bluuebunny/crossref_metadata_2025 huggingface dataset:
Neuromuscular recovery following rocuronium bromide single dose in infants
Authors: Rapp H.‐J. , Altenmueller C.A. , Waschke C.
Published: December 2004

Background : Rocuronium bromide, a steroid nondepolarizing muscle relaxant, has a rapid onset and an intermediate duration of action in infants, children and adults. However, clinical evidence shows a longer duration of recovery in small infants. The aim of this study was to investigate the influence of age on rocuronium recovery during the first year of life.

Methods : ASA I–II infants, scheduled for elective surgery under general anaesthesia and intubation were included after ethics committee approval and parents’ written consent. According to age the patients were randomly allocated to receive either 0.45 mg·kg−1 or 0.6 mg·kg−1 rocuronium bromide in three age‐groups: (A) 0–1 month, (B) 2–4 months and (C) 5–12 months. After induction with thiopentone (5–7 mg·kg−1), anesthesia was maintained with isoflurane without opioids. Prior to surgery, caudal block with bupivacaine (0.125%) 1.0 ml·kg−1 and paracetamol 25 mg·kg−1 rectally were given for analgesia. Efficacy variables were intubation conditions 60 s after administration of muscle relaxant (T0) and recovery of neuromuscular blockade measured as T1 at 10, 25, 50 and 75 % of baseline, train‐of‐four (TOF) of 0.7 and Recovery Index (RI). Data were characterized by summary statistics and analysis of variance.

Results : A total of 61 infants with a median age range of 67 (2–364) days were included. Intubation conditions were excellent or good in all dose and age groups. T0 in group A was reached in a range of 15–30 s, in others up to 60 s. T1 recovery (T75) after 0.45 mg·kg−1 was 56.4 ± 16 (A), 62.7 ± 32 (B) and 45.8 ± 18 (C) min. Recovery times for of 0.6 mg·kg−1 were 100.8 ± 35 (A), 70.6 ± 19 (B) and 63.4 ± 21 (C) min, respectively. The TOF ratio (0.7) was 62.3 ± 18 (A), 64.1 ± 27 (B) and 43.7 ± 12 (C) min using 0.45 mg·kg−1 compared with 94.8 ± 31 (A), 63.8 ± 14 (B) and 67.5 ± 18 (C) min with 0.6 mg·kg−1. The differences of T75 and TOF 0.7 in A and C were significant (P ≤ 0.05).

Conclusions : Recovery of muscle relaxation using rocuronium bromide under isoflurane anesthesia in infants differs widely and shows great differences between age groups as well as dose regimen. A dose of 0.6 mg·kg−1 resulted in a significantly longer duration of action in group A. The reduced dose of 0.45 mg·kg−1 resulted in rapid and good relaxation in all infants without very long lasting effects. Reduced doses of rocuronium should be used in newborns and small infants.
The Monolithic Fetal Pacemaker:
Authors: DELL'ORFANO JOSEPH , CHOU HOWARD A. , PARK DAEGYUN , MIRZA HUMAIR , STYS TOMASZ , MAHAN VICKI , ZAVITZ DANIEL H. , PETRIKOVSKY BORIS M. , OVADIA MARC
Published: December 2004

DELL'ORFANO, J., et al.: The Monolithic Fetal Pacemaker: Prototype Lead Design for Closed Thorax Deployment.
Prenatal sudden cardiac death and hydrops fetalis are often due to complete heart block. However, no pacing modality exists for intrauterine application for fetal bradycardia. A prototype lead for a novel fetal pacemaker has been developed and used in a direct pacing model. It has been demonstrated that the lead can be safely and successfully deployed using a hypochondriac and transdiaphragmatic or subxiphoid approach. Pacing with ventricular capture was evident with the widening of QRS duration from

50.2 ± 9.8

to

95.1 ± 12.8 ms (P = 0.0001)

. Further studies by echocardiogram revealed an increase in the pulse with pacing, confirming pacing. This study documents proof‐of‐concept for closed thorax over‐the‐wire deployment of a novel lead design applicable to fetal pacing. By combining the lead design with microcircuitry and a small power source, it is possible to create a monolithic fetal pacemaker system capable of being deployed in utero. (PACE 2003; 26[Pt. I]:805–811)
High Density Endocardial Mapping of Shifts   in the Site of Earliest Depolarization During Sinus Rhythm and Sinus Tachycardia
Authors: BETTS TIM R. , ROBERTS PAUL R. , HO SIEW YEN , MORGAN JOHN M.
Published: December 2004

BETTS, T.R., et al.: High Density Endocardial Mapping of Shifts in the Site of Earliest Depolarization During Sinus Rhythm and Sinus Tachycardia.
Previous mapping studies of sinus rhythm suggest faster rates arise from more cranial sites within the lateral right atrium. In the intact, beating heart, mapping has been limited to epicardial plaques or single endocardial catheters. The present study was designed to examine shifts in the site of the earliest endocardial depolarization during sinus rhythm and sinus tachycardia using high density activation mapping. Noncontact mapping of the right atrium during sinus rhythm was performed on ten anesthetized swine. Recordings were made during sinus rhythm, phenylephrine infusion, and isoproterenol infusion. The hearts were then excised and the histological sinus node identified. The mean minimum and maximum cycle lengths recorded were

355 ± 43

and

717 ± 108 ms

. A median of three (range two to five) sites of earliest endocardial depolarization were documented in each animal. With increasing heart rate the site of earliest endocardial depolarization remained stationary until a sudden shift in a cranial or caudal direction, often to sites beyond the histological sinoatrial node. The endocardial shift was unpredictable with considerable variation between animals; however, faster rates arose from more cranial sites

(r = 0.46, P = 0.023)

. There was no difference in the mean cycle length of sinus rhythm originating from specific positions on the terminal crest

(r = 0.44, P = 0.17)

. Cranial sites displayed a more diffuse pattern of early depolarization than caudal sites. In the porcine heart the relationship between heart rate and site of earliest endocardial depolarization shows considerable variation between individual animals. These findings may have implications for clinical mapping and ablation procedures. (PACE 2003; 26[Pt. I]:874–882)
Colonic Perforation Following Intraoperative Temporary Pacemaker Implantation
Authors: OZA PARIND M. , REILING RICHARD B.
Published: December 2004

OZA, P.M., et al.: Colonic Perforation Following Intraoperative Temporary Pacemaker Implantation.
This report describes the case of a 73‐year‐old man who was referred for consultation for increasing abdominal free air 1 week after he underwent surgery for aortic valve replacement and coronary artery bypass grafting with intraoperative pacemaker implantation. Laparoscopic exploration revealed that the pacemaker wires had passed through the left transverse colon. Although no previous reports of colonic perforation due to pacemaker lead placement was found, this experience suggests that physicians should suspect this complication in patients with increasing free intraabdominal air and peritoneal signs who have recently undergone placement of a temporary cardiac pacing system. (PACE 2003; 26[Pt. I]:918–919)
Alteration of QT Rate Dependence Reflects Cardiac Autonomic Imbalance in Patients with Obstructive Sleep Apnea Syndrome
Authors: ROCHE FRÉDÉRIC , GASPOZ JEAN‐MICHEL , COURT‐FORTUNE ISABELLE , COSTES FRÉDÉRIC , GEYSSANT ANDRÉ , DUVERNEY DAVID , PICHOT VINCENT , BARTHÉLÉMY JEAN‐CLAUDE
Published: December 2004

QT rate dependence is one of the major properties of ventricular repolarization with its circadian and autonomic modulations. The authors postulated that dynamic alterations in QT interval adaptation could help characterize patients with cardiac autonomic alterations, like those with obstructive sleep apnea syndrome (OSAS). To assess ventricular repolarization features in patients with OSAS, QT parameters and their dynamicity along RR intervals were compared from 24‐hour ECG data of patients with and without this syndrome, assessing cardiac autonomic nervous system equilibrium by means of time‐domain and frequency‐domain analyses of heart rate variability (HRV). The study group consisted of 74 consecutive patients referred to the Sleep Laboratory for clinically suspected OSAS. The syndrome was confirmed in 30 (40.5%) patients according to standard polysomnographic criteria. QT length related to heart rate (HR) was found significantly shorter for HR < 70 beats/min in patients with OSAS

(−1.32 ± 0.35)

compared with patients without OSAS

(−1.99 ± 0.40; P < 0.01)

. This flattened relationship was correlated with the severity of the sleep related disorder. Using multiple linear regression analysis, the apnea/hypopnea index and nocturnal normalized high frequencies (HFnu) were the most significant predictors of the QT/RR slope

(R = 0.61; P < 0.0001)

. OSAS is significantly associated with a flattened relationship between QT duration and RR interval at low HRs. The alteration of cardiac parasympathetic tone occuring in severe OSAS patients may explain this altered rate dependent adaptation of myocardial repolarization. (PACE 2003; 26[Pt. I]:1446–1453)
Study of Precursors of Ventricular Tachycardia from Data Stored in the Memory of a Dual Chamber Implantable Cardioverter Defibrillator
Authors: LEENHARDT ANTOINE , SADOUL NICOLAS , MABO PHILIPPE , KACET SALEM , LAVERGNE THOMAS , SAOUDI NADIR , ISCOLO NICOLAS ,   Defender I clinical trial Investigators
Published: December 2004

This study was performed to examine precursors of ventricular tachyarrhythmias in patients who experienced a sustained ventricular tachyarrhythmia and received appropriate therapy by ICD. From an overall consecutive population of 77 patients, 18 patients (1 woman,

mean age 61.7 ± 10.8 years

) were selected for having experienced a sustained ventricular tachyarrhythmia and received at least one appropriate ICD therapy preceded by 20 minutes of internal information. The number of premature ventricular complexes (PVCs)/min for each of the 20 minutes preceding the onset of ventricular tachyarrhythmia, the shortest coupling intervals between PVC and normal sinus beat, and the presence of short‐long‐short (SLS) interval sequences were examined. Data were stratified according to underlying disease, left ventricular ejection fraction, rate of ventricular tachyarrhythmia, and antiarrhythmic therapy. One hundred twenty‐eight episodes of spontaneous ventricular tachyarrhythmia were retrieved. Rapid ventricular tachyarrhythmia (>160 beats/min) were preceded by a significantly greater mean number

(3.71 ± 6.36)

of PVCs than slower ventricular tachyarrhythmia (≤160 beats/min)

(0.63 ± 0.88, P = 0.0004)

. The mean shortest PVC coupling interval was significantly shorter in patients with

(588 ± 99 ms)

versus without

(643 ± 111 ms, P = 0.03)

ischemic heart disease, before episodes of rapid

(527 ± 55 ms)

versus slower

(636 ± 105 ms, P = 0.0001)

ventricular tachyarrhythmia, and in the absence

(538 ± 80 ms)

versus the presence

(620 ± 105 ms, P = 0.006)

of amiodarone. SLS sequences preceded 29% of rapid ventricular tachyarrhythmic episodes, versus 8% of the slower ventricular tachyarrhythmia

(P < 0.01)
. Significant differences were found in the characteristics of PVCs preceding ventricular tachyarrhythmic episodes in accordance to their rate and the underlying cardiomyopathy. Though insufficient in isolation, these findings may be helpful when combined with other observations to develop preventive algorithms, or to refine the programming of implantable devices. (PACE 2003; 26[Pt. I]:1454–1460)
Electrophysiological Features of Orthodromic Atrioventricular Reentry Tachycardia in Patients with Wolff‐Parkinson‐White Syndrome and Atrial Fibrillation
Authors: KALARUS ZBIGNIEW , KOWALSKI OSKAR , LENARCZYK RADOSŁAW , PROKOPCZUK JANUSZ , PASYK STANISŁAW
Published: December 2004

The aim of this study was to compare the electrophysiological features of tachycardia between WPW patients with and without AF. The study population consisted of 114 patients with WPW syndrome and reciprocating tachycardia during electrophysiological study. Two groups were selected: group I with AF during the procedure

(n = 42)

and the control group

n = 72

without AF (group II). Cycle length (V‐V interval), antero A‐V, retrograde V‐A conduction time during tachycardia and indexes V‐A/V‐V were analyzed. In addition, the relation between antero‐, retrograde conduction time, and V‐V was evaluated. Selection of the most predictive factor for AF presence was performed using regression analysis. Significant differences between the two groups were observed. These included a higher rate of tachycardia, shorter anterograde conduction time, A‐V/V‐V‐indexes, longer retrograde conduction time, and V‐A/V‐V‐indexes in group I compared with group II. Significant, positive correlations between anterograde conduction time and V‐V were present in both groups, but retrograde conduction correlated significantly with the V‐V‐interval only in group II and group I (r = 0.37 vs r =−0.01, respectively). Significant, negative correlations between A‐V and V‐A conduction time in all analyzed points has been found to exist in group I (r =−0.45 for the point of maximal preexcitation [PMP]), whereas there were no significant correlations between these parameters in group II (r = 0.04). The most powerful AF predictor has been identified as the V‐A/V‐V index. The presence of AF in WPW syndrome may be associated with discrete patient characteristics. Ventricular activation occurs earlier, and atrial later, in the tachycardia cycle in AF than in patients free of AF. The different ability of the accessory pathway for adaptation to tachycardia rate changes in group I causes prolonged retrograde conduction over the pathway while the tachycardia rate increases. (PACE 2003; 26[Pt. I]:1479–1488)
Nonpulmonary Vein Foci:
Authors: SHAH DIPEN , HAISSAGUERRE MICHEL , JAIS PIERRE , HOCINI MELEZE
Published: December 2004

Though the majority of foci triggering atrial fibrillation (AF) have been mapped to the pulmonary veins (PV), recurrence of paroxysmal AF after isolation of all four pulmonary veins indicates the presence of other foci. In a series of 160 consecutive patients who underwent PV ablation, endocardial mapping of AF and ectopy recurring after PV isolation was performed. Thirty‐six patients (24%) had a total of 85 non‐PV foci; 39 were mapped to the ostia of ablated PVs, 30 to the posterior left atrium (LA), 5 to other parts of the LA, 5 to the right atrium (RA), 4 to the coronary sinus (CS), and 3 to the superior vena cava (SVC) (including one persistent left SVC). Mapping was confirmed by successful ablation. At least 16 foci could not be localized and after a follow‐up of 8 ± 6 months, 68% of patients were free of AF without any antiarrhythmic treatment. The occurrence of non‐PV foci correlated with recurrence of AF, perhaps as a correlate of insufficient ostial ablation. These data reinforce the requirement for more proximal disconnection of the PVs by performing ablation within the LA. In patients with non‐PV foci that are difficult to map conventionally, the use of surface ECG data, or multielectrode contact or noncontact mapping arrays, or substrate modifying/excluding ablation may be helpful in ablating these foci and therefore eliminating AF. (PACE 2003; 26[Pt. II]:1631–1635)
A chloroplast transgenic approach to hyper‐express and purify Human Serum Albumin, a protein highly susceptible to proteolytic degradation
Authors: Fernández‐San Millán Alicia , Mingo‐Castel Angel , Miller Michael , Daniell Henry
Published: December 2004

Human Serum Albumin (HSA) accounts for 60% of the total protein in blood serum and it is the most widely used intravenous protein in a number of human therapies. HSA, however, is currently extracted only from blood because of a lack of commercially feasible recombinant expression systems. HSA is highly susceptible to proteolytic degradation in recombinant systems and is expensive to purify. Expression of HSA in transgenic chloroplasts using Shine‐Dalgarno sequence (SD), which usually facilitates hyper‐expression of transgenes, resulted only in 0.02% HSA in total protein (tp). Modification of HSA regulatory sequences using chloroplast untranslated regions (UTRs) resulted in hyper‐expression of HSA (up to 11.1% tp), compensating for excessive proteolytic degradation. This is the highest expression of a pharmaceutical protein in transgenic plants and 500‐fold greater than previous reports on HSA expression in transgenic leaves. Electron micrographs of immunogold labelled transgenic chloroplasts revealed HSA inclusion bodies, which provided a simple method for purification from other cellular proteins. HSA inclusion bodies could be readily solubilized to obtain a monomeric form using appropriate reagents. The regulatory elements used in this study should serve as a model system for enhancing expression of foreign proteins that are highly susceptible to proteolytic degradation and provide advantages in purification, when inclusion bodies are formed.
Oryzacystatin I expression in transformed tobacco produces a conditional growth phenotype and enhances chilling tolerance
Authors: Van der Vyver Christell , Schneidereit Jörg , Driscoll Simon , Turner Janice , Kunert Karl , Foyer Christine H.
Published: December 2004

A recent strategy for pest control in plants has involved transformation with genes encoding cysteine proteinase inhibitors (cystatins). Little is known, however, about the effects of constitutive cystatin expression on whole plant physiology. The present study using oryzacystatin I (OC‐I) expression in transformed tobacco was designed to resolve this issue and also to test the effects on abiotic stress tolerance. All transformed plants expressing OC‐I showed a conditional phenotype. A marked effect on stem elongation was observed in plants grown under low light intensities. After 7 weeks of growth at low light, the plants expressing OC‐I were smaller with fewer expanded leaves and a slightly lower total biomass than empty vector controls or wild type plants. Maximal rates of photosynthesis (Amax) were also decreased, the inhibitory effect being greatest in the plants with highest OC‐I expression. After 12 weeks of growth at low light, however, the plants expressing OC‐I performed better in terms of shoot biomass production, which was nearly double that of the empty vector or wild type controls. All plants showed similar responses to drought, however photosynthesis was better protected against chilling injury in plants constitutively expressing OC‐I. Photosynthetic CO2 assimilation was decreased in all plants following exposure to 5 °C, but the inhibition was significantly less in the OC‐I expressing plants than in controls. The transformed tobacco plants expressing OC‐I therefore show a phenotype–environment interaction with important implications for biotechnological applications.
Enhancement of seed phytosterol levels by expression of an N‐terminal truncated Hevea brasiliensis (rubber tree) 3‐hydroxy‐3‐methylglutaryl‐CoA reductase
Authors: Harker Mark , Holmberg Niklas , Clayton John C. , Gibbard Carl L. , Wallace Andrew D. , Rawlins Sally , Hellyer S. Amanda , Lanot Alexandra , Safford Richard
Published: December 2004

Dietary intake of phytosterols (plant sterols) has been shown to be effective in reducing blood cholesterol levels, thereby reducing the risk of cardiovascular disease. Phytosterols are most commonly sourced from vegetable oils, where they are present as minor components. We report here the generation of transgenic tobacco seeds substantially enhanced in phytosterol content by the expression of a modified form of one of the key sterol biosynthetic enzymes, 3‐hydroxy‐3‐methylglutaryl‐CoA reductase (HMGR). The constitutive expression of an N‐terminal truncated Hevea brasiliensis HMGR (t‐HMGR), lacking the membrane binding domain, enhanced seed HMGR activities by 11‐fold, leading to increases in total seed sterol of 2.4‐fold. Seed‐specific expression of t‐HMGR enhanced total seed sterol levels by 3.2‐fold, to 1.36% dry weight or 3.25% of oil. 4‐desmethylsterols were increased by 2.2‐fold, whilst certain sterol biosynthetic intermediates, in particular cycloartenol and 24‐ethylidene lophenol, also accumulated. The additional sterol in seed tissue was present in the form of fatty acid esters. Constitutive expression of t‐HMGR increased leaf phytosterol sterol levels by 10‐fold, representing 1.8% dry weight, and the sterol was sequestered, in acyl ester form, as cytoplasmic ‘oil droplets’. These studies establish HMGR as a key enzyme controlling overall flux into the sterol biosynthesis pathway in seed tissue, but the accumulation of certain intermediates suggests additional slow steps in the pathway. The expression of an N‐truncated HMGR activity has generated novel phytosterol‐enriched raw materials that may provide the basis of new sourcing opportunities for this important class of cholesterol‐lowering actives.
Transgenic indica rice resistant to sap‐sucking insects
Authors: Nagadhara D. , Ramesh S. , Pasalu I. C. , Rao Y. Kondala , Krishnaiah N. V. , Sarma N. P. , Bown D. P. , Gatehouse J. A. , Reddy V. D. , Rao K. V.
Published: December 2004

Agrobacterium‐mediated genetic transformation has been optimized in indica rice susceptible to sap‐sucking insects, viz., brown planthopper (BPH) and green leafhopper (GLH). Snowdrop lectin gene (gna) from Galanthus nivalis, driven by phloem‐specific rice‐sucrose‐synthase promoter, along with herbicide resistance gene (bar) driven by CaMV 35S promoter, was employed for genetic transformation. Embryogenic calli – after co‐cultivation with Agrobacterium strain LBA4404 harbouring Ti plasmid pSB111‐bar‐gna –were selected on the medium containing phosphinothricin. PCR and Southern blot analyses confirmed the stable integration of both the genes into genomes of transgenic (T0) rice plants. Northern and Western blot analyses revealed the expression of gna in the transgenic plants. In the T1 and T2 generations, the gna and bar transgenes showed co‐segregation at a ratio of 3 : 1. Plant progenies expressing gna, in T1 and T2, exhibited substantial resistance against BPH and GLH pests. This is the first report dealing with transgenic indica rice exhibiting high resistance to both insects.
Preferential expression of a plant cystatin at nematode feeding sites confers resistance to Meloidogyne incognita and Globodera pallida
Authors: Lilley Catherine J. , Urwin Peter E. , Johnston Katherine A. , Atkinson Howard J.
Published: December 2004

The expression patterns of three promoters preferentially active in the roots of Arabidopsis thaliana have been investigated in transgenic potato plants in response to plant parasitic nematode infection. Promoter regions from the three genes, TUB‐1, ARSK1 and RPL16A were linked to the GUS reporter gene and histochemical staining was used to localize expression in potato roots in response to infection with both the potato cyst nematode, Globodera pallida and the root‐knot nematode, Meloidogyne incognita. All three promoters directed GUS expression chiefly in root tissue and were strongly up‐regulated in the galls induced by feeding M. incognita. Less activity was associated with the syncytial feeding cells of the cyst nematode, although the ARSK1 promoter was highly active in the syncytia of G. pallida infecting soil grown plants. Transgenic potato lines that expressed the cystatin OcIΔD86 under the control of the three promoters were evaluated for resistance against Globodera sp. in a field trial and against M. incognita in containment. Resistance to Globodera of 70 ± 4% was achieved with the best line using the ARSK1 promoter with no associated yield penalty. The highest level of partial resistance achieved against M. incognita was 67 ± 9% using the TUB‐1 promoter. In both cases this was comparable to the level of resistance achieved using the constitutive cauliflower mosaic virus 35S (CaMV35S) promoter. The results establish the potential for limiting transgene expression in crop plants whilst maintaining efficacy of the nematode defence.
Missing Data and Small Area Estimation in the UK Labour Force Survey
Authors: Longford Nicholas T.
Published: December 2004

We apply multivariate shrinkage to estimate local area rates of unemployment and economic inactivity by using UK Labour Force Survey data. The method exploits the similarity of the rates of claiming unemployment benefit and the unemployment rates as defined by the International Labour Organisation. This is done without any distributional assumptions, merely relying on the high correlation of the two rates. The estimation is integrated with a multiple-imputation procedure for missing employment status of subjects in the database (item non-response). The hot deck method that is used in the imputations is adapted to reflect the uncertainty in the model for non-response. The method is motivated as a development (improvement) of the current operational procedure in which the imputed value is a non-stochastic function of the data. An extension of the procedure to subjects who are absent from the database (unit non-response) is proposed.
An Alternative View of the 2001 Census and Future Census Taking
Authors: Redfern Philip
Published: December 2004

The 2001 census in the UK asked for a return of people ‘usually living at this address’. But this phrase is fuzzy and may have led to undercount. In addition, analysis of the sex ratios in the 2001 census of England and Wales points to a sex bias in the adjustments for net undercount—too few males in relation to females. The Office for National Statistics's abandonment of the method of demographic analysis for the population of working ages has allowed these biases to creep in. The paper presents a demographic account to check on the plausibility of census results. The need to revise preliminary estimates of the national population over a period of years following census day—as experienced in North America and now in the UK—calls into question the feasibility of a one-number census. Looking to the future, the environment for taking a reliable census by conventional methods is deteriorating. The UK Government's proposals for a population register open up the possibility of a Nordic-style administrative record census in the longer term.
A mandelamide pesticide alters lipid metabolism in Phytophthora infestans
Authors: Griffiths Robert G. , Dancer Jane , O'Neill Elizabeth , Harwood John L.
Published: December 2004

Several pesticide classes have been used for control of the notorious plant pathogen, Phytophthora infestans. Some of these alter lipids, suggesting that lipid metabolism may be a target site. Here, we investigate the action of a new, active, mandelamide compound, SX 623509 (N‐2′‐(4″‐ethoxy‐3″‐methoxy) phenylethyl‐3, 4‐dichloromandelamide), on lipid metabolism.

Phytophthora infestans cultured in pea‐broth or minimal media was exposed to different concentrations of SX 623509. Lipid metabolism was followed with radiolabelled acetate, choline or ethanolamine. Products were analysed following separation by thin‐layer chromatography and gas–liquid chromatography.

SX 623509 reduced growth and lipid labelling from [14C]acetate in both media. The inhibition in lipid labelling was not caused merely by a reduction in uptake of the radiolabelled precursor. There were changes in labelling patterns, particularly reductions in phosphatidylcholine and triacylglycerol and increases in phosphatidate and diacylglycerol. The effect of SX 623509 on phosphatidylcholine labelling was followed in more detail.

We conclude that the mandelamide pesticide SX 623509 reduces lipid synthesis at concentrations similar to those inhibiting growth. Specific effects on lipid labelling patterns are probably caused by inhibition of cholinephosphotransferase, which may be a future target site for pesticide development.
Self‐sustained oscillations in plant water regulation: Induction of bifurcations and anomalous rhythmicity
Authors: Prytz Gunnar , Futsaether Cecilia M. , Johnsson Anders
Published: December 2004

The complex dynamics of the water regulatory system was explored by studying the induction of period doublings (period‐1 to period‐2 to period‐4) and other complicated oscillatory patterns (period‐3 and period‐5) in the transpiration of young oat plants.

A gas exchange system was used to record the transpiration of primary leaves of Avena sativa cv. Seger after exposure to various stimuli.

Period‐1 oscillations were induced from steady‐state transpiration by a light pulse, by increasing the xylem resistance to water flow or by temporarily lowering the root medium temperature. Similarly, period doubling (period‐1 to period‐2) was induced by lowering the root medium temperature temporarily or by increasing the xylem resistance. The more complicated oscillatory patterns (period‐3, period‐4, period‐5) were induced by including different concentrations of KCl or KNO3 in the root medium of root excised, xylem‐compressed plants.

The range of oscillatory curve forms resembles those displayed by mildly chaotic nonlinear systems. The water regulatory system is discussed in relation to these nonlinear systems. Few studies of such complicated dynamics in plant systems exist.
Seasonal cycles in the germination capacity of buried seeds of some Leguminosae (Fabaceae)
Authors: Van Assche Jozef A. , Debucquoy Katrien L. A. , Rommens Wouter A. F.
Published: December 2004

The influence of seasonal factors on the germination of impermeable seeds of Fabaceae was studied. Seeds of 14 herbaceous species were buried for up to 2.5 yr and exposed to natural seasons. At regular intervals, seeds were exhumed and germination was tested in four different temperature regimes. Some species had a very low percentage germination regardless of season, others germinated predominantly in the autumn.

Six species showed a marked seasonal cycle with high germination percentages in spring and very low percentages in other seasons. The results of the burial experiment were similar to the pattern of seedling emergence in field conditions.

High percentage germination in spring could be simulated in controlled conditions for Melilotus albus, Medicago lupulina, Lotus corniculatus, Trifolium pratense and T. repens. Seeds of T. pratense had a high percentage germination after cold treatment, whereas seeds of the other four species were brought to germination by chilling for 8 wk followed by exposure to daily alternating temperatures (15/6°C or 20/10°C). Without previous chilling, these seeds did not respond to the alternating temperatures.

At least for some legume species, a combination of temperature treatments may act as a signal for seeds and induce water uptake and germination. If the temperature requirements are not fulfilled, seeds remain impermeable and dormant until the next favourable season.
Contribution of hyphae and roots to uranium uptake and translocation by arbuscular mycorrhizal carrot roots under root‐organ culture conditions
Authors: Rufyikiri Gervais , Thiry Yves , Declerck Stéphane
Published: December 2004

Here, the respective contributions of the arbuscular mycorrhizal (AM) fungus Glomus intraradices and carrot (Daucus carota) roots to the uptake and translocation of uranium (U) were quantified and compared.

The U absorption by the AM fungus and roots was observed by growing mycorrhizal and nonmycorrhizal roots in two‐compartment Petri plates. The central compartment allowed growth of roots and extraradical fungal hyphae. The external compartment (EC), which was labelled with 0.1 µm233U, allowed growth of: hyphae only (hyphal compartment, HC), both mycorrhizal roots and hyphae (root hyphal compartment, RHC), or nonmycorrhizal roots (root compartment, RC).

The U concentration was 5.5 and 9.6 times higher for hyphae than for the mycorrhizal and nonmycorrhizal roots, respectively, both developing in the EC’s. Translocation of U was similar for the RHC and the HC systems, and was 8 times higher for these two systems than for the RC system.

These results indicate that the U flux rate was higher in fungal hyphae than in roots, while the intraradical hyphae may significantly contribute to the U immobilization by mycorrhizal roots.
Aerenchyma formation
Authors: Evans David E.
Published: December 2004

Aerenchyma – tissue containing enlarged gas spaces – occurs in many plants. It is formed either as part of normal development, or in response to stress (e.g. hypoxia). Two mechanisms of aerenchyma formation have been described; schizogeny, in which development results in the cell separation and lysigeny, in which cells die to create the gas space. While schizogenous aerenchyma provides a fascinating system for study and has been described in detail at a morphological and ultrastructural level, little is known about the molecular genetics of its formation. The ultrastructure and morphology of lysigenous aerenchyma has also been researched in detail, and considerable progress has been made in describing the cell death processes involved, particularly in relation to programmed cell death. Once again, the molecular genetics of the process are not well understood. Aerenchyma is of great importance in crop survival in waterlogging. It is also important in being a major pathway for the release of the global warming gas methane to the atmosphere in flooded soils. Understanding the regulation of its development is therefore a research priority.

Contents

Summary
35

I.
Introduction
36

II.
Schizogenous aerenchyma formation
36

III.
Lysigenous aerenchyma formation
37

IV.
Regulators of lysigenous aerenchyma formation
38

V.
Key questions in lysigenous aerenchyma formation
38

VI.
Sensing hypoxia; early events in aerenchyma formation
39

VII.
Ultrastructural changes associated with lysigenous aerenchyma formation
39

VIII.
Late events in cell death in aerenchyma formation
42

IX.
Comparative evidence for programmed cell death in aerenchyma formation
43

X.
Comparison with other abiotic initiators of cell death in plants
45

XI.
Conclusions and future prospects
46

Acknowledgements
47

References
47
Hybridization, polyploidy and speciation inSpartina(Poaceae)
Authors: Ainouche Malika L. , Baumel Alex , Salmon Armel , Yannic Glenn
Published: December 2004

Hybridization and polyploidy are well illustrated in the genusSpartina. This paper examines how recent molecular approaches have helped our understanding of the past and recent reticulate history of species, with special focus on allopolyploid speciation.Spartinaspecies are tetraploid, hexaploid or dodecaploid perennials, most of them being native to the New World. The molecular phylogeny indicates an ancient split between the tetraploid and the hexaploid species, withS.argentinensisas sister to the hexaploid lineage. Recent hybridization and polyploidization events involved hexaploid species, resulting from introductions of the east‐AmericanS. alterniflora. In California, ongoing hybridizations with its sister speciesS. foliosaresult in introgressant hybrid swarms. In Europe, hybridization withS. maritimaresulted inS. × neyrautii(France) andS. × townsendii(England), with.S. alternifloraas the maternal parent. The allopolyploidS. anglicaresulted from chromosome doubling ofS. × townsendii.This young allopolyploid contains divergent homoeologous subgenomes that have not undergone significant changes since their reunion. Hybridization, rather than genome duplication, appears to have shaped the allopolyploid genome at both the structural and epigenetic levels.
Integration of populations and differentiation of species
Authors: Rieseberg Loren H. , Church Sheri A. , Morjan Carrie L.
Published: December 2004

The framework for modern studies of speciation was established as part of the Neo‐Darwinian synthesis of the early twentieth century. Here we evaluate this framework in the light of recent empirical and theoretical studies. Evidence from experimental studies of selection, quantitative genetic studies of species’ differences, and the molecular evolution of ‘isolation’ genes, all agree that directional selection is the primary cause of speciation, as initially proposed by Darwin. Likewise, as suggested by Dobzhansky and Mayr, gene flow does hold species together, but probably more by facilitating the spread of beneficial mutants and associated hitchhiking events than by homogenizing neutral loci. Reproductive barriers are important as well in that they preserve adaptations, but as has been stressed by botanists for close to a century, they rarely protect the entire genome from gene flow in recently diverged species. Contrary to early views, it is now clear that speciation can occur in the presence of gene flow. However, recent theory does support the long‐held view that population structure and small population size may increase speciation rates, but only under special conditions and not because of the increased efficacy of drift as suggested by earlier authors. Rather, low levels of migration among small populations facilitates the rapid accumulation of beneficial mutations that indirectly cause hybrid incompatibilities.
Rapid accumulation of polyphosphate in extraradical hyphae of an arbuscular mycorrhizal fungus as revealed by histochemistry and a polyphosphate kinase/luciferase system
Authors: Ezawa Tatsuhiro , Cavagnaro Timothy R. , Smith Sally E. , Smith F. Andrew , Ohtomo Ryo
Published: December 2004

The rate of polyphosphate accumulation in extraradical hyphae of an arbuscular mycorrhizal fungus was investigated by conventional histochemistry and a new enzymatic method using a bacterial enzyme, polyphosphate kinase. Marigold (Tagetes patula cv. Bonanza Orange) was inoculated with Archaeospora leptoticha and grown under P‐deficient conditions. Extraradical hyphae were harvested at 0, 1, 3 and 24 h after 1 mm P‐application. PolyP levels were assessed by both metachromasy of Toluidine blue O and polyphosphate kinase which converted polyP to ATP followed by the ATP‐luciferase assay. Percentage of hyphae with metachromatic granules was increased from 25 to 44% from 0 to 1 h, and a maximum of 50% was reach by 3 h. Polyphosphate content was doubled from 1 to 3 h after P‐application (4.8–10.0 mol as Pi mg−1 protein) at a rate of 46.4 ± 15.1 nmol min−1 mg−1. The rate of polyphosphate accumulation in the hyphae was surprisingly rapid as those of polyphosphate‐hyper accumulating microorganisms. The enzymatic method employed in the present study allows highly specific and sensitive assessment of polyphosphate in the mycorrhizal system.
Changes in rolandic mu rhythm during observation of a precision grip
Authors: Muthukumaraswamy S.D. , Johnson B.W.
Published: December 2004

We recorded 128‐channel EEG from 16 participants while they observed, imitated, and self‐initiated the precision grip of a manipulandum. Mu rhythm amplitudes were significantly lower during observation of a precision grip than during observation of a simple hand extension without object interaction. Scalp topographies for subtractions of observation, imitation, and execution conditions from the control condition showed a high degree of congruence, supporting the notion of a human observation–execution matching system. Surface Laplacian transformations suggest that the decrease in mu amplitude during precision grip observation reflects desynchronization of mu rhythm generators in the sensorimotor cortex. These results support the hypothesis that sensorimotor cortex is a neural substrate involved in the representation of both self‐ and other‐generated actions and show the mu rhythm is sensitive to subtle changes in observed motor behavior.
The Endocrinology of Melancholic and Atypical Depression: Relation to Neurocircuitry and Somatic Consequences
Authors: Gold Philip W. , Chrousos George P.
Published: December 2004

The cardinal clinical manifestations of major depression with melancholic features include sustained anxiety and dread for the future as well as evidence of physiological hyperarousal (e.g., sustained hyperactivity of the two principal effectors of the stress response, the corticotropin‐releasing‐hormone, or CRH, system, and the locus ceruleus–norepinephrine, or LC‐NE, system). Sustained stress system activation in melancholic depression is thought to confer both behavioral arousal as well as the hypercortisolism, sympathetic nervous system activation, and inhibition of programs for growth and reproduction that consistently occur in this disorder. Data also suggest that activation of the CRH and LC systems in melancholia are involved in the long‐term medical consequences of depression such as premature coronary artery disease and osteoporosis, the two–three‐fold preponderance of females in the incidence of major depression, and the mechanism of action of antidepressant drugs. In addition, recent data reveal important bidirectional interactions between stress‐system hormonal factors in depression and neural substrates implicated in many discrete behavioral alterations in depression (e.g., the medial prefrontal cortex, important in shifting affect based on internal and external cues, the mesolimbic dopaminergic reward system, and the amygdala fear system). We have also advanced data indicating that the hypersomnia, hyperphagia, lethargy, fatigue, and relative paathy of the syndrome of atypical depression are associated with concomitant hypofunctioning of the CRH and LC‐NE systems. These data indicate the need for an entirely different therpaaeutic strategy than that used in melancholia for the treatment of atypical depression, and they suggest that this subtype of major depression will be associated with its own unique repertoire of long‐term medical consequences.
Lysophospholipid Enhancement of Human T Cell Sensitivity to Diphtheria Toxin by Increased Expression of Heparin‐Binding Epidermal Growth Factor
Authors: Goetzl Edward J. , Kong Yvonne , Kenney John S.
Published: December 2004

The effects of lysophosphatidic acid (LPA) and sphingosine 1–phosphate (S1P) on T cell expression of heparin‐binding epidermal growth factor–like growth factor (HB‐EGF), the diphtheria toxin (DT) receptor, were investigated in the Tsup‐1 cultured line of human CD4+ 8+ 3low T lymphoblastoma cells. Tsup‐1 cells bear endothelial differentiation gene (edg)‐2 and ‐4‐encoded G protein–coupled receptors (GPCRs) for LPA and Edg‐3 and ‐5 GPCRs for S1P. Suppression by DT of Tsup‐1 cell protein synthesis was enhanced by LPA and S1P, with lipid structural specificity similar to that required for their recognition by Edg receptors. LPA and S1P increased the Tsup‐1 cell level of immunoreactive HB‐EGF, and neutralizing antibodies to HB‐EGF inhibited LPA and S1P enhancement of Tsup‐1 cell susceptibility to DT. Stabilized transfection of Tsup‐1 cells with a combination of plasmids encoding Edg‐2 plus ‐4 antisense mRNA suppressed the levels of Edg‐2 and ‐4, but not Edg‐3 and ‐5, in Western blots and reduced in parallel the increments in HB‐EGF and susceptibility to DT evoked by LPA but not S1P. Similar transfection with Edg‐3 plus ‐5 antisense plasmids suppressed Tsup‐1 cell levels of immunoreactive Edg‐3 and ‐5, but not Edg‐2 or ‐4, and concurrently reduced S1P‐, but not LPA‐, induced Tsup‐1 cell increases in both HB‐EGF and susceptibility to DT. Edg GPCR‐mediated LPA and S1P enhancement of T cell sensitivity to DT, thus, may be attributable to increased expression of the DT receptor HB‐EGF.
Angiotensin II Induces α3(IV) Collagen Expression in Cultured Murine Proximal Tubular Cells
Authors: Wolf Gunter , Kalluri Raghuram , Ziyadeh Fuad N. , Neilson Eric G. , Stahl Rolf A.K.
Published: December 2004

Angiotensin II (ANG II) induces cellular hypertrophy of cultured proximal tubular cells from various species. This hypertrophic response is associated with an increase in synthesis of basement membrane–associated collagen type IV. Previous investigations by our group have shown that ANG II stimulates mRNA and protein expression of the “classic”α1 and α2(IV) chains in cultured murine proximal tubular cells (murine cortical tubules [MCT cells]). Since it is clearer today that kidney basement membranes also contain heterotrimers of novel type IV collagens, the aim of the present study was to evaluate whether ANG II may influence the expression of α3 and α5(IV) collagen chains in MCT cells. A single dose of 10−8–10−6 M ANG II stimulated mRNA expression of α3(IV), but not of α5(IV), in MCT cells cultured in serum‐free media. This response was mediated through AT1‐receptors because losartan, but not an AT2‐receptor antagonist, abolished the ANG II–induced expression of α3(IV) transcripts. Transient transfection of MCT cells with transforming growth factor–β1 (TGF‐β1) antisense phosphorothioate‐modified oligonucleotides partly abolished the ANG II–induced α3(IV) mRNA expression. Furthermore, Western blots of cellular lysates incubated with polyclonal antibodies generated against the recombinant collagen chains revealed that ANG II stimulated α3(IV) but not α5(IV) protein expression. This stimulation was partly prevented by co‐incubation with a neutralizing anti‐TGF‐β1‐3 antibody. In summary, our data indicate that ANG II stimulates expression of the α3(IV) collagen chain in cultured MCT cells, due in part to TGF‐β1 activation.
Human Retroviruses: Their Role in Cancer
Authors: Blattner William A.
Published: December 2004

Viruses are etiologically linked to approximately 20% of all malignancies worldwide. Retroviruses account for approximately 8%–10% of the total. For human T‐cell leukemia virus 1 (HTLV‐I), the viral regulatory tax gene product is responsible for enhanced transcription of viral and cellular genes that promote cell growth by stimulating various growth factors and through dysregulation of cellular regulatory suppressor genes, such as p53. After a long latent period, adult T‐cell leukemia/lymphoma (ATL) occurs in 1 per 1000 carriers per year, resulting in 2500–3000 cases per year worldwide and over half of the adult lymphoid malignancies in endemic areas. Human immunodeficiency virus 1 (HIV‐1) accounts for a significant cancer burden, and its transactivating regulatory protein Tat enhances direct and indirect cytokine and immunological dysregulation to cause diverse cancers. Kaposi's sarcoma (KS) is a very rare tumor except after HIV‐1 infection, when its incidence is greatly amplified reaching seventy thousand–fold in HIV‐infected homosexual men. Human herpesvirus 8 (HHV‐8), which is also known as Kaposi's sarcoma–associated virus (KSHV), is a necessary but not sufficient etiological factor in KS. The dramatic decline of KS since the introduction of highly active antiretroviral therapy (HAART) could be due to suppression of HIV‐1 tat. B‐cell non–Hodgkin's lymphoma occurs as their first acquired immunodeficiency syndrome–defining diagnosis in 3%–4% of HIV‐infected patients. Hodgkin's lymphoma is also associated with HIV infection but at a lower risk. Human papillomaviruses are linked to invasive cervical cancer and anogenital cancers among HIV‐infected patients. Human retroviruses cause malignancy via direct effects as well as through interactions with other oncogenic herpesviruses and other viruses.