Separate jasmonate-dependent and salicylate-dependent defense-response pathways in Arabidopsis are essential for resistance to distinct microbial pathogens

The endogenous plant hormones salicylic acid (SA) and jasmonic acid (JA), whose levels increase on pathogen infection, activate separate sets of genes encoding antimicrobial proteins in Arabidopsis thaliana. The pathogen-inducible genes PR-1, PR-2, and PR-5 require SA signaling for activation, whereas the plant defensin gene PDF1.2, along with a PR-3 and PR-4 gene, are induced by pathogens via an SA-independent and JA-dependent pathway. An Arabidopsis mutant, coi1, that is affected in the JA-response pathway shows enhanced susceptibility to infection by the fungal pathogens Alternaria brassicicola and Botrytis cinerea but not to Peronospora parasitica, and vice versa for two Arabidopsis genotypes (npr1 and NahG) with a defect in their SA response. Resistance to P. parasitica was boosted by external application of the SA-mimicking compound 2, 6-dichloroisonicotinic acid [Delaney, T., et al. (1994) Science 266, 1247-1250] but not by methyl jasmonate (MeJA), whereas treatment with MeJA but not 2,6-dichloroisonicotinic acid elevated resistance to Alternaria brassicicola. The protective effect of MeJA against A. brassicicola was the result of an endogenous defense response activated in planta and not a direct effect of MeJA on the pathogen, as no protection to A. brassicicola was observed in the coi1 mutant treated with MeJA. These data point to the existence of at least two separate hormone-dependent defense pathways in Arabidopsis that contribute to resistance against distinct microbial pathogens.     

Reduced toxicity and broad spectrum resistance to viral and fungal infection in transgenic plants expressing pokeweed antiviral protein II

Pokeweed antiviral protein II (PAPII), a 30 kDa protein isolated from leaves of Phytolacca americana, inhibits translation by catalytically removing a specific adenine residue from the large rRNA of the 60S subunit of eukaryotic ribosomes. The protein sequence of PAPII shows only 41% identity to PAP and PAP-S, two other antiviral proteins isolated from pokeweed. We isolated a cDNA corresponding to PAPII and introduced it into tobacco plants. PAPII expressed in transgenic tobacco was correctly processed to the mature form as in pokeweed and accumulated to at least 10-fold higher levels than wild-type PAP. We had previously observed a significant decrease in transformation frequency with PAP and recovered only two transgenic lines expressing 1-2 ng per mg protein. In contrast, eight different transgenic lines expressing up to 250 ng/mg PAPII were recovered, indicating that PAPII is less toxic than PAP. Two symptomless transgenic lines expressing PAPII were resistant to tobacco mosaic virus, potato virus X and the fungal pathogen Rhizoctonia solani. The level of viral and fungal resistance observed correlated well with the amount of PAPII protein accumulated. Pathogenesis-related protein PR1 was constitutively expressed in transgenic lines expressing PAPII. Although PR1 was constitutively expressed, no increase in salicylic acid levels was detected, indicating that PAPII may elicit a salicylic acid-independent signal transduction pathway.     

Perfusion-induced changes in cardiac contractility and oxygen consumption are not endothelium-dependent

OBJECTIVE: Are substances released from rat coronary endothelial cells responsible for the increase in contractility and oxygen consumption (Gregg phenomenon) seen with an increase in cardiac perfusion? METHODS: In an isovolumically contracting, Langendorff, crystalloid perfused rat heart (n = 6) at 27 degrees C, coronary flow was changed (from 4.4 to 15.4 ml.min-1.gww(-1)) before and after the endothelium was made dysfunctional by Triton X-100. Vascular endothelium and smooth muscle function were tested with bradykinin (BK, 1 microM, an endothelium-dependent dilator) and papaverine (PAP, 1 microM, an endothelium-independent dilator) in a preconstricted vascular bed (vasopressin, VP, 3 nM). RESULTS: Before Triton X-100, coronary resistance (at constant flow) decreased significantly in response to BK and to PAP. After Triton X-100 treatment the dilatory response to BK was abolished while the PAP response was still present, suggesting endothelial dysfunction with intact smooth muscle function. Due to Triton X-100 treatment, coronary resistance increased significantly. Therefore coronary flow changes were also applied during a similar increase in coronary resistance induced by VP infusion (3 nM) before Triton X-100 treatment. During control, developed left ventricular pressure (dev Plv) increased with 68 +/- 21% and oxygen consumption (VO2) increased with 122 +/- 25% in response to the maximal increase in coronary flow. During increased coronary resistance with and without functional endothelium, dev Plv increased by 57 +/- 16 and 64 +/- 22%, respectively, and VO2 increased by 126 +/- 21 and 103 +/- 20%, respectively, in response to the maximal increase in flow. These changes were not significantly different from control. CONCLUSION: The results suggest that the arterial endothelium is not involved in the Gregg phenomenon.     

Biological control of Botrytis cinerea growth on apples stored under modified atmospheres

The combined effect of modified-atmosphere packaging and the application of a bacterial antagonist (Erwinia sp.) on Botrytis cinerea growth on apples (cv. 'Golden Delicious') was investigated. Inoculated apples were stored in polyethylene bags at 5 degrees C. The initial gas composition in each bag was set according to a central composite experimental design involving five levels of O2 (1 to 15%) and CO2 (0 to 15%). Control samples under ambient conditions were also included. Without the antagonist, measurements of mold colony diameter over time showed that O2 had no effect on the growth of B. cinerea, while increased CO2 levels delayed its growth by about 4 days. Application of the antagonist resulted in a significant interaction between O2 and CO2. At low O2 levels, CO2 had no effect on mold growth, but at high O2, CO2 enhanced mold growth. O2 and the antagonist worked synergistically to reduce mold growth by about 6 days at low levels of CO2. However, at high CO2 levels, O2 had no effect. The strongest antagonistic effect was observed under ambient conditions. Overall, results showed that high CO2 atmospheres can slow the growth of B. cinerea and that Erwinia sp. was an effective antagonist against B. cinerea growth on apples, particularly under ambient conditions.     

Induction of tissue-specific autoimmune prostatitis with prostatic acid phosphatase immunization: implications for immunotherapy of prostate cancer

Prostatic acid phosphatase (PAP) is uniquely expressed in prostatic tissue and prostate cancer. In this study, the immunogenicity of PAP was investigated in a male rat model. We show that immunization with recombinant rat or human PAP in CFA leads to a significant Ab response, but does not generate CTL or result in autoimmune prostatitis. In contrast, immunization with recombinant vaccinia expressing human PAP, but not rat PAP, generates a CTL response and tissue-specific prostatitis in the absence of detectable PAP-specific Abs. These findings suggest that a cellular immune response to PAP, rather than Abs, mediates destructive autoimmune prostatitis. Thus, xenogeneic forms of PAP are a new tool for the induction of prostate-specific immunity and may prove useful for the immunotherapy of prostate cancer.     

Structure of yeast plasma membrane H(+)-ATPase: comparison of activated and basal-level enzyme forms

Experimental evidence suggests that the myocardial phospholipase D (PLD)-phosphatidate phosphohydrolase (PAP) signalling pathway may regulate Ca2+ movements and contractile performance of the heart. As abnormal Ca2+ homeostasis is associated with diabetic cardiomyopathy, we examined the functional status of the PLD/PAP pathway in sarcolemmal (SL) membranes isolated from insulin-dependent diabetic rat hearts at 8 weeks after a single i.v. injection of streptozotocin (65 mh/kg b.w.). Compared to age-matched controls, SL PLD hydrolytic (producing phosphatidic acid, PtdOH) and transphosphatidylation activities were significantly depressed in diabetic animals, while SL PAP was significantly augmented. The net effect of the altered enzyme activities in diabetic animals was a severely diminished (by 67% of controls) membrane level of PLD-derived PtdOH. Two weeks of insulin therapy to the 6 week diabetic animals normalized PLD, while PAP activity and PtdOH level were significantly modified, but had not completely reverted to control values. The observed changes were not due to hypothyroidism associated to the diabetic model as the induction of hypothyroidism in healthy non-diabetic animals did not affect SL PLD and PAP. The results suggest that the severe reduction of PLD-derived PtdOH and increased production of sn-1,2-diacylglycerol by phosphatidate phosphohydrolase may lead to an impairment of the bioprocesses mediated by these signalling lipids.     

Attenuated hematopoietic response to granulocyte-macrophage colony-stimulating factor in patients with acquired pulmonary alveolar proteinosis

The pathogenesis of acquired pulmonary alveolar proteinosis (PAP), a rare lung disease characterized by excessive surfactant accumulation within the alveolar space, remains obscure. Gene-targeted mice lacking the hematopoietic growth factor granulocyte-macrophage colony-stimulating factor (GM-CSF) or the signal-transducing beta-common chain of the GM-CSF receptor have impaired surfactant clearance and pulmonary pathology resembling human PAP. We therefore investigated the hematopoietic effects of GM-CSF in patients with PAP. The hematologic response of 5 infants with congenital PAP to 5 microgram/kg/d was of normal magnitude. By contrast, despite normal expression of GM-CSF receptor alpha- and beta-common chains on peripheral blood myelomonocytic cells (n = 6) and normal binding affinity of bone marrow mononuclear cells for GM-CSF (n = 3), each of the 12 patients with acquired PAP treated displayed impaired responses to GM-CSF; 5 microgram/kg/d produced only minor eosinophilia, and doses of 7.5 to 20 microgram/kg were required to induce >/=1.5-fold neutrophil increments in the 3 patients who underwent dose-escalation. However, neutrophilic responses to 5 microgram/kg granulocyte colony-stimulating factor (G-CSF) were normal (n = 4). In vitro, the proportion of hematopoietic progenitors responsive to GM-CSF (16.1% +/- 8.9%; P = .042) or interleukin-3 (IL-3; 19.3% +/- 7.7%; P = .063), both of which utilize the beta-common chain of the GM-CSF receptor complex, were reduced among patients with acquired PAP (n = 4) compared with normal bone marrow donor controls (47.2% +/- 25.9% and 40.9% +/- 18.6%, respectively). In the one individual who had complete resolution of lung disease during the period of study, this was temporally associated with correction of this defective in vitro response to GM-CSF and IL-3 on serial assessment. These data establish that patients with acquired PAP have an associated impaired responsiveness to GM-CSF that is potentially pathogenic in the development of their lung disease. Based on these observations, we propose a model of the pathogenesis of acquired PAP that suggests the disease arises as a consequence of an acquired clonal disorder within the hematopoietic progenitor cell compartment.     

Regulation of phosphatidic acid phosphohydrolase by epidermal growth factor. Reduced association with the EGF receptor followed by increased association with protein kinase Cepsilon

An important component of receptor-mediated intracellular signal transduction is the generation of lipid second messengers. Lipid second messenger production is a complex process involving a variety of regulatory enzymes that control the intracellular response to the extracellular signal. Phosphatidic acid (PA) is generated in response to phospholipase D and can be converted to other lipid second messengers including diacylglycerol (DG) and lysophosphatidic acid. PA is converted to DG by PA phosphohydrolase (PAP). We report here that PAP activity can be detected in epidermal growth factor (EGF) receptor immunoprecipitates. Following treatment with EGF, there is a substantial reduction in the PAP activity that co-precipitates with the EGF receptor. The loss of EGF receptor-associated PAP activity occurs with a concomitant increase in PAP activity associated with the epsilon isoform of protein kinase C (PKC). The PAP activity associated with PKCepsilon was dependent upon the PKC co-factors phosphatidylserine and DG but was independent of the kinase activity of PKCepsilon. These data suggest a novel signaling mechanism for the regulation of lipid second messenger production and implicate PAP as an important regulatory component for lipid second messenger production in receptor-mediated intracellular signaling.     

Role of neurosympathetic pathways in the vascular response to sepsis

PURPOSE: The aim of this study was to determine the role of sympathetic neural activity in the hemodynamic adaptations to sepsis in pigs with an emphasis on circuit adaptations. A fall in resistance to venous return (RVR) was predicted in contrast to what was previously observed in sympathetically intact animals that had no change in RVR. MATERIALS AND METHODS: We anesthetized and ventilated 13 pigs and gave 5 mg/kg of indomethacin. We measured cardiac output (CO) by thermodilution and measured pulmonary arterial (PAP), pulmonary capillary wedge (Pcw), right atrial pressure (Pra), and arterial pressure (MAP). Intermittent inflation of a 50-mL balloon in the right atrium was used to transiently arrest the circulation for the measurement of mean circulatory filling pressure (MCFP). RVR was calculated from (MCFP - Pra)/CO. Animals were divided into two groups; 6 received 10 mg/kg of the ganglionic blocker, hexamethonium and norepinephrine to maintain MAP; 7 had their spinal cords cut at C-2. After baseline measurements, all animals received 10 microg/kg/h of endotoxin for 2 hours, and hemodynamic measurements were repeated. Plasma samples were obtained for measurements of immunoreactive endothelin-1 (ET-1), which was assayed by a radioimmunoassay. RESULTS: Hexamethonium had no significant effect on hemodynamics except for an increase in heart rate. After endotoxin, MAP and SVR fell, PAP rose, and CO and RVR did not change. Spinal section resulted in an increase in heart rate and small increase in PAP and MCFR After endotoxin, there was a further increase in heart rate, PAP, and MCFP with a marked fall in MAP and CO. RVR increased from 2.1 +/- 0.46 after spinal section to 3.6 +/- 54 mm x min/L (P < .05). ET-1 in the hexamethonium group (n = 2) rose from 2.21 +/- .14 to 11.5 +/- 2.1 pg/ml at 2 hours, and in the spinal group (n = 7) from 2.04 +/- 0.77 to 6.85 +/- 3.9 pg/mL at 45 minutes. CONCLUSION: Spinal section resulted in a more profound fall in blood pressure and less increase in MCFP than in previously studied animals with sympathetic nervous system intact, but there was still an increase in RVR and PAP ET-1 is a possible mediator of the increase in RVR and PAP.     

Efficacy of the combination of nilutamide plus orchidectomy in patients with metastatic prostatic cancer. A meta-analysis of seven randomized double-blind trials (1056 patients)

OBJECTIVE: To review the efficacy of the combination of the anti-androgen nilutamide (Anandron) plus orchidectomy in patients with stage D prostate cancer who had received no previous treatment. PATIENTS AND METHODS: The results of seven randomized double-blind trials were analysed. In these studies patients were followed up until progression of disease or withdrawal for other reasons. Bone pain, urinary symptoms, performance status, levels of prostatic acid phosphatase (PAP) and alkaline phosphatase (AP) were evaluated before treatment and after 1, 3, 6, 12 and 18 months of treatment. Bone scans and X-rays were taken every 6 months. The best objective response, the time of progression and the time of death were recorded. The changes from baseline in symptoms and levels of tumour markers at month six and the percentages of objective regressions in the two treatment groups were compared using the Cochran-Mantel-Haenszel test stratified by study. Peto's method was used for the analysis of time to progression and of survival. RESULTS: Of the 1191 patients enrolled in all the original trials, 1056 were eligible. In the group of patients treated with nilutamide 50% had complete or partial regression of disease compared with 33% of those who were given a placebo (P < 0.001); bone pain and levels of PAP and AP were improved or returned to normal significantly more frequently (P < 0.01); the odds of disease progression were significantly reduced (odds ratio 0.84, P = 0.05); the odds of death from cancer and from other causes were reduced but the difference was not statistically significant. CONCLUSIONS: The combination of nilutamide and orchidectomy has a beneficial effect on pain of metastatic origin, levels of tumour markers, the objective response of disease and the time to disease progression. This treatment combination might also improve survival.     

Diagnosis of the abdominal vascular system by means of electron-beam computed tomography (EBT)]

Pokeweed antiviral protein (PAP) from Phytolacca americana is a highly specific N-glycosidase removing adenine residues (A4324 in 28S rRNA and A2660 in 23S rRNA) from intact ribosomes of both eukaryotes and prokaryotes. Due to the ribosome impairing activity the gene coding for mature PAP has not been expressed so far in bacteria whereas the full-length gene (coding for the mature 262 amino acids plus two signal peptides of 22 and 29 amino acids at both N- and C-termini, respectively) has been expressed in Escherichia coli. In order to determine: 1) the size of the N-terminal region of PAP which is required for toxicity to E. coli; and 2) the location of the putative enzymatic active site of PAP, 5'-terminal progressive deletion of the PAP full-length gene was carried out and the truncated forms of the gene were cloned in a vector containing a strong constitutive promoter and a consensus Shine-Dalgarno ribosome binding site. The ribosome inactivation or toxicity of the PAP is used as a phenotype characterized by the absence of E. coli colonies, while the mutation of PAP open reading frames in the small number of survived clones is used as an indicator of the toxicity to E. coli cells. Results showed that the native full-length PAP gene was highly expressed and was not toxic to E. coli cells although in vitro ribosome inactivating activity assay indicated it was active. However, all of the N-terminal truncated forms (removal of seven to 107 codons) of the PAP gene were toxic to E. coli cells and were mutated into either out of frame, early termination codon or inactive form of PAP (i.e., clone PAP delta107). Deletion of more than 123 codons restored the correct gene sequence but resulted in the loss of the antiviral and ribosome inactivating activities and by the formation of a large number of clones. These results suggest that full-length PAP (with N- and C-terminal extensions) might be an inactive form of the enzyme in vivo presumably by inclusion body formation or other unknown mechanisms and is not toxic to E. coli cells. However, it is activated by at least seven codon deletions at the N-terminus. Deletions from seven through to 107 amino acids were lethal to the cells and only mutated forms (inactive) of the gene were obtained. But deletion of more than 123 amino acids resulted in the loss of enzymatic activity and made it possible to express the correct PAP gene in E. coli. Because deletion of Tyr94 and Val95, which are involved in the binding of the target adenine base, did not abolish the activity of PAP, it is concluded that the location previously proposed for PAP enzymatic active site should be reassessed.     

Dynamic biventricular response to alterations in preload in patients undergoing left ventricular device implantation

Ventricular interdependence is important for the successful use of a left ventricular assist device (LVAD) because the filling of the device depends on right ventricular (RV) function as well as the interactions between the ventricles. The pulmonary arterial (PAP) and systemic arterial (AP) response to inferior vena caval (IVC) occlusion before and after insertion of an LVAD in 15 patients was used to "dissect out" the determinants of these interactions. PAP and AP were recorded during each IVC occlusion and peak systolic values calculated for each beat. Linear regression analysis was used to calculate the slope (k) between peak systolic AP values and peak systolic PAP values. k, a measure of preload responsiveness of the heart, is predominantly linear. k is relatively "flat" in selected LV failure patients pre-LVAD but increases significantly (P < 0.001) after LVAD (0.67 +/- 0.55 vs. 2.71 +/- 1.39). The increase in this parameter after LVAD suggests that the loss of RV-to-LV ventricular interdependence in patients with congestive heart failure appears to recover somewhat once an LVAD is inserted.     

Ventilation above closing volume reduces pulmonary vascular resistance hysteresis

The aim of this study was to determine the relationship of pulmonary vascular resistance (PVR) hysteresis and lung volume, with special attention to the effects of ventilation around closing volume (CV). Isolated, blood-perfused canine left lower lung lobes (LLL) were incrementally inflated and deflated. Airway and pulmonary artery pressures (PAP) were recorded after each stepwise volume change. Constant blood flow was provided (600 ml/min) and the pulmonary vein pressure (PVP) was held constant at 5 cm H2O. PAP changes, therefore, were a direct index of PVR changes. Group 1 lobes underwent a full inflation from complete collapse to total lobe capacity (TLC) followed by a full deflation. Group 2 lobes underwent two deflation/inflation cycles, after an initial full inflation. These cycles, both beginning at TLC, had deflation end above and below CV, respectively. Significant PVR hysteresis was noted when the first inflation and deflation were compared. The maximum difference in PAP on deflation was 3.3 cm H2O or 11%. The mean decrease was 2.7 cm H2O for 18 lobes (p < 0.0001). The PAPs on all subsequent inflations or deflations that began above CV remained 9% lower than the initial inflation (n = 9, p < 0.0001), but were not different from each other. However, the final inflation which began from below CV resulted in a 30% return of PVR hysteresis (mean increase in PAP of 0.8 cm H2O, n = 7, p < 0.004). We conclude that there is hysteresis in the PVR response during ventilation, with decreased PVR during deflation relative to the initial inflation, that this hysteresis is absent when lung volume is maintained greater than CV, and that hysteresis returns when inflation occurs after deflation below CV.     

Deregulation of poly(A) polymerase interferes with cell growth

Vertebrate poly(A) polymerase (PAP) contains a catalytic domain and a C-terminal Ser-Thr-rich regulatory region. Consensus and nonconsensus cyclin-dependent kinase (cdk) sites are conserved in the Ser-Thr-rich region in vertebrate PAPs. PAP is phosphorylated by cdc2-cyclin B on these sites in vitro and in vivo and is inactivated by hyperphosphorylation in M-phase cells, when cdc2-cyclin B is active. In the experiments described here, we undertook a genetic approach in chicken DT40 cells to study the function of PAP phosphorylation. We found that PAP is highly conserved in chicken and is essential in DT40 cells. While cells could tolerate reduced levels of PAP, even modest overexpression of either wild-type PAP or a mutant PAP with two consensus cdk sites mutated (cdk- PAP) was highly deleterious and at a minimum resulted in reduced growth rates. Importantly, cells that expressed cdk- PAP had a significantly lower growth rate than did cells that expressed similar levels of wild-type PAP, which was reflected in increased accumulation of cells in the G0-G1 phase of the cell cycle. We propose that the lower growth rate is due to the failure of hyperphosphorylation and thus M-phase inactivation of cdk- PAP.     

Adenovirus-mediated granulocyte-macrophage colony-stimulating factor improves lung pathology of pulmonary alveolar proteinosis in granulocyte-macrophage colony-stimulating factor-deficient mice

Mutation of the granulocyte-macrophage colony-stimulating factor (GM-CSF) gene by homologous recombination causes progressive pulmonary alveolar proteinosis (PAP) in GM-CSF-deficient mice (GM-/-). The present study tested whether adenovirus-mediated expression of GM-CSF alters the progression of PAP in GM-/- mice. Adult mice were pretreated with an anti-T cell receptor (TCR) antibody to block T cell-mediated immune response, followed by intratracheal instillation of deltaE1-E3 replication-deficient adenovirus expressing mouse GM-CSF (Av1mGM). Mice were killed 1, 3, and 5 weeks after treatment to assess lungs for GM-CSF, surfactant protein B (SP-B), alveolar macrophage maturation, and type II cell proliferation. GM-CSF was detected in BAL fluid from GM-/- mice 1 week after Av1mGM treatment, and GM-CSF mRNA was detected by RT-PCR through 5 weeks. Five weeks after Av1mGM treatment, PAP was improved and SP-B decreased as assessed by ELISA and immunostaining. Increased numbers of alveolar macrophages stained with alpha-naphthyl acetate esterase (alpha-NAE) following treatment with Av1mGM. Local expression of GM-CSF with a recombinant adenovirus ameliorated PAP in the GM-/- mice in association with enhanced maturation of alveolar macrophages.     

An anatomic study of the superficial radial nerve and its clinical implications

BACKGROUND: Acetylcholine produces coronary artery (CA) constriction in diabetic patients, suggesting an impairment of endothelium-dependent dilation. In diabetes, multiple metabolic abnormalities may inactivate nitric oxide through oxygen free radical production. METHODS AND RESULTS: To examine the mechanism of this abnormal response, two physiological tests (ie, a cold pressor test [CPT] and coronary flow increase induced by an injection of 10 mg papaverine [PAP] in the distal left anterior descending CA) were performed before and after either intravenous L-arginine (625 mg/min x 10 minutes) or intravenous deferoxamine (50 mg/min x 10 minutes) in 22 normotensive nonsmoking diabetic patients with angiographically normal CAs and normal cholesterol. Coronary surface areas were measured with quantitative angiography. Before the administration of L-arginine or deferoxamine, CPT induced CA constriction in both groups (-14 +/- 10% and -15 +/- 11%, respectively; each P<.001), and PAP injection in distal LAD did not modify significantly proximal LAD dimensions. In the 10 diabetic patients receiving L-arginine, responses to CPT and PAP were not modified. Conversely, in the 12 patients receiving deferoxamine, CA dilated in response to the two tests (+10 +/- 9% after CPT and +22 +/- 7% after PAP, each P<.001). Intracoronary isosorbide dinitrate, an endothelium-independent dilator, produced similar dilation in the two groups (+47 +/- 19% and +41 +/- 15%, respectively; each P<.001). CONCLUSIONS: This study shows that (1) responses of angiographically normal CAs to CPT and to flow increase are impaired in diabetic patients; (2) abnormal responses are not improved by L-arginine, suggesting that a deficit in substrate for nitric oxide synthesis is not involved; and (3) deferoxamine restores a vasodilator response to the two tests, suggesting that inactivation of NO by oxygen species might be partly responsible for the impairment of CA dilation in diabetic patients.     

Validation of new pulsed Doppler echocardiographic techniques for assessment of pulmonary hemodynamics

In preparation for a vasodilator study on chronic obstructive pulmonary disease (COPD), we investigated the reliability of recently described pulsed Doppler techniques for estimating pulmonary artery pressure (PAP) and cardiac output (CO). Our aims were to determine the following: (1) the imaging success rate for pulsed Doppler measurements; (2) the repeatability of the measurements, and interobserver and intraobserver variability; and (3) the accuracy of Doppler compared with catheter measurements. Doppler studies were attempted in 81 patients (cardiac disease [23], COPD [22], sleep apnea [32], and normal subjects [4]). Suitable images were obtained in 68 subjects (84 percent) and in 76 subjects (94 percent) for PAP and CO estimations, respectively. The lowest imaging success rates were in COPD patients (68 percent for PAP and 86 percent for CO estimation). Repeatability of the techniques was assessed in four cardiac patients and three healthy volunteers by performing four replicate studies in each subject over 1 h. Intrasubject coefficient of variation was < 10 percent for PAP and < 5 percent for CO. The intraobserver variability for Doppler estimation of systolic and mean PAP was 5.5 percent and 5.8 percent, respectively. The corresponding values for interobserver variability were 6.7 percent and 6.2 percent. Intraobserver and interobserver variability for "nongeometric" method of estimating CO was 5.1 percent and 5.9 percent, respectively. Agreement was good between catheter-measured and Doppler-estimated PAP in the 27 patients tested (cardiac [19] and COPD [8]) for both mean and systolic pressures (r = 0.96 and r = 0.97, respectively). The correlations between thermodilution and Doppler estimations of CO in eight COPD patients were 0.77 ("geometric" technique) and 0.97 ("nongeometric" technique). We conclude that pulsed Doppler techniques can be used to obtain accurate and reproducible quantitative information on pulmonary hemodynamics in a wide range of patients. Suitable Doppler images can be obtained in more than two thirds of COPD patients.     

The contemporary value of pretreatment prostatic acid phosphatase to predict pathological stage and recurrence in radical prostatectomy cases

PURPOSE: We examine the clinical prognostic value of the currently available simple and inexpensive immunoenzymatic prostatic acid phosphatase (PAP) assay for the staging and prognosis of radical prostatectomy cases. MATERIALS AND METHODS: Between February 1, 1990 and May 3, 1996 pretreatment PAP was measured in 295 patients who underwent radical prostatectomy. From February 1, 1990 to May 17, 1992 the Hybritech Tandem-E assay was used in 75 cases, from May 18, 1992 to February 28, 1993 the Abbott EIA assay was used in 49 and from March 1, 1993 to May 3, 1996 the Abbott IMx assay was used in 171. PAP assays were analyzed individually and the results were combined with pretreatment prostate specific antigen (PSA) values to assess the ability to predict organ confined prostate cancer and serological recurrence after radical prostatectomy. RESULTS: PAP testing was not of value for predicting organ confined disease or positive margins. However, this test was useful for predicting the first serological PSA recurrence in the 3 periods (77 to 85% correct) and overall (82% correct, p < 0.001, odds ratio 6.06). The Kaplan-Meier disease-free survival rate at 4 years was 78.8% for men with PAP less than 3 ng./ml. and 38.8% for those with PAP 3 ng./ml. or greater, which was significant when pretreatment PSA was less than 10 ng./ml. (p = 0.047), 10 ng./ml. or greater (p = 0.012) and overall (p < 0.001). PAP testing added prognostic information to pretreatment PSA values and it was an independent predictor of recurrence. CONCLUSIONS: The widely available and inexpensive PAP assays of the 1990s are predictors of recurrence after radical prostatectomy. They should be included in future studies of prostate cancer recurrence modeling. However, they do not predict pathological stage or margin status.