bluuebunny/crossref_metadata_2025 huggingface dataset:
Insulinotropic agent ID-1101 (4-hydroxyisoleucine) activates insulin signaling in rat
Authors: Broca Christophe , Breil Vincent , Cruciani-Guglielmacci Céline , Manteghetti Michèle , Rouault Christine , Derouet Michel , Rizkalla Salwa , Pau Bernard , Petit Pierre , Ribes Gérard , Ktorza Alain , Gross René , Reach Gérard , Taouis Mohammed
Published: April 2004

ID-1101 (4-hydroxyisoleucine), an amino acid extracted from fenugreek seeds, exhibits an interesting glucose-dependent insulin-stimulating activity. The present study was undertaken to investigate a possible extrapancreatic effect of ID-1101 on insulin signaling and action besides its previously described insulinotropic action. Insulin-sensitizing effects of ID-1101 were investigated in rat in vivo by three different approaches: 1) using euglycemic hyperinsulinemic clamps in two different rat models of insulin resistance, i.e., Zucker fa/fa rats and rats fed a sucrose-lipid diet; 2) measuring liver and muscle phosphatidylinositol (PI) 3-kinase activity after an acute injection of ID-1101 in normal and insulin-resistant diabetic rats; and 3) after chronic treatment in two rat models of insulin resistance. Euglycemic hyperinsulinemic clamp experiments revealed that ID-1101 can improve insulin resistance through an increase of peripheral glucose utilization rate in sucrose-lipid-fed rats and by decreasing hepatic glucose production in Zucker fa/fa rats. Moreover, we demonstrated that a single injection of ID-1101 activates the PI 3-kinase activity in liver and muscle from normal rats but also in muscle from diabetic rats. Finally, chronic ID-1101 treatment significantly reduced insulinemia in type 2 diabetic rats and reduced the progression of hyperinsulinemia in insulin-resistant obese Zucker fa/fa rats. These findings clearly demonstrate that ID-1101 can reduce insulin resistance through activation of the early steps of insulin signaling in peripheral tissues and in liver. In summary, ID-1101, besides its insulinotropic effect, directly improves insulin sensitivity, making it a potentially very valuable therapeutic agent for diabetes treatment.
5-Oxo-ETE regulates tone of guinea pig airway smooth muscle via activation of Ca2+pools and Rho-kinase pathway
Authors: Mercier Frederic , Morin Caroline , Cloutier Martin , Proteau Sonia , Rokach Joshua , Powell William S. , Rousseau Eric
Published: April 2004

5-Oxo-6,8,11,14-eicosatetraenoic acid (5-oxo-ETE) is a proinflammatory mediator, but its effects on airway smooth muscle (ASM) have never been assessed. Tension measurements performed on guinea pig ASM showed that 5-oxo-ETE induced sustained concentration-dependent positive inotropic responses (EC50= 0.89 μM) of somewhat lower amplitude than those induced by carbamylcholine and the thromboxane A2(TXA2) agonist U-46619. Transient inotropic responses to 5-oxo-ETE were recorded in Ca2+-free medium, suggesting mobilization of intracellular Ca2+. Meanwhile, the sustained contraction, which required Ca2+entry, was partially blocked by 1 μM nifedipine (an L-type Ca2+channel blocker) but relatively insensitive to 100 μM Gd3+. The 5-oxo-ETE responses were also inhibited by indomethacin and SC-560 [a cyclooxygenase (COX-1) inhibitor] pretreatments but not by NS-398 (a selective COX-2 inhibitor). The contractile effects of 5-oxo-ETE on ASM were inhibited by the selective TXA2receptor (TP receptor) antagonist SQ-29548 (−75%) and by 2-(p-amylcinnamoyl) amino-4-chlorobenzoic acid pretreatment, a phospholipase A2inhibitor (−66%), suggesting that the major part of its effect is mediated by the release of TXA2. ASM responses to 5-oxo-ETE were also blocked by the Rho-kinase inhibitor Y-27632, which also partially inhibited the response to the TP receptor agonist U-46619, suggesting that the contractile response is due in part to Ca2+sensitization of ASM cell myofilaments.
Effects of exercise training on the vascular reactivity of the whole kidney circulation in rabbits
Authors: Moraes Roger De , Gioseffi Giovanni , Nóbrega Antonio C. L. , Tibiriçá Eduardo
Published: April 2004

Exercise training is known to improve vasodilating mechanisms mediated by endothelium-dependent relaxing factors in the cardiac and skeletal muscle vascular beds. However, the effects of exercise training on visceral vascular reactivity, including the renal circulation, are still unclear. We used the experimental model of the isolated perfused rabbit kidney, which involves both the renal macro- and microcirculation, to test the hypothesis that exercise training improves vasodilator mechanisms in the entire renal circulation. New Zealand White rabbits were pen confined (Sed; n = 24) or treadmill trained (0% grade) for 5 days/wk at a speed of 18 m/min during 60 min over a 12-wk period (ExT; n = 24). Kidneys isolated from Sed and ExT rabbits were continuously perfused in a nonrecirculating system under conditions of constant flow and precontracted with norepinephrine (NE). We assessed the effects of exercise training on renal vascular reactivity using endothelial-dependent [acetylcholine (ACh) and bradykinin (BK)] and -independent [sodium nitroprusside (SNP)] vasodilators. ACh induced marked and dose-related vasodilator responses in kidneys from Sed rabbits, the reduction in perfusion pressure reaching 41 ± 8% ( n = 6; P < 0.05). In the kidneys from ExT rabbits, vasodilation induced by ACh was significantly enhanced to 54 ± 6% ( n = 6; P < 0.05). In contrast, BK-induced renal vasodilation was not enhanced by training [19 ± 8 and 13 ± 4% reduction in perfusion pressure for Sed and ExT rabbits, respectively ( n = 6; P > 0.05)]. Continuous perfusion of isolated kidneys from ExT animals with Nω-nitro-l-arginine methyl ester (l-NAME; 300 μM), an inhibitor of nitric oxide (NO) biosynthesis, completely blunted the additional vasodilation elicited by ACh [reduction in perfusion pressure of 54 ± 6 and 38 ± 5% for ExT and l-NAME + ExT, respectively ( n = 6; P < 0.05)]. On the other hand, l-NAME infusion did not affect ACh-induced vasodilation in Sed animals. Exercise training also increased renal vasodilation induced by SNP [36 ± 7 and 45 ± 10% reduction in perfusion pressure for Sed and ExT rabbits, respectively ( n = 6; P < 0.05)]. It is concluded that exercise training alters the rabbit kidney vascular reactivity, enhancing endothelium-dependent and -independent renal vasodilation. This effect seems to be related not only to an increased bioavailability of NO but also to the enhanced responsiveness of the renal vascular smooth muscle to NO.
Endogenous Sex Hormones and Progression of Carotid Atherosclerosis in Elderly Men
Authors: Muller Majon , van den Beld Annewieke W. , Bots Michiel L. , Grobbee Diederick E. , Lamberts Steven W.J. , van der Schouw Yvonne T.
Published: April 2004

Background—

The burden of atherosclerosis especially afflicts the increasing older segment of the population. Recent evidence has emphasized a protective role of endogenous sex hormones in the development of atherosclerosis in aging men.

Methods and Results—

We studied the association between endogenous sex hormones and progression of atherosclerosis in 195 independently living elderly men. Participants underwent measurements of carotid intima-media thickness (IMT) at baseline in 1996 and again in 2000. At baseline, serum concentrations of testosterone (total and free) and estradiol (total and free E
2
) were measured. Serum free testosterone concentrations were inversely related to the mean progression of IMT of the common carotid artery after adjustment for age (β=−3.57; 95% CI, −6.34 to −0.80). Higher serum total and free E
2
levels were related to progression of IMT of the common carotid artery after adjustment for age (β=0.38; 95% CI, −0.11 to 0.86; and β=0.018; 95% CI, −0.002 to 0.038, respectively). These associations were independent of body mass index, waist-to-hip ratio, presence of hypertension and diabetes, smoking, and serum cholesterol levels

Conclusions—

Low free testosterone levels were related to IMT of the common carotid artery in elderly men independently of cardiovascular risk factors.
Genome Scan for Familial Abdominal Aortic Aneurysm Using Sex and Family History as Covariates Suggests Genetic Heterogeneity and Identifies Linkage to Chromosome 19q13
Authors: Shibamura Hidenori , Olson Jane M. , van Vlijmen-van Keulen Clarissa , Buxbaum Sarah G. , Dudek Doreen M. , Tromp Gerard , Ogata Toru , Skunca Magdalena , Sakalihasan Natzi , Pals Gerard , Limet Raymond , MacKean Gerald L. , Defawe Olivier , Verloes Alain , Arthur Claudette , Lossing Alan G. , Burnett Marjorie , Sueda Taijiro , Kuivaniemi Helena
Published: April 2004

Background—

Abdominal aortic aneurysm (AAA) is a relatively common disease, with 1% to 2% of the population harboring aneurysms. Genetic risk factors are likely to contribute to the development of AAAs, although no such risk factors have been identified.

Methods and Results—

We performed a whole-genome scan of AAA using affected-relative-pair (ARP) linkage analysis that includes covariates to allow for genetic heterogeneity. We found strong evidence of linkage (logarithm of odds [LOD] score=4.64) to a region near marker
D19S433
at 51.88 centimorgans (cM) on chromosome 19 with 36 families (75 ARPs) when including sex and the number of affected first-degree relatives of the proband (N

aff

) as covariates. We then genotyped 83 additional families for the same markers and typed additional markers for all families and obtained a LOD score of 4.75 (
P
=0.00014) with sex, N

aff

, and their interaction as covariates near marker
D19S416
(58.69 cM). We also identified a region on chromosome 4 with a LOD score of 3.73 (
P
=0.0012) near marker
D4S1644
using the same covariate model as for chromosome 19.

Conclusions—

Our results provide evidence for genetic heterogeneity and the presence of susceptibility loci for AAA on chromosomes 19q13 and 4q31.
Thyrotropin-Releasing Hormone Is Induced in the Left Ventricle of Rats With Heart Failure and Can Provide Inotropic Support to the Failing Heart
Authors: Jin Hongkui , Fedorowicz Grazyna , Yang Renhui , Ogasawara Annie , Peale Franklin , Pham Thinh , Paoni Nicholas F.
Published: April 2004

Background—

We reported previously that left ventricular gene expression for thyrotropin-releasing hormone (TRH) precursor was increased in rats with heart failure 8 weeks after myocardial infarction (MI) and that early ACE inhibition tended to cause further myocardial induction of this gene.

Methods and Results—

Here, we show that after MI, the expression of pro-TRH is induced in the heart coordinately with the protease PC1, an important enzyme in TRH biosynthesis. Pro-TRH gene expression was induced in cardiac interstitial cells after MI, and this effect was restricted to the heart, because no increase in TRH mRNA abundance was observed in the hypothalamus, kidney, or lung. Transcript abundance of pro-TRH can be increased in cultured cardiac fibroblasts by several adrenergic agonists, indicating that the adrenergic axis may play a regulatory role in cardiac TRH production. Acute intravenous administration of TRH to rats with ischemic cardiomyopathy caused a significant increase in heart rate, mean arterial pressure, cardiac output, stroke volume, and cardiac contractility.

Conclusions—

Taken together, these results indicate that TRH is specifically induced in the heart after MI and that it can increase cardiac performance in rats with ischemic cardiomyopathy. Thus, in addition to catecholamine and angiotensin II, pro-TRH/TRH may be another important axis that affects hemodynamics and cardiac function in heart failure.
Cyclooxygenase Involvement in Thromboxane-Dependent Contraction in Rat Mesenteric Resistance Arteries
Authors: Bolla Manlio , You Dong , Loufrani Laurent , Levy Bernard I. , Levy-Toledano Sylviane , Habib Aïda , Henrion Daniel
Published: April 2004

The influence of cyclooxygenase pathway activation following thromboxane-endoperoxide (TP) receptor stimulation was studied in rat mesenteric resistance arteries (n=6 to 10 per group). We studied isolated, perfused, and pressurized mesenteric resistance arteries (mean internal diameter 214 μm) using an arteriograph, enabling us to study arteries in physiological conditions of flow and pressure. Changes in diameter were continuously recorded, and contractions measured as internal diameter reduction. Release of cyclooxygenase pathway metabolites was also assessed by enzyme immunoassay (EIA) analysis of mesenteric bed perfusions. The thromboxane A2 (TxA
2
) analog U-46619 (1 μmol/L) induced a significant contraction (108 μm maximal diameter reduction). Inhibition by 3 chemically different cyclooxygenase inhibitors (ie, flurbiprofen, indomethacin, and aspirin) potently reduced the contraction to 27%, 25%, and 6% of control, respectively. The selective cyclooxygenase-1 inhibitor SC-58560 inhibited U-46619 contraction, whereas selective cyclooxygenase-2 inhibition (SC-58236) had no effect. Thromboxane synthase inhibition (furegrelate) did not affect U-46619-induced contraction, but it was reduced by cytosolic phospholipase A2 inhibition. Measurement of cyclooxygenase derivatives produced by the isolated mesenteric bed showed that PGE
2
was produced after TxA
2
-receptor stimulation with U-46619. Exogenous prostaglandin E
2
(in the presence of the TxA
2
receptor antagonist SQ 29 548) and U-46619 contracted mesenteric arteries with a similar potency (EC
50
: 0.30 and 0.48 μmol/L, respectively). This study provides the first evidence that TxA
2
-receptor-dependent contraction in a resistant artery involved cyclooxygenase stimulation and, at least in part, a PGE
2
formation. This mechanism of TxA
2
-dependent contraction in resistant arteries might be of importance in the understanding of diseases affecting resistant arteries and involving TxA
2
, such as hypertension.
NFATc3-Induced Reductions in Voltage-Gated K
+
Currents After Myocardial Infarction
Authors: Rossow Charles F. , Minami Elina , Chase Eric G. , Murry Charles E. , Santana L.F.
Published: April 2004

Reductions in voltage-activated K
+
(Kv) currents may underlie arrhythmias after myocardial infarction (MI). We investigated the role of β-adrenergic signaling and the calcineurin/NFAT pathway in mediating the reductions in Kv currents observed after MI in mouse ventricular myocytes. Kv currents were produced by the summation of 3 distinct currents: I
to
, I
Kslow1
, and I
Kslow2
. At 48 hours after MI, we found a 4-fold increase in NFAT activity, which coincided with a decrease in the amplitudes of I
to
, I
Kslow1
, and I
Kslow2
. Consistent with this, mRNA and protein levels of Kv1.5, 2.1, 4.2, and 4.3, which underlie I
Kslow1
, I
Kslow2
, and I
to
, were decreased after MI. Administration of the β-blocker metoprolol prevented the activation of NFAT and the reductions in I
to
, I
Kslow1
, and I
Kslow2
after MI. Cyclosporine, an inhibitor of calcineurin, also prevented the reductions in these currents after MI. Importantly, Kv currents did not change after MI in ventricular myocytes from NFATc3 knockout mice. Conversely, chronic β-adrenergic stimulation or expression of an activated NFATc3 decreased Kv currents to a similar extent as MI. Taken together, these data indicate that NFATc3 plays an essential role in the signaling pathway leading to reduced I
to
, I
Kslow1
, and I
Kslow2
after MI. We propose that increased β-adrenergic signaling after MI activates calcineurin and NFATc3, which decreases I
to
, I
Kslow1
, and I
Kslow2
via a reduction in Kv1.5, Kv2.1, Kv4.2, and Kv4.3 expression.
Regional Angiographic Grading System for Collateral Flow
Authors: Kim Jane J. , Fischbein Nancy J. , Lu Ying , Pham Daniel , Dillon William P.
Published: April 2004

Background and Purpose—

Collateral flow plays an important role in maintaining tissue viability in proximal large vessel occlusion. We developed and tested a regional angiographic collateral grading system for patients with angiographically confirmed acute symptomatic middle cerebral artery occlusion to predict regional infarction.

Methods—

A subset of 42 patients was selected from 180 patients enrolled in the Prolyse in Acute Cerebral Thromboembolism II (PROACT II) trial. Readers evaluated baseline cerebral angiograms in a blinded fashion for the degree of regional collateral circulation, which was graded on a 4-point scale in each of 15 anatomic regions. Regional and total collateral flow scores were compared with the presence or absence of infarction on 7- to 10-day follow-up computed tomography (CT), as well as clinical outcome as assessed by National Institute of Health Stroke Scale (NIHSS) scores.

Results—

The collateral flow score on baseline angiography accurately predicted infarction, demonstrating a receiver operating characteristic curve of 0.87 (95% CI: 0.83 to 0.91) for all regions. Collateral grades on baseline angiography correlated moderately with infarct volume on follow-up CT scan at 7 to 10 days (
R
=0.61;
P
=0.0001). Collateral grades also correlated with follow-up NIHSS scores for patients who received thrombolysis (
R
=0.36 to 0.49,
P
<0.05), but not for control patients.

Conclusions—

An angiographic grading system for regional collateral flow accurately predicts the extent and location of cerebral infarction. This study corroborates the correlation between the presence of collateral flow, infarction volume, and clinical outcome, and it reinforces the need to control for collateral flow in clinical trials.
Effect of Carotid Endarterectomy or Stenting on Impairment of Dynamic Cerebral Autoregulation
Authors: Reinhard M. , Roth M. , Müller T. , Guschlbauer B. , Timmer J. , Czosnyka M. , Hetzel A.
Published: April 2004

Background and Purpose—

Analysis of dynamic cerebral autoregulation (DCA) from spontaneous blood pressure fluctuations might contribute to prognosis of severe internal carotid artery stenosis, but its response to carotid recanalization has not been investigated so far. This study investigates the effect of carotid endarterectomy or stenting on various DCA parameters.

Methods—

In 58 patients with severe unilateral stenosis undergoing carotid endarterectomy (n=41) or stenting (n=17), cerebral blood flow velocity (CBFV, transcranial Doppler) and arterial blood pressure (ABP, Finapres method) were recorded over 10 minutes before and on average 3 days after carotid recanalization. Nineteen patients were additionally examined after 7 months. Correlations between diastolic and mean ABP and CBFV fluctuations were averaged to form the correlation coefficient indices (diastolic [Dx] and mean values [Mx]). Transfer function parameters (low-frequency phase and high-frequency gain between ABP and CBFV oscillations) were calculated over the same 10 minutes. CO
2
reactivity was assessed via inhalation of 7% CO
2
.

Results—

Before recanalization, all DCA parameters were clearly impaired ipsilaterally compared with contralateral sides. Phase, Dx, and Mx indicated early normalization of DCA after both endarterectomy and stenting. By multiple regression, the degree of DCA improvement was highly significantly related to the extent of impairment before recanalization. No significant change in DCA was found at follow-up. Ipsilateral gain and CO
2
reactivity increased significantly less after endarterectomy than after stenting (
P
<0.05).

Conclusions—

Dynamic cerebral dysautoregulation in patients with severe carotid obstruction is readily and completely remedied by carotid recanalization.
In vivo activity of nuclease-resistant siRNAs
Authors: LAYZER JULIANA M. , MCCAFFREY ANTON P. , TANNER ALICE K. , HUANG ZAN , KAY MARK A. , SULLENGER BRUCE A.
Published: April 2004

Chemical modifications have been incorporated into short interfering RNAs (siRNAs) without reducing their ability to inhibit gene expression in mammalian cells grown in vitro. In this study, we begin to assess the potential utility of 2′-modified siRNAs in mammals. We demonstrate that siRNA modified with 2′-flouro (2′-F) pyrimidines are functional in cell culture and have a greatly increased stability and a prolonged half-life in human plasma as compared to 2′-OH containing siRNAs. Moreover, we show that the 2′-F containing siRNAs are functional in mice and can inhibit the expression of a target gene in vivo. However, even though the modified siRNAs have greatly increased resistance to nuclease degradation in plasma, this increase in stability did not translate into enhanced or prolonged inhibitory activity of target gene reduction in mice following tail vein injection. Thus, this study shows that 2′-F modified siRNAs are functional in vivo, but that they are not necessarily more potent than unmodified siRNAs in animals.
Role of the yeast Rrp1 protein in the dynamics of pre-ribosome maturation
Authors: HORSEY EDWARD W. , JAKOVLJEVIC JELENA , MILES TIFFANY D. , HARNPICHARNCHAI PIYANUN , WOOLFORD JOHN L.
Published: April 2004

The Saccharomyces cerevisiae gene RRP1 encodes an essential, evolutionarily conserved protein necsessary for biogenesis of 60S ribosomal subunits. Processing of 27S pre-ribosomal RNA to mature 25S rRNA is blocked and 60S subunits are deficient in the temperature-sensitive rrp1-1 mutant. We have used recent advances in proteomic analysis to examine in more detail the function of Rrp1p in ribosome biogenesis. We show that Rrp1p is a nucleolar protein associated with several distinct 66S pre-ribosomal particles. These pre-ribosomes contain ribosomal proteins plus at least 28 nonribosomal proteins necessary for production of 60S ribosomal subunits. Inactivation of Rrp1p inhibits processing of 27SA3 to 27SBS pre-rRNA and of 27SB pre-rRNA to 7S plus 25.5S pre-rRNA. Thus, in the rrp1-1 mutant, 66S pre-ribosomal particles accumulate that contain 27SA3 and 27SBL pre-ribosomal RNAs.
Review of Une expérience rhétorique. L'éloquence de la Révolution. Textes réunis par Éric Négrel et Jean-Paul Sermain. Studies on Voltaire, vol. 2. Oxford: Voltaire Foundation, 2002. Pp. 333.
Authors: Renwick John
Published: April 2004

REVIEW
Lucia Calboli Montefusco, ed., Papers on Rhetoric, vol. 4. Roma: Herder, 2002. Pp. viii + 286
Authors: Vassilaki Ekaterina
Published: April 2004

REVIEW
Clinical, cytogenetic, and molecular characterization of a patient with a de novo interstitial 22q12 duplication
Authors: Gentile M. , Wuyts W. , Grittani S. , Di Carlo A. , Cariola F. , Verdyck P. , Margari L. , Perniola T. , Buonadonna A.L.
Published: April 2004

We report a 19‐year‐old woman with minor craniofacial anomalies, mild mental retardation, and foramina parietalia permagna (FPP) (OMIM 168500). Cytogenetic analysis showed a de novo interstitial chromosome 22 long arm duplication. FISH with a panel of chromosome 22q12‐q13 bands‐specific BAC clones refined the cytogenetic investigation, and restricted the duplicated segment to the q12 region. Mutation analysis of FPP genes identified an insertion mutation in the ALX4 gene (344insC) in the proband and her father with loss of function of the gene. The patient's phenotype is considered in the light of the results of the cytogenetic, FISH, and molecular investigations, and her features are compared with those of other patients with similar duplications. Finally, variable phenotypic findings due to different 22q duplicated chromosomal segments are discussed. Our report indicates that 22q12 interstitial duplications are associated with craniofacial anomalies and mild mental retardation, while life threatening malformations are usually not present. Although these phenotypic changes are common and non‐specific, molecular study of our patient established more precise relationships between clinical findings and 22q duplicated region(s). This approach fosters better counseling of the families of patients with newly diagnosed, similar duplications. © 2004 Wiley‐Liss, Inc.
Analysis of chromosome segregation in sperm from a chromosome 2 inversion heterozygote and assessment of an interchromosomal effect
Authors: Mikhaail‐Philips Monica M. , Ko Evelyn , Chernos Judy , Greene Calvin , Rademaker Alfred , Martin Renée H.
Published: April 2004

Using fluorescence in situ hybridization (FISH) analysis, the chromosome segregation of a pericentric inversion of chromosome 2 was studied in spermatozoa. An interchromosomal effect (ICE) was also determined for chromosomes 13, 21, X, and Y. This chromosome inversion included more than 2/3 of the total length of the chromosome and the breaks points were in G‐light bands. The frequency of non‐recombinant sperm was 55.9%, and that of recombinant sperm was 34.5% (with a 1:1 ratio of duplication of the p arm and deletion of the q arm and vice versa). There was a significantly increased frequency of disomy for chromosome 2 (0.6%) compared to the other autosomes, suggesting that pairing and recombination of the inversion may predispose to nondisjunction. There was no significant difference between the frequencies of aneuploidy for chromosomes 13, 21, X, and Y for the chromosome inversion heterozygote compared to control donors. Thus we did not find evidence for an ICE. © 2004 Wiley‐Liss, Inc.
Second neoplasms in pediatric patients with primary central nervous system tumors
Authors: Broniscer Alberto , Ke Weiming , Fuller Christine E. , Wu Jianrong , Gajjar Amar , Kun Larry E.
Published: April 2004

BACKGROUND

Details on second neoplasms (SNs) following pediatric central nervous system (CNS) tumors are scant, because of the rarity of such SNs. The goal of the current study was to investigate and characterize these rare SNs.

METHODS

The authors reviewed clinical and treatment data on all institutional patients age < 22 years at diagnosis of a primary CNS tumor who developed any type of SN. Patients with neurofibromatosis type 1 were excluded. Cumulative incidence rates were estimated, and putative risk factors were analyzed.

RESULTS

The SNs investigated in the current study included 10 gliomas (42%), 5 meningiomas (21%), 2 desmoid tumors, 2 myelodysplastic syndromes, 2 basal cell carcinomas, 1 leukemia, 1 malignant fibrous histiocytoma, and 1 thyroid carcinoma. Twenty‐one patients had previously received radiotherapy, and 12 patients had received chemotherapy. The SN was related to a genetic cause in 7 patients (29%). Eleven patients died of their SNs, including 8 patients with glioma and 2 patients with myelodysplastic syndromes. The estimated 15‐year cumulative incidence rate for malignant SNs was 4%. Children with choroid plexus tumors had an estimated 10‐year cumulative incidence rate of 20.2%; 2 of those patients had germline TP53 mutations. Age ≤ 2 years was a significant risk factor (P = 0.016) for development of an SN only when patients with genetic conditions were included in the analysis. No significant difference in the estimated cumulative incidence of SNs was found among patients who had received different types of therapy.

CONCLUSIONS

The risk of lethal SNs after pediatric CNS tumors is small. Young patients and patients with choroid plexus tumors appear to have an increased risk of SNs that is associated with genetic factors. Cancer 2004. © 2004 American Cancer Society.
Multicomponent Ionic Complexes of Cobalt(II) Tetraphenylporphyrin with C60 Fullerides − Transition from the σ‐Bonded [(CoIITPP)·(C60−)] Anion to Nonbonded CoIITPP and C60·− Components
Authors: Konarev Dmitri V. , Neretin Ivan S. , Saito Gunzi , Slovokhotov Yury L. , Otsuka Akihiro , Lyubovskaya Rimma N.
Published: April 2004

New multicomponent ionic complexes containing [(Cation+)·(C60−)] fullerides and neutral CoIITPP molecules were obtained [the cations are Cs+ (1), tetramethylammonium (CH3)4N+ (2) and N‐methylpyridinium N‐MePy+ (3)]. The crystal structure of 1 determined from single‐crystal X‐ray diffraction analysis contains chains of alternating CoIITPP and C60·− units with voids accommodating solvated [(Cs+)·(C6H5CN)1.64]·CH3CN counter cations. Relatively long Co···C distances between CoIITPP and C60·− in 1 (2.55−3.05 Å) indicate the absence of noticeable bonding of CoIITPP and C60·−. This is consistent with the EPR spectrum of 1, which manifests two EPR signals with g = 2.0009 and 2.4982 attributable to C60·− and CoIITPP, respectively. In contrast to 1, complexes 2 and 3 contain EPR‐silent, σ‐bonded [(CoIITPP)·(C60−)] anions. The influence of the size of counter cations on the stability of σ‐bonded [(CoIITPP)·(C60−)] anions in ionic [(Cation+)·(CoIITPP)·(C60−)] complexes is analyzed. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
[CuI(im)]∞: Is this Air‐Stable Copper(I) Imidazolate (8210)‐Net Polymer the Species Responsible for the Corrosion‐Inhibiting Properties of Imidazole with Copper Metal?
Authors: Tian Yun‐Qi , Xu Hai‐Jun , Weng Lin‐Hong , Chen Zhen‐Xia , Zhao Dong‐Yuan , You Xiao‐Zeng
Published: April 2004

An air‐stable two‐dimensional (2D) copper(I) imidazolate polymer, [CuI(im)]∞ (1), with a d10‐d10 interaction, was synthesized solvothermally and structurally characterized by X‐ray crystallography: a = 8.069(2), b = 8.068(2), c = 13.425(3) Å, β = 99.414(3)°, monoclinic, C2/c. This is the first example of an air‐stable copper(I) imidazolate polymer that may play a significant role in the corrosion‐inhibition mechanism of imidazole (or its derivatives) with copper metal. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Scale‐up of catalytic wet oxidation under moderate conditions
Authors: Harf Julien , Hug Andreas , Vogel Frédéaric , Von Rohr Philipp Rudolf
Published: April 2004

The Catalytic Wet Oxidation with pure oxygen is a suitable treatment process for the degradation of organic matter in ivastewaters and sludges. The applied moderate reaction conditions lead only to a partial oxidation of the organics. Therefore the resulting process water has to be purified in a biological treatment plant. In this study, experimental data collected during the wet oxidation of phenol and sewage sludge in a laboratory batch reactor as well as in a pilot plant are presented. A generalized kinetic model combined with a residence time analysis allows to predict accurately the degradation of organic matter in the pilot plant. The wet oxidation of wastewaters and sewage sludge was realized in one single plant concept. Treating suspended or diluted organic wastes produces a highly biodegradable process water containing low molecular oxidation products. Tlje investigated Catalytic Wet Oxidation of sewage sludge generates a residual solid complying with the European quality standards of disposal concerning leachability and organic content. Due to its low capital and operating costs, the Catalytic Wet Oxidation process constitutes an acceptable alternative to incineration for the disposal of sludges.
Pervaporation of pharmaceutical waste streams and synthetic mixtures using water selective membranes
Authors: Shah D. , Bhattacharyya D. , Ghorpade A. , Mangum W.
Published: April 2004

The separation characteristics of binary mixtures and complex pharmaceutical wastes were studied using commercial water selective pervaporation membranes. Various synthetic alcohol‐water (plus salt in some cases) systems and actual waste were utilized for this investigation. The total flux (at 60°C)for the ethanol‐water system decreased from 1.26 to 0.05 ty/m2/hrasthe feed ethanol concentration increased from 35 to 97 wt %. The separation factor (water/ethanol) was found to increase by about 100 times for the same range of concentration. The water/isopmpanol selectivity was found to be considerably higher than the water/ethanol selectivity. The total flux (at 60°C)for the isopropanol‐water system varied from 0.85 to 0.48 kg/m2/hras the feed isopropanol concentration was increased from 35 to 70 wt %. The effect of the presence of salt in the feed on the pervaporation separation was also studied. There was a noticeable effect only at high concentrations of salt in the alcohol‐water feed. Both the total flux and the membrane selectivity were observed to decrease at high salt concentrations. Pervaporation can be used for the volume reduction of pharmaceutical wastes. Pervaporation experiments were performed on a complex pharmaceutical “waste A” at two different temperatures. The total flux (0.9 kg/m2/hr) at 60°C for the waste was observed to be six times the total flux at 28°C whereas the TOC (total organic carbon) reduction factor (7.9) at 60°C was found to 2.5 times that at 28°C. A 87 % removal of the TOC and COD of the waste stream was observed. Pervaporation, using water selective membrane, was also performed on a dilute “Waste B” and only 40 % TOC/COD removal was obtained. Based on the experimental results and operating cost calculations, it can be concluded that pervaporation is indeed an attractive strategy for the volume reduction and for simultaneous reduction of organic concentration in the permeate stream.
Treatability studies of groundwater contaminated with bis(2‐cloroethyl) ether
Authors: Huang Frank Y. C. , Li K. Y. , Liu C. C.
Published: April 2004

The groundwater aquifer underneath a chemical manufacturing plant in Southeast Texas has been contaminated with the leachate from its landfill. There are 17 major chlorinated hydrocarbon contaminants found in the groundwater with concentrations ranging from 1 ppm to 1200 ppm. An air‐stripping unit followed by a thermal catalytic oxidation unit is currently operating on‐site to remove all of the chlorinated compounds from the contaminated groundwater. One of the contaminants, bis(2‐chloroethyl)ether (DCEE), has a fairly low Henry's Law constant; therefore, a high airflow rate is employed in the stripping unit to improve the overall stripping efficiency. Nevertheless, the treated groundwater still contains a fair amount of DCEE.

An UV‐peroxidation reactor is set up to study its feasibility for oxidizing DCEE. The treatability data indicate that DCEE at a concentration of 200 ppm can be oxidized effectively in the presence of H2O2. and the effective UV wavelengths lie between 200 and 280 nm. No noticeable reduction of the oxidation rate is observed at low temperature (∼11°C). Apparent oxidation rate equations of DCEE are determined and several process design parameters are discussed.
A mathematical model of an isothermal, flue gas desulforization, copper oxide moving‐bed reactor
Authors: Enick Robert , Gale Tom , Klara Julianne , Jones James
Published: April 2004

An analytical model of an isothermal flue gas desulfurization moving‐bed reactor has been developed. The governing equations can be applied to any moving bed reactor system with pseudo‐first order gas phase kinetics. The average concentrations of SO2 in the effluent gas and CuO in the exiting sorbent are provided by explicit equations. The performance of the moving bed reactor can be predicted with these two simple expressions, thereby eliminating the need for numerical simulators that model the reactor as an array of interconnected microreactors. This analytical model is in agreement with an analytical model developed by Science Applications International Corporation (SAIC). Eight sets of experimental results from DOE's pilot‐scale Life‐Cycle‐Test‐System desulfurization reactor were compared with predictions from both models. No adjustable parameters were used to optimize the fit of the data. The isothermal model underestimated the effluent concentration of SO2 by an average value of 13‐2%, and underestimated the change in composition by 0.066%.
Nitrification of high strength ammonium wastewater in an aerated submerged fixed bed
Authors: Charmot‐Charbonnel Marie‐Louise , Herment Sandrine , Roche Nicolas , Prost Christian
Published: April 2004

The submerged fixed bed offers several advantages for the nitrification process because of its high stability, its compactness, the high applicable volumetric loadings and the very good distribution of the wastewater on the whole biofilm in the reactor. The objectives of this study were to evaluate the performances of this process and the optimal C:N (organic carbon : ammonium‐nitrogen) ratio for the treatment of high strength ammonium wastewaters (0.2 to 5 kg NH4+‐N.m−3). The experiments had been performed with a laboratory‐scale aerated submerged fixed bed, fed by a synthetic substrate (loading rates (Bv) = 0.1 to 2.6 kg NH4+‐N. m−3.d−1). It was found that the best ammonium reduction (72 %) is obtained for a C:N ratio of 1.7 (inlet concentration = 4 kg NH4+‐N.m−3, Bv = 1.9 kg NH4+‐N.m−3.d−1). The COD (Chemical Oxygen Demand) reduction was very good whatever the applied volumetric loading. The nitrification process was stopped when ammonium‐N concentration exceeded 5 kg.m−3 (Bv = 2.6 kg NH4+‐N. m−3.d−1).
Elimination of alkanes from off‐gases using biotrickling filters containing two liquid phases
Authors: Van Groenestijn Johan W. , Lake Mike E.
Published: April 2004

Biological techniques are highly cost‐effective for the treatment of off‐gases containing low concentrations of pollutants (< 5 g/m3). They may also be attractive for the elimination of higher concentrations of explosive hydrocarbons (when compared to incineration). Conventional techniques such as biofilters have low elimination capacities for hydrophobic compounds caused by a poor mass transfer from the gas to the aqueous phase.

To overcome solubility problems, a novel biotrickling filter was developed and is characterized by the use of an organic solvent. In such a biotrickling filter, a mixture of an organic solvent and water is continuously trickled over a packed bed, while the polluted gas passes counter‐current to the liquid. The microorganisms exist on the packing material and in the circulating liquid. The alkanes are absorbed in the oil phase of the liquid, transfer red to the microorganisms and biodegraded.

Laboratory‐scale experiments at 201 scale with hexane as a model pollutant and silicon oil as a solvent revealed that a 90% elimination efficiency can be reached at a volumetric loading rate of 100g hexane per m3 filterbed per hour. The influent gas contained 10 g hexane per m3 and had a temperature of 29°C.

The method described in this paper can be a cost‐effective way to treat gases containing hexane, other alkanes or other strongly hydrophobic compounds. Biological co‐oxidation of other biodegradable pollutants from the gas is to be expected.
Evaluation of a two‐stage biofilter for treatment of POTW waste air
Authors: Chitwood Derek E. , Devinny Joseph S. , Edward Reynolds F.
Published: April 2004

Recent efforts have been made to reduce releases of air toxics and smog precursors from wastewater treatment plants. Hydrgen sulfide is commonly the primary odor and is an important target for removal. Its oxidation, however, generates sulfuric acid and sometimes elemental sulfur, which can create substantial operational problems for biofilters. Declining pH may inhibit the organisms that degrade compounds other than hydrogen sulfide and may hasten aging of organic Biofilter media. A two‐stage biofilter has been designed and installed at the Ojai Valley Sanitary District wastewater treatment plant. The first stage is an enclosed system with a medium of small, inert, porous stones. It is called an acid gas biofilter. The second stage is a section of a traditional open biofilter filled with wood chips. The acid gas biofilter effectively removed H2S and volatile organic compounds while causing much lower headloss than traditional biofilters. However, considerable flow heterogeneity in both the acid gas biofilter and the wood chip biofilter was observed. The two‐stage system presumably will have a longer bed life because the first stage bed is inert and because the second stage is protected from acidification by removal of H2S in the first stage.
A supported polymeric liquid membrane process for removal of carboxylic acids from a waste stream
Authors: Ho Sa V.
Published: April 2004

The re m oval or elimination of organic residues from aqueous waste streams represents a major need in the chemical industry. We have developed a new class of membrane called “supported polymeric liquid membranes” that are capable of removing and concentrating low molecular weight organic compounds from dilute aqueous solutions, especially those that also contain high concentrations of inorganic salts. Attractive features of this membrane process include the ability to recover the contaminants in concentrated form for either recycle or more economical disposal, low pressure (ambient) operation, simple scale‐up using commercial hollow fiber modules, and ease of in‐situ regeneration of the polymeric liquid. The process has shown treatment feasibility for several types of aqueous waste streams. This paper describes the laboratory development activities for treating a waste stream containing a dilute mixture of C2–C6 carboxylic acids and nitric acid.
AIChE offers technological insights to the public policy debate on global climate change
Authors: Gushee David E.
Published: April 2004

Global climate change has been a major issue on the national political agenda since 1988. Several Committees on Capitol Hill conducted hearings concerning the heat waves then searing the nation. Testimony by several well‐regarded scientists at those hearings that “we ain't seen nothing yet” led to impressive headlines in the national media. Since then, unusually high temperatures, a succession of forecasts of serious negative impacts from the projected continued warming, and well‐publicized Congressional hearings led to the creation of the United Nation's Framework Convention on Climate Change (FCCC) and its Kyoto Protocol. As a result, climate change is on just about every technology organization's agenda.

In 1996, the American Institute of Chemical Engineers joined the list of organizations formally responding to the issue. The Government Relations Committee (GRC) formed a Task Force on Climate Change, made up of Institute members active in a number of aspects of the issue area. The charge to the Task Force: Look for opportunities for the Institute to contribute to the public policy debate on the issue and frame position papers accordingly.

The first major conclusion of the Task Force was that AIChE is not in a position to state whether or not global climate change is a real public policy problem. However, to the extent that the public policy process treats climate change as an issue, the Institute is well positioned to comment on the technical merits of proposed policy responses. The Task Force recommended this posture to the GRC, which agreed.
Enhanced scrubbing of chlorinated compounds from air streams
Authors: Johnson Jodi , Parker Wayne , Kennedy Kevin
Published: April 2004

This paper addresses an investigation of mass transfer issues associated with an innovative hybrid process to treat air streams containing chlorinated organics. Three target compounds [dichloromethane (DCM), carbon tetrachloride (CT) and tetra chloroethylene (PCE)] we re evaluated to assess a range of chemical and physical properties.

Vegetable oil was found to be an effective scrubbing solution in removing the target compounds from the air streams and was employed in continuous flow tests of a bench‐scale countercurrent packed co lumn. Removal efficiencies approached 90% for all three target compounds with gas‐liquid flow ratios less than 200.

A gas‐liquid mass transfer model was developed and compared to the existing Onda correlations, to characterize mass transfer under various operating conditions when water and vegetable oil were employed as scrubbing solutions. It was found that the Onda correlations did not fit the experimental data of vegetable oil very well. The existing Onda correlations we re modified by assuming that the gas phase resistance was controlling mass transfer.

In order to enhance mass transfer from the oil phase to an aqueous phase a liquid‐liquid contacting reactor was proposed. The results of the liquid‐liquid reactor suggested that mass transfer could be achieved for compounds that were not highly hydrophobic.
Recovery of sulfur from sour acid gas: A review of the technology
Authors: Eow John S.
Published: April 2004

The modified Claus process is the major technology for the recovery of elemental sulfur from H2S and SO2. A number of commercial technologies for the recovery of sulfur from acid gases are also highlighted here. A Claus tail‐gas clean‐up treatment is essential to give high sulfur recovery efficiency from sour acid gases. Generally, the existing tail‐gas clean‐up technologies can be classified into two groups: those that attain 99% overall sulfur recovery efficiency, and those that achieve 99.9% efficiency, including the sulfur recovered in the Claus unit. These processes are the Amoco's Cold Bed Adsorption (CBA), the SNPA/Lurgi Sulfreen, the IFP, the SCOT, the Beavon, and the Wellman‐Lord processes. The SCOT process is generally the most reliable and flexible technology. Process comparisons are also summarized in terms of the sulfur recovery efficiency, hazards and disadvantages, reliability and advantages, plant capacity and ecological impacts. Several changes and new trends are also highlighted here, such as the introduction of non‐permselective catalytic membrane reactors for the Claus reaction, and the in situ adsorption of water inside the Claus catalytic reactor. The successful utilization of H2S by converting it to sulfur and H2 attains the triple objectives of waste minimization, resource utilization, and environmental pollution reduction. Photochemical and plasmochemical methods are still in the development stage. Application of electrochemical technology to H2S requires further development. Research for an optimum porous catalyst structure is ongoing for obtaining a relation of micropores and macropores which would provide effective conversion of H2S and SO2.
Investigation of a novel jet deflector to avoid slag accumulation around secondary air jets in incinerators and boilers
Authors: Reynolds G. K. , Goh Yoke R. , Sharifi V. Nasserzadeh , Swithenbank Jim
Published: April 2004

A major problem in the operation of incinerators is the build‐up of slag on the walls in the throat region of the plant between the furnace chamber and the radiation shaft. This slag can accumulate to a thickness of about one meter, with a weight of several tonnes. This accumulation reduces the availability of the plant, and poses a safety problem, since injury can occur when the material is removed by pneumatic drills during maintenance operations. The excessive downtime, labor, and other economic costs of the slag removal can be minimized by developing a novel, no‐moving‐part jet deflector that can prevent or minimize the accumulation of slag around the jets. The jet deflector was developed and designed by understanding the fundamental principles of the fluid and particle dynamics around the high‐speed jet.

Two small‐scale laboratory rigs were constructed for this study. The first rig was a wind tunnel specially designed to minimize the turbulent intensity at the main flow inlet. The second was a combustion rig fitted with an ash/burner injection system, a mobile phone networked particle monitor, and a removable refractory panel onto which the jet and deflector were fitted. An extensive series of laboratory experiments were carried out on both rigs. In parallel with the laboratory investigation, computational fluid dynamic (CFD) analysis of the flow field around the jet and deflector under the same experimental conditions were also conducted. Optimization work on the deflector design was also carried out. Fully optimized jet deflectors were then manufactured and tested in a UK municipal waste incinerator plant. Visual inspections of the jets before and after the deflectors were fitted showed a very significant reduction in the slag formation.