To understand the injury pattern of contact burns from therapeutic physical modalities.
A retrospective study was done in 864 patients with contact burns who discharged from our hospital from January 2005 to December 2008. The following parameters were compared between patients with contact burns from therapeutic modalities and from other causes: general characteristics, burn extent, cause of burn injury, place of occurrence, burn injury site, treatment methods, prevalence of underlying disease, and length of hospital stay were compared between patients with contact burns.
Of the 864 subjects, 94 patients were injured from therapeutic modalities. A hot pack (n=51) was the most common type of therapeutic modality causing contact burn followed by moxibustion (n=21), electric heating pad (n=16), and radiant heat (n=4). The lower leg (n=31) was the most common injury site followed by the foot & ankle (n=24), buttock & coccyx (n=9), knee (n=8), trunk (n=8), back (n=6), shoulder (n=4), and arm (n=4). Diabetes mellitus was associated with contact burns from therapeutic modalities; the odds ratio was 3.99. Injuries took place most commonly at home (n=56), followed by the hospital (n=33), and in other places (n=5).
A hot pack was the most common cause of contact burns from therapeutic modalities, and the lower leg was the most common injury site. Injuries took place most commonly at home. The patients with contact burns from therapeutic modalities showed high correlation to presence of diabetes mellitus. These results would be helpful for the prevention of contact burns due to therapeutic modalities.
Burns; Physical therapy modalities; Diabetes mellitus
Spontaneous intracranial hypotension (SIH), typically presents with orthostatic headache, low pressure on lumbar tapping, and diffuse pachymeningeal enhancement on magnetic resonance imaging. SIH is often accompanied by subdural fluid collections, which in most cases responds to conservative treatment or spinal epidural blood patch. Several authors advocate that large subdural hematoma with acute deterioration merits surgical drainage; however, few have reported complications following craniotomy. We describe a complicated case of SIH, which was initially diagnosed as acute subarachnoid hemorrhage with bilateral chronic subdural hematoma (SDH), due to unusual presentation. Burr hole drainage of subdural hematoma was performed due to progressive decrease of consciousness, which then resulted in a huge postoperative epidural hematoma collection. Prompt hematoma evacuation did not restore the patient's consciousness but aggravated downward brain herniation. Trendelenburg position and spinal epidural blood patch achieved a rapid improvement in patient's consciousness. This case indicates that the surgical drainage for chronic SDH in SIH can lead to serious complications and it should be cautiously considered.
Chronic subdural hematoma; craniotomy; spontaneous intracranial hypotension; subarachnoid hemorrhage
Compared to the past decades, in recent decades, environmental and hygienic conditions in the Republic of Korea have improved along with socioeconomic developments, and the incidence of most infectious diseases, especially vaccine-preventable diseases, has greatly decreased due to active immunization with the developed level of health care. However, the incidence of some diseases has been increasing, and new diseases have been emerging. To cope with such changes actively, the government put the "Law for Control and Prevention of Infectious Diseases" into effect; this law was entirely revised on December 30, 2010. In this report, I review the past and recent status of infectious diseases in the Republic of Korea, following the introduction of this law, on the basis of data in the "National Notifiable Disease Surveillance System", which had been accumulated between the years 1960 and 2010.
Infectious diseases; Prevention and control; Child; Adolescent; Disease surveillance system; Korea
Inhalation injury is one of the most severe morbidity and mortality factors in burn patients. The purpose of this study is to analyze the impact of inhalation injury to the prognosis of burn patients and to investigate the relationship between the inhalation injury assessment and the prognosis of patients.
Bronchoscopy was performed in 170 patients who had the suspicion of inhalation injury and the patients were reviewed retrospectively from January 2008 to December 2009. Mortality was compared between the factors of brochoscopic findings, age, total body surface area (TBSA) burned, carboxyhemoglobin (COHb) level, PaO2/FiO2 (P/F) ratio.
Of 170 patients, 28 patients had no inhalation bronchoscopic finding. 109 patients had mild inhalation, 31 patients had moderate inhalation, only 2 patients had severe inhalation findings. The patients of moderate and severe inhalation findings had higher mortality (48.5%) than mild inhalation patients (31.1%). The larger total burnsurface area in inhalation patients, the greater the mortality. When compared to total admitted burn patients during the same period, inhalation patients showed higher mortality in the patients between 10 to 40% total burn surface area. Inhalation patients whose P/F ratio was below 300 showed higher mortality than above 300. But inhalation patients whose COHb level was below 1.5 had no difference in mortality with patients above 1.5. The COHb level and P/F ratio was the statistically different factors between inhalation patients and non-inhalation group in the mortality.
Bronchoscopic findings, age, TBSA burned, P/F ratio were related with mortality in inhalation patients. When the international standardization of bronchoscopic classification developed, it can be possible to assess the inhalation patients more objectively and that will lead to the advancement in inhalation treatment and research.
Inhalation injury assessment; Prognosis; Burn patients
Xanthium stramarium (XAS) and Psoralea corylifolia (PSC), phototoxic oriental medicinal plants, has been used in traditional medicines in Asian countries.
The effects of highly purified XAS or PSC extract combined with ultraviolet A1 (UVA1) irradiation on cell proliferation and transforming growth factor-beta1 (TGF-β1) expression of the keloid fibroblast were being investigated to define potential therapeutic uses for keloid treatments.
The keloid fibroblasts were treated with XAS or PSC alone or in the combination with UVA1 irradiation. The cell viability, apoptosis, and expression of TGF-β1 and collagen I were investigated.
XAS and PSC in combination with UVA1 irradiation suppressed cell proliferation and induced apoptosis of keloid fibroblasts. Furthermore, the XAS and PSC in combination with UVA1 irradiation inhibited TGF-β1 expression and collagen synthesis in keloid fibroblasts.
These findings may open up the possibility of clinically used XAS or PSC in combination with UVA1 irradiation for keloid treatments.
Apoptosis; Keloid; Psoralea corylifolia; Transforming growth factor-beta 1; Xanthium stramarium
This article contains the recommended immunization schedule by the Committee on Infectious Diseases of the Korean Pediatric Society, updated in March 2013, when Haemophilus influenzae type b vaccine is now included in the National Immunization Program in Korea. It also includes catch-up immunization schedule for children and adolescents who are behind the recommended schedule. These schedules are a minor revision of the corresponding parts of Immunization Guideline, 7th edition, of the Korean Pediatric Society, released in 2012. Pediatricians should be aware of these schedules to provide adequate immunization to Korean children and adolescents.
Immunization Schedule; Infant; Child; Adolescent
This phase II clinical trial was conducted to compare the immunogenicity and safety of a newly developed tetanus-reduced diphtheria (Td) vaccine (GC1107-T5.0 and GC1107-T7.5) and control vaccine. This study was also performed to select the proper dose of tetanus toxoid in the new Td vaccines. Healthy adolescents aged between 11 and 12 yr participated in this study. A total of 130 subjects (44 GC1107-T5.0, 42 GC1107-T7.5 and 44 control vaccine) completed a single dose of vaccination. Blood samples were collected from the subjects before and 4 weeks after the vaccination. In this study, all subjects (100%) in both GC1107-T5.0 and GC1107-T7.5 groups showed seroprotective antibody levels (≥ 0.1 U/mL) against diphtheria or tetanus toxoids. After the vaccination, the geometric mean titer (GMT) against diphtheria was significantly higher in Group GC1107-T5.0 (6.53) and GC1107-T7.5 (6.11) than in the control group (3.96). The GMT against tetanus was 18.6 in Group GC1107-T5.0, 19.94 in GC1107-T7.5 and 19.01 in the control group after the vaccination. In this study, the rates of local adverse reactions were 67.3% and 59.1% in GC1107-T5.0 and GC1107-7.5, respectively. No significant differences in the number of adverse reactions, prevalence and degree of severity of the solicited and unsolicited adverse reactions were observed among the three groups. Thus, both newly developed Td vaccines appear to be safe and show good immunogenicity. GC1107-T5.0, which contains relatively small amounts of tetanus toxoid, has been selected for a phase III clinical trial.
Tetanus-Reduced Diphtheria (Td) Vaccine; Immunogenicity; Safety
Wilson disease (WD) is an autosomal recessive disorder of copper transport caused by alteration of the adenosine triphosphatase 7B gene. It is rare to diagnose WD below the age of three years. Molecular genetic testing is one of the most important diagnostic methods and may confirm the diagnosis in equivocal cases. We report a case of a 9-mo old boy with WD who presented as chronic hepatitis. Genetic analysis showed compound heterozygotes of p.G1186S and c.4006delA.
Hepatolenticular degeneration; Wilson disease; Early diagnosis; Molecular genetics; Mutation
In 2009, the first outbreak of hand, foot and mouth disease (HFMD) or herpangina (HP) caused by enterovirus 71 occurred in the Republic of Korea. This study inquired into risk factors associated with complications of HFMD or HP. A retrospective medical records review was conducted on HFMD or HP patients for whom etiologic viruses had been verified in 2009. One hundred sixty-eight patients were examined for this investigation. Eighty patients were without complications while 88 were accompanied by complications, and 2 had expired. Enterovirus 71 subgenotype C4a was the most prevalent in number with 67 cases (54.9%). In the univariate analysis, the disease patterns of HFMD rather than HP, fever longer than 4 days, peak body temperature over 39℃, vomiting, headache, neurologic signs, serum glucose over 100 mg/dL, and having an enterovirus 71 as a causative virus were significant risk factors of the complications. After multiple logistic analysis, headache (Odds ratio [OR], 10.75; P < 0.001) and neurologic signs (OR, 42.76; P < 0.001) were found to be the most significant factors. Early detection and proper management of patients with aforementioned risk factors would be necessary in order to attain a better clinical outcome.
Coxsackievirus; Hand, Foot and Mouth Disease; Herpangina; Enterovirus A, Human; Risk Factors
A recent resurgence of pertussis has raised public health concerns even in developed countries with high vaccination coverage. The aim of this study was to describe the clinical characteristics of infant pertussis, and to determine the relative importance of household transmission in Korea. The multicenter study was prospectively conducted from January 2009 to September 2011. We identified the demographic and clinical data from these patients and performed the diagnostic tests for pertussis in their household contacts. Twenty-one patients with confirmed pertussis were included in the analysis. All infections occurred in infants younger than 6 months of age (mean age, 2.5 months) who had not completed the primary DTaP vaccination except for one patient. Infants without immunization history had a significant higher lymphocytosis and longer duration of hospital stay compared to those with immunization. All were diagnosed with PCR (100%), however, culture tests showed the lowest sensitivity (42.9%). Presumed source of infection in household contacts was documented in 85.7%, mainly parents (52.6%). Pertussis had a major morbidity in young infants who were not fully immunized. Household members were responsible for pertussis transmission of infants in whom a source could be identified. The control of pertussis through booster vaccination with Tdap in family who is taking care of young infants is necessary in Korea.
Pertussis; Infant; Epidemiology; Transmission
To determine which drug-eluting stents are more effective in acute myocardial infarction (MI) patients with chronic kidney disease (CKD).
This study included a total of 3,566 acute MI survivors with CKD from the Korea Acute Myocardial Infarction Registry who were treated with stenting and followed up for 12 months: 1,845 patients who received sirolimus-eluting stents (SES), 1,356 who received paclitaxel-eluting stents (PES), and 365 who received zotarolimus-eluting stents (ZES). CKD was defined as an estimated glomerular filtration rate < 60 mL/min/1.73 m2 calculated by the modification of diet in renal disease method.
At the 12-month follow-up, patients receiving ZES demonstrated a higher incidence (14.8%) of major adverse cardiac events (MACEs) compared to those receiving SES (10.1%) and PES (12%, p = 0.019). The ZES patients also had a higher incidence (3.9%) of target lesion revascularization (TLR) compared to those receiving SES (1.5%) and PES (2.4%, p = 0.011). After adjusting for confounding factors, ZES was associated with a higher incidence of MACE and TLR than SES (adjusted hazard ratio [HR], 0.623; 95% confidence interval [CI], 0.442 to 0.879; p = 0.007; adjusted HR, 0.350; 95% CI, 0.165 to 0.743; p = 0.006, respectively), and with a higher rate of TLR than PES (adjusted HR, 0.471; 95% CI, 0.223 to 0.997; p = 0.049).
Our findings suggest that ZES is less effective than SES and PES in terms of 12-month TLR, and has a higher incidence of MACE due to a higher TLR rate compared with SES, in acute MI patients with CKD.
Myocardial infarction; Renal insufficiency; Chronic; Stents
The enhanced migration found in tumor cells is often caused by external stimuli and the sequential participation of cytoskeleton-related signaling molecules. However, until now, the molecular connection between the lysophosphatidic acid (LPA) receptor and nonmuscle myosin II (NM II) has not been analyzed in detail for LPA-induced migration. Here, we demonstrate that LPA induces migration by activating the LPA1 receptor which promotes phosphorylation of the 20kDa NM II light chain through activation of Rho kinase (ROCK). We show that LPA-induced migration is insensitive to pertussis toxin (PTX) but does require the LPA1 receptor as determined by siRNA and receptor antagonists. LPA activates ROCK and also increases GTP-bound RhoA activity, concomitant with the enhanced membrane recruitment of RhoA. LPA-induced migration and invasion are attenuated by specific inhibitors including C3 cell-permeable transferase and Y-27632. We demonstrate that NM II plays an important role in LPA-induced migration and invasion by inhibiting its cellular function with blebbistatin and shRNA lentivirus directed against NM II-A or II-B. Inhibition or loss of either NM II-A or NM II-B in 4T1 cells results in a decrease in migration and invasion. Restoration of the expression of NM II-A or NM II-B also rescued LPA-induced migration. Taken together, these results suggest defined pathways for signaling through the LPA1 receptor to promote LPA-mediated NM II activation and subsequent cell migration in 4T1 breast cancer cells.
Nonmuscle myosin II; LPA receptor; phosphorylation; migration
Hepatitis A virus is one of the most prominent causes of fecally transmitted acute hepatitis worldwide. In order to characterize the viral agents causing an outbreak in Korea (comprising North and South Korea) from June 2007 to May 2009, we collected specimens and performed genotyping of the VP1/P2A and VP3/VP1 regions of hepatitis A virus. We then used a multiple-alignment algorithm to compare the nucleotide sequences of the 2 regions with those of reference strains. Hepatitis A virus antibodies were detected in 64 patients from 5 reported outbreaks (North Korea, June 2007 [n = 11]; Jeonnam, April 2008 [n = 15]; Daegu, May 2008 [n = 13]; Seoul, May 2009 [n = 22]; and Incheon, May 2009 [n = 3]). We found 100% homology between strains isolated from the Kaesong Industrial Region and Jeonnam. While those strains were classified as genotype IA strains, strains from Seoul and Incheon were identified as genotype IIIA strains and showed 98.9 to 100% homology. Genotype IIIA was also dominant in Daegu, where strains were 95.7 to 100% homologous. All hepatitis A virus strains isolated from the Kaesong Industrial Region, Jeonnam, Seoul, and Incheon belonged to a single cluster. However, strains from Daegu could be classified into 2 clusters, suggesting that the outbreak had multiple sources. This study indicates that hepatitis A virus strains of 2 different genotypes are currently cocirculating in Korea. Moreover, it documents an increasing prevalence of genotype IIIA strains in the country.
Modified charcoal-cefoperazone-deoxycholate agar (mCCDA) was improved by supplementation with a high concentration of polymyxin B. The ability of the supplemented medium to isolate Campylobacter jejuni and C. coli from chicken carcass rinses was compared to that of Campy-Cefex agar and mCCDA. Modification of mCCDA with increased polymyxin B yielded a significantly (P < 0.05) higher isolation rate and greater selectivity than those achieved using Campy-Cefex agar and mCCDA.
Major burn injury induces an inflammatory response that is accompanied by the release of various cytokines. We investigated the gradual changes in the levels of pro-inflammatory and anti-inflammatory cytokines following burn injury and determined the relationship between these levels and burn size in adult Korean patients with burn injury.
Blood samples from 9 healthy controls and 60 Korean burn patients were collected on days 1, 3, 7, 14, and 21 after burn injury, and concentrations of interleukin (IL)-6, IL-8, IL-10, tumor necrosis factor (TNF)-α, and granulocyte-colony stimulating factor (G-CSF) were measured. Burn patients were divided into 3 groups according to burn size (15-30%, 31-50%, >50% total body surface area), and the concentrations of the cytokines were compared between these groups and the control group over 3 weeks.
Compared to their levels in controls, IL-6, IL-8, IL-10, TNF-α, and G-CSF levels in burn patients were significantly higher during the observation period. Median concentrations of IL-8, IL-10, and G-CSF at each time point increased with burn size, although peak levels and time to peak levels of these cytokines differed from patient to patient.
These findings indicate that IL-6, IL-8, IL-10, TNF-α, and G-CSF are important mediators in inflammatory changes after burn injury; however, various factors, including burn size, may influence the concentrations of these cytokines.
Burns; Cytokines; Body surface area; Time
Background and Objectives
Prehypertension according to JNC7 is common and is associated with increased vascular mortality. The importance of management in high-normal blood pressure (BP) is underemphasized.
Subjects and Methods
We analyzed major adverse cardiac events (MACEs) in the Korea Acute Myocardial Infarction Registry in normal BP (group I) and high-normal BP (group II) patients.
Among 14871 patients, 159 (61±12.3 years, 122 males) satisfied the study indication. Six-month and one-year clinical follow-up rate was 88.9% and 85.8%, respectively. Group I had 78 patients (60.9±12.4 years). Group II had 81 patients (61.6±12.5 years). Demographics of patients were not different between groups. Treatment strategy was not different. Initial Thrombolysis in Myocardial Infarction flow grade 0 was less frequent in group II (n=32, 47.1%) than in group I (n=16, 21.9%) (p=0.001). Successful intervention rate was not different between group II (93.8%) and group I (97.1%) (p=0.590). Six-month MACE occurred in 3 patients in group I (4.4%) and 10 in group II (15.6%) (p=0.031). Compared with normal BP, the odds ratio for patients with high-normal BP was 1.147 (p=0.045, 95% confidence interval 1.011-1.402) for 6-month MACE.
Even though high-normal BP patients had a better baseline clinical status, the prognosis was poorer than patients with normal BP. Therapeutic BP target goal for the patients with acute myocardial infarction should be <140/90 mm Hg, which is recommended in JNC7.
Blood pressure; Prognosis
The majority of Korean patients with pandemic influenza A (H1N1) during the 2009 epidemic were under 20 yr of age. The limited data on the clinical characteristics of these children led us to conduct a case note-based investigation of children admitted to 6 university hospitals with 2009 H1N1 influenza. A total of 804 children was enrolled. The median age was 5 yr; 63.8% were males; and 22.4% had at least one chronic underlying disease. Ninety-five of the patients (11.8%) were critically ill and they suffered more from shortness of breath, dyspnea and lymphopenia than the other patients. Among all the patients, 98.8% were treated with antivirals and 73% received treatment within 48 hr of illness onset. All the enrolled patients are alive and appear to have had good outcomes, probably due to the early intervention and antiviral treatment. This study deals with hospitalized children whose diagnoses of influenza A (H1N1) were confirmed, and therefore provides important new information about the clinical patterns of children with influenza A (H1N1) in Korea.
Pandemic Influenza A (H1N1); Children; Korea; Epidemiology; Clinical Characteristics
The aim of this study was to assess the prevalence of diabetes and to study the effects of excess growth hormone (GH) on insulin sensitivity and β-cell function in Korean acromegalic patients. One hundred and eighty-four acromegalic patients were analyzed to assess the prevalence of diabetes, and 52 naïve acromegalic patients were enrolled in order to analyze insulin sensitivity and insulin secretion. Patients underwent a 75 g oral glucose tolerance test with measurements of GH, glucose, insulin, and C-peptide levels. The insulin sensitivity index and β-cell function index were calculated and compared according to glucose status. Changes in the insulin sensitivity index and β-cell function index were evaluated one to two months after surgery. Of the 184 patients, 17.4% were in the normal glucose tolerance (NGT) group, 45.1% were in the pre-diabetic group and 37.5% were in the diabetic group. The insulin sensitivity index (ISI0,120) was significantly higher and the HOMA-IR was lower in the NGT compared to the diabetic group (P = 0.001 and P = 0.037, respectively). The ISI0,120 and disposition index were significantly improved after tumor resection. Our findings suggest that both insulin sensitivity and β-cell function are improved by tumor resection in acromegalic patients.
Insulin Resistance; Acromegaly
We report a patient who underwent gamma knife radiosurgery to treat recurrent meningioma after microsurgery and thereafter developed secondary malignancy adjacent to the original tumor. A 47-year-old woman had underwent resection of the olfactory groove meningioma. Then radiosurgery was done three times over 4 year period for the recurrent tumor. After 58 months from the initial radiosurgery, she presented with headache and progressive mental dullness. Huge tumor in bifrontal location was revealed in MRI. Subsequent operation and pathological examination confirmed diagnosis of glioblastoma. This case fits the criteria of radiation-induced tumor and the clinical implication of the issue is discussed.
Glioblastoma multiforme (GBM) is the most common glial tumor of the adult brain. However, the primary GBM of medulla oblongata is a rarity. To the best of our knowledge, only four cases of GBM of medulla oblongata have been reported so far in the literature, and this is the second report of conventional GBM of the medulla oblongata in adults. We describe a case of 51-year-old female, who presented with a heterogeneous mass with exophytic feature located in the caudal brain stem that was approached and a near total tumor removal was achieved by median suboccipital route. A literature review with emphasis on anatomical location, radiological and histopathological findings, extent of tumor resectibility, and outcome is included.
Brain stem; exophytic lesion; glioblastoma multiforme; medulla oblongata
Wireless machine-to-machine sensor networks with multiple radio interfaces are expected to have several advantages, including high spatial scalability, low event detection latency, and low energy consumption. Here, we propose a network model design method involving network approximation and an optimized multi-tiered clustering algorithm that maximizes node lifespan by minimizing energy consumption in a non-uniformly distributed network. Simulation results show that the cluster scales and network parameters determined with the proposed method facilitate a more efficient performance compared to existing methods.
clustering algorithm; lifespan; machine to machine; multiple radio interfaces; network modeling; wireless sensor networks
A set of proteins reflecting the prognosis of patients have clinical significance since they could be utilized as predictive biomarkers and/or potential therapeutic targets. With the aim of finding novel diagnostic and prognostic markers for glioblastoma (GBM), a tissue microarray (TMA) library consisting of 62 GBMs and 28 GBM-associated normal spots was constructed. Immunohistochemistry against 78 GBM-associated proteins was performed. Expression levels of each protein for each patient were analyzed using an image analysis program and converted to H-score [summation of the intensity grade of staining (0–3) multiplied by the percentage of positive cells corresponding to each grade]. Based on H-score and hierarchical clustering methods, we divided the GBMs into two groups (n=19 and 37) that had significantly different survival lengths (p<0.05). In the two groups, expression of nine proteins (survivin, cyclin E, DCC, TGF-β, CDC25B, histone H1, p-EGFR, p-VEGFR2/3, p16) was significantly changed (q<0.05). Prognosis-predicting potential of these proteins were validated with another independent library of 82 GBM TMAs and a public GBM DNA microarray dataset. In addition, we determined 32 aberrant or mislocalized subcellular protein expression patterns in GBMs compared with relatively normal brain tissues, which could be useful for diagnostic biomarkers of GBM. We therefore suggest that these proteins can be used as predictive biomarkers and/or potential therapeutic targets for GBM.
biomarker; therapeutic target; glioblastoma; tissue micro-array; bioinformatics; automated image analysis
The aim of this study was to assess the safety and efficacy of radiation-sterilized allografts of iliac bone and fascia lata from cadaver specimens to repair skull base defects after transsphenoidal surgery.
Between May 2009 and January 2010, 31 consecutive patients underwent endonasal transsphenoidal surgery and all patients received sellar reconstruction using allografts following tumor removal. The allografts were obtained from the local tissue bank and harvested from cadaver donors. The specimens used in our approach were tensor fascia lata and the flat area of iliac bone. For preparation, allografts were treated with gamma irradiation after routine screening by culture, and then stored at -70℃.
The mean follow-up period after surgery was 12.6 months (range, 7.4-16 months). Overall, postoperative cerebrospinal fluid (CSF) leaks occurred in three patients (9.7%) and postoperative meningitis in one patient (3.2%). There was no definitive evidence of wound infection at the routine postoperative follow-up examination or during re-do surgery in three patients. Postoperative meningitis in one patient was improved with the use of antibiotics and prolonged CSF diversion.
We suggest that allograft materials can be a feasible alternative to autologous tissue grafts for sellar reconstruction following transsphenoidal surgery under selected circumstances such as no or little intraoperative CSF leaks.
Endoscopic endonasal approach; Transsphenoidal approach; Allograft; Sellar reconstruction; CSF leak
Naegleria fowleri, a ubiquitous free-living ameba, causes fatal primary amebic meningoencephalitis in humans. N. fowleri trophozoites are known to induce cytopathic changes upon contact with microglial cells, including necrotic and apoptotic cell death and pro-inflammatory cytokine release. In this study, we treated rat microglial cells with amebic lysate to probe contact-independent mechanisms for cytotoxicity, determining through a combination of light microscopy and scanning and transmission electron microscopy whether N. fowleri lysate could effect on both necrosis and apoptosis on microglia in a time- as well as dose-dependent fashion. A 51Cr release assay demonstrated pronounced lysate induction of cytotoxicity (71.5%) toward microglial cells by 24 hr after its addition to cultures. In an assay of pro-inflammatory cytokine release, microglial cells treated with N. fowleri lysate produced TNF-α, IL-6, and IL-1β, though generation of the former 2 cytokines was reduced with time, and that of the last increased throughout the experimental period. In summary, N. fowleri lysate exerted strong cytopathic effects on microglial cells, and elicited pro-inflammatory cytokine release as a primary immune response.
Naegleria fowleri; microglial cell; pro-inflammatory cytokine; cytotoxicity
Efficient high throughput screening systems of useful mutants are prerequisite for study of plant functional genomics and lots of application fields. Advance in such screening tools, thanks to the development of analytic instruments. Direct analysis in real-time (DART)-mass spectrometry (MS) by ionization of complex materials at atmospheric pressure is a rapid, simple, high-resolution analytical technique. Here we describe a rapid, simple method for the genetic discrimination of intact Arabidopsis thaliana mutant seeds using metabolic profiling by DART-MS.
To determine whether this DART-MS combined by multivariate analysis can perform genetic discrimination based on global metabolic profiling, intact Arabidopsis thaliana mutant seeds were subjected to DART-MS without any sample preparation. Partial least squares-discriminant analysis (PLS-DA) of DART-MS spectral data from intact seeds classified 14 different lines of seeds into two distinct groups: Columbia (Col-0) and Landsberg erecta (Ler) ecotype backgrounds. A hierarchical dendrogram based on partial least squares-discriminant analysis (PLS-DA) subdivided the Col-0 ecotype into two groups: mutant lines harboring defects in the phenylpropanoid biosynthetic pathway and mutants without these defects. These results indicated that metabolic profiling with DART-MS could discriminate intact Arabidopsis seeds at least ecotype level and metabolic pathway level within same ecotype.
The described DART-MS combined by multivariate analysis allows for rapid screening and metabolic characterization of lots of Arabidopsis mutant seeds without complex metabolic preparation steps. Moreover, potential novel metabolic markers can be detected and used to clarify the genetic relationship between Arabidopsis cultivars. Furthermore this technique can be applied to predict the novel gene function of metabolic mutants regardless of morphological phenotypes.
Arabidopsis thaliana; Direct analysis in real-time mass spectrometry (DART-MS); partial least squares-discriminant analysis (PLS-DA); seed