ABSTRACT
Purpose@#The incidence of early-onset colorectal cancer (CRC) and associated mortality have been increasing. However, the potential benefits of CRC screening are largely unknown in young individuals. We aimed to evaluate the effect of CRC screening with colonoscopy on all-cause and CRC mortality among young (aged < 45 years) and older (aged ≥ 45 years) individuals. @*Materials and Methods@#This cohort study included 528,046 Korean adults free of cancer at baseline who underwent a comprehensive health examination. The colonoscopic screening group was defined as those who reported undergoing colonoscopy for CRC screening. Mortality follow-up until December 31, 2019 was ascertained based on nationwide death certificate data from the Korea National Statistical Office. @*Results@#Colonoscopic screening was associated with a lower risk of all-cause mortality in both young and older individuals. Multivariable-adjusted time-dependent hazard ratios (95% confidence intervals) for all-cause mortality comparing ever- to never-screening were 0.86 (0.75-0.99) for young individuals and 0.71 (0.65-0.78) for older individuals. Colonoscopic screenings were also associated with a reduced risk of CRC mortality without significant interaction by age, although this association was significant only among participants aged ≥ 45 years, with corresponding time-dependent hazard ratios of 0.47 (0.15-1.44) for young individuals and 0.52 (0.31-0.87) for those aged ≥ 45 years. @*Conclusion@#Colonoscopic CRC screening decreased all-cause mortality among both young and older individuals, while significantly decreased CRC mortality was observed only in those aged ≥ 45 years. Screening initiation at an earlier age warrants more rigorous confirmatory studies.
ABSTRACT
Lespedeza cuneata (LC) is a perennial plant used in herbal medicine to treat numerous diseases, including prostatic hyperplasia, diabetes, early atherosclerosis, and hematuria. Reference collections of bioactive compounds of LC are crucial for the determination of their pharmacological properties. However, little is known regarding its anti-oxidative and anti-inflammatory effects in alveolar macrophage (MH-S) cells. This study examined whether LC can inhibit reactive oxygen species and Coal fly ash (CFA) induced inflammation in MH-S cells. The anti-oxidative effects of LC were evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays, anti-inflammatory effects were examined using nitric oxide (NO) assay, and cytotoxicity was analyzed using methyl thiazolyl tetrazolium assay. The expression of inflammatory cytokine genes was assessed through a reverse-transcription polymerase chain reaction. Our results revealed that LC exhibited high radical scavenging activity and a dose-dependent (7.8–1,000 μg/mL) inhibition of oxidation as compared to ascorbic acid and Trolox. It also inhibited CFA-induced NO production in MH-S cells. Moreover, it suppressed the CFA exposure-mediated expression of pro-inflammatory mediators and cytokines, including inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), interleukin (IL)-1β, IL-6, and tumor necrosis factor-α. These results suggest that LC is a potent antioxidant and anti-inflammatory agent that can be useful as a nutraceutical product.
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Background@#Clinical ethics support is a form of preventive ethics aimed at mediating ethicsrelated conflicts and managing ethical issues arising in the healthcare setting. However, limited evidence exists regarding the specific ethical issues in clinical practice. This study aimed to explore the diverse ethical issues of cases referred to clinical ethics support after the new legislation on hospice palliative care and end-of-life decision-making was implemented in Korea in 2018. @*Methods@#A retrospective study of cases referred to clinical ethics support at a university hospital in Korea from February 2018 to February 2021 was conducted. The ethical issues at the time of referral were analyzed via qualitative content analysis of the ethics consultationrelated documents. @*Results@#A total of 60 cases of 57 patients were included in the study, of whom 52.6% were men and 56.1% were older than 60 years of age. The majority of cases (80%) comprised patients from the intensive care unit. One-third of the patients were judged as being at the end-of-life stage. The most frequent ethical categories were identified as goals of care/ treatment (78.3%), decision-making (75%), relationship (41.7%), and end-of-life issues (31.7%). More specifically, best interests (71.7%), benefits and burdens/harms (61.7%), refusal (53.3%), and surrogate decision-making (33.3%), followed by withholding or withdrawal (28.3%) were the most frequent ethical issues reported, which became diversified by year. In addition, the ethical issues appeared to differ by age group and judgment of the end-of-life stage. @*Conclusion@#The findings of this study expand the current understanding of the diverse ethical issues including decision-making and goals of care/treatment that have been referred to clinical ethics support since the enforcement of the new legislation in Korea. This study suggests a need for further research on the longitudinal exploration of ethical issues and implementation of clinical ethics support in multiple healthcare centers.
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Background@#The aim of this study was to capture multifaceted clinical characteristics of congenital cytomegalovirus (CMV) infection from diagnosis to treatment using a multidisciplinary approach including obstetrics, pediatrics, pathology, and otorhinolaryngology-head and neck surgery. @*Methods@#This is a retrospective study including 30 consecutive cases of congenital CMV infection that were diagnosed at a single tertiary hospital located in Seoul, Korea from January 2009 to December 2020. Congenital CMV infection was defined as a positive result by polymerase chain reaction from urine, saliva or cerebrospinal fluid or positive CMV IgM from neonatal blood sampled within 3 weeks after birth. All cases were analyzed with respect to whole clinical characteristics from diagnosis to treatment of congenital CMV by a multidisciplinary approach including prenatal sonographic findings, maternal immune status regarding CMV infection, detailed placental pathology, neonatal clinical manifestation, auditory brainstem response test, and antiviral treatment (ganciclovir or valganciclovir). Long-term outcomes including developmental delay and hearing loss were also investigated. @*Results@#The total number of births during the study period in our institution was 19,385, with the prevalence of congenital infection estimated to be 0.15%. Among 30 cases of congenital CMV, the median gestational age at delivery was 32.2 weeks [range, 22.6–40.0] and 66.7% of these infants were delivered preterm at less than 37 weeks. Suspected fetal growth restriction was the most common prenatal ultrasound finding (50%) followed by ventriculomegaly (17.9%) and abnormal placenta (17.9%), defined as thick placenta with calcification. No abnormal findings on ultrasound examination were observed in one-third of births. Maternal CMV serology tests were conducted in only 8 cases, and one case each of positive and equivocal IgM were found. The most common placental pathologic findings were chronic villitis (66.7%) and calcification (63.0%), whereas viral inclusions were identified in only 22.2%. The most common neonatal manifestations were jaundice (58.6%) followed by elevation of aspartate aminotransferase (55.2%) and thrombocytopenia (51.7%). After excluding cases for which long-term outcomes were unavailable due to death (n = 4) or subsequent follow up loss (n = 3), developmental delay was confirmed in 43.5% of infants (10/23), and hearing loss was confirmed in 42.9% (9/21) during the follow-up period. In our cohort, 56.7% (17/30) of neonates were treated for congenital CMV with ganciclovir or valganciclovir. @*Conclusion@#Our data show that prenatal findings including maternal serologic tests and ultrasound have limited ability to detect congenital CMV in Korea. Given that CMV is associated with high rates of developmental delay and hearing loss in infants, there is an urgent need to develop specific strategies for the definite diagnosis of congenital CMV infection during the perinatal period by a multidisciplinary approach to decrease the risks of neurologic impairment and hearing loss through early antiviral treatment.
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In the era of coronavirus disease 2019 (COVID-19), social distancing and strict visitation policies at hospitals have made it difficult for medical staff to provide high-quality endof-life (EOL) care to dying patients and their families. There are various issues related to EOL care, including psychological problems of patients and their families, difficulties in EOL decision-making, the complicated grief of the bereaved family, moral distress, and exhaustion of medical staff. In relation to these issues, we aimed to discuss practical considerations in providing high-quality EOL care in the COVID-19 pandemic. First, medical staff should discuss advance care planning as early as possible and use the parallel planning strategy. Second, medical staff should play a role in facilitating patient-family communication. Third, medical staff should actively and proactively evaluate and alleviate dying patients’ symptoms using non-verbal communication. Lastly, medical staff should provide care for family members of the dying patient, who may be particularly vulnerable to postbereavement problems in the COVID-19 era. Establishing a system of screening highrisk individuals for complicated grief and connecting them to bereavement support services might be considered. Despite the challenging and limited environment, providing EOL care is essential for patients to die with dignity in peace and for the remaining family to return to life after the loved one’s death. Efforts considering the practical issues faced by all medical staff and healthcare institutions caring for dying patients should be made.
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Purpose@#This study aimed to investigate difficulties doctors experience during life-sustaining treatment (LST) discussion with seriously ill patients and their families after enactment of the LST Decisions Act in February 2018. @*Materials and Methods@#A cross-sectional survey was conducted in a tertiary hospital in the Republic of Korea in August 2019. Six hundred eighty-six doctors who care for seriously ill patients were given a structured questionnaire, and difficulties during the discussion were examined. @*Results@#One hundred thirty-two doctors completed the questionnaire. Eighty-five percent answered they treat cancer patients. Most (86.4%) experienced considerable difficulties during LST discussions (mean score, 7.4±1.6/10). The two most common difficulties were communication with patients and family and determining when to discuss LST. Two-thirds of doctors found direct discussions with the patient difficult and said they would initiate LST discussions only with family. LST discussions were actually initiated later than considered appropriate. When medically assessing whether the patient is imminently dying, 56% of doctors experienced disagreements with other doctors, which could affect their decisions. @*Conclusion@#This study found that most doctors experienced serious difficulties regarding communication with patients and family and medical assessment of dying process during LST discussions. To alleviate these difficulties, further institutional support is needed to improve the LST discussion between doctors, patients, and family.
ABSTRACT
Purpose@#This study aimed to investigate difficulties doctors experience during life-sustaining treatment (LST) discussion with seriously ill patients and their families after enactment of the LST Decisions Act in February 2018. @*Materials and Methods@#A cross-sectional survey was conducted in a tertiary hospital in the Republic of Korea in August 2019. Six hundred eighty-six doctors who care for seriously ill patients were given a structured questionnaire, and difficulties during the discussion were examined. @*Results@#One hundred thirty-two doctors completed the questionnaire. Eighty-five percent answered they treat cancer patients. Most (86.4%) experienced considerable difficulties during LST discussions (mean score, 7.4±1.6/10). The two most common difficulties were communication with patients and family and determining when to discuss LST. Two-thirds of doctors found direct discussions with the patient difficult and said they would initiate LST discussions only with family. LST discussions were actually initiated later than considered appropriate. When medically assessing whether the patient is imminently dying, 56% of doctors experienced disagreements with other doctors, which could affect their decisions. @*Conclusion@#This study found that most doctors experienced serious difficulties regarding communication with patients and family and medical assessment of dying process during LST discussions. To alleviate these difficulties, further institutional support is needed to improve the LST discussion between doctors, patients, and family.
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Background@#Diseases related to cerebrospinal fluid flow, such as hydrocephalus, syringomyelia, and Chiari malformation, are often found in small dogs. Although studies in human medicine have revealed a correlation with cerebrospinal fluid flow in these diseases by magnetic resonance imaging, there is little information and no standard data for normal dogs. @*Objectives@#The purpose of this study was to obtain cerebrospinal fluid flow velocity data from the cerebral aqueduct and subarachnoid space at the foramen magnum in healthy beagle dogs. @*Methods@#Six healthy beagle dogs were used in this experimental study. The dogs underwent phase-contrast and time-spatial labeling inversion pulse magnetic resonance imaging. Flow rate variations in the cerebrospinal fluid were observed using sagittal time-spatial labeling inversion pulse images. The pattern and velocity of cerebrospinal fluid flow were assessed using phase-contrast magnetic resonance imaging within the subarachnoid space at the foramen magnum level and the cerebral aqueduct. @*Results@#In the ventral aspect of the subarachnoid space and cerebral aqueduct, the cerebrospinal fluid was characterized by a bidirectional flow throughout the cardiac cycle. The mean ± SD peak velocities through the ventral and dorsal aspects of the subarachnoid space and the cerebral aqueduct were 1.39 ± 0.13, 0.32 ± 0.12, and 0.76 ± 0.43 cm/s, respectively. @*Conclusions@#Noninvasive visualization of cerebrospinal fluid flow movement with magnetic resonance imaging was feasible, and a reference dataset of cerebrospinal fluid flow peak velocities was obtained through the cervical subarachnoid space and cerebral aqueduct in healthy dogs.
ABSTRACT
In the era of coronavirus disease 2019 (COVID-19), social distancing and strict visitation policies at hospitals have made it difficult for medical staff to provide high-quality endof-life (EOL) care to dying patients and their families. There are various issues related to EOL care, including psychological problems of patients and their families, difficulties in EOL decision-making, the complicated grief of the bereaved family, moral distress, and exhaustion of medical staff. In relation to these issues, we aimed to discuss practical considerations in providing high-quality EOL care in the COVID-19 pandemic. First, medical staff should discuss advance care planning as early as possible and use the parallel planning strategy. Second, medical staff should play a role in facilitating patient-family communication. Third, medical staff should actively and proactively evaluate and alleviate dying patients’ symptoms using non-verbal communication. Lastly, medical staff should provide care for family members of the dying patient, who may be particularly vulnerable to postbereavement problems in the COVID-19 era. Establishing a system of screening highrisk individuals for complicated grief and connecting them to bereavement support services might be considered. Despite the challenging and limited environment, providing EOL care is essential for patients to die with dignity in peace and for the remaining family to return to life after the loved one’s death. Efforts considering the practical issues faced by all medical staff and healthcare institutions caring for dying patients should be made.
ABSTRACT
Purpose@#In Korea, since the Act on Hospice and Palliative Care and Decisions on LifeSustaining Treatment for Patients at the End of Life was implemented in February 2018, advance directives (ADs) have become legally effective and should be documented after sufficient explanation by a registered counselor. However, little is known regarding the adequacy of current AD counseling. This qualitative study aimed to explore the barriers to AD counseling based on counselors’ experiences. @*Methods@#We conducted focus group interviews using purposive sampling. Seven counselors working at hospitals, community health institutions, and non-profit organizations participated in this study. They were asked about the challenges and problems they encountered during AD counseling. @*Results@#Three themes emerged from this study; 1) issues regarding consistency in AD counseling, 2) issues regarding AD counselors’ competency and work environment, and 3) issues regarding the adequacy of the service system. The interviewees stated that the lack of a manual for standardized service made AD counseling inconsistent. The limited competency and poor work environment of counselors were pointed out as major barriers. The interviewees also stated that a proper service system considering individual circumstances is absent. @*Conclusion@#The goals of AD counseling should be clarified and guidance should be implemented for providing standardized services. Further efforts to enhance the competency of AD counselors and to improve their working conditions are needed. Establishing an integrated framework for an adequate service system is also essential to overcome systematic barriers to AD counseling.
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Purpose@#Life-sustaining treatment (LST) decisions for patients and caregivers at the end-of-life (EOL) process are supported by the “Act on Hospice and Palliative Care and Decisions on LST for Patients at the EOL,” enforced in February 2018. Itremains unclearwhetherthe act changes EOL decisions and LST implementation in clinical practice. For this study, we investigated patients’ decision-making regarding LSTs during the EOL process since the act’s enforcement. @*Materials and Methods@#Retrospective reviews were conducted on adult patients who were able to decide to terminate LST and died at Seoul National University Hospital between February 5, 2018, and February 5, 2019. We examined demographics, who made the decisions, the type and date of documentation confirming patient's LST, and whether the LST was withheld or withdrawn. @*Results@#Of 809 patients who were enrolled, 29% (n=231) completed forms regarding LST themselves, and 71% (n=578) needed family members to decide. The median time from confirmation of the EOL process to death and from the Advance Statement to death were 2 and 5 days, respectively (both ranges, 0 to 244). In total, 90% (n=727) of patients withheld treatment, and 10% (n=82)withdrewit. We found a higherwithdrawalratewhen family members made the decisions (13.3% vs. 1.7%, p < 0.001). @*Conclusion@#After the act’s enforcement, withdrawing LSTs became lawful and self-determination rates increased. Family members still make 71% of decisions regarding LSTs, but these are often inconsistent with the patients’ wishes; thus, further efforts are needed to integrate the new act into clinical practice.
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Background@#Immunohistochemistry (IHC) has played an essential role in the diagnosis of hematolymphoid neoplasms. However, IHC interpretations can be challenging in daily practice, and exponentially expanding volumes of IHC data are making the task increasingly difficult. We therefore developed a machine-learning expert-supporting system for diagnosing lymphoid neoplasms. @*Methods@#A probabilistic decision-tree algorithm based on the Bayesian theorem was used to develop mobile application software for iOS and Android platforms. We tested the software with real data from 602 training and 392 validation cases of lymphoid neoplasms and compared the precision hit rates between the training and validation datasets. @*Results@#IHC expression data for 150 lymphoid neoplasms and 584 antibodies was gathered. The precision hit rates of 94.7% in the training data and 95.7% in the validation data for lymphomas were not statistically significant. Results in most B-cell lymphomas were excellent, and generally equivalent performance was seen in T-cell lymphomas. The primary reasons for lack of precision were atypical IHC profiles for certain cases (e.g., CD15-negative Hodgkin lymphoma), a lack of disease-specific markers, and overlapping IHC profiles of similar diseases. @*Conclusions@#Application of the machine-learning algorithm to diagnosis precision produced acceptable hit rates in training and validation datasets. Because of the lack of origin- or disease- specific markers in differential diagnosis, contextual information such as clinical and histological features should be taken into account to make proper use of this system in the pathologic decision-making process.
ABSTRACT
Background@#Immunohistochemistry (IHC) has played an essential role in the diagnosis of hematolymphoid neoplasms. However, IHC interpretations can be challenging in daily practice, and exponentially expanding volumes of IHC data are making the task increasingly difficult. We therefore developed a machine-learning expert-supporting system for diagnosing lymphoid neoplasms. @*Methods@#A probabilistic decision-tree algorithm based on the Bayesian theorem was used to develop mobile application software for iOS and Android platforms. We tested the software with real data from 602 training and 392 validation cases of lymphoid neoplasms and compared the precision hit rates between the training and validation datasets. @*Results@#IHC expression data for 150 lymphoid neoplasms and 584 antibodies was gathered. The precision hit rates of 94.7% in the training data and 95.7% in the validation data for lymphomas were not statistically significant. Results in most B-cell lymphomas were excellent, and generally equivalent performance was seen in T-cell lymphomas. The primary reasons for lack of precision were atypical IHC profiles for certain cases (e.g., CD15-negative Hodgkin lymphoma), a lack of disease-specific markers, and overlapping IHC profiles of similar diseases. @*Conclusions@#Application of the machine-learning algorithm to diagnosis precision produced acceptable hit rates in training and validation datasets. Because of the lack of origin- or disease- specific markers in differential diagnosis, contextual information such as clinical and histological features should be taken into account to make proper use of this system in the pathologic decision-making process.
ABSTRACT
GV1001 is a peptide derived from the human telomerase reverse transcriptase (hTERT) sequence that is reported to have anti-cancer and anti-inflammatory effects. Enolase1 (ENO1) is a glycolytic enzyme, and stimulation of this enzyme induces high levels of pro-inflammatory cytokines from concanavalin A (Con A)-activated peripheral blood mononuclear cells (PBMCs) and ENO1-expressing monocytes in healthy subjects, as well as from macrophages in rheumatoid arthritis (RA) patients. Therefore, this study investigated whether GV1001 downregulates ENO1-induced pro-inflammatory cytokines as an anti-inflammatory peptide. The results showed that GV1001 does not affect the expression of ENO1 in either Con A-activated PBMCs or RA PBMCs. However, ENO1 stimulation increased the production of pro-inflammatory cytokines such as tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta, and IL-6, and these cytokines were downregulated by pretreatment with GV1001. Moreover, p38 mitogen-activated protein kinase (MAPK) and nuclear factor (NF)-kappaB were activated when ENO1, on the surface of Con A-activated PBMCs and RA PBMCs, was stimulated, and they were successfully suppressed by pre-treatment with GV1001. These results suggest that GV1001 may be an effective anti-inflammatory peptide that downregulates the production of pro-inflammatory cytokines through the suppression of p38 MAPK and NF-kappaB activation following ENO1 stimulation.
Subject(s)
Humans , Arthritis, Rheumatoid , Concanavalin A , Cytokines , Down-Regulation , Inflammation , Interleukin-6 , Interleukins , Macrophages , Monocytes , NF-kappa B , p38 Mitogen-Activated Protein Kinases , Protein Kinases , Telomerase , Tumor Necrosis Factor-alphaABSTRACT
Asthma is a well-known inflammatory lung disease; however, the specific underlying mechanism is largely unknown. We previously demonstrated that alloferon effectively downregulates pulmonary inflammation. In this study, we examined whether alloferon has a therapeutic effect on asthma. Alloferon remarkably decreased the number of eosinophils, macrophages, and neutrophils in the bronchoalveolar lavage fluid (BALF) from ovalbumin (OVA)-induced asthma mice. It was synergistically decreased with 2.5 mg/kg prednisolone (PDA). Inflammatory cell infiltration around the bronchioles and in the alveolus of OVA-induced asthma mice was effectively prevented by alloferon alone and combined treatment with alloferon and PDS. The production of IL-5 and IL-17 was decreased by alloferon alone and combined treatment with alloferon and PDS. There was no change the level of total immunoglobulin (Ig) following alloferon administration; however, total Ig was decreased by PDS. IgG2a levels were not changed by either alloferon alone or alloferon in combination with PDS. However, the levels of OVA-specific IgG1 and IgE were decreased by alloferon and PDS. In conclusion, our results suggest that a combination of alloferon and prednisolone is effective for the treatment of asthma, as it prevents inflammatory cell infiltration via the down-regulation of IL-5 and IL-17 production and decreases IgG1 and IgE production via the suppression of T helper type 2 immune response.
Subject(s)
Animals , Mice , Asthma , Bronchioles , Bronchoalveolar Lavage Fluid , Down-Regulation , Eosinophils , Immunoglobulin E , Immunoglobulin G , Immunoglobulins , Interleukin-17 , Interleukin-5 , Lung Diseases , Macrophages , Neutrophils , Ovalbumin , Pneumonia , PrednisoloneABSTRACT
L-ascorbic acid (vitamin C) is one of the well-known anti-viral agents, especially to influenza virus. Since the in vivo anti-viral effect is still controversial, we investigated whether vitamin C could regulate influenza virus infection in vivo by using Gulo (-/-) mice, which cannot synthesize vitamin C like humans. First, we found that vitamin C-insufficient Gulo (-/-) mice expired within 1 week after intranasal inoculation of influenza virus (H3N2/Hongkong). Viral titers in the lung of vitamin C-insufficient Gulo (-/-) mice were definitely increased but production of anti-viral cytokine, interferon (IFN)-alpha/beta, was decreased. On the contrary, the infiltration of inflammatory cells into the lung and production of pro-inflammatory cytokines, tumor necrosis factor (TNF)-alpha and interleukin (IL)-alpha/beta, were increased in the lung. Taken together, vitamin C shows in vivo anti-viral immune responses at the early time of infection, especially against influenza virus, through increased production of IFN-alpha/beta.
Subject(s)
Animals , Humans , Mice , Ascorbic Acid , Cytokines , Influenza A virus , Influenza, Human , Interferons , Interleukins , Lung , Mustelidae , Orthomyxoviridae , Tumor Necrosis Factor-alpha , VitaminsABSTRACT
The L-gulono-gamma-lactone oxidase gene (Gulo) encodes an essential enzyme in the synthesis of ascorbic acid from glucose. On the basis of previous findings of bone abnormalities in Gulo-/- mice under conditions of ascorbic acid insufficiency, we investigated the effect of ascorbic acid insufficiency on factors related to bone metabolism in Gulo-/- mice. Four groups of mice were raised for 4 weeks under differing conditions of ascorbic acid insufficiency, namely, wild type; ascorbic acid-sufficient Gulo-/- mice, 3-week ascorbic acid-insufficient Gulo-/- mice, and 4-week ascorbic acid-insufficient Gulo-/- mice. Four weeks of ascorbic acid insufficiency resulted in significant weight loss in Gulo-/- mice. Interestingly, average plasma osteocalcin levels were significantly decreased in Gulo-/- mice after 3 weeks of ascorbic acid insufficiency. In addition, the tibia weight in ascorbic acid-sufficient Gulo-/- mice was significantly higher than that in the other three groups. Moreover, significant decreases in trabecular bone volume near to the growth plate, as well as in trabecular bone attachment to the growth plate, were evident in 3- or 4-week ascorbic acid-insufficient Gulo-/-. In summary, ascorbic acid insufficiency in Gulo-/- mice results in severe defects in normal bone formation, which are closely related to a decrease in plasma osteocalcin levels.
Subject(s)
Animals , Mice , Ascorbic Acid , Down-Regulation , Glucose , Growth Plate , L-Gulonolactone Oxidase , Metabolism , Osteocalcin , Osteogenesis , Plasma , Tibia , Weight LossABSTRACT
BACKGROUND: Vitamin C is an essential nutrient for maintaining human life. Vitamin C insufficiency in the plasma is closely related with the development of scurvy. However, in vivo kinetics of vitamin C regarding its storage and consumption is still largely unknown. METHODS: We used Gulo-/- mice, which cannot synthesize vitamin C like human. Vitamin C level in plasma and organs from Gulo-/- mice was examined, and it compared with the level of wild-type mice during 5 weeks. RESULTS: The significant weight loss of Gulo-/- mice was shown at 3 weeks after vitamin C withdrawal. However, there was no differences between wild-type and vitamin C-supplemented Gulo-/- mice (3.3 g/L in drinking water). The concentration of vitamin C in plasma and organs was significantly decreased at 1 week after vitamin C withdrawal. Vitamin C is preferentially deposited in adrenal gland, lymph node, lung, and brain. There were no significant changes in the numbers and CD4/CD8 ratio of splenocytes in Gulo-/- mice with vitamin C withdrawal for 4 weeks. And the architecture of spleen in Gulo-/- mice was disrupted at 5 weeks after vitamin C withdrawal. CONCLUSION: The vitamin C level of Gulo-/- mice was considerably decreased from 1 week after vitamin C withdrawal. Vitamin C is preferentially stored in some organs such as brain, adrenal gland and lung.
Subject(s)
Animals , Humans , Mice , Adrenal Glands , Ascorbic Acid , Brain , Drinking , Kinetics , Lung , Lymph Nodes , Plasma , Scurvy , Spleen , Vitamins , Weight LossABSTRACT
Vitamin C is an essential water-soluble nutrient which primarily exerts its effect on host defense mechanisms and immune homeostasis, but the mechanism related to immune-potentiation is poorly understood. Since dendritic cells (DCs) are known as a potent antigen presenting cell (APC) that could enhance the antigen specific immune responses, we investigate the effects of vitamin C on activation of DCs and its related mechanism by using dendritic cell lines, DC-1. First, we found that there was no damage on DC-1 by 2.5 mM of vitamin C. In the presence of vitamin C, the expression of CD80, CD86, and MHC molecules was increased, but it was decreased by the pre-treatment of SB203580, p38 MAPK-specific inhibitor. We confirmed the phosphorylation of p38 MAPK was increased by the treatment of vitamin C. Taken together, these results suggest that vitamin C could enhance the activity of dendritic cells via the up-regulation of the expression of CD80, CD86, and MHC molecules and the activation of p38 MAPK is related to this process.
Subject(s)
Ascorbic Acid , Defense Mechanisms , Dendritic Cells , Homeostasis , Imidazoles , p38 Mitogen-Activated Protein Kinases , Phosphorylation , Pyridines , Up-Regulation , VitaminsABSTRACT
BACKGROUND: It is already known that high concentration of vitamin C induces apoptosis on tumor cells. However, there is no report regarding the function of vitamin C on the modulation of immune susceptibility of cancer. Therefore, we investigated whether vitamin C can modulate immune susceptibility of tumor cells, especially on the induction of Fas-mediated apoptosis. METHODS: First, the optimal concentration of vitamin C, which cannot induce damages on tumor cells for 36 hrs. We found that 2 mM of vitamin C did not show harmful effect. In addition, the optimal concentration of agonistic anti-Fas Abs for 18 hrs was examined. RESULTS: As a result, 400 ng/ml of agonistic anti-Fas Abs did not induce apoptosis on tumor cells. Next, we tried to find the effect of 2 mM of vitamin C on the modulation of the susceptibility to agonistic anti-Fas Abs. When tumor cells were cultured with 400 ng/ml of agonistic anti-Fas Abs for 18 hrs, after pre-treatment with 2 mM of vitamin C for 24 hrs, viability of cells was decreased. Interestingly, we found that the expression of Fas (CD95) and MHC class I was increased by the treatment of vitamin C. CONCLUSION: Taken together, vitamin C increases the susceptibility of tumor cells to anti-Fas Abs and the expression of Fas (CD95) and MHC class I on tumor cells.