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2.
Trop Dis Travel Med Vaccines ; 9(1): 4, 2023 Mar 01.
Article in English | MEDLINE | ID: mdl-36855197

ABSTRACT

BACKGROUND: Despite being first identified in 1947, Zika virus-related outbreaks were first described starting from 2007 culminating with the 2015 Latin American outbreak. Hypotheses indicate that the virus has been circulating in Asia for decades, but reports are scarce. METHODS: We performed serological analysis and screened placental samples isolated in 2008 for the presence of Zika virus from pregnant women in Ho Chi Minh City (Vietnam). RESULTS: None of the placental samples was positive for Zika virus. Four serum samples out of 176 (2.3%) specifically inhibited Zika virus, with variable degrees of cross-reactivity with other flaviviruses. While one of the four samples inhibited only Zika virus, cross-reactivity with other flaviviruses not included in the study could not be ruled out. CONCLUSION: Our results support the conclusion that the virus was not present among pregnant women in the Vietnamese largest city during the initial phases of the epidemic wave.

4.
Am J Physiol Endocrinol Metab ; 323(6): E492-E502, 2022 12 01.
Article in English | MEDLINE | ID: mdl-36223522

ABSTRACT

Secretion of insulin from the pancreas is pulsatile, driven by intrinsic oscillations within individual islets of Langerhans. The secretions are coordinated among the many islets distributed throughout the pancreas producing a synchronized rhythm in vivo that is essential for maintaining normal glucose levels. One hypothesized mechanism for the coordination of islet activity is negative feedback, whereby sequestration of glucose in response to elevated insulin leads to a reduction in the blood glucose level that is sensed by the islet population. This global signal of glucose then coordinates the individual islets. In this study, we tested how this coordination mechanism is affected by time delays in the negative feedback, using a microfluidic system to monitor Ca2+ levels in a small population of islets and implementing glucose control through a negative feedback system. We found that islet synchronization occurs even with time delays in the feedback of up to 7 min. We also found that a second, slower closed-loop oscillation period is produced during delayed feedback in which islet oscillations are clustered into episodes. The period of this second oscillatory mode increases with the time delay and appears to be a second stable behavior that coexists with the faster synchronized oscillation. The general conclusion is that islet coordination through negative feedback is a viable means of islet coordination that is robust to delays in the timing of the feedback, and could complement other potential coordination mechanisms such as entrainment by pancreatic ganglia.NEW & NOTEWORTHY Insulin secretion from islets of Langerhans is rhythmic, and these rhythms are coordinated to produce oscillatory plasma insulin levels. Using a combination of microfluidics and computational modeling, we demonstrate that coordination can occur through negative feedback of the type provided by the liver, even if that feedback is delayed by several minutes. We also demonstrate that a second, slower, mode of oscillations can occur when feedback is delayed where faster oscillations are grouped into episodes.


Subject(s)
Islets of Langerhans , Feedback , Islets of Langerhans/metabolism , Insulin Secretion , Insulin/metabolism , Glucose/metabolism
5.
Osteoporos Int ; 30(5): 1043-1049, 2019 May.
Article in English | MEDLINE | ID: mdl-30706096

ABSTRACT

Benign prostatic hyperplasia is one of the most common diseases in the elderly male population. The urinary tract symptoms may increase the risk of falls and fractures. The results indicated that patients with benign prostatic hyperplasia could increase the risk of vertebral compression fractures in both the thoracic and lumbar spine and also hip fractures, but did not increase the risk of wrist fracture. INTRODUCTION: The relationship between benign prostatic hyperplasia and the development of fall-related fractures, especially vertebral compression fractures, has been seldom mentioned in the literature. This study aimed to evaluate the risk of developing vertebral compression fracture, hip fracture, and wrist fracture in patients with benign prostatic hyperplasia. METHODS: This study obtained claims data retrospectively from the National Health Insurance Research Database of Taiwan and identified 48,114 patients who were diagnosed as having benign prostatic hyperplasia. Subjects of the control cohort were individually matched at a ratio of 4:1 with those in the benign prostatic hyperplasia cohort according to age and the index day. Comorbidities were classified as those existing before the index day and included a previous fracture history, osteoporosis, myocardial infarction, congestive heart failure, diabetes mellitus, hypertension, cerebrovascular accident, etc. The end of the follow-up period of the analyses was the day when the patient developed new vertebral compression fractures, hip fractures, or wrist fractures, terminated enrollment from the National Health Insurance, or died or until the end of 2012. The study used the Cox proportion hazard model to determine the hazard ratio for developing new hip fractures. RESULTS: Patients with benign prostatic hyperplasia were significantly more likely than those in the control cohort to develop new vertebral compression fractures in the thoracic spine (0.43% vs. 0.40%, adjusted hazard ratio 3.03, confidence interval 2.12-4.31) and lumbar spine (1.26% vs. 1.23%, adjusted hazard ratio 4.12, confidence interval 3.39-5.01), and hip fracture (1.47% vs. 2.09%, adjusted hazard ratio 1.22, confidence interval 1.10-1.36), but does not increase the risk of wrist fracture (0.61% vs. 0.67%, adjusted hazard ratio 1.07, confidence interval 0.85-1.34). CONCLUSIONS: Patients with benign prostatic hyperplasia exhibited an increased risk of developing vertebral compression fractures in both the thoracic and lumbar spine and also hip fractures, but did not increase the risk of wrist fracture. However, more research is needed to confirm this trend in the clinical setting.


Subject(s)
Hip Fractures/etiology , Osteoporotic Fractures/etiology , Prostatic Hyperplasia/complications , Spinal Fractures/etiology , Wrist Injuries/etiology , Accidental Falls/statistics & numerical data , Adult , Aged , Comorbidity , Databases, Factual , Hip Fractures/epidemiology , Humans , Incidence , Male , Middle Aged , Osteoporotic Fractures/epidemiology , Prostatic Hyperplasia/epidemiology , Retrospective Studies , Risk Assessment/methods , Spinal Fractures/epidemiology , Taiwan/epidemiology , Wrist Injuries/epidemiology
6.
Transplant Proc ; 50(9): 2601-2605, 2018 Nov.
Article in English | MEDLINE | ID: mdl-30401359

ABSTRACT

BACKGROUND: Liver transplantation (LT) has become established therapy for end-stage liver disease and small-cell hepatocellular carcinoma (HCC), relying mainly on living donor LT (LDLT) in Taiwan. The cost of LDLT varies in different countries depending on the insurance system, the costs of the facility, and staff. In this study we aimed to investigate cost outcomes and determinants of LDLT in Taiwan. METHODS: From January 2014 to December 2015, 184 LDLT patients were enrolled in a study performed at the Kaohsiung Chang Gung Memorial Hospital. Patients' transplantation costs were defined as expense from immediately after surgery to discharge during hospitalization for LDLT. Antiviral therapy and hepatitis B immunoglobulin (HBIG) for prevention of hepatitis B virus (HBV) were included, but direct-acting antiviral (DAA) therapy for hepatitis C (HCV) was excluded. RESULTS: The median total, intensive care unit (ICU), and ward costs of LT were US$64,250, $43,357, and $16,138 (currency ratio 1:30), respectively. HBV significantly increased the total cost of LT, followed by postoperative reintubation and bile duct complications. CONCLUSION: The charges associated with anti-HBV viral therapy and HBIG increase the cost of LDLT. Disease severity of liver cirrhosis showed less importance in predicting cost. Postoperative complications such as reintubation or bile duct complications should be avoided to reduce the cost of LT.


Subject(s)
Health Care Costs/statistics & numerical data , Liver Transplantation/economics , Living Donors , Postoperative Complications/economics , Adult , Female , Hepatitis B/complications , Hepatitis B/economics , Hepatitis B virus , Humans , Male , Middle Aged , Taiwan , Treatment Outcome
7.
Bone Joint J ; 100-B(10): 1359-1363, 2018 Oct.
Article in English | MEDLINE | ID: mdl-30295529

ABSTRACT

AIMS: This study reports the outcomes of a technique of soft-tissue coverage and Chopart amputation for severe crush injuries of the forefoot. PATIENTS AND METHODS: Between January 2012 to December 2016, 12 patients (nine male; three female, mean age 38.58 years; 26 to 55) with severe foot crush injury underwent treatment in our institute. All patients were followed-up for at least one year. Their medical records, imaging, visual analogue scale score, walking ability, complications, and functional outcomes one year postoperatively based on the American Orthopedic Foot and Ankle Society (AOFAS) and 36-Item Short-Form Health Survey (SF-36) scores were reviewed. RESULTS: The mean length of follow-up was 18.6 months (13 to 28). Two patients had a local infection, flap necrosis was seen in one patient, and one patient experienced a skin graft wound healing delay. Of the 12 patients, one had persistent infection and eventually required below-knee amputation, but pain-free walking was achieved in all the other patients. The mean one-year postoperative AOFAS and SF-36 scores were 75.6 (68 to 80) and 82 (74 to 88), respectively. CONCLUSION: Although our sample size was small, we believe that this treatment method may be a valuable alternative for treating severe foot crush injuries. Cite this article: Bone Joint J 2018;100-B:1359-63.


Subject(s)
Amputation, Surgical/methods , Ankle Joint/surgery , Arthrodesis/methods , Foot Injuries/surgery , Free Tissue Flaps/transplantation , Adult , Female , Follow-Up Studies , Humans , Male , Middle Aged , Plastic Surgery Procedures , Retrospective Studies , Treatment Outcome
8.
Phys Rev Lett ; 120(20): 206401, 2018 May 18.
Article in English | MEDLINE | ID: mdl-29864304

ABSTRACT

We report a de Haas-van Alphen (dHvA) effect study on the Dirac type-II semimetallic candidates MAl_{3} (where, M=V, Nb and Ta). The angular dependence of their Fermi surface (FS) cross-sectional areas reveals a remarkably good agreement with our first-principles calculations. Therefore, dHvA supports the existence of tilted Dirac cones with Dirac type-II nodes located at 100, 230 and 250 meV above the Fermi level ϵ_{F} for VAl_{3}, NbAl_{3} and TaAl_{3} respectively, in agreement with the prediction of broken Lorentz invariance in these compounds. However, for all three compounds we find that the cyclotron orbits on their FSs, including an orbit nearly enclosing the Dirac type-II node, yield trivial Berry phases. We explain this via an analysis of the Berry phase where the position of this orbit, relative to the Dirac node, is adjusted within the error implied by the small disagreement between our calculations and the experiments. We suggest that a very small amount of doping could displace ϵ_{F} to produce topologically nontrivial orbits encircling their Dirac node(s).

9.
J Nanosci Nanotechnol ; 18(6): 4217-4221, 2018 Jun 01.
Article in English | MEDLINE | ID: mdl-29442765

ABSTRACT

The flicker noise of source follower transistors is the dominant noise source in image sensors. This paper reports a systematic study of the shallow trench isolation effect in transistors with different sizes under high temperature conditions that correspond to the quantity of empty defect sites. The effects of shallow trench isolation sidewall defects on flicker noise characteristics are investigated. In addition, the low-frequency noise and subthreshold swing degrade simultaneously in accordance to the device gate width scaling. Both serious subthreshold leakage and considerable noise can be attributed to the high trap density near the STI edge. Consequently, we propose a coincidental relationship between the noise level and the subthreshold characteristic; its trend is identical to the experiments and simulation results.

11.
Nano Lett ; 17(3): 1616-1622, 2017 03 08.
Article in English | MEDLINE | ID: mdl-28145719

ABSTRACT

MoTe2 is an exfoliable transition metal dichalcogenide (TMD) that crystallizes in three symmetries: the semiconducting trigonal-prismatic 2H- or α-phase, the semimetallic and monoclinic 1T'- or ß-phase, and the semimetallic orthorhombic γ-structure. The 2H-phase displays a band gap of ∼1 eV making it appealing for flexible and transparent optoelectronics. The γ-phase is predicted to possess unique topological properties that might lead to topologically protected nondissipative transport channels. Recently, it was argued that it is possible to locally induce phase-transformations in TMDs, through chemical doping, local heating, or electric-field to achieve ohmic contacts or to induce useful functionalities such as electronic phase-change memory elements. The combination of semiconducting and topological elements based upon the same compound might produce a new generation of high performance, low dissipation optoelectronic elements. Here, we show that it is possible to engineer the phases of MoTe2 through W substitution by unveiling the phase-diagram of the Mo1-xWxTe2 solid solution, which displays a semiconducting to semimetallic transition as a function of x. We find that a small critical W concentration xc ∼ 8% stabilizes the γ-phase at room temperature. This suggests that crystals with x close to xc might be particularly susceptible to phase transformations induced by an external perturbation, for example, an electric field. Photoemission spectroscopy, indicates that the γ-phase possesses a Fermi surface akin to that of WTe2.

12.
Clin Otolaryngol ; 42(1): 53-59, 2017 Feb.
Article in English | MEDLINE | ID: mdl-27102375

ABSTRACT

OBJECTIVE: To assess the efficacy of septoplasty and the correlation between the subjective evaluations of a visual analogue scale (VAS) and the Nasal Obstruction Symptom Evaluation (NOSE) questionnaire and active anterior rhinomanometry of the nasal airway after septoplasty. DESIGN: A retrospective, individual cohort study. SETTING: Ear, Nose and Throat Department, Taipei City Hospital, Taipei, Taiwan. PARTICIPANTS: Fifty patients with chronic nasal obstruction were enrolled in the study. All 50 patients underwent septoplasty because of nasal septal deviation. Another 28 patients without nasal symptoms served as controls. MAIN OUTCOME MEASURES: VAS, NOSE and active anterior rhinomanometry were used to measure the sensation of nasal obstruction. All measurements were performed in both groups preoperatively and then repeated on three postoperative visits (3, 6 and 12 months). RESULTS: The mean VAS score, NOSE score and the nasal resistance in the narrow side of the nose in the study group showed reduced symptoms at 3, 6 and 12 months postoperatively compared with the respective preoperative measurements (P < 0.001, all). The VAS and NOSE scores did not significantly correlate with total nasal resistance preoperatively or postoperatively. The VAS and nasal resistance in the obstructed nasal cavity correlated significantly preoperatively (P < 0.05), but not postoperatively. CONCLUSIONS: The subjective and objective symptoms of nasal obstruction had improved 1 year after septoplasty. A significant correlation between VAS scores and nasal resistance in the narrow side of the nose was found before surgery. The subjective and objective measurements of nasal obstruction lacked significant correlation postoperatively.


Subject(s)
Nasal Obstruction/diagnosis , Nasal Septum/abnormalities , Nasal Septum/surgery , Rhinomanometry , Symptom Assessment , Visual Analog Scale , Adult , Aged , Female , Follow-Up Studies , Humans , Male , Middle Aged , Nasal Obstruction/etiology , Nasal Obstruction/surgery , Retrospective Studies , Rhinoplasty , Surveys and Questionnaires , Taiwan , Time Factors , Treatment Outcome
13.
Transplant Proc ; 48(4): 1080-2, 2016 May.
Article in English | MEDLINE | ID: mdl-27320562

ABSTRACT

BACKGROUND: The aim of this study was to compare the outcomes of pain management with the use of patient-controlled analgesia (PCA) fentanyl with IV parecoxib between patients with healthy liver with patients with diseased liver undergoing major liver resection. METHODS: Patients with healthy liver undergoing partial hepatectomy as liver donors for liver transplantation (group 1) and patients with liver cirrhosis (Child's criteria A) undergoing major liver resection for hepatoma (group 2) were identified retrospectively. Both groups routinely received post-operative IV PCA fentanyl and a single dose of parecoxib 40 mg. They were followed up for 3 days or until PCA fentanyl was discontinued post-operatively. Daily Visual Analog Scale, PCA fentanyl usage, rescue attempts, and common drug side effects were collected and analyzed with the use of SPSS version 20. RESULTS: One hundred one patients were included in the study: 54 in group 1, and 47 in group 2. There were no statistical differences between the two groups in terms of the daily and total fentanyl usage, VAS resting, and incidence of itchiness. The rate of rescue analgesia on post-operative day (POD) 1 was lower in group 2, with a value of P = .045. VAS dynamics were better on POD 1 and 2 for group 2, with P = .05 and P = .012, respectively. CONCLUSIONS: We found that combining a single dose of IV parecoxib 40 mg with PCA fentanyl is an easy and effective method of acute pain control after major liver resection. We propose the careful usage of post-operative fentanyl and parecoxib in patients with diseased liver, given the difference in effect as compared with healthy liver.


Subject(s)
Analgesics/therapeutic use , Fentanyl/therapeutic use , Hepatectomy/adverse effects , Isoxazoles/therapeutic use , Liver Cirrhosis/surgery , Pain, Postoperative/drug therapy , Acute Pain/diagnosis , Acute Pain/drug therapy , Acute Pain/etiology , Adult , Aged , Analgesia, Patient-Controlled , Drug Therapy, Combination , Female , Humans , Liver Transplantation , Living Donors , Male , Middle Aged , Pain Management , Pain Measurement , Pain, Postoperative/diagnosis , Pain, Postoperative/etiology , Retrospective Studies
14.
Leukemia ; 30(2): 274-84, 2016 Feb.
Article in English | MEDLINE | ID: mdl-26376228

ABSTRACT

Distinct microRNA (miRNA) and mRNA signatures were reported in nucleophosmin (NPM1)-mutated acute myeloid leukemia (AML). However, it remains unknown whether the mutation participates in the dynamic interaction between miRNA and mRNA. In this study, we aimed to investigate the role of NPM1 mutation in modulating miRNA-mRNA regulation (MMR). From the sample-paired miRNA/mRNA microarrays of 181 de novo AML patients, we found that MMR was dynamic and could be affected by NPM1 mutation. By a systematic framework, we identified 493 NPM1 mutation-modulated MMR pairs, where the strength of MMR was significantly attenuated in patients carrying NPM1 mutations, compared to those with wild-type NPM1. These miRNAs/mRNAs were associated with pathways implicated in cancer and known functions of NPM1 mutation. Such modulation of MMR was validated in two independent cohorts as well as in cells with different NPM1 mutant burdens. Furthermore, we showed that the regulatory strength of nine MMR pairs could predict patients' outcomes. Combining these pairs, a scoring system was proposed and shown to predict survival in discovery and validation data sets, independent of other known prognostic factors. Our study provides novel biological insights into the role of NPM1 mutation as a modulator of MMR, based on which a novel prognostic marker is proposed in AML.


Subject(s)
Leukemia, Myeloid, Acute/genetics , MicroRNAs/analysis , Mutation , Nuclear Proteins/genetics , RNA, Messenger/analysis , Cell Line, Tumor , Humans , Leukemia, Myeloid, Acute/mortality , Nucleophosmin , Prognosis
15.
Cell Death Dis ; 6: e1642, 2015 Feb 12.
Article in English | MEDLINE | ID: mdl-25675302

ABSTRACT

Human Lon protease is a mitochondrial matrix protein with several functions, including protein degradation, mitochondrial DNA (mtDNA) binding, and chaperone activity. Lon is currently emerging as an important regulator of mitochondria-contributed tumorigenesis due to its overexpression in cancer cells. To understand the mechanism of increased Lon in tumor cells, we studied the interactome to identify the chaperone Lon-associated proteins by proteomics approaches using the cells overexpressing Lon. In the present study, we designed a method connecting co-immunoprecipitation (Co-IP) to in-solution digestion for the shotgun mass spectrometry. We identified 76 proteins that were putative Lon-associated proteins that participated in mitochondrial chaperone system, cellular metabolism and energy, cell death and survival, and mtDNA stability. The association between Lon and NDUFS8 or Hsp60-mtHsp70 complex was confirmed by Co-IP and immunofluorescence co-localization assay. We then found that the protein stability/level of Hsp60-mtHsp70 complex depends on the level of Lon under oxidative stress. Most importantly, the ability of increased Lon-inhibited apoptosis is dependent on Hsp60 that binds p53 to inhibit apoptosis. These results suggest that the mechanism underlying cell survival regulated by Lon is mediated by the maintenance of the protein stability of Hsp60-mtHsp70 complex. This new knowledge of chaperone Lon interactome will allow us to better understand the cellular mechanism of Lon in mitochondrial function and of its overexpression in enhancing cell survival and tumorigenesis.


Subject(s)
Chaperonin 60/metabolism , HSP70 Heat-Shock Proteins/metabolism , Mitochondria/enzymology , Protease La/metabolism , Apoptosis , Blotting, Western , Cell Line , Cell Survival/genetics , Cell Survival/physiology , Computational Biology , Humans , Immunoprecipitation , Protein Binding , Tandem Mass Spectrometry
16.
Chem Commun (Camb) ; 51(13): 2562-4, 2015 Feb 14.
Article in English | MEDLINE | ID: mdl-25567112

ABSTRACT

Supramolecular electrets consisting of poly(4-vinylpyridine) (P4VP) and conjugated molecules of phenol, 2-naphthol and 2-hydroxyanthracene were investigated for non-volatile transistor memory applications. The memory windows of these supramolecular electret devices were significantly enhanced upon increasing the π-conjugation size of the molecule. A high ON/OFF current ratio of more than 10(7) over 10(4) s was achieved on the supramolecule based memory devices.

17.
Tech Coloproctol ; 19(2): 111-5, 2015 Feb.
Article in English | MEDLINE | ID: mdl-25560967

ABSTRACT

BACKGROUND: It could be helpful to ascertain which patients are at risk of poor bowel preparation prior to performing sedated colonoscopy. The aim of the present study was to identify the predictive factors for poor colon preparation prior to colonoscopy. METHODS: A prospective study was performed at Kaohsiung Chang Gung Memorial Hospital, Taiwan, from September 2011 to May 2013. Patient characteristics, food consumed within 2 days of colonoscopy, volume of polyethylene glycol (PEG) solution, interval between completing PEG and examination, number of bowel movements, and character of the last stool were evaluated. RESULTS: Seven hundred and three patients were enrolled (mean age 50.3 ± 11.6 years, 43 % female). In univariate analysis, character of the last stool (<0.001), body weight (p = 0.007), body mass index (p = 0.047), waist circumference (p = 0.008), buttock girth (p = 0.016), meal residue score (<0.001), and interval between end of PEG and colonoscopy (p = 0.01) were related to inadequate colon preparation. In multivariate analysis, waist circumference (p < 0.001), meal residue score (p < 0.001), and characteristics of last stool (p < 0.001) were variables that predicted poor colon preparation. CONCLUSIONS: Patients who have consumed a high residue diet and/or who report that their last stool is semisolid are likely to have poor bowel preparation, and consideration could be given to rescheduling the examination.


Subject(s)
Colonoscopy , Preoperative Care/standards , Adult , Analysis of Variance , Cathartics/administration & dosage , Defecation , Diet/adverse effects , Eating , Feces/chemistry , Female , Humans , Male , Middle Aged , Polyethylene Glycols/administration & dosage , Preoperative Care/methods , Preoperative Care/statistics & numerical data , Prospective Studies , Risk Factors , Taiwan , Time Factors
18.
Leukemia ; 29(5): 1051-9, 2015 May.
Article in English | MEDLINE | ID: mdl-25428263

ABSTRACT

As a highly heterogeneous disease, acute myeloid leukemia (AML) needs fine risk stratification to get an optimal outcome of patients. MicroRNAs have florid biological functions and have critical roles in the pathogenesis and prognosis in AML. Expression levels of some single microRNAs are influential for prognosis, but a system integrating several together and considering the weight of each should be more powerful. We thus analyzed the clinical, genetic and microRNA profiling data of 138 de novo AML patients of our institute. By multivariate analysis, we identified that high expression of hsa-miR-9-5p and hsa-miR-155-5p were independent poor prognostic factors, whereas that of hsa-miR-203 had a trend to be a favorable factor. We constructed a scoring system from expression of these three microRNAs by considering the weight of each. The scores correlated with distinct clinical and biological features and outperformed single microRNA expression in prognostication. In both ours and another validation cohort, higher scores were associated with shorter overall survival, independent of other well-known prognostic factors. By analyzing the mRNA expression profiles, we sorted out several cancer-related pathways highly correlated with the microRNA prognostic signature. We conclude that this 3-microRNA scoring system is simple and powerful for risk stratification of de novo AML patients.


Subject(s)
Gene Expression Regulation, Leukemic , Leukemia, Myeloid, Acute/diagnosis , MicroRNAs/metabolism , Adolescent , Adult , Aged , Aged, 80 and over , Chromosome Aberrations , Cohort Studies , Cytogenetics , DNA Mutational Analysis , Female , Gene Expression Profiling , Humans , Leukemia, Myeloid, Acute/metabolism , Male , Microarray Analysis , Middle Aged , Multivariate Analysis , Prognosis , Proportional Hazards Models , Real-Time Polymerase Chain Reaction , Regression Analysis , Young Adult
19.
Lett Appl Microbiol ; 56(1): 1-7, 2013 Jan.
Article in English | MEDLINE | ID: mdl-23020241

ABSTRACT

UNLABELLED: Naegleria spp. is a free-living amoeba that can be found in the natural environment. A number of Naegleria spp. can cause fatal infections in the central nervous system in humans and animals, and the most important source of infection is through direct water contact. In this study, water samples from various thermal springs were taken from four thermal spring areas. Naegleria spp. was detected via culture confirmation and molecular taxonomic identification. Among the 60 samples obtained, Naegleria spp. was identified in 26 (43·3%) samples. The identified species included Naegleria australiensis, Naegleria gruberi, Naegleria lovaniensis and Naegleria mexicana. The presence of living Naegleria spp. was significantly associated with elevated pH value in the water sample. SIGNIFICANCE AND IMPACT OF STUDY: In this study, we examined the presence of living Naegleria spp. in thermal spring waters in south-eastern Taiwan. Naegleria spp. was isolated and culture-confirmed from thermal spring water. Naegleria fowleri was not found in all water samples, and Naegleria australiensis was the most common Naegleria genotype.


Subject(s)
Hot Springs/parasitology , Naegleria/isolation & purification , Water/parasitology , Hydrogen-Ion Concentration , Naegleria/genetics , Phylogeny , Polymerase Chain Reaction , Sequence Analysis, DNA , Taiwan , Water/chemistry , Water Quality
20.
Diabetologia ; 55(12): 3252-61, 2012 Dec.
Article in English | MEDLINE | ID: mdl-22930160

ABSTRACT

AIMS/HYPOTHESIS: Sympathetic nerves influence islet hormone levels in the circulation. Insights into islet sympathetic innervation and its remodelling in diabetes may impact future therapeutics. However, standard immunohistochemistry and microtome-based microscopy cannot provide an integral view of the islet neurovascular complex. We prepared transparent islet specimens to investigate the spatial relationship between sympathetic nerves, blood vessels and islet cells in normal, streptozotocin-injected and non-obese diabetic mouse models. METHODS: Cardiac perfusion of fluorescent lectin was used to label pancreatic blood vessels. Tyrosine hydroxylase and nuclear staining were used to reveal islet sympathetic innervation and microstructure. Optical clearing (i.e. use of immersion solution to reduce scattering) was applied to enable 3-dimensional confocal microscopy of islets to visualise the sympathetic neurovascular complex in space. RESULTS: Unlike previously reported morphology, we observed perfusive intra-islet, perivascular sympathetic innervation, in addition to peri-islet contacts of sympathetic nerves with alpha cells and sympathetic fibres encircling the adjacent arterioles. The intra-islet axons became markedly prominent in streptozotocin-injected mice (2 weeks after injection). In non-obese diabetic mice, lymphocytic infiltration remodelled the peri-islet sympathetic axons in early insulitis. CONCLUSIONS/INTERPRETATION: We have established an imaging approach to reveal the spatial features of mouse islet sympathetic innervation. The neurovascular complex and sympathetic nerve-alpha cell contact suggest that sympathetic nerves modulate islet hormone secretion through blood vessels, in addition to acting directly on alpha cells. In islet injuries, sympathetic nerves undergo different remodelling in response to different pathophysiological cues.


Subject(s)
Diabetes Mellitus, Experimental/pathology , Imaging, Three-Dimensional , Islets of Langerhans/innervation , Islets of Langerhans/pathology , Pancreas/pathology , Sympathetic Nervous System/pathology , Animals , Female , Mice , Ventricular Remodeling
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