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PubMed2006

Applicability of the Bethesda System 2001 to a public health setting.

BACKGROUND: The degree of applicability of the Bethesda System 2001 (TBS 2001) for cervicovaginal cytology to a public health setting is unknown, and extrapolations from available data are unwarranted. METHODS: A "before/after" study design was used to evaluate the impact of TBS 2001 on an organized, population-based screening program in northern Italy. Between 2003-2004, 6 cytology laboratories converted from TBS 1991 to TBS 2001. A set of screening indicators based on TBS 2001 (85,012 patients) were compared with those based on TBS 1991 (199,833 patients) by means of their laboratory- and patient age-standardized ratio with a 95% confidence interval (CI). RESULTS: The prevalence of cervical intraepithelial neoplasm (CIN)2-3/carcinoma was stable between the 2 populations. TBS 2001 had no effect on the unsatisfactory rate (1.99% vs. 2.03% for TBS 1991) nor on follow-up compliance rate (93.2% vs. 92.3%). The reporting rate of atypical squamous cells (ASC) decreased from 17.1 to 14.7 per 1000 (ratio, 0.86; 95% CI, 0.81-0.91), the total positivity rate from 31.1 to 29.0 per 1000 (ratio, 0.93; 95% CI, 0.90-0.97), and the ASC:SIL (squamous intraepithelial lesion) ratio from 1.38 to 1.16. Compared with the ASCUS (ASC of undetermined significance) reports of TBS 1991, the predictive value for CIN2-3/carcinoma decreased from 5.2 to 3.5% (ratio, 0.68; 95% CI, 0.48-0.93) among ASCUS reports, but increased from 5.1 to 17.2% (ratio, 3.41; 95% CI, 1.64-6.28) among ASC-cannot exclude high grade lesion (ASC-H) reports. ASC-H had a 5.01-fold (95% CI, 2.23-10.2) greater predictive value than ASCUS. CONCLUSIONS: TBS 2001 is applicable to cervical screening in a public health setting.

Female↗

PubMed2006

The significance of "low-grade squamous intraepithelial lesion, cannot exclude high-grade squamous intraepithelial lesion" as a distinct squamous abnormality category in Papanicolaou tests.

BACKGROUND: Early cytologic detection and treatment of high-grade squamous intraepithelial lesion (HSIL) is critical to cervical cancer prevention. The term atypical squamous cells (ASC), cannot exclude HSIL (ASC-H) was introduced in 2001 in the Bethesda System (TBS 2001) to define changes suggestive, but not diagnostic, of HSIL in the absence of unequivocal squamous intraepithelial lesion (SIL). Previous studies showed that women with ASC-H cytology are at an increased risk of harboring underlying histopathologic HSIL. TBS 2001, however, did not address the significance of finding ASC-H changes in a background of unequivocal low-grade SIL (LSIL). There may be a tendency for cytologists to lump these changes with either LSIL or HSIL, depending on their level of comfort. In their laboratory, the authors have referred to these changes as "LSIL, cannot exclude HSIL" (LSIL-H). METHODS: Between July 2001 and July 2003, all Papanicolaou (Pap) tests that were obtained by using the ThinPrep technique were retrieved from the computer data base at the authors' institution. All categories of squamous cell abnormalities, including LSIL-H, were evaluated for their incidence and follow-up diagnoses of HSIL and more severe lesions (HSIL +). All patients had a minimum of 2 year follow-up by biopsy and cytology (range, 2-4 years). RESULTS: LSIL-H comprised 0.15% (n = 194) of all Pap tests (n = 129,911) that were evaluated during the study period. Follow-up biopsy was available on 59 patients (30.4%), which showed HSIL + in 40.7% of patients. This rate of associated HSIL + differed significantly from that of LSIL (13%; P < .001) and HSIL (74%; P < .001), but was similar to that of ASC-H (44.6%). CONCLUSIONS: The results from this study showed that patients with cytologic diagnoses of LSIL-H had an intermediate risk of harboring histopathologic HSIL +. This risk was similar to ASC-H but fell between the low risk associated with ACS-US and LSIL and the high risk associated with HSIL cytologic diagnoses. The authors believe that LSIL-H should be considered as a distinct cytologic diagnostic interpretation and should be separated from LSIL and HSIL. Although LSIL-H does not represent a unique biologic entity, it has clinical usefulness because of its high positive predictive value for HSIL + lesions.

Female↗

PubMed2006

A comparison of the clinical utility of p16(INK4a) immunolocalization with the presence of human papillomavirus by hybrid capture 2 for the detection of cervical dysplasia/neoplasia.

BACKGROUND: Evidence suggests that overexpression of p16(INK4a) protein indicates infection and genomic integration of high-risk human papillomavirus (HR HPV) and predicts progression to cervical high-grade squamous intraepithelial lesions (HSILs) and carcinoma. The authors compared the ability of p16(INK4a) and HR HPV detection by Hybrid Capture 2 (HC2) to detect the presence of significant cervical disease. METHODS.: Four hundred ThinPrep specimens (100 each in 4 categories: 100 specimens that were negative for intraepithelial lesions, 100 specimens of atypical squamous cells of undetermined significance [ASC-US], 100 specimens of low-grade squamous intraepithelial lesions [LSILs], and 100 specimens of HSILs) were analyzed. p16(INK4a) protein was immunolocalized using a specific monoclonal antibody, and the detection of HR HPV in all 400 specimens was determined using HC2. RESULTS: p16(INK4a) was found to be positive in 78% of HSIL specimens, 42% of LSIL specimens, and 36% of ASC-US specimens; whereas HC2 was positive in 92% of HSIL specimens, 81% of LSIL specimens, and 45% of ASC-US specimens. In the HSIL category, the sensitivity, which was calculated using Grade 2 or greater cervical intraepithelial neoplasia as the endpoint, was 78% (50 of 66 specimens) for p16(INK4a) and 91% (60 of 66 specimens) for HC2. For LSIL, the sensitivity was 75% (3 of 4 specimens) for p16(INK4a) and 100% (4 of 4 specimens) for HC2. In the ASC-US category, the sensitivity was 89% (8 of 9 specimens) for p16(INK4a) and 100% (9 of 9 specimens) for HC2. Overall, the sensitivity for HSIL was 92% for HC2 and 78% for p16(INK4a). The specificity for HC2 was 8.3% for HSIL, 16.9% for LSIL, and 48.7% for ASC-US; whereas the specificity for p16(INK4a) was 25% in HSIL, 59.1% in LSIL, and 68.4% in ASC-US. The overall specificity was 25% for HC2 and 56% for p16(INK4a). CONCLUSIONS: Although both p16(INK4a) and HC2 may aid in the clinical management of patients with clinically significant lesions, HC2 was found to have greater sensitivity, and p16(INK4a) greater specificity. The labeling of normal cells and bacteria may preclude the use of p16(INK4a) in automated screening or nonmorphologic assays.

Adolescent↗

PubMed2004

Appraisal of social concerns: a cognitive assessment instrument for social phobia.

The current study describes the validation of a new cognitive assessment measure for social phobia, entitled the Appraisal of Social Concerns (ASC). Item content is relevant to a range of social situations. The ASC can be used to tailor interventions to patients' idiosyncratic concerns. Data are presented from both clinical (n = 71) and non-clinical (n = 550) samples. Preliminary data indicate that the ASC has good internal consistency and test-retest reliability. The construct validity of the ASC is comparable to that of well-established measures in use with social phobics. A strength of the ASC is its sensitivity to the effect of treatment. An exploratory factor analysis yielded three factors tapping concerns about negative evaluation, observable symptoms, and social helplessness. Subscale scores were strongly correlated. Preliminary findings suggest that the ASC is a psychometrically sound, time efficient instrument that can be used for both clinical and research purposes.

Adult↗

PubMed2004

P16INK4a as an adjunct marker in liquid-based cervical cytology.

Cytological screening for cervical cancer is hampered by high false negative rates. Inter-observer reproducibility needs optimizing. The potential of p16(INK4a) as a biomarker for cervical lesions was examined in a study of liquid-based cytology (LBC), HPV DNA testing by MY09/MY11 consensus PCR and type-specific PCRs and p16(INK4a) immunocytochemistry on a series of 291 patients selected from routine screening. Comparison of the number of p16(INK4a) immunoreactive cells/1,000 cells exhibited a significantly higher mean count in HSIL (8.80 +/- 1.13) than other cytological groups. The mean count of LSIL (1.09 +/- 0.18) was significantly higher than that of the negative group (0.82 +/- 0.40). ASC-H and HSIL combined showed a significantly higher mean count (6.46 +/- 1.17) than negative, ASC, ASC-US and LSIL. The mean count of immunoreactive cells/1,000 cells was significantly higher in HPV16 positive samples (3.22 +/- 0.72) than in samples containing infections with types of unknown malignant potential (0.83 +/- 0.26) or HPV negative samples (1.17 +/- 0.41). The mean count in infections with other high-risk HPV types (2.55 +/- 0.52) was significantly higher than that in HPV negative samples. Receiver-operating characteristic curves yielded a test accuracy (area under curve) of 0.76, 0.79, 0.88 and 0.95 for ASCUS, LSIL, ASC-H/HSIL and HSIL, respectively. Thresholds for 95% sensitivity were at 0.005, 0.007, 0.098 and 0.445 immunopositive cells/1,000 cells for ASCUS, LSIL, ASC-H/HSIL and HSIL, respectively. The 95% specificity threshold for the detection of HSIL was at 1.87 immunopositive cells/1,000 cells. P16(INK4a) immunocytochemistry can be used as an adjunct to LBC in cervical screening, because it has a good diagnostic accuracy to discriminate HSIL and ASC-H from other lesions. It could be used as a surrogate marker of high-risk HPV infections.

Biomarkers, Tumor↗

PubMed1980

Cell density and amino acid transport in 3T3, SV3T3, and SV3T3 revertant cells.

The transport of selected neutral and cationic amino acids has been studied in Balb/c 3T3, SV3T3, and SV3T3 revertant cell lines. After properly timed preincubations to control the size of internal amino acid pools, the activity of systems A, ASC, L, and Ly+ has been discriminated by measurements of amino acid uptake (initial entry rate) in the presence and absence of sodium and of transport-specific model substrates. L-Proline, 2-aminoisobutyric acid, and glycine were primarily taken up by system A; L-alanine and L-serine by system ASC; L-phenylalanine by system L; and L-lysine by system Ly+ in SV3T3 cells. L-Proline and L-serine were also preferential substrates of systems A and ASC, respectively, in 3T3 and SV3T3 revertant cells. Transport activity of the Na+-dependent systems A and ASC decreased markedly with the increase of cell density, whereas the activity of the Na+-independent systems L and Ly+ remained substantially unchanged. The density-dependent change in activity of system A occurred through a mechanism affecting transport maximum (Vmax) rather than substrate concentration for half-maximal velocity (Km). Transport activity of systems A and ASC was several-fold higher in transformed SV3T3 cells than in 3T3 parental cells at all the culture densities that could be compared. In SV3T3 revertant cells, transport activity by these systems remained substantially similar to that observed in transformed SV3T3 cells. The results presented here add cell density as a regulatory factor of the activity of systems A and ASC, and show that this control mechanism of amino acid transport is maintained in SV40 virus-transformed 3T3 cells that have lost density-dependent inhibition of growth, as well as in SV3T3 revertant cells that have resumed it.

Amino Acids↗

PubMed1995

Ascorbic acid stimulates barrier function of cultured endothelial cell monolayer.

The macromolecular permeability of cultured bovine aortic, bovine venous, and human umbilical vein endothelial cell monolayers was decreased significantly in culture medium containing L-ascorbic acid (Asc Acid; 0.01-0.1 mM) and L-ascorbic acid 2-phosphate (Asc 2-P). Dithiothreitol, which shows reducing activity equivalent to that of Asc Acid, did not affect endothelial permeability. Asc Acid induced a sixfold increase in collagen synthesis by the endothelial cells. The coexistence of L-azetidine 2-carboxylic acid, an inhibitor of collagen synthesis, attenuated the effect of Asc 2-P in a dose-dependent manner. Another collagen synthesis inhibitor, ethyl-3,4-dihydroxybenzoate, also inhibited collagen synthesis and increased endothelial permeability. The decrease in permeability of the endothelial monolayer was dependent on a reduction of the permeability coefficient of the endothelial monolayer. These findings indicate that endothelial barrier function is stimulated by Asc Acid via an increase in collagen synthesis.

Animals↗

PubMed2006

Characterization of freshly isolated and cultured cells derived from the fatty and fluid portions of liposuction aspirates.

Liposuction aspirates (primarily saline solution, blood, and adipose tissue fragments) separate into fatty and fluid portions. Cells isolated from the fatty portion are termed processed lipoaspirate (PLA) cells and contain adipose-derived adherent stromal cells (ASCs). Here we define cells isolated from the fluid portion of liposuction aspirates as liposuction aspirate fluid (LAF) cells. Stromal vascular fractions (SVF) were isolated separately from both portions and characterized under cultured and non-cultured conditions. A comparable number of LAF and PLA cells were freshly isolated, but fewer LAF cells were adherent. CD34+ CD45- cells from fresh LAF isolates were expanded by adherent culture, suggesting that LAF cells contain ASCs. Although freshly isolated PLA and LAF cells have distinct cell surface marker profiles, adherent PLA and LAF cells have quite similar characteristics with regard to growth kinetics, morphology, capacity for differentiation, and surface marker profiles. After plating, both PLA and LAF cells showed significant increased expression of CD29, CD44, CD49d, CD73, CD90, CD105, and CD151 and decreased expression of CD31 and CD45. Multicolor FACS analysis revealed that SVF are composed of heterogeneous cell populations including blood-derived cells (CD45+), ASCs (CD31- CD34+ CD45- CD90+ CD105- CD146-), endothelial (progenitor) cells (CD31+ CD34+ CD45- CD90+ CD105low CD146+), pericytes (CD31- CD34- CD45- CD90+ CD105- CD146+), and other cells. After plating, ASCs showed a dramatic increase in CD105 expression. Although some adherent ASCs lost CD34 expression with increasing culture time, our culture method maintained CD34 expression in ASCs for at least 10-20 weeks. These results suggest that liposuction-derived cells may be useful and valuable for cell-based therapies.

Adipocytes↗

PubMed1994

A physiological level of ascorbate inhibits galactose cataract in guinea pigs by decreasing polyol accumulation in the lens epithelium: a dehydroascorbate-linked mechanism.

It was reported previously that dietary ascorbate (ASC) delays the development of galactose-induced cataract in guinea pigs compared to the rate which is observed in ASC-deficient animals. Experiments were conducted to explore the possible mechanism of this phenomenon. Guinea pigs were fed for a period of up to 4 weeks either a normal diet (1 g ASC/kg diet) or a scorbutic diet (< 0.04 g ASC/kg diet) combined with 10% galactose in the drinking water. After 2 weeks, levels of ASC in animals on the scorbutic diet decreased by 95% in the aqueous humor and by 78% in the lens. Slit lamp examination showed that galactose-induced vacuoles in the lens equator formed at a significantly faster rate in the scorbutic animals. However, examination of biochemical parameters in whole lenses of the two groups of animals after 2 weeks showed no significant differences with regard to accumulation of galactose and galactitol, decreases in the levels of myoinositol, taurine and GSH or changes in cation concentrations. In order to examine possible regional changes in the lenses, various parameters were studied in the lens capsule-epithelium. On day 4, the capsule epithelia of scorbutic animals on a galactose diet had a content of galactitol two-and-a-half times higher than that of normal galactose-fed animals. Scorbutic conditions also intensified the loss of Na(+)-K+ ATPase activity in the lens capsule-epithelium caused by galactose feeding. Oxidized glutathione was not detectable in the lens capsule epithelia of any of the animals studied. Hexose monophosphate shunt activity was elevated in lenses of normal galactose-fed animals during the first hour of culture after death whereas lenses of scorbutic galactose-fed animals were not. Consistent with the in vivo findings, galactitol accumulation in dog lens epithelial cells exposed to 30 mM galactose was significantly inhibited by the presence of either ASC or dehydroascorbate (DHA) in the medium. Hexose monophosphate shunt activity in the cells was stimulated to two-and-a-half times its initial level by either 1 mM DHA or 30 mM galactose and slightly more than three-fold by a combination of the two challenges. The results suggest that decreased polyol accumulation in the lens epithelium of the normal galactose-fed guinea pig, which has a high level of ASC in the aqueous humor, accounts for the delay in onset of cataract compared to that for the ASC-deficient animal.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

PubMed1997

Postprandial hyperinsulinaemia, insulin resistance and inappropriately high phosphaturia are features of younger males with idiopathic calcium urolithiasis: attenuation by ascorbic acid supplementation of a test meal.

In idiopathic recurrent calcium urolithiasis (RCU) the state of insulin and carbohydrate metabolism, and relationships to minerals such as phosphate, are insufficiently understood. Therefore, in two groups of males with RCU (n = 30) and healthy controls (n = 8) the response to an oral carbohydrate- and calcium-rich test meal was studied with respect to glucose, insulin, and C-peptide in peripheral venous blood (taken before and up to 180 min post-load), and phosphate and glucose in fasting and post-load urine. In one RCU group (n = 16) the meal was supplemented with ascorbic acid (ASC; 5 mg/kg body weight). The mean age (RCU 29, RCU + ASC 30, controls 27 years) and mean body mass index [RCU 24.4, RCU + ASC 25.0, controls 24.0 kg/m2] were similar. Insulin resistance (synonymous sensitivity of peripheral organs to insulin) was calculated from insulin serum concentration, as was also integrated insulin, C-peptide, and glucose. Untreated stone patients (RCU) developed hyperinsulinaemia between 60 and 120 min post-load, increased integrated insulin, and insulin resistance (P < or = 0.05 vs controls), whereas the rise of C-peptide and glycaemia (absolute and integrated values) was only of borderline significance. Fasting phosphaturia was low in both RCU subgroups vs controls; however, phosphaturia in untreated RCU rose in response to the meal, contrasting sharply with a decrease in controls. ASC supplementation of the meal (in the RCU + ASC subgroup) normalized insulin, failed to normalize post-load phosphaturia, but reduced post-load glucosuria and urinary pH significantly (mean pH values 5.55 vs 5.93 in untreated RCU, controls 5.50). Postprandial urinary oxalate, calcium, protein, and supersaturation products were not changed. The postprandial changes in phosphaturia and insulin sensitivity were inversely correlated (n = 38, r = -0.44, P = 0.007). It was concluded that in younger RCU males: (1) postprandial hyperinsulinaemia, the failure to reduce phosphaturia and - within limits - glucosuria, appropriately, as well as poor urine acidification are important features of the metabolism; (2) these phenomena are probably caused by insulin resistance of organs, the kidney included; and (3) the addition of a supraphysiological dose of ASC to a meal, the subsequent abolition of hyperinsulinaemia, and the restoration of normal urine acidification suggest that this antioxidant is capable of counteracting some pre-existing basic abnormality of cell metabolism in RCU.

Adult↗

PubMed1987

Persistence of influenza virus-specific antibody-secreting cells and B-cell memory after primary murine influenza virus infection.

Influenza virus-specific antibody-secreting cells (ASCs), enumerated using an ELISA-plaque assay, were found in the lung and spleen up to 18 months after primary murine influenza infection. The number of ASCs generated in stimulated lung and spleen cell cultures increased 50- to 200-fold after influenza infection. Whereas the level of response did not change in spleen cell cultures up to 18 months after infection, there was a gradual reduction in ASCs in lung cell cultures obtained more than 6 months after infection, predominantly due to a reduction in B memory cells. Homotypic re-infection increased ASCs in the lung only, whereas B-cell memory increased in both the lung and spleen. Although ASCs increased in both the lung and spleen after heterotypic challenge, ASCs and B-cell memory specific for the original subtype were not increased.

Animals↗

PubMed1983

Effects of ascorbic acid and EDTA on vascular concentration-response to catecholamines.

Concentration-response curves are often used as indicators of vascular reactivity and receptor sensitivity. Some investigators use ethylenediaminetetraacetate (EDTA) or ascorbic acid (ASC) to prevent catecholamine oxidation but many others do not. This difference may affect estimates of reactivity. We tested the effect of EDTA or ASC on contractile responses of hamster cremaster arterioles and rat aortic strips to epinephrine (EPI) or norepinephrine (NOR). Comparable contractile responses were elicited by lower EPI or NOR concentrations in the presence than in the absence of EDTA or ASC. Individual responses to EPI or NOR were maintained in the presence of EDTA or ASC, but rapidly declined if neither were present. Rapidly prepared and administered solutions of EPI or NOR elicited similar initial responses in the presence or absence of EDTA or ASC. However, catecholamine solutions prepared without these compounds lose effectiveness within minutes. We conclude that oxidation of EPI and NOR reduces apparent vascular reactivity and that EDTA or ASC prevents or delays the reduction.

Animals↗

PubMed1985

Modulation of stromal cell function in DBA/2J and B6C3F1 mice exposed to benzene or phenol.

Inbred B6C3F1 (B6) mice are more resistant to benzene myelotoxicity than are inbred DBA/2J (D2) mice. This difference may be due to increased sensitivity of the hemopoietic microenvironment in D2 mice to benzene or benzene metabolites relative to B6 mice. The objectives of this investigation were to determine whether stromal cells which support hemopoiesis in the marrow were more sensitive to benzene in D2 mice than in B6 mice and to determine whether these strains would continue to express differences in susceptibility to phenol, an oxidative metabolite of benzene. Mice were given benzene (100 mg/kg) or phenol (100 mg/kg) intraperitoneally, twice a day for four consecutive days. On Day 5 marrow cell suspensions were removed from mice given benzene or phenol and from controls, plated in culture and assayed for (1) the relative number of adherent stromal cell (ASC) colonies present, (2) the number of granulocyte/monocyte precursors from benzene or phenol treated mice that could be supported by ASC from normal mice in coculture, and (3) the number of granulocyte/monocyte precursors from normal mice which could be supported by ASC from benzene or phenol treated mice. After benzene administration, only reductions in body weight and marrow cellularity followed the expected pattern and were reduced to a greater extent among D2 mice than B6 mice. Benzene had no significant effect on ASC colonies or on the number of granulocyte/monocyte precursors present. In contrast, the ability of ASC to support hemopoiesis of granulocyte/monocytes from normal donors was reduced to a greater degree among B6 mice than among D2 mice which paradoxically showed an increase in the ability to support hemopoiesis in coculture. Phenol significantly reduced the ability of ASC to support hemopoiesis of granulocyte/monocyte precursors but no preferential effect between strains was evident. These results suggest that benzene, but not phenol, is metabolized differently between the two strains and that bone marrow stromal cells, components of the hemopoietic microenvironment, are sensitive targets for benzene or its oxidative metabolites.

Animals↗

PubMed1990

The use of monoclonal antibodies in an enzyme immunospot assay to detect isotype-specific antibody-secreting cells in pigs and chickens.

Monoclonal antibodies directed against porcine immunoglobulin isotypes G, G1, G2, M, and A and against chicken immunoglobulin isotopes G, M, and A were tested in an antigen-specific spot-forming cell (SFC) assay based on the principle of the enzyme immunoassay. The SFC assay was used to quantitate ovalbumin (OA)-specific antibody-secreting cells (ASC) in pigs that had been primed and boosted with OA. The SFC assay was also used to quantitate trinitrophenyl (TNP)-specific ASC in chickens that had been primed with TNP-conjugated keyhole lympet haemocyanin (TNP-KLH). Although, the classical plaque-forming cell (PFC) assay cannot reliably detect isotope-specific ASC in pigs and chickens, it can detect these cells in mice. Therefore, we compared the OA- and TNP-specific SFC assays with PFC assays that were specific for these antigens in mice. The study demonstrated that the SFC assay is superior to the PFC assay in detecting both OA-specific ASC and TNP-specific ASC. The frequencies of OA-specific and TNP-specific SFC detected in mice were of the same order of magnitude as those detected in pigs and chickens. We concluded that the SFC assay is the better method for quantitating ASC in pigs, chickens, and probably all domestic animals for which isotype-specific monoclonal antibodies are available.

Animals↗

PubMed1993

Virus specificity and isotype expression of intraparenchymal antibody-secreting cells during Sindbis virus encephalitis in mice.

To study the generation of specific antibody responses within the central nervous system (CNS), we have utilized a murine model of acute viral encephalitis. When Sindbis virus (SV) is injected intracerebrally into weanling mice it causes an acute non-fatal encephalitis and recovery is primarily dependent on the development of antiviral antibody. We used a modified enzyme-linked immunoassay to determine the number of antibody-secreting cells (ASC) specific for SV and their Ig isotype in brain, spleen and cervical lymph nodes over the course of the acute encephalitis. The numbers of SV-specific ASC peak early in spleen and lymph nodes and then begin to increase in brain, suggesting that initial stimulation of B cells occurs primarily in peripheral lymphoid tissue followed by B cell entry into the circulation and appearance in the brain. The pattern for each individual isotype was similar with peak numbers of SV-specific cells present in the spleen 5-7 days after infection, while numbers in the brain continue to rise through day 20 when most ASC were secreting IgG2a or IgA SV-specific antibody. The data suggest therefore that most isotype switching from IgM to IgG and IgA occurs in peripheral lymphoid tissue. An exception to this pattern is IgG1, where numbers of ASC producing IgG1 do not show a peak in spleen and continue to rise in brain through the course of acute encephalitis. The data also indicate that early in infection a large proportion of ASC in the brain are not specific for SV and demonstrate that recruitment of ASC into the CNS is non-specific.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗

PubMed1991

Comparative biochemistry of mammalian arylsulfatase C and steroid sulfatase.

1. Hepatic arylsulfatase C (ASC) and steroid sulfatase (SS) from six of eleven mammals (rat, dog, baboon, cow, goat, and sheep) coeluted from DEAE-Sephacel as a single anionic species. A minor cationic peak of ASC and SS activity was also recovered from solubilized microsomes derived from the domestic cat. Characterization of the cationic activities indicated they were most likely contributed by a protein structurally related to the anionic isozyme. Properties of ASC and SS activities occurring in these seven species were most consistent with the presence of both activities in the same enzyme. 2. Guinea-pig liver SS activity was partitioned between an alkylsulfatase (hydrolyzing dehydroepiandrosterone sulfate (DHEAS)) and an arylsulfatase (hydrolyzing both estrone sulfate (E1S) and 4-methylumbelliferyl sulfate (4MUS) at a common active site). These enzymes were physically separable by ion-exchange chromatography and possessed distinct immunological and chemical properties. 3. Porcine, squirrel, and human livers possessed a major isozyme of ASC that lacked both E1S- and DHEAS-sulfatase activities. The human hepatic ASC was separable from SS by electrophoresis and was partially resolved from SS by DEAE-Sephacel chromatography. The ASC isozyme lacking SS activity was heat-labile in all three species.

Animals↗

PubMed1994

Measurement of ascorbic acid in human plasma and urine by high-performance liquid chromatography. Results in healthy subjects and patients with idiopathic calcium urolithiasis.

A simple, reliable high-performance liquid chromatographic method was developed to measure ascorbic acid (ASC), with ultraviolet detection (250 nm), in human plasma and urine. Immediately following blood withdrawal, the heparinized plasma samples were deproteinized with 10% m-phosphoric acid, while the freshly voided urine samples were diluted with m-phosphoric acid. ASC was separated on a reversed-phase column by elution with 0.1 M KH2PO4 adjusted to pH 2.35. In urine, after reduction of dehydroascorbic acid to ASC, total ASC was measured using the same mobile phase. The method was sensitive down to 0.1 and 0.4 mg ASC per litre of urine and plasma, respectively. In patients with idiopathic calcium urolithiasis, both plasma and urinary ASC were within the range observed in age-matched controls.

Adult↗

PubMed1994

Interrelationship of ascorbate, arachidonic acid and prostaglandin E2 in B16 melanoma cells.

Previous studies have shown that ascorbate (Asc) supplementation affects arachidonic acid (AA) and prostaglandin E2 (PGE2) levels in B16 murine melanoma cells. In this study, non-malignant LLCMK cells and malignant B16 cells were respectively supplemented with 20 microCi 15-3H AA, to investigate whether these two cell types were able to take up AA from the media. Furthermore, these cells were also supplemented with Asc (0-100 micrograms/ml) to determine the effect of Asc supplementation on 15-3H AA uptake. Both cell types incorporated 15-3H AA, while Asc supplementation enhanced this 15-3H AA uptake. To determine the site of the AA incorporation, both cell types were supplemented with 2.5 microM AA and Asc (0-100 micrograms/ml). The % AA composition of the stroma fractions of both cell types was increased with 100 micrograms/ml Asc supplementation. Supplementation of these cells with AA (0-50 microM) resulted in an increase in PGE2 levels in the B16 cells. Since PGE2 has been shown, in turn, to stimulate adenylate cyclase (AC) activity, the LLCMK and B16 cells were supplemented with 0-100 microM PGE2. A 3-fold increase of AC activity in the B16 cells occurred as a result of this supplementation.

Adenylyl Cyclases↗