Cytoreductive surgery and HIPEC in recurrent epithelial ovarian cancer: a prospective randomized phase III study.

BACKGROUND: The current treatment of ovarian cancer consists of cytoreductive surgery (CRS) and systemic chemotherapy. The aim of this study was to examine if hyperthermic intraperitoneal chemotherapy (HIPEC) is an alternative modality to treat this category of patients along with a second attempt of surgical resection and second- or third-line systemic chemotherapy afterward. METHODS: In an 8-year period (2006-2013), 120 women with advanced ovarian cancer (International Federation of Gynecology and Obstetrics [FIGO] IIIc and IV) who experienced disease recurrence after initial treatment with conservative or debulking surgery and systemic chemotherapy were randomized into two groups. Group A comprised 60 patients treated with CRS followed by HIPEC and then systemic chemotherapy. Group B comprised 60 patients treated with CRS only and systemic chemotherapy. RESULTS: The mean survival for group A was 26.7 versus 13.4 months in group B (p < 0.006). Three-year survival was 75 % for group A versus 18 % for group B (p < 0.01). In the HIPEC group, the mean survival was not different between patients with platinum-resistant disease versus platinum-sensitive disease (26.6 vs. 26.8 months). On the other hand, in the non-HIPEC group, there was a statistically significant difference between platinum-sensitive versus platinum-resistant disease (15.2 vs. 10.2 months, p < 0.002). Complete cytoreduction was associated with longer survival. Patients with a peritoneal cancer index score of <15 appeared also to have longer survival. CONCLUSIONS: The use of HIPEC along with the extent of the disease and the extent of cytoreduction play an important role in the survival of patients with recurrence in an initially advanced ovarian cancer.

Association of the advanced lung cancer inflammation index (ALI) with immune checkpoint inhibitor efficacy in patients with advanced non-small-cell lung cancer.

BACKGROUND: The advanced lung cancer inflammation index [ALI: body mass index × serum albumin/neutrophil-to-lymphocyte ratio (NLR)] reflects systemic host inflammation, and is easily reproducible. We hypothesized that ALI could assist guidance of non-small-cell lung cancer (NSCLC) treatment with immune checkpoint inhibitors (ICIs). PATIENTS AND METHODS: This retrospective study included 672 stage IV NSCLC patients treated with programmed death-ligand 1 (PD-L1) inhibitors alone or in combination with chemotherapy in 25 centers in Greece and Germany, and a control cohort of 444 stage IV NSCLC patients treated with platinum-based chemotherapy without subsequent targeted or immunotherapy drugs. The association of clinical outcomes with biomarkers was analyzed with Cox regression models, including cross-validation by calculation of the Harrell's C-index. RESULTS: High ALI values (>18) were significantly associated with longer overall survival (OS) for patients receiving ICI monotherapy [hazard ratio (HR) = 0.402, P < 0.0001, n = 460], but not chemo-immunotherapy (HR = 0.624, P = 0.111, n = 212). Similar positive correlations for ALI were observed for objective response rate (36% versus 24%, P = 0.008) and time-on-treatment (HR = 0.52, P < 0.001), in case of ICI monotherapy only. In the control cohort of chemotherapy, the association between ALI and OS was weaker (HR = 0.694, P = 0.0002), and showed a significant interaction with the type of treatment (ICI monotherapy versus chemotherapy, P < 0.0001) upon combined analysis of the two cohorts. In multivariate analysis, ALI had a stronger predictive effect than NLR, PD-L1 tumor proportion score, lung immune prognostic index, and EPSILoN scores. Among patients with PD-L1 tumor proportion score ≥50% receiving first-line ICI monotherapy, a high ALI score >18 identified a subset with longer OS and time-on-treatment (median 35 and 16 months, respectively), similar to these under chemo-immunotherapy. CONCLUSIONS: The ALI score is a powerful prognostic and predictive biomarker for patients with advanced NSCLC treated with PD-L1 inhibitors alone, but not in combination with chemotherapy. Its association with outcomes appears to be stronger than that of other widely used parameters. For PD-L1-high patients, an ALI score >18 could assist the selection of cases that do not need addition of chemotherapy.

Adjuvant platinum-based chemotherapy in patients with epithelial ovarian cancer: prognostic factors and final outcome.

PURPOSE: epithelial ovarian cancer (OVCA) prognosis depends on the clinical stage, histological grade and surgical cytoreduction. Our goal was to retrospectively analyze several prognostic factors in relation with the final outcome in patients with OVCA subjected to adjuvant platinum (PL)- based chemotherapy (CT). METHODS: three hundred OVCA patients were treated at the Department of Medical Oncology A', "Metaxa" Cancer Hospital, between 11/1989-3/2010. Of those, analyzed were patients with R0 debulking operation, treated with adjuvant PL-based CT. Their clinico/imaging/pathological findings and serum tumor marker CA 125 levels were analyzed and related to relapse rate (RR), progression-free survival (PFS) and overall survival (OS). RESULTS: out of 53 R0 OVCA patients 35 (66%) experienced long-term PFS (median follow up time 63 months, range 5-195(+)) and 18 (34%) relapsed after a median of 19 months. Fifteen of the 18 relapsing patients were treated with first-line CT. Twelve (80%) of them were PL-sensitive and 3 (20%) PL-resistant. Their median PFS was 9 and 3 months in PL-sensitive and PL-resistant cases, respectively (p=0.073). Statistical analysis of prognostic factors demonstrated FIGO stage and abnormal postoperative CA 125 values as significant. Patients with FIGO stage III had significantly shorter PFS (p=0.002) and OS (p=0.078) than those in earlier stages, and patients with abnormal postoperative CA 125 values had significantly worse PFS (p=0.017) but not OS (p=0.386) than those with normal values. Age, histological subtype and grade did not affect PFS and OS. CONCLUSION: FIGO stage and abnormal postoperative CA 125 have prognostic significance in OVCA patients after R0 surgical therapy and adjuvant PL-based CT. Patients with PL-sensitive disease achieved better results during therapy for relapse.

Clinicopathological features of primary fallopian tube carcinoma: a single institution experience.

PURPOSE OF INVESTIGATION: Primary fallopian tube carcinoma (PFTC) is a rare malignancy with only few data existing on the impact of prognostic factors. METHODS: We retrospectively analyzed 26 patients. Tissue blocks were reviewed and sections were stained for vascular endothelial growth factor (VEGF), matrix metalloproteinases 2 and 9 (MMP-2, MMP-9), tissue inhibitors of metalloproteinases 1 and 2 (TIMP-1, TIMP-2), c-erbB-2, estrogen (ER), and progesterone receptors (PgR). RESULTS: Reactivity for VEGF, ER, PgR, MMP-2, MMP-9, TIMP-1, TIMP-2 and c-erbB-2 was observed in 85%, 46%, 27%, 11.5%, 58%, 0%, 23% and 8% of specimens, respectively. None of the markers studied displayed prognostic significance. Regarding clinical prognostic factors, the hazard ratio (HR) for progression and death for patients with tumor residuum > 2 cm was 5.24 (p < 0.01) and 11.19 (p < 0.005), respectively. Patients with advanced stage disease had a HR of 12.55 (p < 0.05) for progression, while the HR for death was not found to be statistically significant. CONCLUSION: None of the biomarkers studied seems to influence survival. Early-stage disease and optimal debulking are associated with improved outcome.

The role of socio-demographic factors in depression and anxiety of patients on hemodialysis: an observational cross-sectional study.

PURPOSE: Depression and anxiety have high prevalence in patients on hemodialysis and are strongly associated with socio-economic factors. The aim of this study was to evaluate the prevalence of depression and anxiety in hemodialyzed patients in Greece and its association with socio-demographic factors. METHODS: Four hundred and fourteen (414) patients on hemodialysis (262 males and 152 females) from 24 dialysis centers in Greece participated in this observational cross-sectional study. Mean age was 63.54 (54.06-72.41), and mean time of dialysis treatment was 36 (16-72) months. Depression and anxiety were assessed by the state-trait anxiety inventory (STAI), the beck depression inventory (BDI) and the hospital anxiety and depression scale (HADS). Multinomial logistic regression was performed to estimate the factors being independently associated with anxiety and depression levels (HADS scale). Multiple linear regression was performed to estimate the factors being independently associated with BDI and STAI. RESULTS: From a total of 414 participants, (29.4%, n = 122) had depression and 35.9% (n = 149) had anxiety. Depression and anxiety were significantly associated with females, low level of education, increased patients' age, retirement, poor financial situation, marital status and co-morbidities. CONCLUSION: The overall study findings indicated a significant correlation between the levels of anxiety and depression in patients on hemodialysis. Patients with high levels of anxiety had higher levels of depression and those with high depression scores had higher anxiety scores.

Synthesis of hydroxyeicosatetraenoic acids and leukotrienes in rat nephrotoxic serum glomerulonephritis. Role of anti-glomerular basement membrane antibody dose, complement, and neutrophiles.

The basal and stimulated synthesis of immunoassayable 12- and 5-monohydroxyeicosatetraenoic acids (HETE) and leukotrienes (LT) B4 and C4 was studied in glomeruli isolated from rats with nephrotoxic serum glomerulonephritis (NSGN) induced by low (30 micrograms/g body weight) or high (105 micrograms/g) doses of anti-rat glomerular basement membrane (GBM) immunoglobulin (Ig). In the early heterologous phase of the disease, low doses of anti-GBM Ig enhanced the basal synthesis of 12-HETE but not that of 5-HETE or LT. High anti-GBM Ig doses enhanced the basal synthesis of 5-HETE and LTB4 as well. Under stimulated conditions, enhanced glomerular production of 5-HETE and LTB4 occurred at 15 min after infusion of anti-GBM Ig, peaked at 1 h, and returned toward control levels by 24 h. At 48 h, 72 h, and on day 12, the synthesis of these eicosanoids was impaired. Neutrophile depletion only partially reduced glomerular eicosanoid synthesis after induction of NSGN whereas complement depletion significantly reduced 5-HETE, 12-HETE, and LTB4. These observations indicate that in the heterologous phase of NSGN there is enhanced but short-lived glomerular 5-HETE and LTB4 synthesis. This phenomenon is mediated by complement activation and may be an important proinflammatory event leading to capillary wall injury in the early stages of the disease.

Glomerular arachidonate lipoxygenation in rat nephrotoxic serum nephritis.

Arachidonate lipoxygenation to monohydroxylated eicosatetraenoic acids (HETE) was studied in rat nephrotoxic serum nephritis (NSN). A single infusion of nephrotoxic serum enhanced conversion of [3H]arachidonic acid ([3H]C20:4) to [3H]12-HETE in glomeruli isolated from nephritic rats compared with controls. The percent conversion of [3H]arachidonic acid was 1.95 +/- 0.2% in control glomeruli and 14.2 +/- 2% in nephritic glomeruli 2 d after induction of disease. No significant changes in the conversion of [3H]C20:4 to [3H]5-, 8-, and 9-HETE were noted. Extraction of glomerular HETE by alkaline hydrolysis, to evaluate possible reacylation of HETE after their production, confirmed the presence of 12-HETE and did not provide evidence of 5-HETE synthesis. Increased glomerular 12-HETE synthesis in nephritic rats was also demonstrated by high pressure liquid chromatography-UV detection and by 12-HETE radioimmunoassay. The enhanced glomerular 12-HETE synthesis commenced as early as 3-5 h after administration of nephrotoxic serum and peaked at day 2 with 10-fold enhancement of 12-HETE production. Increments of glomerular 12-HETE persisted on day 7 and returned toward control levels by day 14. Platelet depletion, induced by antiplatelet antisera, did not decrease glomerular 12-HETE synthesis in NSN, thereby eliminating platelets as the cellular origin of 12-HETE. Glomerular epithelial and mesangial cells are the most likely sources of enhanced 12-lipoxygenase activity. The enhanced arachidonate 12-lipoxygenation in glomerular immune injury could have important proinflammatory effects in the evolution of glomerulonephritis since 12-HETE has important effects on leukocyte function.

Mesangial cell immune injury. Synthesis, origin, and role of eicosanoids.

The synthesis, cell origin, and physiologic role of eicosanoids were investigated in a model of mesangial cell immune injury induced by a monoclonal antibody against the rat thymocyte antigen Thy 1.1 also expressed in rat mesangial cells. A single intravenous injection of the antibody resulted in enhanced glomerular synthesis of thromboxane (Tx)B2, leukotriene (LT)B4, and 12-hydroxyeicosatetraenoic acid (HETE), whereas that of PGE2 and PGF2 alpha was either unaltered or impaired. The enhanced eicosanoid synthesis was associated with decrements in glomerular filtration rate (GFR) and renal blood flow (RBF). Complement activation mediated both the increments in TxB2, LTB4, and 12-HETE and the decrements in GFR and RBF. The decrements in GFR were abolished by the TxA2 receptor antagonist SQ-29,548. Although both neutrophiles and Ia (+) leukocytes infiltrated glomeruli, glomerular LTB4 originated mainly from the latter. Platelets entirely accounted for the enhanced 12-HETE synthesis in isolated glomeruli and to a lesser extent for that of LTB4 and TxB2. Glomerular PGE2 and PGF2 alpha originated from mesangial cells as their impaired synthesis coincided with extensive mesangial cell lysis. The observations indicate that in mesangial cell immune injury vasoactive and proinflammatory eicosanoids originate from recruited or activated Ia (+) leukocytes and platelets and may exert paracrine effects on mesangial cells.

Glomerular prostaglandin and thromboxane synthesis in rat nephrotoxic serum nephritis. Effects on renal hemodynamics.

Glomerular arachidonate cyclooxygenation by isolated rat glomeruli was assessed in vitro in antiglomerular basement membrane (anti-GBM) antibody-induced glomerulonephritis by radioimmunoassay for prostaglandins (PG) and thromboxane. After a single intravenous injection of rabbit anti-rat GBM serum, we observed enhancement of glomerular thromboxane B2 (TxB2) synthesis as early as 2 to 3 h with smaller increments in PGF2 alpha, PGE2 and 6-keto-PGF1 alpha synthetic rates. On day 2 of the disease, the glomerular synthesis of TxB2 and, to a lesser extent, PGF2 alpha and PGE2 remained enhanced, whereas on days 8, 11, and 14, TxB2 was the only prostanoid synthesized at increased rates. Glomerular TxB2 synthesis correlated with the presacrifice 24-h protein excretion. 60 min after intravenous infusion of anti-GMB serum, glomerular filtration rate (GFR) decreased (0.66 +/- 0.04 to 0.44 +/- 0.03 ml/min per 100 g, P less than 0.05), without a significant change in renal plasma flow (RPF): 1.97 +/- 0.23 to 1.80 +/- 0.23 ml/min per 100 g) and without a change in glomerular PG synthetic rates. At 2 h, GFR and RPF reached a nadir (0.25 +/- 0.04 and 1.3 +/- 0.1 ml/min per 100 g, respectively) coinciding with a fivefold increment in glomerular TxB2. By 3 h GFR and RPF partially recovered to 0.43 +/- 0.07 and 1.77 +/- 0.20 ml/min per 100 g, respectively, P less than 0.05, despite further increments in TxB2 synthesis. This recovery of GFR and RPF coincided with increments in vasodilatory PG, (PGE2 and PGI2). The thromboxane synthetase inhibitor OKY-1581 markedly inhibited platelet and glomerular TxB2 synthesis and preserved GFR at 1, 2, and 3 h. Another thromboxane synthetase inhibitor, UK-38485, also completely inhibited platelet and glomerular TxB2 synthesis and prevented decrements of GFR at 2 and 3 h. A cyclooxygenase inhibitor, ibuprofen, inhibited platelet TxB2 and PGE2 synthesis and significantly reduced glomerular PGE2 but not TxB2 synthesis. In the ibuprofen-treated rats, the partial recoveries of GFR and RPF at 3 h were attenuated. The in vitro glomerular TxB2 synthesis correlated inversely with the presacrifice GFR and filtration fraction. These observations indicate that in anti-GBM nephritis there is enhanced synthesis of TxA2 and PG in the glomerulus that mediate changes in renal hemodynamics.

Mechanism of action of glucocorticosteroids. Inhibition of T cell proliferation and interleukin 2 production by hydrocortisone is reversed by leukotriene B4.

The mechanism whereby glucocorticosteroids are immunosuppressive is unknown. One potential mechanism of action of these compounds is inhibition of arachidonic acid metabolism. We found that the inhibition of lymphocyte proliferation by hydrocortisone or dexamethasone was mimicked by nonspecific lipoxygenase inhibitors and also by a specific 5-lipoxygenase inhibitor, but not by a specific cyclooxygenase inhibitor. Mitogen-stimulated cultures of T cells produce approximately 5 X 10(-9) M leukotriene B4 (LTB4) in 24 h. This production of LTB4 is completely inhibited by concentrations of hydrocortisone or lipoxygenase inhibitors that inhibit mitogen-induced [3H]thymidine incorporation. The inhibition of lymphocyte proliferation by either hydrocortisone or by the 5-lipoxygenase inhibitor was totally reversed by LTB4 but not by leukotriene C4 or leukotriene D4. LTB4 had no effect on the inhibition of lymphocyte proliferation by noncorticosteroids such as prostaglandin E2, histamine, or gamma-interferon. The inhibition of interleukin 2 (IL-2) production by hydrocortisone or dexamethasone was also completely reversed by exogenous LTB4. LTB4 alone did not cause IL-2 production or cell proliferation when added to resting lymphocytes. Thus, endogenous LTB4 production appears to be necessary but not sufficient for phytohemagglutinin-induced IL-2 production and lymphocyte proliferation. Glucocorticosteroids inhibit IL-2 production and lymphocyte proliferation by inhibiting endogenous LTB4 production.

Leukotriene D4 is a mediator of proteinuria and glomerular hemodynamic abnormalities in passive Heymann nephritis.

We assessed the role of leukotrienes (LTs) in Munich-Wistar rats with passive Heymann nephritis (PHN), an animal model of human membranous nephropathy. 10 d after injection of anti-Fx1A antibody, urinary protein excretion rate (Upr) in PHN was significantly higher than that of control. Micropuncture studies demonstrated reduced single nephron plasma flow and glomerular filtration rates, increased transcapillary hydraulic pressure difference, pre- and postglomerular resistances, and decreased ultrafiltration coefficient in PHN rats. Glomerular LTB4 generation from PHN rats was increased. Administration of the 5-LO activating protein inhibitor MK886 for 10 d markedly blunted proteinuria and normalized glomerular hemodynamic abnormalities in PHN rats. An LTD4 receptor antagonist SK&F 104353 led to an immediate reduction in Upr and to reversal of glomerular hemodynamic impairment. Ia(+) cells/glomerulus were increased in PHN rats. In x-irradiated PHN rats, which developed glomerular macrophage depletion, augmented glomerular LT synthesis was abolished. Thus, in the autologous phase of PHN, LTD4 mediates glomerular hemodynamic abnormalities and a hemodynamic component of the accompanying proteinuria. The synthesis of LTD4 likely occurs directly from macrophages or from macrophage-derived LTA4, through LTC4 synthase in glomerular cells.

Mesangial cell immune injury. Hemodynamic role of leukocyte- and platelet-derived eicosanoids.

The role of leukocytes and platelets and of leukocyte- and platelet-derived eicosanoids in mediating acute changes in renal and glomerular hemodynamics was assessed in a model of antibody-induced mesangial cell injury in the rat. After a single intravenous injection (6 mg/kg) of the monoclonal antibody (ER4) against the mesangial cell membrane antigen Thy 1, significant decrements in glomerular filtration rate (GFR) and renal blood flow (RBF) were observed at 1 h, and were associated with increments in glomerular LC (+) leukocyte counts and in the synthesis of thromboxane (Tx)B2, leukotriene (LT)B4, and 12-hydroxyeicosatetraenoic acid (HETE). In rats with immune leukopenia, the rise in glomerular LC (+) leukocytes and in eicosanoid synthesis were abolished and the fall in GFR and RBF after administration of ER4 were completely ameliorated. Likewise, pretreatment of rats with both a thromboxane synthase and a 5-lipoxygenase inhibitor also blocked the fall in GFR and RBF and the rise in glomerular synthesis of TxB2 and LTB4 produced by ER4 without changing glomerular LC (+) leukocyte counts. Selective inhibition of thromboxane or 5-lipoxygenase alone only partially ameliorated the decrements in GFR and RBF produced by ER4. In animals with immune thrombocytopenia, the elevated glomerular synthesis of 12-HETE and fall in RBF but not GFR was ameliorated after administration of ER4. The ER4 antibody-induced fall in GFR was mainly caused by a marked decrement in the ultrafiltration coefficient, Kf, which was dependent on TxA2 and 5-lipoxygenase products, since pretreatment of animals with a thromboxane receptor antagonist or with a 5-lipoxygenase inhibitor partially ameliorated this decrement. Structural changes such as infiltration of glomerular capillaries by leukocytes and endothelial cell damage may also have accounted for the fall in Kf. These observations indicate that in antibody-mediated mesangial cell injury, infiltrating leukocytes and platelets mediate the changes in renal hemodynamics via synthesis of thromboxane and arachidonate 5-lipoxygenation products.

Activation of extracellular signal-regulated kinase in proliferative glomerulonephritis in rats.

Multiple extracellular mitogens are involved in the pathogenesis of proliferative forms of glomerulonephritis (GN). In vitro studies demonstrate the pivotal role of extracellular signal-regulated kinase (ERK) in the regulation of cellular proliferation in response to extracellular mitogens. In this study, we examined whether this kinase, as a convergence point of mitogenic stimuli, is activated in proliferative GN in vivo. Two different proliferative forms of anti-glomerular basal membrane (GBM) GN in rats were induced and whole cortical tissue as well as isolated glomeruli examined using kinase activity assays and Western blot analysis. Administration of rabbit anti-rat GBM serum to rats, preimmunized with rabbit IgG, induced an accelerated crescentic anti-GBM GN. A significant increase in cortical, and more dramatically glomerular ERK activity was detected at 1, 3, and 7 d after induction of GN. Immunization of Wistar-Kyoto rats with bovine GBM also induced a crescentic anti-GBM GN with an increase of renal cortical ERK activity after 4, 6, and 8 wk. ERK is phosphorylated and activated by the MAP kinase/ERK kinase (MEK). We detected a significant increase in the expression of glomerular MEK in the accelerated form of anti-GBM GN, providing a possible mechanism of long-term activation of ERK in this disease model. In contrast to ERK, activation of stress-activated protein kinase was only detectable at early stages of proliferative GN, indicating these related kinases to serve distinct roles in the pathogenesis of GN. Our observations point to ERK as a putative mediator of the proliferative response to immune injury in GN and suggest that upregulation of MEK is involved in the long-term regulation of ERK in vivo.

Dermatomyositis associated with breast cancer.

An increased risk of underlying malignancy has been found in patients with dermatomyositis (DM). The risk is increased even in patients with DM aged 45 or younger and remains high for many years after diagnosis. Breast carcinoma does not represent the most common solid tumor associated with this autoimmune disorder. In the present report, two new cases of DM associated with breast cancer are described, together with an extensive literature review.

The biological activity of acetylated sphingosylphosphorylcholine derivatives.

Taking into account their stereochemical similarity with 1-O-alkyl-2-acetyl-sn-glycerol-3-phosphorylcholine (PAF), which is known to exhibit a diverse spectrum of biological actions, including platelet aggregating and glycogenolytic activity, the acetylated derivatives of sphingosylphosphorylcholine and sphingomyelin were synthesized and tested for their ability to promote washed rabbit platelet aggregation and glycogenolysis in Tetrahymena pyriformis cells. Sphingomyelin (SPM) and sphingosylphosphorylcholine (SPC) were subjected to acetylation, following chromatographic purification and physicochemical characterization. The synthesized compounds N-acetyl, O-acetyl SPC (NAc, OAc SPC), N-acetyl SPC (NAc SPC) and O-acetyl SPM (OAc, SPM) were tested for their biological activity in the washed rabbit platelets and washed Tetrahymena pyriformis cell systems. These derivatives induced [3H]serotonin and ATP release and a monophasic aggregation of washed rabbit platelets in the concentration range 10(-8)-10(-6) M. However, authentic PAF-induced washed rabbit platelet aggregation was inhibited at higher concentrations of the acetylated sphingophospholipid compounds ( > 10(-6) M) and by the PAF-specific receptor(s) antagonists kadsurenone and triazolam. Platelet desensitization and crossed desensitization experiments with authentic PAF and the acetylated sphingophospholipids, suggested interaction with the same receptor(s) as PAF and different from the ADP or thrombin receptor. The involvement of calmodulin and protein kinase C in the biological activity of the prepared analogues was also demonstrated. Besides their action on rabbit platelets, the PAF-like activity of the acetylated sphingophospholipids was also demonstrated in a platelet-independent system, by showing that they stimulate glycogenolysis in washed Tetrahymena pyriformis cells. These observations indicate that a new class of compounds with PAF-like activity were synthesized but their role in the cellular metabolism remains to be shown. The existence of acetylated sphingophospholipids with PAF-like activity has so far been reported only in Urtica dioica.

Influence of prostaglandins on papillary blood flow and pressure-natriuretic response.

The present study examined whether renal prostaglandins influence the pressure-natriuretic response by altering medullary hemodynamics or renal interstitial pressure. The diuretic and natriuretic responses to changes in renal perfusion pressure were compared in control rats (n = 15) and in rats receiving either meclofenamate (2 mg/kg, n = 9) or indomethacin (2 mg/kg, n = 4). In control rats, urine flow and sodium excretion increased from 10 +/- 2 to 118 +/- 10 microliters/min/g kidney wt and from 1.8 +/- 0.3 to 21.0 +/- 1.5 mueq/min/g kidney wt, respectively, when renal perfusion pressure was increased from 109 to 167 mm Hg. Urinary excretion of prostaglandin E2 and thromboxane B2 increased significantly by 152% and 190%, respectively. Meclofenamate lowered thromboxane B2 and prostaglandin E2 excretion and prevented the increase in eicosanoid excretion produced by elevations in perfusion pressure. The pressure-diuretic and pressure-natriuretic responses of rats given meclofenamate or indomethacin were approximately half of those observed in the control rats. Papillary blood flow increased 21% and renal interstitial pressure rose from 5.0 +/- 0.7 to 8.2 +/- 0.7 mm Hg in control rats when pressure was elevated from 100 to 150 mm Hg. Meclofenamate and indomethacin lowered papillary blood flow and renal interstitial pressure and blunted the increases in these values produced by elevations in perfusion pressure. These results support the view that renal prostaglandins modulate the pressure-natriuresis relation by altering renal medullary hemodynamics and suggest that an intact renal prostaglandin system is necessary for the full expression of the medullary hemodynamic and natriuretic responses to increases in renal perfusion pressure.

Regulation of human P2X1 promoter activity by beta helix-loop-helix factors in smooth muscle cells.

We isolated and characterized genomic clones of the human P2X1 receptor (hP2X1) gene in an effort to understand its tissue specific expression. The hP2X1 gene contains 12 exons spanning 20 kb, with exon sizes ranging from 59 to 143 bp. A 385 bp upstream fragment promoted hP2X1 gene expression in smooth muscle (A7R5 and primary trachealis) and fibroblast (NIH3T3) cell lines, and mutation of a consensus E box sequence (CACCTG) within this fragment (-340 to -345) did not alter basal promoter activity. However, co-transfected bHLH factors regulated activity of the 385 bp minimal P2X1 promoter in a tissue-specific manner. E12 expression inhibited and ITF2b augmented activity in A7R5 cells, but had no effect in NIH3T3 cells. ITF2a, Myo-D, and Id1 proteins had no effect on either cell line, but co-expression of ITF2a blocked E12 inhibition in A7R5 cells, while ITF2b failed to reverse the inhibition. Northern analysis of A7R5 RNA identified high levels of E12 and ITF2b transcripts, and gel shift assays using A7R5 and NIH3T3 nuclear extracts indicated the formation of a protein-DNA complex with an oligonucleotide corresponding to -330 and -348, which was abolished by base substitutions within the E box motif. Our results identify a critical E box response element in the hP2X1 promoter that binds bHLH factors and demonstrate smooth muscle specific transcriptional regulation by E proteins.

Induction of heme oxygenase 1 in radiation nephropathy: role of angiotensin II.

Datta, P. K., Moulder, J. E., Fish, B. L., Cohen, E. P. and Lianos, E. A. Induction of Heme Oxygenase 1 in Radiation Nephropathy: Role of Angiotensin II. Radiat. Res. 155, 734-739 (2001). In a rat model of radiation-induced nephropathy, we investigated changes in expression of heme oxygenase 1 (Hmox1, also known as HO-1), an enzyme that catalyzes conversion of heme into biliverdin, carbon monoxide and iron. The study explored whether radiation induces Hmox1 expression in the irradiated kidney and whether angiotensin II (AII) mediates Hmox1 expression in glomeruli isolated from irradiated kidneys. To assess the effects of radiation on Hmox1 expression, rats received 20 Gy bilateral renal irradiation and were randomized to groups receiving an AII type 1 (AT(1)) receptor antagonist (L-158,809) or no treatment. Drug treatment began 9 days prior to bilateral renal irradiation and continued for the duration of the study. Estimation of Hmox1 levels in glomerular protein lysates assessed by Western blot analysis revealed a significant increase in Hmox1 protein at 50 and 65 days postirradiation. In animals treated with the AT(1) receptor antagonist, there was no induction of Hmox1, suggesting that AII may be a mediator of Hmox1 induction. To confirm that AII stimulates Hmox1 expression, animals were infused with 200, 400 or 800 ng/kg min(-1) of AII for 18-19 days, and Hmox1 protein levels in glomeruli were assessed. There was a significant induction of Hmox1 in glomeruli of animals infused with 800 ng/kg min(-1) of AII. These studies demonstrate that glomerular Hmox1 expression is elevated in the middle phase of radiation nephropathy and that AII can increase glomerular Hmox1 levels.