289 research outputs found
A common origin of complex life cycles in parasitic flatworms: evidence from the complete mitochondrial genome of Microcotyle sebastis (Monogenea: Platyhelminthes)
BACKGROUND: The parasitic Platyhelminthes (Neodermata) contains three parasitic groups of flatworms, each having a unique morphology, and life style: Monogenea (primarily ectoparasitic), Trematoda (endoparasitic flukes), and Cestoda (endoparasitic tapeworms). The evolutionary origin of complex life cyles (multiple obligate hosts, as found in Trematoda and Cestoda) and of endo-/ecto-parasitism in these groups is still under debate and these questions can be resolved, only if the phylogenetic position of the Monogenea within the Neodermata clade is correctly estimated. RESULTS: To test the interrelationships of the major parasitic flatworm groups, we estimated the phylogeny of the Neodermata using complete available mitochondrial genome sequences and a newly characterized sequence of a polyopisthocotylean monogenean Microcotyle sebastis. Comparisons of inferred amino acid sequences and gene arrangement patterns with other published flatworm mtDNAs indicate Monogenea are sister group to a clade of Trematoda+Cestoda. CONCLUSION: Results confirm that vertebrates were the first host for stem group neodermatans and that the addition of a second, invertebrate, host was a single event occurring in the Trematoda+Cestoda lineage. In other words, the move from direct life cycles with one host to complex life cycles with multiple hosts was a single evolutionary event. In association with the evolution of life cycle patterns, our result supports the hypothesis that the most recent common ancestor of the Neodermata giving rise to the Monogenea adopted vertebrate ectoparasitism as its initial life cycle pattern and that the intermediate hosts of the Trematoda (molluscs) and Cestoda (crustaceans) were subsequently added into the endoparasitic life cycles of the Trematoda+Cestoda clade after the common ancestor of these branched off from the monogenean lineage. Complex life cycles, involving one or more intermediate hosts, arose through the addition of intermediate hosts and not the addition of a vertebrate definitive host. Additional evidence is required from monopisthocotylean monogeneans in order to confirm the monophyly of the group
Long-term Results of Primary Total Knee Arthroplasty with and without Patellar Resurfacing
Among patients that underwent total knee arthroplasty from June, 1990 to January, 1999, 61 cases (44 patients) that could be followed for more than 10 years were included in this study. The patients were divided into a patellar retention group and a patellar resurfacing group, and were compared with regard to their clinical and radiological outcomes. In patients undergoing primary TKA, a selective patellar resurfacing protocol was used. The indications for patellar retention were a small patella, nearly normal articular cartilage, minimal preoperative patellofemoral pain, poor patellar bone quality, and young patient age. When patellar retention was performed, osteophytes of the patella were removed and marginal electrocauterization was carried out. There were 25 cases (20 patients) in the patellar retention group and 36 cases (29 patients) in the patellar resurfacing group. The mean follow-up period was 140.7 months in the patellar retention group and 149.0 months in the patellar resurfacing group. The selective patellar resurfacing with total knee arthroplasty had a favorable outcome;there were a significant difference noted between the 2 groups in the functional scores, which showed better outcomes in the patellar resurfacing group than in the patellar retention group
Clinical Outcomes of Silk Patch in Acute Tympanic Membrane Perforation
ObjectivesThe silk patch is a thin transparent patch that is produced from silk fibroin. In this study, we investigated the treatment effects of the silk patch in patients with traumatic tympanic membrane perforation (TTMP).MethodsThe closure rate, otorrhea rate, and closure time in all patients and the closure time in successful patients were compared between the paper patch and silk patch groups.ResultsDemographic data (gender, site, age, traumatic duration, preoperative air-bone gap, and perforation size and location) were not significantly different between the two groups. The closure rate and otorrhea rate were not significantly different between the two groups. However, the closure time was different between the two groups (closure time of all patients, P=0.031; closure time of successful patients, P=0.037).ConclusionThe silk patch which has transparent, elastic, adhesive, and hyper-keratinizing properties results in a more efficient closure time than the paper patch in the treatment of TTMP patients. We therefore believe that the silk patch should be recommended for the treatment of acute tympanic membrane perforation
Outcomes of adjunctive surgery for nontuberculous mycobacterial pulmonary disease
Background
Owing to the unsatisfactory results of antibiotic treatment alone, surgical resection is currently considered as adjunctive therapy in patients with nontuberculous mycobacterial pulmonary disease (NTM-PD). However, reports regarding the outcomes of surgery vary considerably by institution. Here, we investigated the surgical outcomes and risk factors associated with unfavorable outcomes after surgery.
Methods
We analyzed patients with NTM-PD who underwent pulmonary resection at Seoul National University Hospital between January 1, 2006, and December 31, 2020, and assessed the types of surgical procedures, complications, and long-term outcomes. Multivariate logistic regression analysis was used to identify the risk factors associated with treatment refractoriness or recurrence after surgery.
Results
Among 67 patients who underwent surgery during the study period, the most common indication for surgery was persistent culture positivity despite rigorous medical treatment (80.6%), followed by longstanding cavitary lesions or radiographic aggravation (10.4%) and massive hemoptysis (4.5%). Among 53 patients with positive mycobacterial cultures at the time of surgery, 38 (71.7%) achieved initial negative culture conversion, 9 (17.0%) of whom experienced recurrence. Nine (13.4%) patients experienced postoperative complications, which were managed without lasting morbidity and mortality. Female sex (adjusted odds ratio [aOR] 6.63; 95% confidence interval [CI] 1.04–42.4; P = .046), preoperative positive mycobacterial culture (aOR 5.87; 95 %CI 1.04–33.08; P = .045), and residual lesions (aOR 6.86; 95 %CI 1.49–31.56; P = .013) were associated with refractoriness or recurrence.
Conclusions
Pulmonary resection is a reasonable treatment modality for patients with refractory NTM-PD or major complications such as massive hemoptysis. The potential risk factors associated with unfavorable outcomes included female sex, preoperative positive mycobacterial culture, and residual lesions after surgery
Pure Red Cell Aplasia Caused by Acute Hepatitis A
Pure red cell aplasia is characterized as a normocytic anemia associated with reticulocytopenia and the absence of erythroblasts in the bone marrow. Pure red cell aplasia can be induced by various causes such as thymoma, connective tissue disease, viral infection, lymphoma, and adverse drug reactions. There have been only a few reports of pure red cell aplasia associated with acute viral hepatitis A. In Korea, no case of pure red cell aplasia caused by acute hepatitis A has yet been reported. We recently experienced a case of acute viral hepatitis A complicated by pure red cell aplasia. The patient was successfully treated with corticosteroids. Here we report this case and review the literature
The Relation between Anger Management Style and Organ System-Related Somatic Symptoms in Patients with Depressive Disorders and Somatoform Disorders
PURPOSE: The objective of this study was to examine the relation between anger management style and organ system- related somatic symptoms in depressive disorder and somatoform disorder patients.
MATERIALS AND METHODS: The subjects included 73 patients with depressive disorders and 47 with somatoform disorders. Anger management styles were assessed by the Anger Expression Scale, while the severity of organ system-related somatic symptoms was evaluated using the Somatic Stress Response Scale (SSRS). The severity of depression and hostility was assessed by the Symptom Checklist-90-Revised (SCL-90-R) depression and hostility subscales.
RESULTS: The results of multiple regression analyses showed that, in depressive disorder patients, the level of anger expression was significantly associated with the severity of somatic symptoms related to neuromuscular, cardiorespiratory and gastrointestinal systems. However, in these patients, the level of anger suppression was not significantly associated with the severity of somatic symptoms related to any specific organ systems. In patients with somatoform disorders, there was no significant association between the level of anger suppression or anger expression and the severity of the somatic symptoms related to any specific organ systems.
CONCLUSION: These results suggest that, in depressive disorder patients, anger expression is likely to be predominantly involved in the neuromuscular, cardiorespiratory and gastrointestinal organ systems. However, in each of depressive disorder and somatoform disorder patients, anger suppression is not likely to be associated with any specific organ systems.ope
Development of the Somatic Stress Response Scale and Its Application in Clinical Practice
The objective of this study was to develop the Somatic Stress Response Scale (SSRS), and then to use the scale in clinical practice. A preliminary survey was conducted using 109 healthy adults to obtain somatic stress responses. Then, 215 healthy subjects completed a preliminary questionnaire. A comparison was made regarding the somatic stress responses among 191 patients (71 with anxiety disorders, 73 with depressive disorders and 47 with somatoform disorders) and 215 healthy subjects. Factor analysis of the SSRS yielded five subscales: the cardiorespiratory response, somatic sensitivity, gastrointestinal response, general somatic response and genitourinary response subscales. The test-retest reliability for the five subscales and the total score was significantly high, ranging from .86 to .94. The Cronbach's α for the five subscales ranged from .72 to .92, and was .95 for the total score. By correlating the five subscales and the total score of the SSRS with the somatization subscale scores of the Symptom Checklist-90-Revised (SCL-90-R), convergent validity was calculated. The correlations were all at significant levels. Each of the disorder groups was significantly higher in scores of the cardiorespiratory response, gastrointestinal response, general somatic response and genitourinary response subscale, and in the total SSRS score than the healthy group. Only the depressive disorder group scored significantly higher on the somatic sensitivity subscale than the healthy group, and they also scored significantly higher on the genitourinary response subscale than the anxiety disorder group did. These results suggest that the SSRS is highly reliable and valid, and that it can be effectively utilized as a measure for research of the somatic symptoms related to stress. It also implies that somatic sensitivity and genitourinary responses are associated with depressive disorders
In vitro photodynamic therapy of methylene blue-loaded acetyl resistant starch nanoparticles
Background : Combination therapies comprising multiple methods, such as photodynamic therapy have been applied to be complements chemotherapy as they increase the therapeutic efficiency by enabling the intelligent drug delivery to target sites by exposing the photosensitizer to light and activating it in the tumor tissue. This study evaluated in vitro photodynamic therapy of methylene blue (MB)-loaded acetyl resistant starch (ARS) nanoparticles (NPs).
Methods : ARS was synthesized by the reaction between resistant starch (RS) and acetic anhydride. MB-loaded ARS NPs and ARS NPs were prepared by a single emulsion method. Synthesized ARS was measured by NMR. Prepared ARS NPs and MB-loaded ARS NPs were characterized by transmission electron microscopy (TEM), dynamic light scattering (DLS), X-ray diffraction, UV/Vis, and circular dichroism (CD). MB-loaded ARS NPs were treated in mouse colon cancer cells (CT-26) and they were treated under near-infrared (NIR) laser irradiation.
Results : Synthesis of ARS was confirmed by NMR and the degree of substitutions in the ARS was 7.1. The morphologies of ARS NPs observed by TEM were spherical shapes and the particle sizes of ARS NPs were 173.4 nm with a surface charge of − 17.24 mV. The d-spacing of ARS NPs was smaller than those of RS and the conformational changes of RS occurred by the formation of self-assembled polymeric NPs with induction of CD of the MB by chiral ARS NPs. The phototoxicity of CT-26 cells treated by MB-loaded ARS NPs dramatically decreased in a dose-dependent manner under NIR laser irradiation compared to free MB.
Conclusion : This study demonstrated the ordered nanosized structures in the ARS NPs and conformational change from random coil structure of RS to alpha-helices one of ARS occurred and CD of the achiral MB was induced. The MB-loaded ARS NPs showed a higher generation of reactive oxygen species (ROS) in the CT-26 cells than free MB with the NIR laser irradiation and resulting in phototoxicity under irradiation.This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (NRF-2020R111A1A01053275)
Occurrence of microplastics in municipal sewage treatment plants: a review
Municipal sewage treatment plants (STPs) are thought to be important point sources of microplastics in freshwater systems and many peer-reviewed articles have been published on this issue since mid-2010s. In this review, we summarize existing literature on the occurrence of microplastics in STPs and experimental methods used for isolation and identification of microplastics. The number concentrations of microplastics in STP influents were 15.1-640 L-1, whereas those in the STP effluents were highly variable and ranged from not detectable to 65 L-1. For most of cases, conventional STPs are removing microplastics very effectively. Fragments and fibers are dominant shapes of microplastics. Thermoplastics (polyethylene and polypropylene) and polyester are the predominant materials recovered. Although further research is needed, size distribution of microplastics in STPs is likely to follow a power law, implying that different studies using different size cutoffs may be compared after establishing a power law relationship
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