Biomedical subjects

J D Pearson

Publications and source records attributed to J D Pearson.

At least 55 records · Page 3Linked to original sources

PubMed1997

Recommended prostate-specific antigen testing intervals for the detection of curable prostate cancer.

OBJECTIVE: To evaluate prostate-specific antigen (PSA) testing intervals that maintain the detection of curable cancer and reduce unnecessary testing. DESIGN AND PATIENTS: Historical prospective study of serial PSA measurements at 2- and 4-year intervals from frozen serum samples of 40 men who eventually developed prostate cancer and 272 men without prostate cancer who were participants in a prospective aging study (Gerontology Research Center of the National Institute on Aging, the Baltimore Longitudinal Study of Aging) and the case series of 389 consecutive men treated surgically for nonpalpable prostate cancer. MAIN OUTCOME MEASURES: Probability of a PSA conversion to 4.1 to 5.0 ng/mL and to greater than 5.0 ng/mL at 2 and 4 years and probability of detecting curable prostate cancer by age and PSA level. RESULTS: When the pretreatment PSA level was less than or equal to 4.0 ng/mL, nonpalpable prostate cancers were highly likely (34/36, 94%) to be curable (organ-confined or capsular penetration with Gleason score < 7 and negative margins), and the majority (25/36, 69%) were small cancers (confined tumor < or = 0.5 cm3 with no Gleason pattern 4 or 5). When the pretreatment PSA level was greater than 4.0 ng/mL and less than or equal to 5.0 ng/mL, cancers were highly likely to be curable (32/36, 89%), and a minority were small cancers (12/36, 33%). When the pretreatment PSA level was greater than 5.0 ng/mL, 96 (30%) of 317 cancers were noncurable. The PSA conversion (for cancer cases) to a level at which cure is less likely (> 5.0 ng/mL) is rare (0%) after 2 or 4 years when the initial PSA is less than 2.0 ng/mL. PSA conversion to a range at which cancers are likely to be curable and less likely to be small (4.1-5.0 ng/mL) is rare after 2 years (0%-4%) when the baseline PSA level is less than 2.0 ng/mL but common when the baseline PSA level is between 2.1 and 3.0 ng/mL (27%) or 3.1 and 4.0 ng/mL (36%). CONCLUSIONS: These data suggest that for men with no cancer suspected on digital rectal examination, a PSA level of 4.0 to 5.0 ng/mL is an acceptable range for maintaining the detection of curable prostate cancer and a 2-year PSA testing interval is not likely to miss a curable prostate cancer when the initial PSA level is less than 2.0 ng/mL. Recognizing that 70% of a screened population between the ages of 50 years and 70 years have PSA levels less than 2.0 ng/mL, elimination of annual PSA testing for these men would result in large health care cost savings.

Aged↗

PubMed1997

Percentage of free prostate-specific antigen in sera predicts aggressiveness of prostate cancer a decade before diagnosis.

OBJECTIVES: To evaluate serial measurements of free and total prostate-specific antigen (PSA) as a predictor of prostate cancer aggressiveness. METHODS: Twenty men diagnosed with adenocarcinoma of the prostate in the pre-PSA era had serum PSA measurements made on multiple stored frozen sera samples available for up to 18 years prior to diagnosis. Subjects were categorized as having aggressive cancer (n = 12) based on the presence of clinical Stage T3, or nodal or bone metastases (N+, M+), or pathologic positive-margin disease, or a Gleason score of 7 or greater; nonaggressive cancer (n = 8) was identified by the absence of these criteria. RESULTS: There was no statistically significant difference in free PSA levels among men with aggressive and nonaggressive prostate cancers from 0 to 15 years before diagnosis. Total PSA levels were significantly different between the groups by 5 years before diagnosis (P = 0.04). At a time when total PSA levels were not different between groups (10 years before diagnosis), there was a statistically significant difference in the percentage of free PSA between aggressive and nonaggressive cancers (P = 0.008). Among 14 men who had sera available for analysis at 10 years before diagnosis, all 8 men with aggressive cancers had a percent free PSA of 0.14 or less; this compares with only 2 of 6 men (33%) with nonaggressive cancer. CONCLUSIONS: These data suggest that the percentage of free PSA in sera is predictive of tumor behavior at a time when total PSA levels provide no information on tumor aggressiveness. Evaluation of the percentage of free serum PSA may be helpful in making the decision between expectant management and treatment for those men who are diagnosed with early prostate cancers by PSA testing.

Adenocarcinoma↗

PubMed1997

Role of prostate-specific antigen velocity in prediction of final pathologic stage in men with localized prostate cancer.

OBJECTIVES: Prostate-specific antigen (PSA) velocity prior to radical retropubic prostatectomy was evaluated to determine if men with a faster rate of rise in PSA have locally more extensive prostate cancer. METHODS: Of 368 men who underwent radical retropubic prostatectomy, 82 had two to seven PSA measurements between 1.3 and 6.7 years before prostate biopsy for evaluation of PSA velocity. PSA velocity and the pretreatment parameters of PSA, Gleason score, and T stage were evaluated as predictive parameters of pathologic stage. RESULTS: In men with pathologically organ-confined disease, PSA velocity was 1.12 ng/mL/yr; in non-organ-confined cases, it was 1.88 ng/mL/yr. There was a statistically significant relationship between a Gleason score of 7 and above and the pathologic extent of disease. There was no statistically significant relationship between T stage, the PSA at diagnosis, and PSA velocity with respect to final pathologic stage. CONCLUSIONS: PSA velocity is not a strong predictor of pathologic stage in men with localized prostate cancer.

Adult↗

PubMed1997

Prostate-specific antigen velocity and repeated measures of prostate-specific antigen.

Numerous studies evaluating different populations have shown similar findings with respect to repeated PSA measurements and PSAV. First, there is substantial within-individual variability between repeated PSA measures. Second, this variability between PSA measurements precludes the use of a simple change in PSA as a marker for prostate cancer. Third, when one adjusts the changes that occur in PSA over an elapsed time of 1.5 to 2 years (PSAV), less than 5% of men without prostate cancer will have a PSAV of 0.75 ng/mL/ y or greater, and approximately 70% of men with prostate cancer will have a PSAV of 0.75 ng/mL/ y or greater. These data strongly suggest that PSAV is a specific marker for the presence of prostate cancer.

Aging↗

PubMed1997

Human IgG xenoreactive antibodies mediate damage to porcine endothelial cells in vitro by both humoral and cellular mechanisms.

A major barrier to the transplantation of a porcine organ into a human recipient is the hyperacute rejection response which has been shown to be mediated by xenoreactive antibodies (XAb) and complement proteins. Here, evidence is presented that normal human sera contain IgG XAb that are able to mediate increased adhesion of polymorphonuclear leucocytes (PMN) to porcine aortic endothelial cells (PAEC) in vitro, to initiate damage to endothelial cells via antibody-dependent cellular cytotoxicity mechanisms (ADCC) along with peripheral blood mononuclear cells (PBMC) and to activate the classical complement cascade. PMN exhibit a 2.8-fold increase in adhesion to PAEC from 19.9 +/- 4% to 56 +/- 1.7% at an IgG concentration of 16 mg/ml. This increase is independent of treatment of the PMN with interferon-gamma. PAEC are lysed in the presence of complement: 42.8 +/- 0.7% lysis occurs with a 1/8 dilution of human serum as a source of immunoglobulin of all classes, while 39.3 +/- 3% lysis occurs with purified IgG at 13 mg/ml in the presence of baby rabbit complement. PAEC are also lysed by PBMC in the presence of human IgG XAb, a maximum of 52.0 +/- 5% being observed at effector-to-target (E:T) ratios of 30:1. PBMC bearing Fc gamma RIII receptors for the Fc portion of the IgG molecule mediate the endothelial cell damage since the anti-Fc gamma RIII monoclonal antibody, 3G8, can inhibit lysis by up to 77 +/- 5%. We conclude that human IgG are able to damage porcine endothelial cells using cellular and humoral mechanisms and that IgG XAb can efficiently activate the classical complement cascade in this model system.

Animals↗

PubMed1997

Age-associated changes in blood pressure in a longitudinal study of healthy men and women.

BACKGROUND: Current knowledge of age-associated increases in blood pressure is based primarily on unscreened population studies that may not be representative of healthy men and women. We examined longitudinal patterns of change in blood pressure in healthy male and female volunteers from the Baltimore Longitudinal Study of Aging (BLSA). METHODS: Longitudinal mixed-effects regression models are used to estimate the age-associated changes in blood pressure in 1307 men (age 17-97) and 333 women (age 18-93) who have been followed for up to 32 years (mean: 8.4 years for men and 3.4 years for women) and who have been screened for health problems or medications that affect blood pressure. RESULTS: On average, systolic pressure is relatively stable in men and women until approximately age 45, increases at 5-8 mm Hg per decade in middle age, then accelerates in men and stabilizes in women. Diastolic pressure increases at 1 mm Hg per decade at all ages in men, whereas in women the rate of change in diastolic pressure increases in middle age and then plateaus and may decline after age 70. Additional findings include: (a) BLSA cross-sectional and longitudinal findings are more similar than has been observed in studies of unscreened samples; (b) there is no evidence of a gender cross-over in this group of healthy men and women; and (c) compared to previous studies of unscreened samples, healthy BLSA men and women show a weaker association between baseline blood pressure and subsequent rate of blood pressure change. CONCLUSIONS: These findings suggest that several previously described age-associated patterns of blood pressure change partially reflect the effects of hypertension and its treatment, rather than intrinsic age changes in the blood pressure of healthy individuals.

Adolescent↗

PubMed1997

Scleroderma fibroblasts show increased responsiveness to endothelial cell-derived IL-1 and bFGF.

Fibroblasts cultured from lesional skin in scleroderma (systemic sclerosis) demonstrate an activated phenotype that may be important in pathogenesis. Endothelial cell-derived cytokines can modulate fibroblast properties, and endothelial cell changes occur early in scleroderma. Thus, endothelial cell and fibroblast dysfunction may be linked through the paracrine activity of soluble endothelial cell products. We have explored endothelial cell-fibroblast interactions in vitro by investigating the modulation of scleroderma and control fibroblast properties by endothelial cell-conditioned medium (EC-CM). EC-CM caused a concentration-dependent stimulation of fibroblast DNA and protein synthesis and upregulation of cell surface ICAM-1 expression. Scleroderma fibroblasts showed consistently greater responses than control cells. Medium conditioned by mechanically wounded endothelial cells had a greater effect than that from resting endothelial cells. Pre-incubation of EC-CM with anti-bFGF significantly reduced the promotion of fibroblast thymidine incorporation but did not affect endothelial cell-induced leucine incorporation. Conversely, anti-IL-1 antibodies abrogated EC-CM-induced leucine incorporation and ICAM-1 expression but did not diminish thymidine incorporation. Recombinant bFGF or IL-1 modulated fibroblast properties similarly. These data demonstrate that endothelial cell-derived IL-1 and bFGF modulate fibroblast properties independently and that lesional scleroderma strains are more responsive than control fibroblasts to endothelial cell-induced modulation, which supports the hypothesis that altered endothelial cell-fibroblast communication may be involved in the pathogenesis of scleroderma.

Cell Count↗

PubMed1997

Modulation of vascular tone by low density lipoproteins: effects on L-arginine transport and nitric oxide synthesis.

Low density lipoprotein (LDL) plays an important role in atherogenesis. Focal accumulation within the arterial intima of excess amounts of cholesterol-rich LDL leads to the migration and recruitment of monocytes, which then differentiate into macrophages after taking up large amounts of oxidatively modified LDL via their scavenger receptors and become lipid-laden 'foam cells' within the subendothelial space. It is generally accepted that oxidized LDL and hyperlipidaemia impair endothelial-dependent vascular relaxation, yet the existing literature on the effects of oxidatively modified LDL on endothelium-derived nitric oxide (NO) and prostacyclin (PGI2) release is inconclusive, since oxidized LDL has been reported to enhance or reduce NO and PGI2 production. Our studies using cultured human endothelial and smooth muscle cells have established that basal rates of L-arginine (NO precursor) transport, NO and PGI2 production and soluble guanylyl cyclase activity are unaffected by pretreatment (for 1 or 24 h) with native LDL, or with mildly or highly oxidized LDL. In contrast, highly oxidized LDL inhibited histamine-stimulated release of NO and PGI2 from human endothelial cells and induced an adaptive increase in the level of intracellular glutathione in human smooth muscle cells, a response which was prevented by the chain-breaking antioxidant alpha-tocopherol. Although initial rates of L-arginine transport and basal NO and PGI2 release from human endothelium are unaffected by oxidized LDL, agonist-stimulated release of these vasodilators is markedly attenuated. Elucidation of the mechanisms regulating these responses and their sensitivity to dietary antioxidants could lead to alternative strategies for reducing atherogenesis.

Animals↗

PubMed1996

Perfluorinated acid alternatives to trifluoroacetic acid for reversed-phase high-performance liquid chromatography.

Over the past decade trifluoroacetic acid (TFA) has become the ion-pairing agent (IPA) of choice for reversed-phase high-performance liquid chromatography (RP-HPLC) of peptides and proteins. Reagent grade TFA is highly pure, water soluble, transparent at 220 nm and readily volatile. A drawback of this universal appeal is that several alternative perfluorinated carboxylic acids tend to be overlooked when TFA does not work in a particular separation. Examples are given comparing TFA selectivity with those of pentafluoropropionic acid, heptafluorobutyric acid, perfluoropentanoic acid, perfluorohexanoic acid and perfluoroheptanoic acid. We have found that increasing the IPA n-alkyl chain length can resolve sample components that otherwise co-elute in the void volume of TFA-based RP-HPLC. Examples are given for the resolution of an oligoglycine series and enhanced selectivity for a bovine hypothalamic extract.

Animals↗

PubMed1996

Hypoxanthine enters human vascular endothelial cells (ECV 304) via the nitrobenzylthioinosine-insensitive equilibrative nucleoside transporter.

The transport properties of the nucleobase hypoxanthine were examined in the human umbilical vein endothelial cell line ECV 304. Initial rates of hypoxanthine influx were independent of extracellular cations: replacement of Na+ with Li+, Rb+, N-methyl-D-glucamine or choline had no significant effect on hypoxanthine uptake by ECV 304 cells. Kinetic analysis demonstrated the presence of a single saturable system for the transport of hypoxanthine in ECV 304 cells with an apparent K(m) of 320 +/- 10 microM and a Vmax of 5.6 +/- 0.9 pmol/10(6) cells per s. Hypoxanthine uptake was inhibited by the nucleosides adenosine, uridine and thymidine (apparent Ki 41 +/- 6, 240 +/- 27 and 59 +/- 8 microM respectively) and the nucleoside transport inhibitors nitrobenzylthioinosine (NBMPR), dilazep and dipyridamole (apparent Ki 2.5 +/- 0.3, 11 +/- 3 and 0.16 +/- 0.006 microM respectively), whereas the nucleobases adenine, guanine and thymine had little effect (50% inhibition at > 1 mM). ECV 304 cells were also shown to transport adenosine via both the NBMPR-sensitive and -insensitive nucleoside carriers. Hypoxanthine specifically inhibited adenosine transport via the NBMPR-insensitive system in a competitive manner (apparent Ki 290 +/- 14 microM). These results indicate that hypoxanthine entry into ECV 304 endothelial cells is mediated by the NBMPR-insensitive nucleoside carrier present in these cells.

Adenosine↗

PubMed1996

Inhibition of MAP kinase kinase (MEK) blocks endothelial PGI2 release but has no effect on von Willebrand factor secretion or E-selectin expression.

We have examined the potential role of MAP kinase in the regulation of endothelial cell PG12 synthesis, vWF secretion and E-selectin expression using the specific MEK inhibitor PD98059. PD98059 dose-dependently attenuated the tyrosine phosphorylation and activation of p42 mapk in response to thrombin or inflammatory cytokines. Inhibition of thrombin-induced p42 mapk activation was paralleled by an inhibitory effect of PD98059 on thrombin-driven PG12 generation but not on vWF secretion or IL-1 alpha/TNF alpha-induced E-selectin expression. These results provide evidence for a key role for p42 mapk in the acute regulation of PG12 synthesis in human endothelial cells and suggest that activation of the MAP kinase cascade is not obligatory for cytokine-stimulated E-selectin expression.

Calcium-Calmodulin-Dependent Protein Kinases↗

PubMed1996

Protein tyrosine kinases regulate agonist-stimulated prostacyclin release but not von Willebrand factor secretion from human umbilical vein endothelial cells.

The rapid synthesis and release of prostacyclin (PGI2) and the exocytotic secretion of von Willebrand Factor (vWF) elicited by activation of G-protein-coupled receptors on endothelium occur via signaling mechanisms which are incompletely defined. Activation of protein tyrosine kinases (PTKs) and modulation of the tyrosine-phosphorylation state of endogenous proteins have been implicated in several cellular processes including arachidonate release and exocytosis. In the present study we have examined the regulatory role of PTKs in agonist-stimulated release of PGI2 and vWF from human umbilical vein endothelial cells (HUVECs) using two chemically and mechanistically dissimilar PTK inhibitors (genistein and ST271). Genistein, but not the less active analogue daidzein, dose-dependently attenuated PGI2 release in response to thrombin and histamine (IC50 approx. 20 microM), and to the thrombin-receptor-activating peptide. A more potent inhibition of thrombin- and histamine-induced PGI2 synthesis was observed in cells exposed to ST271. In contrast, neither genistein nor ST271 modulated agonist-drive vWF secretion. At concentrations that abolished PGI2 release, genistein blocked thrombin- or histamine-evoked tyrosine phosphorylation of a 42 kDa protein. Ca2+ ionophore-induced PGI2 generation, but not vWF secretion, was also inhibited by both genistein and ST271, suggesting that these agents modulate PGI2 synthesis by acting at, or distal to, agonist-induced changes in intracellular CA2+ ([Ca2+]i). In fura-2-loaded HUVECs genistein partially reduced the histamine-induced peak [Ca2+]i but had no effect on the thrombin response. Ca(2+)-induced PGI2 release from electrically permeabilized HUVECs was abolished in the presence of ST271 or genistein, but not diadzein. The generation of PGI2 in response to exogenous arachidonic acid was not modulated by genistein or ST271, suggesting that PTK inhibitors do not directly inhibit cyclo-oxygenase activity. Taken together, these results suggest that PTKs regulate PGI2 synthesis and release in HUVECs by modulating, directly or indirectly, a CA(2+)-sensitive step upstream of cyclo-oxygenase.

Calcium↗

PubMed1996

Regulation of L-arginine transport and nitric oxide release in superfused porcine aortic endothelial cells.

1. We have investigated whether changes in extracellular ion composition and substrate deprivation modulate basal and/or bradykinin-stimulated L-arginine transport and release of nitric oxide (NO) and prostacyclin (PGI2) in porcine aortic endothelial cells cultured and superfused on microcarriers. 2. Saturable L-arginine transport (Km = 0.14 +/- 0.03 mM; Vmax = 2.08 +/- 0.54 nmol min-1 (5 x 10(6) cells)-1) was pH insensitive and unaffected following removal of extracellular Na+ or Ca2+. 3. Cationic arginine analogues, including L-lysine and L-ornithine, inhibited L-arginine transport, whilst 2-methylaminoisobutyric acid, beta-2-amino-bicyclo[2,2.1]-heptane-2-carboxylic acid, L-phenylalanine, 6-diazo-5-oxo-norleucine, L-glutamine, L-cysteine and L-glutamate were poor inhibitors. 4. Deprivation of L-arginine (30 min to 24 h) reduced intracellular free L-arginine levels from 0.87 +/- 0.07 to 0.40 +/- 0.05 mM (P < 0.05) and resulted in a 40% stimulation of L-arginine, L-lysine and L-ornithine transport. 5. L-arginine and NG-monomethyl-L-arginine (L-NMMA), but not N omega-nitro-L-arginine methyl ester (L-NAME), trans-stimulated efflux of L-[3H]arginine. 6. Depolarization of endothelial cells with 70 mM K+ reduced L-arginine influx and prevented the stimulation of transport by 100 nM bradykinin, but agonist-induced release of NO and PGI2 was still detectable. 7. Basal rates of L-arginine transport and NO release were unaffected during superfusion of cells with a nominally Ca(2+)-free solution. Bradykinin-stimulated L-arginine transport was insensitive to removal of Ca2+, whereas agonist-induced NO release was abolished. 8. Although bradykinin-stimulated NO release does not appear to be coupled directly to the transient increase in L-arginine transport, elevated rates of L-arginine influx via system y+ in response to agonist-induced membrane hyperpolarization or substrate deprivation provide a mechanism for enhanced L-arginine supply to sustain NO generation.

Animals↗

PubMed1996

IgG antiendothelial cell autoantibodies from scleroderma patients induce leukocyte adhesion to human vascular endothelial cells in vitro. Induction of adhesion molecule expression and involvement of endothelium-derived cytokines.

IgG autoantibodies that bind human endothelial cells (AECA) were detected by ELISA in 30 of 42 samples of sera from patients with scleroderma. Pretreatment of human umbilical vein endothelial cells with AECA-positive scleroderma sera, or IgG purified from these sera, led to a dose- and time-dependent increase in the ability of the cells to bind human U937 monocytic cells. Threshold-active IgG concentrations were 1-10 micrograms/ml; effects were significant after 3 h and maximal after 6-12 h. IgG from AECA-negative sera or normal sera were without effect. Increased adhesion of U937 cells was accompanied by increased expression of endothelial intercellular adhesion molecule-1, vascular cell adhesion molecule-1, and E-selectin. Transfer of endothelial cell-conditioned media after pretreatment with AECA and immunodepletion of IgG demonstrated the presence of transferable activity that mimicked the effects of AECA. Treatment with neutralizing anticytokine antibodies indicated that IL-1, generated by the endothelial cells in response to AECA, was involved in the upregulation of adhesion molecules and U937 cell adhesion. We conclude that AECA can play a pathogenic role in scleroderma by activating endothelial cells, in part due to autocrine or paracrine actions of IL-1.

Antibodies, Blocking↗

PubMed1996

Histone H4 stimulates glucose uptake through the insulin receptor.

Histone H4 stimulates the uptake of glucose in rat adipocytes and muscle cells. However, the mechanism of this unusual activity is not known. Therefore, we have begun to investigate the mechanism by which histone H4 stimulates the glucose uptake in rat adipocytes. We report that histone H4 requires 15-20 min to achieve its maximum effect and its time course is virtually indistinguishable from the time course of insulin itself. Reduction of the concentration of insulin receptors on the surface of adipocytes, either by trypsin digestion of the receptor, or by insulin-induced down regulation of the receptor, reduced the histone H4 effect as well as the insulin effects. Also, quercetin, a bioflavenoid that inhibits the insulin receptor tyrosine kinase activity, inhibits the actions of both histone H4 and insulin. However, histone H4 activity is somewhat more resistant to these interventions than insulin activity. In contrast to the activity of insulin, histone H4 does not appear to be able to down regulate the insulin receptor, since the pretreatment of adipocytes with histone H4 did not affect the subsequent actions of either insulin or histone H4. Finally, Scatchard analysis of the binding of 125I-insulin in the presence and absence of histone H4 increases the specific binding of insulin in a concentration dependent fashion. Histone H2b, a histone that does not have insulin-like activity, does not affect insulin binding. Taken together, these data suggest that the greatest portion of the insulin-like activity of histone H4 is initiated at the insulin receptor. However, the interaction of histone H4 and the insulin receptor is more complex than a simple binding of H4 to the insulin binding site. These studies may provide additional insight into alternate mechanisms for activation of the insulin receptor.

Adipocytes↗

PubMed1996

Longitudinal analysis of serial measurements of free and total PSA among men with and without prostatic cancer.

OBJECTIVES: Evaluation of free and total serum prostate specific antigen (PSA) levels before diagnosis of prostate cancer. METHODS: Free and total PSA levels were measured on frozen sera samples of 26 men with no history of prostate disease (controls), 29 men with a histologic diagnosis of benign prostatic hyperplasia (BPH) made at simple prostatectomy (BPH cases), and 23 men with a histologic diagnosis of prostatic cancer (cancer cases). Longitudinal regression analysis was used to evaluate PSA levels as a function of years before diagnosis of prostate disease. RESULTS: On average, mean total serum PSA was statistically significantly greater for subjects with cancer (5.0 ng/mL +/- 0.9) versus BPH (2.8 ng/mL +/- 0.3) and control subjects (0.8 ng/mL +/- 0.1) by 4 years before diagnosis, whereas free PSA levels were similar among groups at 4 years before diagnosis. The ratio of free to total serum PSA continuously decreased among cancer cases over the decade before cancer diagnosis. At a time when mean total and free PSA levels were similar among groups (8 years before diagnosis), the ratio of free to total PSA was statistically significantly lower for cancer cases (0.13 +/- 0.01) compared with BPH (0.17 +/- 0.01) and control cases (0.21 +/- 0.02). Use of a free to total PSA ratio of < or = 0.12 when total PSA was between 4.0 and 10.0 ng/mL resulted in the highest sensitivity (76%) and specificity (94%) for diagnosis among subjects with and without cancer. Lowering the reflex range to 2.5 ng/mL increased false positive tests more than it increased sensitivity. CONCLUSIONS: The ratio of free to total PSA is the earliest serum marker predicting a subsequent diagnosis of prostate cancer. Measurement of the free to total serum PSA ratio would appear to reduce false positive results among men without prostate cancer.

Aged↗

PubMed1996

Raised anti-endothelial cell autoantibodies (AECA), but not anti-neutrophil cytoplasmic autoantibodies (ANCA), in recurrent oral ulceration: modulation of AECA binding by tumour necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma).

Recurrent oral ulceration (ROU) is a common oral mucosal condition of unknown etiology. However, there is evidence to suggest that vasculitis may play a role. Here we investigate the presence in ROU of two autoantibodies associated with vasculitis, AECA and ANCA. AECA target as yet unidentified antigens on the endothelial cell surface and have been identified in patients with vasculitic disorders and inflammatory conditions with a vasculitic component. ANCA target specific neutrophil-associated proteins and are detected in specific vasculitic and chronic inflammatory disorders. AECA and ANCA levels were studied in 20 ROU patients and 20 controls. IgG AECA to the endothelial cell line ECV 304 were detected in 19 ROU patients and four controls. Levels were significantly raised in ROU both to ECV 304 (P < 0.000 05) and to human umbilical vein endothelial cells (HUVEC) (P < 0.005). Although levels were highest during episodes of ulceration, they were also raised between episodes. Stimulation of endothelial cells with TNF-alpha significantly increased AECA binding of both ROU (P < 0.005) and control samples (P < 0.0001), while IFN-gamma decreased binding (ROU P < 0.0001; controls P < 0.05). In contrast, ANCA were detected in only one patient and none of the controls. The presence of raised levels of AECA lends support to the hypothesis that a vasculitic process may underlie ROU. Moreover, these findings suggest that endothelial cell expression of AECA target antigens is increased by TNF-alpha and decreased by IFN-gamma stimulation.

Adolescent↗

PubMed1996

Longitudinal changes in smell identification.

BACKGROUND: Cross-sectional studies have demonstrated that olfactory function diminishes with increasing age, which may impact on the safety and quality of life of older persons. To date, however, there have been no published longitudinal studies on olfaction. The purpose of this study was to examine the influence of age and gender on smell identification over a 3-year period in a group of generally healthy men and women. METHODS: Males (n = 85) and females (n = 76) between the ages of 19 and 95 years were administered the University of Pennsylvania Smell Identification Test (SIT) over a 3-year span as part of the oral physiology component of the Baltimore Longitudinal Study of Aging. A linear mixed-effects regression model was used to determine how longitudinal changes in SIT scores differ with respect to gender, history of medical problems, and use of prescription medications. RESULTS: Over the 3-year period, SIT scores diminished progressively with increased age. Women and men in the eighth decade of life experienced a decline of greater than one SIT point per year. Females consistently performed better than males in smell identification. Similar results were obtained regardless of medical problems or medication usage. CONCLUSIONS: These results extend the conclusions of previous cross-sectional olfactory studies and indicate that smell identification deteriorates progressively with greater age. Furthermore, age-related declines in olfaction occur even in the absence of overt medical problems.

Adult↗