environmental monitoring and smart farming. The system achieves video rate frame transfer and exposure times down to a few hundred microseconds in typical daylight conditions with ∼63,000 spatial points and 32 spectral channels across the 470nm to 700nm wavelength range. We designed portable, ruggedized opto-mechanics to allow for imaging from an airborne platform. To ensure successful data collection prior to flight, imaging speed and signal-to-noise ratio was characterized for imaging a variety of land covers from the air. The system was validated by performing a series of observations including: Liriope Muscari plants under a range of water-stress conditions in a controlled laboratory experiment and field observations of sorghum plants in a variety of soil conditions. Finally, we collected data from a series of engineering flights and present reassembled images and spectral sampling of rural and urban landscapes.


Subject(s)
Diagnostic Imaging , Remote Sensing Technology , Environmental Monitoring , Plants
8.
Int J Gynecol Pathol ; 41(2): 132-141, 2022 Mar 01.
Article in English | MEDLINE | ID: mdl-33782344

ABSTRACT

There is increasing evidence that many endometrial cancers (EC) diagnosed as clear cell carcinoma (CCC) have substantial overlap with both serous carcinoma (SC) and endometrioid carcinoma (EmC), not only in terms of morphology and immunophenotype but also by molecular characterization. Now with use of HER2-based therapy in SC, a CCC diagnosis in serous-like tumors has the potential to exclude patients from receiving beneficial therapy. To assess HER2 in CCC in relation to other characteristics, a tissue microarray of archived CCC, EmC, and SC was stained for HER2 alongside a battery of immunostains used in EC. Cases with equivocal HER2 IHC were also assessed by in situ hybridization. HER2 status was assessed in 229 cases (23 CCC, 74 SC, 132 EmC). HER2 was positive in 48% of cases diagnosed as CCC, 19% of SC, and 0% of EmC. Rigorous morphologic and immunophenotypic review by 5 gynecologic pathologists revealed diagnostic disagreement in 8/11 HER2+ cases diagnosed as CCC, with SC as the other major diagnostic consideration. All HER2+ (n=25) cases were MMR-intact and most HER2+ EC had aberrant p53 staining (22/25, 88%); the 3 cases with a wild type pattern for p53 (12%) were all negative for ER. Based on these findings, patients with a diagnosis of CCC should be included in future clinical trials of HER2-targeted therapy. Moreover, given the diagnostic difficulty surrounding CCC, immunohistochemistry-based algorithms that include aberrant p53 and/or the absence of ER expression may provide a more objective means of establishing eligibility criteria than is currently possible using traditional histologic classification.


Subject(s)
Adenocarcinoma, Clear Cell , Carcinoma, Endometrioid , Cystadenocarcinoma, Serous , Endometrial Neoplasms , Adenocarcinoma, Clear Cell/diagnosis , Adenocarcinoma, Clear Cell/pathology , Biomarkers, Tumor , Carcinoma, Endometrioid/diagnosis , Carcinoma, Endometrioid/pathology , Cystadenocarcinoma, Serous/pathology , Endometrial Neoplasms/genetics , Female , Humans
9.
Mol Cancer Res ; 20(1): 56-61, 2022 01.
Article in English | MEDLINE | ID: mdl-34670862

ABSTRACT

Stromal cells play a central role in promoting the progression of colorectal cancer. Here, we analyze molecular changes within the epithelial and stromal compartments of dysplastic aberrant crypt foci (ACF) formed in the ascending colon, where rapidly developing interval cancers occur. We found strong activation of numerous neutrophil/monocyte chemokines, consistent with localized inflammation. The data also indicated a decrease in interferon signaling and cell-based immunity. The immune checkpoint and T-cell exhaustion gene PDCD1 was one of the most significantly upregulated genes, which was accompanied by a decrease in cytotoxic T-cell effector gene expression. In addition, CDKN2A expression was strongly upregulated in the stroma and downregulated in the epithelium, consistent with diverse changes in senescence-associated signaling on the two tissue compartments. IMPLICATIONS: Decreased CD8 T-cell infiltration within proximal colon ACF occurs within the context of a robust inflammatory response and potential stromal cell senescence, thus providing new insight into potential promotional drivers for tumors in the proximal colon.


Subject(s)
Colonic Neoplasms/genetics , Epithelial Cells/metabolism , Stromal Cells/metabolism , Colonic Neoplasms/pathology , Female , Humans , Male , Middle Aged , Tumor Microenvironment
10.
Opt Express ; 29(19): 30174-30197, 2021 Sep 13.
Article in English | MEDLINE | ID: mdl-34614746

ABSTRACT

The tunable light-guide image processing snapshot spectrometer (TuLIPSS) is a novel remote sensing instrument that can capture a spectral image cube in a single snapshot. The optical modelling application for the absolute signal intensity on a single pixel of the sensor in TuLIPSS has been developed through a numerical simulation of the integral performance of each optical element in the TuLIPSS system. The absolute spectral intensity of TuLIPSS can be determined either from the absolute irradiance of the observed surface or from the tabulated spectral reflectance of various land covers and by the application of a global irradiance approach. The model is validated through direct comparison of the simulated results with observations. Based on tabulated spectral reflectance, the deviation between the simulated results and the measured observations is less than 5% of the spectral light flux across most of the detection bandwidth for a Lambertian-like surface such as concrete. Additionally, the deviation between the simulated results and the measured observations using global irradiance information is less than 10% of the spectral light flux across most of the detection bandwidth for all surfaces tested. This optical modelling application of TuLIPSS can be used to assist the optimal design of the instrument and explore potential applications. The influence of the optical components on the light throughput is discussed with the optimal design being a compromise among the light throughput, spectral resolution, and cube size required by the specific application under consideration. The TuLIPSS modelling predicts that, for the current optimal low-cost configuration, the signal to noise ratio can exceed 10 at 10 ms exposure time, even for land covers with weak reflectance such as asphalt and water. Overall, this paper describes the process by which the optimal design is achieved for particular applications and directly connects the parameters of the optical components to the TuLIPSS performance.

11.
Am J Cardiol ; 155: 1-8, 2021 09 15.
Article in English | MEDLINE | ID: mdl-34281673

ABSTRACT

With aging of the population, cardiovascular conditions (CC) are increasingly common in individuals undergoing PCI for stable angina pectoris (AP). It is unknown if the overall burden of CCs associates with diminished symptom improvement after PCI for stable AP. We prospectively administered validated surveys assessing AP, dyspnea, and depression to patients undergoing PCI for stable AP at our institution, 2016-2018. The association of CC burden and symptoms at 30-days post-PCI was assessed via linear mixed effects models. Included individuals (N = 121; mean age 68 ± 10 years; response rate = 42%) were similar to non-included individuals. At baseline, greater CC burden was associated with worse dyspnea, depression, and physical limitations due to AP, but not AP frequency or quality of life. PCI was associated with small improvements in AP and dyspnea (p ≤ 0.001 for both), but not depression (p = 0.15). After multivariable adjustment, including for baseline symptoms, CC burden was associated with a greater improvement in AP physical limitations (p = 0.01) and depression (p = 0.002), albeit small, but not other symptom domains (all p ≥ 0.05). In patients undergoing PCI for stable AP, increasing CC burden was associated with worse dyspnea, depression, and AP physical limitations at baseline. An increasing number of CCs was associated with greater improvements, though small, in AP physical limitations and depression. In conclusion, the overall number of cardiovascular conditions should not be used to exclude patients from PCI for stable AP on the basis of an expectation of less symptom improvement.


Subject(s)
Angina, Stable/surgery , Health Status , Percutaneous Coronary Intervention/methods , Quality of Life , Registries , Aged , Angina, Stable/diagnosis , Coronary Angiography , Disease Progression , Female , Follow-Up Studies , Humans , Male , Prognosis , Retrospective Studies , Time Factors
12.
Dev Neurorehabil ; 24(6): 397-407, 2021 Aug.
Article in English | MEDLINE | ID: mdl-33706637

ABSTRACT

Aim: Comorbid psychopathology refers to having a diagnosis of two or more co-occurring psychological disorders. The current study investigated the differences between children and adolescents with no-mild, moderate and severe comorbid psychopathology in children and adolescents with ASD.Method: Parents of 133 children completed the Autism Spectrum Disorder-Comorbid for Children, Behavior Problems Inventory-Short Form, Pediatric Quality of Life Inventory, Vineland Adaptive Behavior Scales, Social Communication Questionnaire, Short Sensory Profile, and Behavioral/Educational Interventions and Complementary/Alternative Medicine (CAM) Interventions of the Autism Treatment Network Registry Parent Baseline Assessment.Results: A significant difference was found between severity of comorbid psychopathology and all types of challenging behavior and all sensory issues except movement. A small effect size was also found between comorbid psychopathology and quality of life.Conclusion: The findings from this study show significant difficulties associated with those with comorbid psychopathology in ASD in challenging behavior, sensory issues and quality of life.


Subject(s)
Adaptation, Psychological/physiology , Autism Spectrum Disorder/psychology , Mental Disorders/psychology , Quality of Life/psychology , Adolescent , Autism Spectrum Disorder/complications , Child , Child, Preschool , Female , Humans , Male , Mental Disorders/complications , Problem Behavior/psychology , Surveys and Questionnaires
13.
BMC Cancer ; 21(1): 186, 2021 Feb 23.
Article in English | MEDLINE | ID: mdl-33622270

ABSTRACT

BACKGROUND: Targeting Protein for Xenopus Kinesin Like Protein 2 (TPX2) is a microtubule associated protein that functions in mitotic spindle assembly. TPX2 also localizes to the nucleus where it functions in DNA damage repair during S-phase. We and others have previously shown that TPX2 RNA levels are strongly associated with chromosomal instability (CIN) in breast and other cancers, and TPX2 RNA levels have been demonstrated to correlate with aggressive behavior and poor clinical outcome across a range of solid malignancies, including breast cancer. METHODS: We perform TPX2 IHC on a cohort of 253 primary breast cancers and adopt a clinically amenable scoring system to separate tumors into low, intermediate, or high TPX2 expression. We then correlate TPX2 expression against diverse pathologic parameters and important measures of clinical outcome, including disease-specific and overall survival. We link TPX2 expression to TP53 mutation and evaluate whether TPX2 is an independent predictor of chromosomal instability (CIN). RESULTS: We find that TPX2 nuclear expression strongly correlates with high grade morphology, elevated clinical stage, negative ER and PR status, and both disease-specific and overall survival. We also show that increased TPX2 nuclear expression correlates with elevated ploidy, supernumerary centrosomes, and TP53 mutation. TPX2 nuclear expression correlates with CIN via univariate analyses but is not independently predictive when compared to ploidy, Ki67, TP53 mutational status, centrosome number, and patient age. CONCLUSIONS: Our findings demonstrate a strong correlation between TPX2 nuclear expression and aggressive tumor behavior, and show that TPX2 overexpression frequently occurs in the setting of TP53 mutation and elevated ploidy. However, TPX2 expression is not an independent predictor of CIN where it fails to outperform existing clinical and pathologic metrics.


Subject(s)
Breast Neoplasms/genetics , Cell Cycle Proteins/physiology , Cell Nucleus/chemistry , Chromosomal Instability , Microtubule-Associated Proteins/physiology , Mutation , Tumor Suppressor Protein p53/genetics , Adult , Aged , Aged, 80 and over , Breast Neoplasms/mortality , Breast Neoplasms/pathology , Cell Cycle Proteins/analysis , Cell Cycle Proteins/genetics , Cell Proliferation , Cohort Studies , Female , Humans , Microtubule-Associated Proteins/analysis , Microtubule-Associated Proteins/genetics , Middle Aged , RNA, Messenger/analysis
14.
Gynecol Oncol Rep ; 34: 100658, 2020 Nov.
Article in English | MEDLINE | ID: mdl-33204793

ABSTRACT

INTRODUCTION: Elevated serum inhibin B is a classic marker of adult granulosa cell tumors. Here we discuss an extremely rare and informative case of elevated inhibin B associated with an ovarian thecoma. CASE: A 57 year-old postmenopausal female presented with recurrent bleeding and was found to have an adnexal mass with an elevated serum inhibin B level of 1,915 pg/mL (normal range 10-200 pg/mL). With a preoperative diagnosis of adult granulosa cell tumor, she underwent surgical management for what was ultimately a benign ovarian thecoma. The diagnosis of thecoma was confirmed by a pericellular pattern of reticulin staining and the lack of a FOXL2 mutation by molecular testing. CONCLUSION: This case demonstrates that inhibin B lacks specificity as a tumor marker for adult granulosa cell tumor, even at very high levels. Knowledge of benign alternative explanations for this finding can facilitate improved preoperative patient counseling. Pertinent literature is reviewed, with an emphasis on proposed hypotheses for inhibin overproduction.

15.
J Gerontol B Psychol Sci Soc Sci ; 75(2): 308-315, 2020 01 14.
Article in English | MEDLINE | ID: mdl-29522128

ABSTRACT

OBJECTIVES: Purpose in life (PIL), a feeling of meaning and direction in life, is associated with favorable health outcomes including lower mortality and reduced risk of disease, disability, and cognitive impairment. Since centenarian offspring have been shown to have long health spans we sought to examine whether they have higher PIL than individuals without familial longevity. METHOD: We compared PIL scores from the Ryff Scales of Psychological Well-Being in centenarian offspring from the New England Centenarian Study (N = 361, mean age = 82.0 years) with 3 referent groups: spouses, birth cohort-matched referents, and Health and Retirement Study (HRS) participants. RESULTS: Logistic regression analyses adjusted for age, sex, education, and marital status indicated greater odds of high PIL among centenarian offspring compared with spouse (adjusted odds ratio [aOR] = 1.92, 95% confidence interval [CI] = 1.002-3.68, p = .049) and birth cohort referents (aOR = 2.64, 95% CI = 1.36-5.14, p = .004). Offspring had an almost 3 times greater odds of having high PIL than HRS participants (odds ratio [OR] = 2.93, 95% CI = 2.17-3.96, p < .0001). DISCUSSION: Higher PIL is associated with being an offspring of a long-lived parent and may play a role in the ability to delay age-associated illnesses and functional decline. Increasing purposefulness may be a target for interventions to promote healthy aging.


Subject(s)
Adult Children/psychology , Aged, 80 and over/psychology , Attitude to Health , Culture , Longevity , Educational Status , Female , Humans , Male , Marital Status , Personal Satisfaction , Surveys and Questionnaires
16.
Fungal Genet Biol ; 124: 78-87, 2019 03.
Article in English | MEDLINE | ID: mdl-30664933

ABSTRACT

The sesquiterpenoid deoxynivalenol (DON) is an important trichothecene mycotoxin produced by the cereal pathogen Fusarium graminearum. DON is synthesized in specialized subcellular structures called toxisomes. The first step in DON synthesis is catalyzed by the sesquiterpene synthase (STS), Tri5 (trichodiene synthase), resulting in the cyclization of farnesyl diphosphate (FPP) to produce the sesquiterpene trichodiene. Tri5 is one of eight putative STSs in the F. graminearum genome. To better understand the F. graminearum terpenome, the volatile and soluble fractions of fungal cultures were sampled. Stringent regulation of sesquiterpene accumulation was observed. When grown in trichothecene induction medium, the fungus produces trichothecenes as well as several volatile non-trichothecene related sesquiterpenes, whereas no volatile terpenes were detected when grown in non-inducing medium. Surprisingly, a Δtri5 deletion strain grown in inducing conditions not only ceased accumulation of trichothecenes, but also failed to produce the non-trichothecene related sesquiterpenes. To test whether Tri5 from F. graminearum may be a promiscuous STS directly producing all observed sesquiterpenes, Tri5 was cloned and expressed in E. coli and shown to produce primarily trichodiene in addition to minor, related cyclization products. Therefore, while Tri5 expression in F. graminearum is necessary for non-trichothecene sesquiterpene biosynthesis, direct catalysis by Tri5 does not explain the sesquiterpene deficient phenotype observed in the Δtri5 strain. To test whether Tri5 protein, separate from its enzymatic activity, may be required for non-trichothecene synthesis, the Tri5 locus was replaced with an enzymatically inactive, but structurally unaffected tri5N225D S229T allele. This allele restores non-trichothecene synthesis but not trichothecene synthesis. The tri5N225D S229T allele also restores toxisome structure which is lacking in the Δtri5 deletion strain. Our results indicate that the Tri5 protein, but not its enzymatic activity, is also required for the synthesis of non-trichothecene related sesquiterpenes and the formation of toxisomes. Toxisomes thus not only may be important for DON synthesis, but also for the synthesis of other sesquiterpene mycotoxins such as culmorin by F. graminearum.


Subject(s)
Cytoplasmic Vesicles/metabolism , Endoplasmic Reticulum/metabolism , Fusarium/metabolism , Sesquiterpenes/metabolism , Carbon-Carbon Lyases/genetics , Carbon-Carbon Lyases/metabolism , Cyclohexenes/metabolism , Fusarium/genetics , Mycotoxins/metabolism , Polyisoprenyl Phosphates/metabolism
17.
Appl Environ Microbiol ; 84(11)2018 06 01.
Article in English | MEDLINE | ID: mdl-29625976

ABSTRACT

The wood-rotting mushroom Stereum hirsutum is a known producer of a large number of namesake hirsutenoids, many with important bioactivities. Hirsutenoids form a structurally diverse and distinct class of sesquiterpenoids. No genes involved in hirsutenoid biosynthesis have yet been identified or their enzymes characterized. Here, we describe the cloning and functional characterization of a hirsutene synthase as an unexpected fusion protein of a sesquiterpene synthase (STS) with a C-terminal 3-hydroxy-3-methylglutaryl-coenzyme A (3-hydroxy-3-methylglutaryl-CoA) synthase (HMGS) domain. Both the full-length fusion protein and truncated STS domain are highly product-specific 1,11-cyclizing STS enzymes with kinetic properties typical of STSs. Complementation studies in Saccharomyces cerevisiae confirmed that the HMGS domain is also functional in vivo Phylogenetic analysis shows that the hirsutene synthase domain does not form a clade with other previously characterized sesquiterpene synthases from Basidiomycota. Comparative gene structure analysis of this hirsutene synthase with characterized fungal enzymes reveals a significantly higher intron density, suggesting that this enzyme may be acquired by horizontal gene transfer. In contrast, the HMGS domain is clearly related to other fungal homologs. This STS-HMGS fusion protein is part of a biosynthetic gene cluster that includes P450s and oxidases that are expressed and could be cloned from cDNA. Finally, this unusual fusion of a terpene synthase to an HMGS domain, which is not generally recognized as a key regulatory enzyme of the mevalonate isoprenoid precursor pathway, led to the identification of additional HMGS duplications in many fungal genomes, including the localization of HMGSs in other predicted sesquiterpenoid biosynthetic gene clusters.IMPORTANCE Hirsutenoids represent a structurally diverse class of bioactive sesquiterpenoids isolated from fungi. Identification of their biosynthetic pathways will provide access to this chemodiversity for the discovery and synthesis of molecules with new bioactivities. The identification and successful cloning of the previously elusive hirsutene synthase from the S. hirsutum provide important insights and strategies for biosynthetic gene discovery in Basidiomycota. The finding of a terpene synthase-HMGS fusion, the discovery of other sesquiterpenoid biosynthetic gene clusters with dedicated HMGS genes, and HMGS gene duplications in fungal genomes give new importance to the role of HMGS as a key regulatory enzyme in isoprenoid and sterol biosynthesis that should be exploited for metabolic engineering.


Subject(s)
Acyl Coenzyme A/genetics , Alkyl and Aryl Transferases/genetics , Basidiomycota/enzymology , Basidiomycota/genetics , Sesquiterpenes/metabolism , Cloning, Molecular , Gene Expression Regulation, Enzymologic , Genome, Fungal , Multigene Family , Phylogeny , Polycyclic Sesquiterpenes , Recombinant Fusion Proteins/metabolism
18.
Int J Audiol ; 57(sup2): S27-S40, 2018 05.
Article in English | MEDLINE | ID: mdl-28885072

ABSTRACT

OBJECTIVE: We investigated effects of aetiology and age at implantation on changes in threshold (T) levels, comfortable (C) levels and dynamic range (DR) for cochlear implants (CIs) in children over the first five years of life. DESIGN: Information was collected at 6 months post-activation of CIs, and at 3 and 5 years of age. STUDY SAMPLE: One hundred and sixty-one children participating in the Longitudinal Outcomes of Children with Hearing Impairment (LOCHI) study. RESULTS: Children with neural and structural cochlear lesions had higher T-levels and C-levels as compared to those without these conditions. Parameter settings varied from manufacturer's defaults more often in the former than in the latter group. Investigation of the effect of age at implantation for children without neural and structural cochlear lesions showed that those implanted at ≤12 months of age had higher T-levels and narrower DR at 6 months post-activation, as compared to the later-implanted group. For both early- and later-implanted groups, the C-levels at 6 months post-activation were lower than those at age 3 and 5 years. There were no significant differences in T-levels, C-levels, or DR between age 3 and 5 years. CONCLUSIONS: Aetiology and age at implantation had significant effects on T-levels and C-levels.


Subject(s)
Auditory Perception , Cochlear Implantation/instrumentation , Cochlear Implants , Disabled Children/rehabilitation , Hearing Loss/rehabilitation , Persons With Hearing Impairments/rehabilitation , Acoustic Stimulation , Age Factors , Auditory Threshold , Australia , Child, Preschool , Disabled Children/psychology , Electric Stimulation , Female , Hearing , Hearing Loss/etiology , Hearing Loss/physiopathology , Hearing Loss/psychology , Humans , Infant , Longitudinal Studies , Male , Persons With Hearing Impairments/psychology , Risk Factors
19.
Int J Audiol ; 57(sup2): S70-S80, 2018 05.
Article in English | MEDLINE | ID: mdl-28687057

ABSTRACT

OBJECTIVE: We investigated the factors influencing speech perception in babble for 5-year-old children with hearing loss who were using hearing aids (HAs) or cochlear implants (CIs). DESIGN: Speech reception thresholds (SRTs) for 50% correct identification were measured in two conditions - speech collocated with babble, and speech with spatially separated babble. The difference in SRTs between the two conditions give a measure of binaural unmasking, commonly known as spatial release from masking (SRM). Multiple linear regression analyses were conducted to examine the influence of a range of demographic factors on outcomes. STUDY SAMPLE: Participants were 252 children enrolled in the Longitudinal Outcomes of Children with Hearing Impairment (LOCHI) study. RESULTS: Children using HAs or CIs required a better signal-to-noise ratio to achieve the same level of performance as their normal-hearing peers but demonstrated SRM of a similar magnitude. For children using HAs, speech perception was significantly influenced by cognitive and language abilities. For children using CIs, age at CI activation and language ability were significant predictors of speech perception outcomes. CONCLUSIONS: Speech perception in children with hearing loss can be enhanced by improving their language abilities. Early age at cochlear implantation was also associated with better outcomes.


Subject(s)
Cochlear Implantation/instrumentation , Cochlear Implants , Disabled Children/rehabilitation , Early Medical Intervention/methods , Hearing Aids , Hearing Loss/rehabilitation , Noise/adverse effects , Perceptual Masking , Persons With Hearing Impairments/rehabilitation , Speech Perception , Acoustic Stimulation , Age Factors , Australia , Child Development , Child Language , Child, Preschool , Cognition , Disabled Children/psychology , Electric Stimulation , Female , Hearing , Hearing Loss/diagnosis , Hearing Loss/physiopathology , Hearing Loss/psychology , Humans , Longitudinal Studies , Male , Persons With Hearing Impairments/psychology , Severity of Illness Index , Speech Reception Threshold Test , Time Factors
20.
Int J Audiol ; 57(sup2): S41-S54, 2018 05.
Article in English | MEDLINE | ID: mdl-28971727

ABSTRACT

OBJECTIVE: This study examined the influence of prescription on hearing aid (HA) fitting characteristics and 5-year developmental outcomes of children. DESIGN: A randomised controlled trial implemented as part of a population-based study on Longitudinal Outcomes of Children with Hearing Impairment (LOCHI). STUDY SAMPLE: Two-hundred and thirty-two children that were fit according to either the National Acoustic Laboratories (NAL) or Desired Sensation Level (DSL) prescription. RESULTS: Deviation from targets and root-mean-square error in HA fitting revealed no significant difference between fitting prescriptions. Aided audibility quantified by using the Speech Intelligibility Index (SII) model showed that DSL provided higher audibility than NAL at low and medium input levels but not at high input level. After allowing for hearing loss desensitisation, differences in audibility between prescription groups were significant only at low input level. The randomised trial of prescription that was implemented for 163 children revealed no significant between-group differences in speech production, perception, and language; but parent-rated functional performance was higher for the DSL than for the NAL group. CONCLUSIONS: Proximity to prescriptive targets was similar between fitting prescriptions. The randomised trial revealed differences in aided audibility at low input level between prescription groups, but no significant differences in speech and language abilities.


Subject(s)
Adolescent Behavior , Child Behavior , Child Language , Correction of Hearing Impairment/instrumentation , Disabled Children/rehabilitation , Hearing Aids , Hearing Loss, Bilateral/rehabilitation , Persons With Hearing Impairments/rehabilitation , Speech Perception , Acoustic Stimulation , Adolescent , Age Factors , Auditory Threshold , Australia , Child , Child, Preschool , Disabled Children/psychology , Equipment Design , Female , Hearing , Hearing Loss, Bilateral/etiology , Hearing Loss, Bilateral/physiopathology , Hearing Loss, Bilateral/psychology , Humans , Male , Neuropsychological Tests , Persons With Hearing Impairments/psychology , Speech Intelligibility , Speech Production Measurement , Speech Reception Threshold Test , Time Factors , Treatment Outcome
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