Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 22
Filter
Add more filters










Publication year range
1.
J Infect Chemother ; 2024 Jun 27.
Article in English | MEDLINE | ID: mdl-38944381

ABSTRACT

BACKGROUND: Human cytomegalovirus (HCMV) infection occurs in immunosuppressed individuals and is known to increase mortality. Patients with coronavirus disease 2019 (COVID-19) are often treated with steroids, require intensive care unit (ICU) treatment, and may therefore be at risk for HCMV infection. However, which factors predispose severely ill patients with COVID-19 to HCMV infection and the prognostic value of such infections remain largely unexplored. This study aimed to examine the incidence and potential risk factors of HCMV infection in patients with severe or critical COVID-19 and evaluate the relationship between HCMV infection and mortality. METHODS AND FINDINGS: We used administrative claims data from advanced treatment hospitals in Japan to identify and analyze patients with severe or critical COVID-19. We explored potential risk factors for HCMV infection using multivariable regression models and their contribution to mortality in patients with COVID-19. Overall, 33,151 patients who progressed to severe or critical COVID-19 illness were identified. The incidence of HCMV infection was 0.3-1.7% depending on the definition of HCMV infection. Steroids, immunosuppressants, ICU admission, and blood transfusion were strongly associated with HCMV infection. Furthermore, HCMV infection was associated with patient mortality independent of the observed risk factors for death. CONCLUSIONS: HCMV infection is a notable complication in patients with severe or critical COVID-19 who are admitted to the ICU or receive steroids, immunosuppressants, and blood transfusion and can significantly increase mortality risk.

2.
Resuscitation ; 200: 110257, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38823473

ABSTRACT

AIM: To develop a new scoring model for patients with cardiogenic out-of-hospital cardiac arrest (OHCA) to facilitate neurological prognosis prediction upon hospital arrival by using prehospital resuscitation features alone. METHODS: Between 2005 and 2019, we enrolled 942,891 adult patients with OHCA of presumed cardiac aetiology from the All-Japan Utstein Registry. Scoring models applied prehospital resuscitation features a priori from the variables the American College of Cardiology algorithm including age, duration to return of spontaneous circulation (ROSC) or hospital arrival, no bystander cardiopulmonary resuscitation (CPR), unwitnessed arrest, and nonshockable rhythm (R-EDByUS score) to predict unfavorable neurological outcomes defined as Cerebral Performance Category 3, 4, or 5 at 1 month. We created nomograms as a "Regression-based model," and created a "Simplified model" in which points were assigned by category for predicting unfavorable neurological outcomes for both the prehospital ROSC cohort (67,064 patients) and the ongoing CPR cohort (875,827 patients). For internal validation, bootstrap optimism-corrected estimates of predictive performance were calculated. RESULTS: A total of 46,971 (70.0%) and 870,991 (99.4%) patients in the prehospital ROSC and ongoing CPR cohorts, respectively, had unfavorable neurological outcomes. In the prehospital ROSC cohort, the C-statistics of the Regression-based and Simplified models were 0.851 and 0.842, and the bootstrap-validated C-statistics were 0.852 and 0.841, respectively. In the ongoing CPR cohort, the C-statistics of the Regression-based and Simplified models were 0.872 and 0.865, and the bootstrap-validated C-statistics were 0.852 and 0.841, respectively. CONCLUSIONS: The R-EDByUS score accurately predicted the neurological prognosis of cardiogenic OHCA upon hospital arrival.


Subject(s)
Cardiopulmonary Resuscitation , Emergency Medical Services , Out-of-Hospital Cardiac Arrest , Registries , Humans , Out-of-Hospital Cardiac Arrest/therapy , Out-of-Hospital Cardiac Arrest/mortality , Out-of-Hospital Cardiac Arrest/etiology , Male , Female , Cardiopulmonary Resuscitation/methods , Cardiopulmonary Resuscitation/statistics & numerical data , Aged , Prognosis , Middle Aged , Japan/epidemiology , Emergency Medical Services/methods , Emergency Medical Services/statistics & numerical data , Return of Spontaneous Circulation , Nomograms , Aged, 80 and over
3.
Article in English | MEDLINE | ID: mdl-38696756

ABSTRACT

OBJECTIVE: This study aimed to establish a screening model for differentiating anti-synthetase syndrome (ASS) from other antinuclear antibody (ANA)-associated rheumatic diseases (AARD) using a combination of cytoplasmic and non-cytoplasmic ANA (ncANA) patterns. METHODS: This retrospective observational study included patients with AARDs such as systemic lupus erythematosus (SLE), systemic sclerosis (SSc), Sjögren's syndrome (SS), mixed connective tissue disease (MCTD), and polymyositis/dermatomyositis (PM/DM) who underwent ANA screening between April 2012 and December 2021. Variables included age, sex, ANA patterns (Cytoplasmic and ncANA), and titers. Logistic regression analysis of Cytoplasmic and ncANA patterns was performed to differentiate ASS from other AARDs. RESULT: The 981 diagnosed cases of AARDs consisted of SS (n = 451), SSc (n = 264), SLE (n = 201), PM/DM (n = 104), MCTD (n = 52), and ASS, including PM/DM (n = 64). Of these, 155 patients had ≥2 overlapping diseases; however, there was no overlap between AARDs and ASS. ASS is more likely to occur when the cytoplasmic titer is positive and the ncANA <320. Receiver operating characteristic (ROC) analysis of the Cytoplasmic and ncANA range revealed an area under the ROC curve (AUC) of 0.885 (95% CI: 0.844 to 0.927). CONCLUSION: It is important to detect cytoplasmic patterns as an ANA screening test for ASS diagnosis, even if the titer is low. Additionally, combining the cytoplasmic and ncANA patterns yields more accurate ASS screening results.

5.
Animal ; 18(2): 101050, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38215678

ABSTRACT

Taste plays an essential role in regulating the feeding behaviors of animals. The present study aimed to characterize the taste sensory profiles of amino acids and sugars in chickens. To achieve this, we employed a conditioned taste aversion learning method, which is characterized by a specific pairing of gastrointestinal malaise and taste perception. Our findings revealed that chickens were able to learn to avoid L-Val, L-Lys, and L-His through conditioned taste aversion learning, and exhibited a strong aversion to L-Arg. These results suggest that chickens are primarily sensitive to basic amino acids, including L-Lys, which is a crucial limiting amino acid in feeds. Interstingly, this sensitivity to basic amino acids in chickens contrasts with humans, who are mainly sensitive to acidic amino acids as umami taste. Furthermore, despite the absence of a mammalian sweet taste receptor gene in the chicken genome, we demonstrated that chickens learned to avoid glucose, galactose, sucrose, and maltose by conditioned taste aversion learning. Taken together, the present study provides the idea that chickens possess a gustatory perception toward specific amino acids and sugars for the detection of beneficial nutrients in their feeds.


Subject(s)
Amino Acids , Taste Perception , Humans , Animals , Taste Perception/physiology , Taste/physiology , Chickens , Sugars , Avoidance Learning/physiology , Arginine , Amines , Mammals
6.
PLoS One ; 18(12): e0293676, 2023.
Article in English | MEDLINE | ID: mdl-38051708

ABSTRACT

Lactate, which is synthesized as an end product by lactate dehydrogenase A (LDHA) from pyruvate during anaerobic glycolysis, has attracted attention for its energy metabolism and oxidant effects. A novel histone modification-mediated gene regulation mechanism termed lactylation by lactate was recently discovered. The present study examined the involvement of histone lactylation in undifferentiated cells that underwent differentiation into osteoblasts. C2C12 cells cultured in medium with a high glucose content (4500 mg/L) showed increases in marker genes (Runx2, Sp7, Tnap) indicating BMP-2-induced osteoblast differentiation and ALP staining activity, as well as histone lactylation as compared to those cultured in medium with a low glucose content (900 mg/L). Furthermore, C2C12 cells stimulated with the LDH inhibitor oxamate had reduced levels of BMP-2-induced osteoblast differentiation and histone lactylation, while addition of lactate to C2C12 cells cultured in low glucose medium resulted in partial restoration of osteoblast differentiation and histone lactylation. These results indicate that lactate synthesized by LDHA during glucose metabolism is important for osteoblast differentiation of C2C12 cells induced by BMP-2. Additionally, silencing of p300, a possible modifier of histone lactylation, also inhibited osteoblast differentiation and reduced histone lactylation. Together, these findings suggest a role of histone lactylation in promotion of undifferentiated cells to undergo differentiation into osteoblasts.


Subject(s)
Histones , Lactic Acid , Histones/metabolism , Lactic Acid/pharmacology , Lactic Acid/metabolism , Cell Differentiation , Osteoblasts/metabolism , Glucose/pharmacology , Glucose/metabolism
7.
Support Care Cancer ; 31(12): 730, 2023 Nov 29.
Article in English | MEDLINE | ID: mdl-38019339

ABSTRACT

PURPOSE: Chemotherapy-induced peripheral neuropathy (CIPN) has been reported to reduce patients' quality of life and impair cancer treatment by causing anticancer drug withdrawal or interruption. However, there are currently no effective methods for the prevention of CIPN. Renin-angiotensin-aldosterone system (RAAS) inhibitors may be associated with a reduced risk of developing oxaliplatin-induced peripheral neuropathy, and it would be valuable to examine whether they have the same effect on CIPN caused by other anticancer drugs. Our study explored the potential preventive effects of RAAS inhibitors on preventing paclitaxel-induced peripheral neuropathy (PIPN). METHODS: An exploratory cohort study was conducted using commercially available administrative claims data on lung cancer patients treated with paclitaxel-based chemotherapy. Cumulative paclitaxel doses, RAAS inhibitor prescriptions, and incidences of PIPN were identified using patient medical records. Fine-Gray analyses with death as a competing risk were performed. A propensity score approach was applied to address the problem of confounding. RESULTS: Patients with lung cancer who received paclitaxel-based chemotherapy were classified into users of RAAS inhibitor (n = 1320) and non-users of RAAS inhibitor (n = 4566). The doses of RAAS inhibitors in our study were similar to those commonly used to treat hypertension. The PIPN incidence was significantly lower in users of RAAS inhibitor than in the non-users of RAAS inhibitor (sub-distribution hazard ratio, 0.842; 95% confidence interval, 0.762-0.929). The result was consistent in various sensitivity analyses and important subgroup analyses. CONCLUSIONS: RAAS inhibitors at doses commonly used for hypertension were associated with a reduced incidence of PIPN in patients with lung cancer.


Subject(s)
Hypertension , Lung Neoplasms , Peripheral Nervous System Diseases , Humans , Renin-Angiotensin System , Paclitaxel/adverse effects , Lung Neoplasms/drug therapy , Cohort Studies , Quality of Life , Peripheral Nervous System Diseases/chemically induced , Peripheral Nervous System Diseases/prevention & control , Antihypertensive Agents
8.
In Vitro Cell Dev Biol Anim ; 59(1): 10-18, 2023 Jan.
Article in English | MEDLINE | ID: mdl-36689044

ABSTRACT

Osteoblasts produce the receptor activator of nuclear factor-kappa B ligand (RANKL) and osteoprotegerin, the inducer and the suppressor of osteoclast differentiation and activation. We previously proposed that the degradation of osteoprotegerin by lysine-specific gingipain of Porphyromonas gingivalis and neutrophil elastase is one of the mechanisms of bone resorption associated with infection and inflammation. In the present study, we found that cathepsin K (CTSK) also degraded osteoprotegerin in an acidic milieu and the buffer with a pH of 7.4. The 37 k fragment of osteoprotegerin produced by the reaction with CTSK was further degraded into low molecular weight fragments, including a 13 k fragment, depending on the reaction time. The N-terminal amino acid sequence of the 37 k fragment matched that of the intact osteoprotegerin, indicating that CTSK preferentially hydrolyzes the death domain-like region of osteoprotegerin, not its RANKL-binding region. The 13 k fragment of osteoprotegerin was the C-terminal 13 k portion within the RANKL-binding region of the 37 k fragment. Finally, CTSK restored RANKL-dependent osteoclast differentiation that was suppressed by the addition of osteoprotegerin. Collectively, CTSK is a possible positive regulator of osteoclastogenesis.


Subject(s)
Osteogenesis , Osteoprotegerin , Animals , Osteoprotegerin/metabolism , Cathepsin K/metabolism , Glycoproteins/metabolism , Osteoclasts/metabolism , Receptor Activator of Nuclear Factor-kappa B/metabolism , Membrane Glycoproteins/metabolism , Receptors, Cytoplasmic and Nuclear/metabolism , Carrier Proteins/metabolism , RANK Ligand/metabolism , Cell Differentiation
9.
Sci Rep ; 12(1): 22413, 2022 12 27.
Article in English | MEDLINE | ID: mdl-36575200

ABSTRACT

Long-term sequelae of the coronavirus disease (COVID-19) constitute Long COVID. Although Long COVID has been reported globally, its risk factors and effects on quality of life (QOL) remain unclear. We conducted a cross-sectional study using questionnaires and electronic medical records of COVID-19 patients who were diagnosed or hospitalized at five facilities in Japan. Responses were obtained from 285 out of 1,150 patients. More than half of the participants reported Long COVID symptoms of varying severity 1 year after COVID-19. Common sequelae included fatigue, dyspnea, alopecia, concentration problems, memory problems, sleeplessness, and joint pain, which often significantly reduced their QOL. COVID-19 severity was strongly associated with sputum production, chest pain, dyspnea, sore throat, and diarrhea, but not with fatigue, dysgeusia, anosmia, alopecia, and sleeplessness. Fatigue, dysgeusia, anosmia, alopecia, and sleeplessness affected the QOL among participants with asymptomatic or mild COVID-19 during the acute phase. Moreover, these sequelae persisted for prolonged periods.


Subject(s)
COVID-19 , Sleep Initiation and Maintenance Disorders , Humans , COVID-19/epidemiology , COVID-19/complications , Cross-Sectional Studies , Post-Acute COVID-19 Syndrome , Quality of Life , Sleep Initiation and Maintenance Disorders/complications , Anosmia , Dysgeusia , Prevalence , Risk Factors , Chest Pain , Dyspnea/epidemiology , Fatigue/epidemiology , Fatigue/complications , Alopecia/complications
10.
Biochem Biophys Res Commun ; 597: 44-51, 2022 Mar 15.
Article in English | MEDLINE | ID: mdl-35123265

ABSTRACT

Osteocytes sense the microenvironmental stimuli, including mechanical stress, and regulate bone resorption by osteoclasts and bone formation by osteoblasts. Diabetes and cancer metastasis to bone raise l-lactic acid in the bone tissue, causing acidification. Here, we investigated the effects of l-lactic acid and extracellular acidification on the function of mouse Ocy454 osteocytes. L- and d-lactic acid with low chiral selectivity and acidification of the medium raised the production of sclerostin and osteoprotegerin by Ocy454 cells. The mRNA expression of their genes increased after either treatment of L- and d-lactic acid or acidification of the medium. Furthermore, the conditioned medium of Ocy454 cells cultured in an acidic environment suppressed the induction of alkaline phosphatase activity in MC3T3-E1 cells, which was recovered by the anti-sclerostin antibody. While it is reported that HDAC5 inhibits the transcription of the sclerostin gene, extracellular acidification reduced the nuclear localization of HDAC5 in Ocy454 cells. While calmodulin kinase II (CaMKII) is known to phosphorylate and induce extranuclear translocation of HDAC5, KN-62, an inhibitor of CaMKII lowered the expression of the sclerostin gene in Ocy454 cells. Collectively, extracellular acidification is a microenvironmental factor that modulates osteocyte functions.

11.
Front Cell Dev Biol ; 9: 681347, 2021.
Article in English | MEDLINE | ID: mdl-34497803

ABSTRACT

Blood outgrowth smooth muscle cells (BO-SMCs) offer the means to study vascular cells without the requirement for surgery providing opportunities for drug discovery, tissue engineering, and personalized medicine. However, little is known about these cells which meant that their therapeutic potential remains unexplored. Our objective was to investigate for the first time the ability of BO-SMCs and vessel-derived smooth muscle cells to sense the thromboxane mimetic U46619 by measuring intracellular calcium elevation and contraction. U46619 (10-6 M) increased cytosolic calcium in BO-SMCs and vascular smooth muscle cells (VSMCs) but not in fibroblasts. Increased calcium signal peaked between 10 and 20 s after U46619 in both smooth muscle cell types. Importantly, U46619 (10-9 to 10-6 M) induced concentration-dependent contractions of both BO-SMCs and VSMCs but not in fibroblasts. In summary, we show that functional responses of BO-SMCs are in line with VSMCs providing critical evidence of their application in biomedical research.

12.
Biochem Biophys Res Commun ; 554: 173-178, 2021 05 21.
Article in English | MEDLINE | ID: mdl-33798944

ABSTRACT

Neural crest-derived cells (NCDCs), a class of adult stem cells not restricted to embryonic tissues, are attractive tissue regenerative therapy candidates because of their ease of isolation, self-renewing properties, and multipotency. Although adult NCDCs can undergo osteogenic differentiation in vitro, whether they induce bone formation in vivo remains unclear. Previously, our group reported findings showing high amounts of NCDCs scattered throughout nasal concha tissues of adult mice. In the present study, NCDCs in nasal conchae labeled with enhanced green fluorescent protein (EGFP) were collected from adult P0-Cre/CAG-CAT-EGFP double transgenic mice, then cultured in serum-free medium to increase the number. Subsequently, NCDCs were harvested and suspended in type I atelocollagen gel, then an atelocollagen sponge was used as a scaffold for the cell suspension. Atelocollagen scaffolds with NCDCs were placed on bone defects created in a mouse calvarial bone defect model. Over the ensuing 12 weeks, micro-CT and histological analysis findings showed that mice with scaffolds containing NCDCs had slightly greater bone formation as compared to those with a scaffold alone. Furthermore, Raman spectroscopy revealed spectral properties of bone in mice that received scaffolds with NCDCs similar to those of native calvarial bone. Bone regeneration is important not only for gaining bone mass but also chemical properties. These results are the first to show the validity of biomolecule-free adult nasal concha-derived NCDCs for bone regeneration, including the chemical properties of regenerated bone tissue.


Subject(s)
Adult Stem Cells/cytology , Bone Regeneration/physiology , Neural Crest/cytology , Stem Cell Transplantation/methods , Turbinates/cytology , Adult Stem Cells/metabolism , Animals , Cell Differentiation , Cells, Cultured , Disease Models, Animal , Green Fluorescent Proteins/genetics , Green Fluorescent Proteins/metabolism , Mice , Mice, Inbred ICR , Mice, Transgenic , Neural Crest/metabolism , Turbinates/metabolism
13.
Soft Matter ; 17(19): 4979-4988, 2021 May 19.
Article in English | MEDLINE | ID: mdl-33899905

ABSTRACT

A full understanding of the elastic properties of hydrogels under swelling is required for their practical application in the chemical and biomedical engineering fields. This is because hydrogels are expected to retain water during mechanical use in moist atmospheres. In the present study, we investigated the relationship between the elastic modulus and the swelling ratio in a specific type of hydrogel (a polyacrylamide gel). The elasticity and swelling data revealed that these two parameters are proportionally related in hydrogels comprising adequate amounts of monomers and crosslinkers. We also demonstrated that this proportional relationship inherently conforms to the linear elastic behaviour predicted by the Flory-Rehner free energy function (the F-R model). The implicit rule is established by the extended F-R model with two scaling exponents. The extended model is capable of representing the irregular elasticity of swollen gels formed from low- or high-molecular-weight polymers.

15.
RSC Adv ; 11(44): 27121-27125, 2021 Aug 09.
Article in English | MEDLINE | ID: mdl-35480637

ABSTRACT

Carbon dioxide is regarded as a reliable C1 building block in organic synthesis because of the nontoxic, abundant, and economical characteristics of carbon dioxide. In this manuscript, a commercially available oxovanadium(v) compound was demonstrated to serve as an efficient catalyst for the catalytic amination of carbon dioxide under ambient pressure in the synthesis of ureas. The catalytic transformation of chiral amines into the corresponding chiral ureas without loss of chirality was also performed. Furthermore, a gram-scale catalytic urea synthesis under ambient pressure was successfully achieved to validate the scalability of this catalytic activation of carbon dioxide.

16.
FASEB J ; 34(1): 1745-1754, 2020 01.
Article in English | MEDLINE | ID: mdl-31914612

ABSTRACT

Blood vessels are comprised of endothelial and smooth muscle cells. Obtaining both types of cells from vessels of living donors is not possible without invasive surgery. To address this, we have devised a strategy whereby human endothelial and smooth muscle cells derived from blood progenitors from the same donor could be cultured with autologous leukocytes to generate a same donor "vessel in a dish" bioassay. Autologous sets of blood outgrowth endothelial cells (BOECs), smooth muscle cells (BO-SMCs), and leukocytes were obtained from four donors. Cells were treated in monoculture and cumulative coculture conditions. The endothelial specific mediator endothelin-1 along with interleukin (IL)-6, IL-8, tumor necrosis factor α, and interferon gamma-induced protein 10 were measured under control culture conditions and after stimulation with cytokines. Cocultures remained viable throughout. The profile of individual mediators released from cells was consistent with what we know of endothelial and smooth muscle cells cultured from blood vessels. For the first time, we report a proof of concept study where autologous blood outgrowth "vascular" cells and leukocytes were studied alone and in coculture. This novel bioassay has usefulness in vascular biology research, patient phenotyping, drug testing, and tissue engineering.


Subject(s)
Endothelial Cells/physiology , Leukocytes/physiology , Muscle, Smooth, Vascular/physiology , Myocytes, Smooth Muscle/physiology , Biological Assay/methods , Cells, Cultured , Coculture Techniques/methods , Cytokines/metabolism , Drug Discovery/methods , Endothelial Cells/metabolism , Humans , Interleukin-6/metabolism , Leukocytes/metabolism , Muscle, Smooth, Vascular/metabolism , Myocytes, Smooth Muscle/metabolism , Phenotype , Tissue Engineering/methods , Tumor Necrosis Factor-alpha/metabolism
17.
Micromachines (Basel) ; 10(7)2019 Jun 28.
Article in English | MEDLINE | ID: mdl-31261677

ABSTRACT

In this paper, we demonstrate that 20 µm microbeads can be preferentially assembled into substrate trenches of similar width by employing a polymer (depletant) that induces the depletion volume effect (depletion attraction). In previous works, we proved that this strategy is useful to assemble mesoscale parts in a site-specific manner. Here, we show that it is also applicable to assemble functional parts, such as fluorescent particles, into trenches engraved on the surface of two- and three-dimensional template components. A convenient advantage of this strategy is that it is independent of material properties for assembling mesoscale functional components into desired patterns.

18.
Sci Rep ; 8(1): 13987, 2018 09 18.
Article in English | MEDLINE | ID: mdl-30228360

ABSTRACT

Amine quantification is an important strategy in patient stratification and personalised medicine. This is because amines, including amino acids and methylarginines impact on many homeostatic processes. One important pathway regulated by amine levels is nitric oxide synthase (NOS). NOS is regulated by levels of (i) the substrate, arginine, (ii) amino acids which cycle with arginine and (iii) methylarginine inhibitors of NOS. However, biomarker research in this area is hindered by the lack of a unified analytical platform. Thus, the development of a common metabolomics platform, where a wide range of amino acids and methylarginines can be measured constitutes an important unmet need. Here we report a novel high-throughput ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) platform where ≈40 amine analytes, including arginine and methylarginines can be detected and quantified on a molar basis, in a single sample of human plasma. To validate the platform and to generate biomarkers, human plasma from a well-defined cohort of patients before and after coronary artery bypass surgery, who developed systemic inflammatory response syndrome (SIRS), were analysed. Bypass surgery with SIRS significantly altered 26 amine analytes, including arginine and ADMA. Consequently, pathway analysis revealed significant changes in a range of pathways including those associated with NOS.


Subject(s)
Amines/blood , Amino Acids/blood , Arginine/analogs & derivatives , Biomarkers/blood , Chromatography, High Pressure Liquid/methods , Systemic Inflammatory Response Syndrome/blood , Tandem Mass Spectrometry/methods , Aged , Arginine/blood , Female , Humans , Male , Prognosis , Systemic Inflammatory Response Syndrome/surgery
19.
J Toxicol Sci ; 38(4): 571-9, 2013.
Article in English | MEDLINE | ID: mdl-23824013

ABSTRACT

T-cell dependent antibody response (TDAR) incorporating both primary and secondary responses to keyhole limpet hemocyanin (KLH) in canine models have not yet been fully understood. To develop a practical dog TDAR model, we characterized primary and secondary antibody responses by intravenous or intramuscular immunization of KLH twice at intervals of 8 days during a 28-day course of study. Primary immunization with KLH by both routes induced a maximum IgM response on 6 to 8 days after the treatment, whereas the IgG response started 6 to 8 days after the treatment with relatively low levels. Remarkable increases in anti-KLH IgG levels (about 10-times compared with the primary response) were produced 5 to 7 days after the secondary KLH immunization by both routes. These results indicate that IgM-predominant and IgG-predominant responses were respectively induced by the primary and secondary immunization. Furthermore, the intravenous route showed higher baseline titers of primary and secondary anti-KLH IgM responses, suggesting that intravenous immunization of KLH might be a more suitable method for immunotoxicity evaluation. No remarkable inter-individual variability was noted in our canine models. Treatment with cyclophosphamide at 2 mg/kg/day for a consecutive 28 days significantly suppressed primary and secondary anti-KLH IgM and IgG responses induced by KLH injection on Days 15 and 23 of CPA treatment. These results demonstrate that these experimental designs could provide valuable information about the influence on both the primary and secondary humoral immune responses in dogs when exposed to potential immunomodulatory drugs.


Subject(s)
Adjuvants, Immunologic , Antibody Formation/immunology , Hemocyanins/immunology , Immunity, Humoral/immunology , Immunization, Secondary , T-Lymphocytes/immunology , Animals , Cyclophosphamide/pharmacology , Dogs , Female , Hemocyanins/administration & dosage , Humans , Immunoglobulin G/blood , Immunosuppressive Agents/pharmacology , Injections, Intramuscular , Injections, Intravenous , Male
20.
J Immunotoxicol ; 10(1): 40-8, 2013.
Article in English | MEDLINE | ID: mdl-22953734

ABSTRACT

To develop a rat T-cell-dependent antibody response (TDAR) model evaluating both primary and secondary antibody responses, keyhole limpet hemocyanin (KLH) was used to immunize rats twice during a 14-day course of study, a pattern closely linked to that of a short-term general toxicity study. Female rats of four representative strains (e.g., Sprague-Dawley, Wistar, Fischer, and Lewis) were immunized twice with intravenous administrations of KLH (300 µg/rat) on Days 5 and 9 during a 14-day treatment regimen with cyclophosphamide (CPA) at 1, 3, or 6 mg/kg/day. The primary and secondary immunizations of KLH markedly elevated serum anti-KLH IgM and IgG levels in all strains on Days 9 and 15. Remarkable higher levels of anti-KLH IgG (≈ 1000 µg/ml) were noted in all strains, which were more than 4-times compared with those of anti-KLH IgM levels at Day 9, indicating that predominant IgG reactions were induced by the dual immunizations. A large inter-individual variability in KLH-specific IgM and IgG production was observed in all strains. However, levels of the KLH-specific antibodies were considered sufficient for the evaluation, even in Sprague-Dawley and Wistar rats reported as strains with a wide range of variability since immunosuppression of CPA on responses in both anti-KLH IgM and IgG were observed in all strains to the same extent. In addition, the sensitivity of the KLH-ELISA assay system detecting the immunosuppressive effects of CPA was comparable to other assay systems with PFC assay or ELISA using SRBC. The results here demonstrated that these experimental designs could provide valuable information about the influence on both the primary and secondary humoral immune responses in rats when exposed to potential immunomodulatory drugs. Furthermore, the design of the presented TDAR study would support comprehensive evaluation together with the outcome of the conventional general toxicity study.


Subject(s)
Antibody Formation , Hemocyanins/immunology , Immunologic Memory , T-Lymphocytes, Helper-Inducer/immunology , Animals , Female , Immunization, Secondary , Lymphocyte Activation , Rats , Rats, Inbred F344 , Rats, Inbred Lew , Rats, Sprague-Dawley , Rats, Wistar
SELECTION OF CITATIONS
SEARCH DETAIL
...