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PubMed1991

Active immunity is seen as a reduction in the cell response to oral live vaccine.

Oral immunization elicits a response of antibody-secreting cells (ASC) in the peripheral blood; these cells are believed to originate in the mucosa and hence give information on the mucosal immune response. We have shown earlier that oral booster immunization is followed by an elevated ASC response reflecting an immunologic memory. In the present study we show that a booster dose of a live bacterial vaccine given at a time of active mucosal immunity elicits a low ASC response only. This is probably because the multiplication of the live vaccine is inhibited in the gut, resulting in a low actual dose of the antigen. This situation may be an example of the protective immunity manifested when an orally immunized person encounters the pathogen in nature, and could be used to assess the protective immunity.

Administration, Oral↗

PubMed1994

An early humoral immune response in peripheral blood following parenteral inactivated influenza vaccination.

The enzyme-linked immunospot assay was used to examine the humoral immune response in 15 healthy volunteers immunized with either split or subunit inactivated trivalent influenza vaccine containing A/Beijing/353/89 (H3N2), A/Taiwan/1/86 (H1N1) and B/Yamagata/16/88. The rapidity of the individual B-cell and serum antibody response was examined in lymphocyte and serum samples collected at various time intervals after vaccination. A rapid serological response was detected with increases in antibody titre detected in the majority of volunteers by 7-8 days postvaccination. Influenza-specific plasma cells were detected as early as 4 days postvaccination, higher numbers of IgA and IgG antibody-secreting cells (ASC) were observed which peaked at 7-8 days postvaccination. The number of ASCs then declined, with low numbers of cells detected at 11 days postvaccination. Influenza-specific IgA ASCs were predominantly of the IgA1 subclass. This rapid immune response may have a bearing on future vaccination policies of unimmunized 'at risk groups' in times of high influenza activity.

Adult↗

PubMed1981

Comparison of the rate of aminoacylation of tRNA isolated from NMRI mouse liver with tRNA isolated from Krebs II ascites or mouse plasmacytoma cells.

A comparison of the initial rates of aminoacylation of tRNAs isolated from different sources for 17 amino acids was performed. tRNA was isolated from NMRI mouse liver (tRNA L) and from Krebs II ascites tumors (tRNA Asc), and aminoacyl-tRNA synthetases were prepared from the latter cells. The aminoacylation of tRNA Asc was 31-88% slower than the charging of tRNA L. In similar studies, tRNA from a mouse plasmacytoma tumor (tRNA Mt) and from suspension cultured cells of the same cell line (tRNA M) were compared to tRNA L in the aminoacylation reaction catalysed by synthetases isolated from tumor or suspension cultured cells. About half of the tRNAs (Mt or M) for the 17 amino acids tested differed in charging rate when compared to tRNA L, but the differences were not as great as those observed in the experiments where tRNA Asc and tRNA L were compared.

Amino Acyl-tRNA Synthetases↗

PubMedDate not supplied

Immune recognition of cytochrome c. I. Molecular requirements for antibody recognition and immune response stimulation studied in vitro with synthetic peptides.

The epitope specificity of antibodies to horse cytochrome c (cyt.c) in the primary and secondary immune response of C57BL mice was studied by means of the ELISA technique with synthetic peptides of cyt.c. It was found that, in the early primary response, N- and C-end fragments of cyt.c (peptides 2-13, 14-22 and 92-104) were preferentially recognized. In the secondary response, more antibodies to the epitopes of the central part of the molecule (peptides 61-69 and 46-56) were found. This was presumed to be due to the mode of cyt.c processing and presentation in the course of immune response: at first, cyt.c was recognized in the native form and then in the processed one. The capacity of cyt.c peptides to stimulate the formation of cyt.c-specific antibody-secreting cells (ASC) was studied in splenocyte culture of C57BL mice. Peptides stimulated more ASC than cyt.c did, but larger molar doses of peptides were required. Comparison of the capacity of related peptides (1-13 and 2-13, 61-69, 61-77 and 57-77) to be recognized by antibodies produced to native cyt.c in vivo and to stimulate anti-cyt.c ASC in vitro suggested certain molecular requirements for cyt.c epitope and agretope formation. These were partially confirmed by computer analysis.

Animals↗

PubMed1994

Disaccharide analysis of dermal fibroblast-derived glycosaminoglycans in the three-dimensional culture.

We performed the quantitative and qualitative analysis on the main disaccharide units of glycosaminoglycans produced by human dermal fibroblasts in the 3-dimensional culture supplemented with L-ascorbic acid 2-phosphate (Asc 2-p) comparing with the monolayer culture system. The addition of Asc 2-p rendered fibroblasts to the organization of the dermis-like 3-dimensional structure in vitro without any pre-treatments with the plastic dish. Main disaccharide units were analyzed using HPLC after 1-phenyl-3-methyl-5-pyrasolone (PMP) labeling. The addition of Asc 2-p significantly increased the total amount of main disaccharide units and, furthermore, the composition revealed it to be more similar to that of the dermis. This 3-dimensional culture may offer a simple and useful system to investigate the glycosaminoglycan metabolism of human dermal fibroblasts in vitro.

Ascorbic Acid↗

PubMed1996

The relationship between quantitative changes in collagen and formation of wrinkles on hairless mouse skin after chronic UV irradiation.

Female albino hairless mice were irradiated chronically with sub-erythemal doses of UVB radiation. Collagen extracted from the irradiated or non-irradiated dorsal skin of mice was fractionated into neutral salt-soluble (NSC), acid-soluble (ASC) and insoluble fractions (ISC). An age-related exponential decrease in the content and proportion of acid-soluble collagen was found in each group. The contents and the proportions of ASC from irradiated mice were always significantly lower than those from age-matched control animals. Age-related slight decreases were observed in the contents (per fresh weight of tissues) of NSC, ISC and total collagen in the control group but decreases in these collagen contents after UVB irradiation were marked. A dramatic decrease in ASC occurred nearly concomitantly with wrinkle formation in the irradiated mice. The decrease of acid-soluble skin collagen in irradiated mice may play a role in the formation of wrinkles on hairless mouse dorsal skin.

Animals↗

PubMed2006

An ascorbate-reducible cytochrome b561 is localized in macrophage lysosomes.

Cytochromes b561 (Cyts b561) are a family of intrinsic membrane proteins involved in ascorbate-mediated transmembrane electron transport. The chromaffin granule Cyt b561 (CGCytb) is believed to transport electrons donated by extravesicular ascorbate (ASC) across the membrane to intravesicular monodehydroascorbate (MDA) supporting catecholamine synthesis in neuroendocrine tissues. Another isoform, the duodenal Cyt b561 (Dcytb), was reported to have ferric reductase activity, possibly facilitating intestinal iron uptake. Herein, a new Cyt b561 homologue, LCytb (for lysosomal Cytb561) was found expressed in the late endosomal-lysosomal membrane. LCytb shared high sequence similarity with CGCytb (45% identity) and Dcytb (42% identity). Moreover, four heme-coordinating His residues, and putative ASC and MDA binding sites were highly conserved. Recombinant LCytb exhibited an ASC-reducible b-type Cyt absorbance spectrum with alpha-band maximum at 561 nm in the spectrum of the reduced protein. Northern blots and Western blots revealed that LCytb was predominantly expressed in lung, spleen, thymus, testis and placenta. In situ hybridization and immunofluorescence studies further demonstrated that the protein was expressed in the alveolar macrophages of the lung, in the white pulp of the spleen, widespread in the thymus, and in the Sertoli cells of the testis. Sequence analysis indicated the presence of a (DE)XXXL(LI)-type signal in the C-terminal of the protein, predicting a late endosomal-lysosomal subcellular localization. This localization was confirmed by double labeling experiments in RAW264.7 and 293 cells, stably transfected with LCytb.

Amino Acid Sequence↗

PubMed2005

Elevation of cyclooxygenase-2 is related to lymph node metastasis in adenocarcinoma of uterine cervix.

In a previous study, we demonstrated that elevation of COX-2 is significantly associated with lymph node metastasis in squamous cell carcinoma (SCC) of cervix. The main objective of this study is to characterize the relationship between elevation of COX-2 and its possible clinical role in adenocarcinoma (AC) of cervix. Using immunohistochemistry, we examined COX-2 expression levels in 84 patients with AC of uterine cervix [71 ACs, 13 adenosquamous carcinomas (ASCs)]. Elevation of COX-2 was correlated with clinicopathological variables and p53 expression, as detected by immunohistochemistry. Elevation of COX-2 was detected in 13.0% (11 of 84) of the tumors. Elevation of COX-2 was significantly correlated with histologic type (AC 8.5% vs. ASC 38.5%, P=0.011). Both tumor stage and lymph node metastasis were correlated with elevation of COX-2 with a borderline significance (P=0.062 and 0.068, respectively). Elevation of p53 was not associated with elevation of COX-2. The association between lymph node metastasis and elevation of COX-2 was stronger in cases of AC than in cases of ASC (28.4 vs. 4.3%, P=0.023). According to the results of univariate analysis, elevation of COX-2 was significantly associated with decreased overall survival (P=0.003, log-rank test). However, multivariate analyses revealed that only tumor stage was independently associated with overall survival, suggesting that elevation of COX-2 itself may not be an independent prognostic factor. The present study shows that elevation of COX-2 may contribute to lymph node metastasis in AC of uterine cervix. This suggests that the potential therapeutic role of COX-2 inhibitors should be validated, not only in SCC, but also in AC of uterine cervix.

Adenocarcinoma↗

PubMed2004

Relationship between the action of reactive oxygen and nitrogen species on bilayer membranes and antioxidants.

Membrane lipid peroxidation (LPO) induced by hydroxyl (*OH) and ascorbyl (*Asc) radicals and by peroxynitrite (ONOO-) was investigated in asolectin (ASO), egg phosphatidylcholine (PC) and PC/phosphatidic acid mixtures (PC:PA) liposomes and rat liver microsomes (MC). Enthalpy variation (DeltaH) of PC:PA at different molar ratios were obtained by differential scanning calorimetry. It was also evaluated the LPO inhibition by quercetin, melatonin and Vitamin B6. The oxidant effect power follows the order *OH approximately *Asc > ONOO- on PC and MC; whilst on ASO liposomes, it follows *Asc > *OH approximately ONOO-. Increasing amounts of PA in PC liposomes resulted in lower levels of LPO. The DeltaH values indicate a more ordered membrane arrangement as a function of PA amount. The results were discussed in order to provide a complete view involving the influence of membranes, oxidants and antioxidants intrinsic behavior on the LPO dynamics.

Animals↗

PubMed2006

The involvement of the antioxidant system in protection of desert cyanobacterium Nostoc sp. against UV-B radiation and the effects of exogenous antioxidants.

In this study, we found that UV-B radiation decreased photosynthetic activity and boosted lipid peroxidation of desert Nostoc sp., and exogenous chemicals (ascorbate acid (ASC), N-acetylcysteine (NAC), and sodium nitroprusside (SNP)) had obvious protective effects on photosynthesis and membranes under UV-B radiation. High-concentration SNP boosted the activities of antioxidant enzymes, but low-concentration SNP reduced the activities of antioxidant enzymes. Both NAC and ASC treatments of cells decreased activities of antioxidant enzymes. The results suggested that those chemicals possibly had different mechanisms of protection of algae cells against UV-B radiation. SNP might play double roles as a signal molecule in the formation of algae cell protection of Photosystem II under UV-B radiation and as a (reactive oxygen species) scavenger, while NAC and ASC might function as antioxidant reagents or precursors of other antioxidant molecules, which could protect cells directly against ROS initiated by UV-B radiation.

Antioxidants↗

PubMed2005

Reduced expression of 1-cys peroxiredoxin in oxidative stress-induced cataracts.

1-cys peroxiredoxin (1-cysPrx), a member of the peroxiredoxin family with a single conserved cysteine residue, reduces a broad spectrum of hydroperoxides. This study was undertaken to examine changes in 1-cysPrx expression in human cataract samples, human lens epithelial (HLE B3) cell line, and rat organ-cultured lenses in response to oxidative insult induced by H2O2 or transforming growth factor-beta1 (TGF-beta1). Expression of 1-cysPrx mRNA and protein in HLE B3 cells increased in response to 2-8 ng ml(-1) TGF-beta1 and 50-75 microm H2O2 and then decreased below the control level at high doses (10 ng ml(-1) TGF-beta1 and 100-150 microm H2O2), as determined by Northern blot and immunoblot analysis. This reduction coincided with the decrease of cell viability. Immunoreactive 1-cysPrx protein was measured in capsulorrhexis specimens obtained from patients with anterior subcapsular cataract (ASC), nuclear sclerosis (NS), cortical spokes (CS), posterior subcapsular cataract (PSC), or white mature cataract (WC) at the time of cataract surgery. Significant reduction of 1-cysPrx protein was observed in ASC, PSC, and WC samples, but there was no statistical difference in CS and NS samples relative to normal control. Also, rat lens explants were cultured with 10 ng ml(-1) TGF-beta1 for approximately 5 days or 500 microm H2O2 for approximately 2 days. Subsequently, expression of 1-cysPrx mRNA and protein in the lens capsules was evaluated. Rat lens explants treated with TGF-beta1 or H2O2 developed a cataract similar to human ASC or WC, respectively, which resulted in a markedly decreased expression of 1-cysPrx mRNA and protein. Collectively, these findings show that expression patterns of 1-cysPrx gene in the lens are changed in response to oxidative stress, a major factor in the etiology of cataract.

Animals↗

PubMed2004

Ascorbate distribution during hibernation is independent of ascorbate redox state.

Distribution of ascorbate into tissues is an essential process in ascorbate antioxidant defense. Hibernating animals are studied as a model of tolerance to ischemia-reperfusion because of their tolerance to fluctuations in blood flow associated with prolonged torpor and periodic arousal episodes. Throughout hibernation, plasma ascorbate concentration ([Asc](p)) repetitively increases during torpor, then falls during periodic arousal bouts. We previously proposed that high [Asc](p) provides a ready source of antioxidant protection for distribution to the central nervous system and peripheral tissues during arousal. Here we tested whether deliberate oxidation of plasma ascorbate by intravenous administration of ascorbate oxidase (AO), prior to arousal, compromised tissue levels of ascorbate or the other water-soluble antioxidants, glutathione (GSH) and urate. Although AO decreased [Asc](p) to below the level of detection during torpor and after arousal, ascorbate oxidation did not decrease post-arousal tissue levels of reduced ascorbate, glutathione, or urate in any tissue examined, except liver. The data imply that ascorbate is taken up equally well into brain and other tissues as either ascorbate or its oxidized product dehydroascorbate, with subsequent intracellular reduction of dehydroascorbate. Lack of effect of ascorbate oxidation on tissue levels of GSH or urate indicates that dehydroascorbate uptake and reduction do not compromise tissue concentrations of these other water-soluble antioxidants. Thus, we show equal availability of reduced and oxidized plasma ascorbate during metabolically demanding thermogenesis and reperfusion associated with arousal from hibernation.

Animals↗

PubMed2004

[Colposcopy: the value of HPV testing in clinical practice].

The indications for colposcopy have changed recently because of the new Bethesda terminology, the introduction of HPV testing in clinical practice, and the latest consensus guidelines on management of patients with an abnormal cervical cytological test. Colposcopy remains the reference technique to assess patients with abnormal cytological test results, especially those with ASC-H, LSIL, HSIL, and AGC. In women with an ASC-US result, colposcopic examination of only those who test positive for high-risk HPV increases the specificity of the technique. When liquid-based cytology is used, HPV DNA testing is the preferred approach in these women. In primary screening using combined cytology and HPV DNA testing in women over the age of 30, colposcopy is indicated in patients with normal cytology and two HR HPV DNA positive tests performed at a nine month interval. For the follow up of untreated patients with ASC-US/LSIL and CIN I, colposcopy carried out at one year after a single HR HPV DNA positive test is as sensitive as colposcopy after two or three abnormal cytology tests. After excision or conization in patients with high-grade CIN, colposcopy after a single HR HPV DNA positive test is as sensitive as cytology testing and colposcopy at six months. Therapeutic decisions must not be based solely on the results of HPV DNA testing except in specific cases.

Adult↗

PubMed2006

[ASCUS: an update].

A report of ASCUS is always confusing or painful to the clinician, as histological correlate of this diagnosis is wide, ranging from a totally normal cervix mucosa to infiltrating carcinoma; most of the time it is the result of benign inflammatory or reactive changes. This is the reason why this category has evolved since its introduction in the Bethesda system for reporting cervical cytology in 1988, to achieve a closer link to the lesional diagnosis. The most recent modification took place in 2001, to subcategorize the ASC into ASC-US and ASC-H. The present review provides guidelines to manage these diagnoses.

Cytodiagnosis↗

PubMed2006

Alteration of serum cytokine balances among different phases of chronic hepatitis B virus infection.

To understand the pathogenesis of chronic hepatitis B virus (HBV) infection, we examined the serum levels of IL-10, TNF-alpha IL-12 p70, and IL-12 p40 in 77 patients chronically infected with HBV and 19 controls. The patients were classified into four groups: asymptomatic carriers (ASC), patients with chronic hepatitis (CH), patients with liver cirrhosis (LC), and patients with hepatocellular carcinomas (HCC). The cytokine values among these groups were compared and their relations to clinical parameters were investigated. All these cytokine values were higher in the patient groups than in controls. IL-10 and TNF-alpha became higher in accordance with the progress of the disease phases, from ASC to LC, and lowest when the patients had HCC. IL-12 p40 was also lowest in HCC, however, the group with highest levels was CH. IL-12 p70 was unchanged among ASC, CH, and LC, but were raised in HCC. Serial analyses for the cytokine values in the same patients showed the similar tendencies. Regression analysis showed the significant correlations between ALT and IL-10. Serum cytokine values well reflected the pathological differences of the individual disease phases, and may become useful indices to understand the pathogenesis of chronic HBV infection.

Journal Article↗

PubMed2006

Hepatitis B virus genotypes in acute and fulminant hepatitis patients from north India using two different molecular genotyping approaches.

Data from India on hepatitis B virus (HBV) genotype related differences in clinical progression and outcome of acute and fulminant hepatitis B are limited. Sera from patients with acute hepatitis B (AHB) (n=80), fulminant hepatitis B (FHB) (n=40) and asymptomatic HBsAg carriers (ASC) (n=40) were tested for HBV genotype using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and type-specific primers-based PCR (TSP-PCR). The genotype distribution for 160 patients with HBV related hepatitis/carriers were as follows: A, 3/80 (3.7%) in AHB, 2/40 (5%) in FHB and 7/40 (17.5%) in ASC; D, 77/80 (96.2%) in AHB, 38/40 (95%) in FHB and 33/40 (82.5%) in ASC. C, 0; B, 0; E, 0; F, 0 (p<0.01, genotype D versus A). Compared with genotype D, genotype A patients had no significant clinical or biochemical differences (p>0.05). HBV genotypes A and D were found to be prevalent in patients with HBV related acute and fulminant hepatitis from New Delhi, India. Genotype D was the dominant genotype prevalent in all patient categories while genotype A was solely responsible for AHB leading to chronic hepatitis B in 3.7% of the cases from this region.

Journal Article↗

PubMed2005

The effect of osmoticum on ascorbate and glutathione metabolism during white spruce (Picea glauca) somatic embryo development.

Water stress is an important factor which regulates organized development of both zygotic and somatic embryos. Somatic embryos of white spruce were cultured in the presence of polyethylene glycol (PEG), a non-plasmolyzing agent which increases embryo quality and number, and mannitol, a plasmolyzing agent. The effects of these two compounds on both ascorbate and glutathione metabolism were investigated at different stages of embryo development. Compared to control and mannitol-treated embryos, embryos treated with PEG accumulated higher levels of endogenous ascorbate (ASC) in its reduced form, especially during the first half of the maturation period. This increase, also observed in immature seeds, was mainly the result of two different processes: activation of the de novo ASC machinery, and recycling of ASC from ascorbate free radicals (AFR) which was modulated by the activity of ascorbate free radical reductase (AFRR, EC. 1.6.5.4). The activity of this enzyme increased during the early phases of development in both PEG-treated somatic embryos and seeds. Compared to control somatic embryos, mannitol and PEG were shown to change the levels of reduced (GSH) and oxidized glutathione (GSSG). In particular, a constant decline in the GSH/GSSG ratio was observed in the presence of PEG. This pattern was also observed in maturing white spruce seeds. Overall, these data indicate that applications of non-plasmolyzing agents in the culture medium of spruce somatic embryos result in seed-like fluctuations of the ascorbate-glutathione metabolism, which may have a positive effect on embryo yield.

Ascorbic Acid↗

PubMed2004

The nitric oxide synthase inhibitor N(G)-nitro-L-arginine decreases defibrillation-induced free radical generation.

OBJECTIVES: to demonstrate that nitric oxide (NO) contributes to free radical generation after epicardial shocks and to determinethe effect of a nitric oxide synthase (NOS) inhibitor, N(G)-nitro-L-arginine (L-NNA), on free radical generation. BACKGROUND: Free radicals are generated by direct current shocks for defibrillation. NO reacts with the superoxide (O2*-) radical to for peroxynitrite (O = NOO-), which is toxic and initiates additional free radical generation. The contribution of NO to free radical generation after defibrillation is not fully defined. METHODS AND RESULTS: Fourteen open chest dogs were studied. In the initial eight dogs, 40 J damped sinusoidal monophasic epicardial shocks was administered. Using electron paramagnetic resonance, we monitored the coronary sinus concentration of ascorbate free radical (Asc*-), a measure of free radical generation (total oxidative flux). Epicardial shocks were repeated after L-NNA, 5 mg/kg IV. In six additional dogs, immunohistochemical staining was done to identify nitrotyrosine, a marker of reactive nitrogen species-mediated injury, in post-shock myocardial tissue. Three of these dogs received L-NNA pre-shock. After the initial 40 J shock, Asc*- rose 39 +/- 2.5% from baseline. After L-NNA infusion, a similar 40 J shock caused Asc*- to increase only 2 +/- 3% form baseline (P < 0.05, post-L-NNA shock versus initial shock). Nitrotyrosine staining was more prominent in control animals than dogs receiving L-NNA, suggesting prevention of O = NOO- formation. CONCLUSION: NO contributes to free radical generation and nitrosative injury after epicardial shocks; NOS inhibitors decrease radical generation by inhibiting the production of O = NOO-.

Animals↗