bluuebunny/crossref_metadata_2025 huggingface dataset:
Leaf photosynthesis and carbohydrate dynamics of soybeans grown throughout their life‐cycle under Free‐Air Carbon dioxide Enrichment
Authors: ROGERS A. , ALLEN D. J. , DAVEY P. A. , MORGAN P. B. , AINSWORTH E. A. , BERNACCHI C. J. , CORNIC G. , DERMODY O. , DOHLEMAN F. G. , HEATON E. A. , MAHONEY J. , ZHU X.‐G. , DELUCIA E. H. , ORT D. R. , LONG S. P.
Published: December 2004

A lower than theoretically expected increase in leaf photosynthesis with long‐term elevation of carbon dioxide concentration ([CO2]) is often attributed to limitations in the capacity of the plant to utilize the additional photosynthate, possibly resulting from restrictions in rooting volume, nitrogen supply or genetic constraints. Field‐grown, nitrogen‐fixing soybean with indeterminate flowering might therefore be expected to escape these limitations. Soybean was grown from emergence to grain maturity in ambient air (372 µmol mol−1[CO2]) and in air enriched with CO2 (552 µmol mol−1[CO2]) using Free‐Air CO2 Enrichment (FACE) technology. The diurnal courses of leaf CO2 uptake (A) and stomatal conductance (gs) for upper canopy leaves were followed throughout development from the appearance of the first true leaf to the completion of seed filling. Across the growing season the daily integrals of leaf photosynthetic CO2 uptake (A′) increased by 24.6% in elevated [CO2] and the average mid‐day gs decreased by 21.9%. The increase in A′ was about half the 44.5% theoretical maximum increase calculated from Rubisco kinetics. There was no evidence that the stimulation of A was affected by time of day, as expected if elevated [CO2] led to a large accumulation of leaf carbohydrates towards the end of the photoperiod. In general, the proportion of assimilated carbon that accumulated in the leaf as non‐structural carbohydrate over the photoperiod was small (< 10%) and independent of [CO2] treatment. By contrast to A′, daily integrals of PSII electron transport measured by modulated chlorophyll fluorescence were not significantly increased by elevated [CO2]. This indicates that A at elevated [CO2] in these field conditions was predominantly ribulose‐1,5‐bisphosphate (RubP) limited rather than Rubisco limited. There was no evidence of any loss of stimulation toward the end of the growing season; the largest stimulation of A′ occurred during late seed filling. The stimulation of photosynthesis was, however, transiently lost for a brief period just before seed fill. At this point, daytime accumulation of foliar carbohydrates was maximal, and the hexose:sucrose ratio in plants grown at elevated [CO2] was significantly larger than that in plants grown at current [CO2]. The results show that even for a crop lacking the constraints that have been considered to limit the responses of C3 plants to rising [CO2] in the long term, the actual increase in A over the growing season is considerably less than the increase predicted from theory.
Comparative epidemiology ofPyrenopeziza brassicae(light leaf spot) ascospores and conidia from Polish and UK populations
Authors: Karolewski Z. , Evans N. , Fitt B. D. L. , Baierl A. , Todd A. D. , Foster S. J.
Published: December 2004

Despite differences in climate and in timing of light leaf spot epidemics between Poland and the UK, experiments provided no evidence that there are epidemiological differences between populations ofPyrenopeziza brassicaein the two countries. Ascospores of Polish or UKP. brassicaeisolates germinated on water agar at temperatures from 8 to 24°C. After 12 h of incubation, percentages of ascospores that germinated were greatest at 16°C: 85% (Polish isolates) and 86% (UK isolates). The percentage germination reached 100% after 80 h of incubation at all temperatures tested. The rate of increase in germ tube length increased with increasing temperature from 8 to 20°C but decreased from 20 to 24°C, for both Polish and UK isolates. Percentage germination and germ tube lengths of UKP. brassicaeascospores were less affected by temperature than those of conidia.P. brassicaeproduced conidia on oilseed rape leaves inoculated with ascospores or conidia of Polish or UK isolates at 16°C with leaf wetness durations from 6 to 72 h, with most sporulation after 48 or 72 h wetness. Detection of both mating types ofP. brassicaeand production of mature apothecia on leaves inoculated with mixed Polish populations suggest that sexual reproduction does occur in Poland, as in the UK.
Alternative methods to describe virulence of Erwinia amylovora and host‐plant resistance against fireblight
Authors: Bogs J. , Richter K. , Kim W.‐S. , Jock S. , Geider K.
Published: December 2004

The evaluation of host‐plant susceptibility to Erwinia amylovora and of colonization of host‐plant tissue by individual strains was facilitated by labelling the pathogen with green fluorescent protein (GFP). Colonization of apple leaves assayed with a fluorescence microscope was associated with visual disease ratings on plants to describe virulence (= aggressiveness) of the fireblight pathogen. Resistance induced with 2,6‐dichloro‐isonicotinic acid (INA) and benzo(1,2,3‐) thiadiazol‐7‐carbothioic acid‐S‐methyl ester (BTH, the active component of BION™) restricted colonization by the pathogen to an area adjacent to the inoculation site. Migration in leaves was associated with symptom formation on pear slices and host plants of mutant strains. Non‐virulent E. amylovora mutants did not migrate into the leaf veins and strains with intermediate‐to‐low virulence moved slowly. To compare the migration efficiency of individual wild‐type strains in apple and plum cultivars, a blend of five wild‐type E. amylovora strains with specific numbers of short‐sequence DNA repeats (SSRs) in the common plasmid pEA29 was applied to distinguish them by PCR. Fast‐moving strains identified in the GFP assays were dominant, independent of the apple cultivar. When apple shoots, pear slices or leaves of apple plants were coinoculated with streptomycin (Sm)‐resistant strains and the corresponding parent strains, Sm‐resistant mutants were able to dominate the wild‐type strain for tissue colonization.
The impact of pharmacogenomic factors on steroid dependency in pediatric heart transplant patients using logistic regression analysis
Authors: Zheng H. X. , Webber S. A. , Zeevi A. , Schuetz E. , Zhang J. , Lamba J. , Boyle G. J. , Wilson J. W. , Burckart G. J.
Published: December 2004

Abstract:  Many pharmacogenomic predictors of drug response are now available, and include both drug metabolism‐disposition factors and drug targets. Information on statistical approaches to analyzing large clinical data sets in relation to genetic polymorphisms is limited. The objective of this study was to evaluate whether logistic regression could identify pharmacogenomic predictors of outcome in a large data set in a complex transplant patient population. Seventy pediatric heart transplant patients were studied. Patients were followed for at least 1 yr post‐transplantation as outpatients, and weaned from corticosteroids if clinically appropriate. Logistic regression analysis was used to identify the predictors of steroid dependency. The dependent variable was the presence or absence of steroid therapy at 1 yr post‐transplantation. The independent variables were the patients’ transplant age, gender, MDR1 C3435T and G2677T, CYP3A53B and cytokine polymorphisms. By chi‐square test for the MDR1 C3435T polymorphism, 12 of 18 (67%) patients in the CC group were still on prednisone, whereas only 18 of 47 (38%) of the CT/TT group were still receiving prednisone (p = 0.04). For the IL‐10 groups, two of 15 patients with the high producer genotype (13.3%) remained on prednisone, in comparison with 16 of 28 patients with the intermediate producer genotype (57.1%) and 15 of 26 patients with the low producer genotype (57.7%, p = 0.01). Logistic regression analysis confirmed MDR1 C3435T (p = 0.021), and IL‐10 polymorphisms (intermediate producer genotype p = 0.015; low producer genotype p = 0.013) as independent risk factors for steroid dependency at 1 yr after transplantation. This approach identifies pharmacogenomic factors, which can be studied more extensively in larger data sets, and used in prospective studies to individualize immunosuppressive therapy following solid organ transplantation.
Answered and unanswered controversies in the surgical management of extra hepatic biliary atresia
Authors: Dolgin Stephen E.
Published: December 2004

Abstract:  Almost a half‐century since Kasai described the portoentersotomy for extrahepatic biliary atresia (EHBA), some questions about the management of this condition have been resolved and many are unanswered. The most useful diagnostic steps to aid in the diagnosis are debated. Sonography can be helpful but its sensitivity and selectivity are arguable with strong advocates for its effectiveness. Likewise, the magnetic resonance imaging has forceful advocates but also has not been universalized. The liver biopsy, done commonly before an operation for cholestasis, is often not discriminating. The radionuclide scan hepatobiliary iminodiacetic acid (HIDA) scan after phenobarbital stimulation is helpful if negative, but false positive results are common. It is agreed to proceed expeditiously to the operation in the cholestatic infant after a prompt investigation. The proposal to avoid this step and provide liver transplantation as initial management for EHBA has been suppressed by several clinical findings. The Kasai procedure has not worsened the outcome of eventual liver transplantation. The Kasai, even if it eventually fails, will often buy time and allow the child to grow before transplantation is needed. Multiple reoperations prior to the transplant are discouraged. Revisions to improve bile flow have not gained wide popularity. Use of a stoma to divert the bile has been largely abandoned. The need for frozen section examination of the liver at the site chosen for the portoenterostomy is no longer demanded. The preferred type of intestinal conduit is argued. Unanswered questions about the post‐operative management include the role of steroids and of prophylactic antibiotics. The Biliary Atresia Research Consortium, a multi‐institutional National Institutes of Health (NIH)‐supported project, will address many of the unanswered issues.
Treatment of chronic hepatitis C in children
Authors: González‐Peralta Regino P.
Published: December 2004

Abstract:  Since the discovery of hepatitis C virus (HCV) in 1989, significant advances have been made in our understanding of this important viral pathogen. Children at risk for HCV infection include recipients of potentially contaminated blood products and organ transplants, and infants born to HCV‐infected mothers. Chronic HCV infection is usually asymptomatic in children but active hepatitis, cirrhosis and hepatocellular carcinoma can occur. The development of treatment strategies for chronic hepatitis C in children has directly evolved from clinical trials in adults. Sustained virologic response, defined by undetectable HCV RNA in serum 24 wk after completion of treatment, occurs in approximately 36% of children treated with conventional interferon alone and in about 50% of those given conventional interferon in combination with ribavirin. Pegylated interferon‐based treatment regimens are better than those based on conventional interferon in adults but little is known about pegylated interferon in children. Factors associated with a favorable response to antiviral therapy in children are similar to those in adults and include infection with HCV genotype 2 or 3 and low pretreatment serum HCV RNA levels. Treatment related adverse events in children include ‘flu‐like’ syndrome, fatigue, anorexia, weight loss, depression, anemia, leukopenia and thrombocytopenia.
Liver tumors in children
Authors: Emre Sukru , McKenna Greg J.
Published: December 2004

Abstract:  Primary hepatic neoplasms in children are relatively infrequent, accounting for between 0.5 and 2.0% of all pediatric neoplasms. They are a diverse group of epithelial and mesenchymal tumors whose incidence can vary considerably with patient age. They are clinically relevant tumors however as two thirds of them are malignant. The therapy of these tumors has evolved over time and it currently involves a combination of surgery, adjuvant and neoadjuvant chemotherapy and possible transplantation.
Approaches to acute liver failure in children
Authors: Dhawan Anil , Cheeseman Paul , Mieli‐Vergani Giorgina
Published: December 2004

Abstract:  Acute liver failure (ALF) is a rare but often fatal disorder in childhood. Its aetiology includes infections, toxins, metabolic disorders, infiltrative diseases, autoimmune hepatitis, ischaemia, irradiation damage, but in a high proportion of cases it remains unknown. In contrast to adults, in children with ALF hepatic encephalopathy can be a late event, and may not develop at all, despite a lethal outcome, particularly in infants. Children with ALF should be managed in experienced centres with facilities for liver transplantation. Transplantation should be offered only if the underlying disease is treatable by liver replacement and if the prognosis of transplant is better than that of the underlying disease, as in many cases of ALF the liver has the potential to recover with supportive treatment, if the child is kept alive and stable long enough. Universally accepted criteria for listing for transplantation have not been defined as yet. In our centre, maximum INR, bilirubin level, and white cell count, together with age have proven to be reliable predictors of outcome. Future efforts in the management of ALF should concentrate on designing efficient supportive therapy and specific treatments to provide effective non‐transplant therapeutic options.
Reproductive Performance of Thoroughbred Mares in Sweden
Authors: Hemberg E , Lundeheim N , Einarsson S
Published: December 2004

Contents

During 1997–2001, a total of 430 Thoroughbred mares were mated by one of the two Thoroughbred stallions on a well‐managed stud farm in the central part of Sweden. On arrival, a thorough gynaecological examination of all mares was performed. An early pregnancy examination was performed on days 14 and 15 after ovulation. The overall conception rates for the two stallions were 92.2 and 88.8%, and the corresponding live foal rates were 82.6 and 75.2%, respectively. The mean number of served oestrous cycles was 1.60 per mare per conception and 1.86 per live foal. The first and second cycle conception rates are reported for different age groups, mare categories and month of mating. The age of the mares had a significant influence on the live foal rate, being lower for mares >13 years of age. Resorption and abortion occurred in higher percentages among mares >8 years of age. The highest embryonic death occurred among mares with a history of being barren, or with having resorbed or aborted foetuses during the previous season. The month of mating had no significant influence on the first cycle conception rate or the second cycle conception rate. The frequency of twinning was 10.5% and the results of manual crushing of one of the conceptuses was successful in 88.9% of all cases, according to the ultrasound scanning 2 days later.
Effects of Developmental Stage, Embryonic Interferon‐τ Secretion and Recipient Synchrony on Pregnancy Rate after Transfer of in vitro Produced Bovine Blastocysts
Authors: Kubisch HM , Sirisathien S , Bosch P , Hernandez‐Fonseca HJ , Clements G , Liukkonen JR , Brackett BG
Published: December 2004

Contents

Three separate trials of bovine embryo transfers were performed consisting of 32, 41 and 33 transfers, respectively, to examine the effects of (a) the developmental stage of in vitro‐derived blastocysts, (b) the amount of interferon‐τ (IFN‐τ) they secreted during culture and (c) the cyclic stage of the recipient at the time of transfer on the probability of establishment of pregnancy. One blastocyst was transferred into the ipsilateral uterine horn to the CL. At the time of transfer, blastocysts were classified into one of three developmental stages (early blastocyst, blastocyst and expanded blastocyst) and the cyclic stage of each cow was assessed (−12 h, on time, +12 h, +24 h, >24 h). Prior to the second and third trials, blastocysts were individually cultured for 24 h in 50 μl medium droplets and the IFN‐τ concentration in the droplet was determined. Logistic regression analyses revealed that expanded blastocysts had a significantly higher likelihood of establishing pregnancy (p = 0.009), and that there was a significant interaction with the cyclic stage of the recipient in this group with lower rates of pregnancy resulting from decreasing synchrony with the recipient (p = 0.033). IFN‐τ secretion during culture was significantly higher in expanded blastocysts than in the other two groups (p < 0.05). A significant effect of the pre‐transfer level of IFN‐τ secretion was found only in the ‘Blastocyst’ group where transfer of embryos with lower IFN‐τ production prior to transfer resulted in higher pregnancy rates (p = 0.047). These results demonstrate that IFN‐τ secretion may be a useful tool to predict pregnancy outcome, but only within certain developmental stages.
Phenomenological features of auditory hallucinations and their symptomatological relevance
Authors: HAYASHI NAOKI , IGARASHI YOSHITO , SUDA KIYOKO , NAKAGAWA SEISHU
Published: December 2004

Abstract  Auditory hallucinations include particularly diverse phenomena that reflect various mental functions and pathologies. Their assessment may provide valuable clinical information. This article describes the development of the Matsuzawa Assessment Schedule for Auditory Hallucination (MASAH), which was designed to obtain a broadened view of the phenomena by investigating a wide  range  of  their  characteristics.  The  aim  was  to  identify  the  basic  phenomenological  features of auditory hallucinations by performing a factor analytic study of the MASAH ratings of 214 patients with schizophrenia or schizoaffective disorder. Four identified factors were intractability, delusion, influence, and externality, on the basis of which we constructed composite scales that were assumed to represent the features. The correlation analysis of the scales with symptom dimensions derived from the positive and negative syndrome scale verified their clinical relevance. They were also interpretable in terms of human responses to the abnormal experience and some symptom constructs such as delusion and influence experience. It is concluded that the MASAH is an efficient means for evaluating the features, and that this study elicited new understandings of the phenomena such as their multifarious composition and contiguities with other psychotic symptoms.
Chronic ‘speech catatonia’ with constant logorrhea, verbigeration and echolalia successfully treated with lorazepam: a case report
Authors: LEE JOSEPH W Y
Published: December 2004

Abstract Logorrhea, verbigeration and echolalia persisted unremittingly for 3 years, with occasional short periods of motoric excitement, in a patient with mild intellectual handicap suffering from chronic schizophrenia. The speech catatonic symptoms, previously refractory to various antipsychotics, responded promptly to lorazepam, a benzodiazepine with documented efficacy in the treatment of acute catatonia but not chronic catatonia. It is suggested that pathways in speech production were selectively involved in the genesis of the chronic speech catatonic syndrome, possibly a rare form of chronic catatonia not previously described.
Landiolol attenuates acute hemodynamic responses but does not reduce seizure duration during maintenance electroconvulsive therapy
Authors: SAKAMOTO ATSUHIRO , OGAWA RYO , SUZUKI HIROKO , KIMURA MAHITO , OKUBO YOSHIRO , FUJIYA TESTUO
Published: December 2004

Abstract Maintenance electroconvulsive therapy (mECT) is an outpatient procedure that requires further consideration in terms of management of ambulatory anesthesia. Although many adjunctive drugs for stabilizing hemodynamic changes during ECT have been reported, side‐effects of these drugs may delay recovery and discharge from hospital. The effects of landiolol, a novel ultra‐short‐acting β‐adrenergic blocker, have been measured on seizure duration, hemodynamic changes, recovery from anesthesia, and cognitive function during mECT under propofol anesthesia. A total of 10 patients with depression in the remission phase, were studied in a randomized, double‐blind, placebo‐controlled, crossover manner. Administration of 0.1 mg/kg of landiolol immediately before anesthesia significantly blunted the increase in heart rate and blood pressure during convulsions compared with placebo; landiolol was not associated with excessive hypotension or bradycardia. Landiolol did not affect seizure duration, recovery from anesthesia, or cognitive function before or after ECT. These results suggest that landiolol can be used effectively and safely during mECT.
Use of spinal anaesthesia in paediatric patients: a single centre experience with 1132 cases
Authors: Puncuh Franco , Lampugnani Elisabetta , Kokki Hannu
Published: December 2004

Background : Spinal anaesthesia has been used in children for over 100 years and in the last two decades its popularity for newborns and infants has increased, but there are still unanswered questions with the technique.

Methods : We evaluated the characteristics of spinal block including ease of performance, efficacy, adverse effects and complications in 1132 children, aged 6 months to 14 years, undergoing surgery in the lower part of the body. Local ethical committee approved the protocol of this prospective study, and parents gave written informed consent and older children their assent. All patients were sedated with midazolam, thiopental or propofol intravenously during spontaneous ventilation. No inhalation anaesthetics were used. Spinal block was performed with 0.5% hyperbaric bupivacaine at a dose of 0.2 mg·kg−1.

Results : Efficacy, safety and ease of performance of the spinal block were shown to be satisfactory in most children. Only 27 of the 1132 children needed any supplementation. The incidence and severity of complications was low. Only nine of 942 children, <10 years of age and eight of 190 children, 10 years or older, developed hypotension. The incidences of postdural puncture headache, in five of the 1132 children, and backache, in nine of the 1132, were low. No other neurological complications were reported.

Conclusions : Spinal anaesthesia with hyperbaric bupivacaine is a feasible anaesthetic method in children for surgery in the lower part of the body.
Anaesthesia induction in children: a psychological evaluation of the efficiency of parents’ presence
Authors: Messeri Andrea , Caprilli Simona , Busoni Paolo
Published: December 2004

Background : The induction of anaesthesia for surgery is a stressful time for both child and parents. To treat preoperative anxiety in children, pharmacological methods (premedication) and behavioural methods (the presence of parents during the induction of anaesthesia) have been used, both independently and in combination.

The purpose of this investigation was to study the effect of both premedication and parental presence on preoperative anxiety in a homogeneous population.

Methods : In this study conducted between January and April 2001 in the Meyer Hospital in Florence (Anaesthesia Department and Surgical Department), we studied 39 Italian speaking children aged 2–14 years who were undergoing minor surgery. Before the surgical intervention the State Trait Anxiety Inventory (STAI) questionnaire and a questionnaire for the social‐demographic characteristics were given to the parents. The stress of the children was evaluated during induction of anaesthesia. We also studied behavioural areas of both children and parents with two specific questionnaires administered after the surgery.

Results : The STAI scores showed that the mothers had a higher level of anxiety compared with the fathers. The induction of anaesthesia for surgery was a stressful time for 23% of children of our sample. The correlation between stress of the child at induction and state (P = 0.034) and trait (P = 0.049) anxiety of parents was statistically significant. The child's loss of consciousness was for the majority of parents (56%) the moment of greatest stress and 97% of parents did feel useful during the induction of anaesthesia. There was a significant difference, P = 0.032, in the presence or absence of stress depending on whether the mother or father accompanied the child to the operating room. There was no significant difference in the presence of stress between children who did and did not receive premedication.

Conclusions : Maternal presence, compared with the father's presence, is fundamental in helping to overcome anxiety in a child receiving anaesthesia. If the parents are present during the induction, the addition of premedication does not offer further benefit. Parents themselves judged their presence during the induction of anaesthesia in their child as a positive event. We also found a statistical significant correlation between anxiety of the parents with the level of the stress of the child during induction of anaesthesia.
Hypercapnia: what is the limit in paediatric patients? A case of near‐fatal asthma successfully treated by multipharmacological approach
Authors: Mazzeo Anna Teresa , Spada Antonella , Praticò Caterina , Lucanto Tullio , Santamaria Letterio Bruno
Published: December 2004

We describe a case of prolonged severe hypercapnia with respiratory acidosis occurring during an episode of near‐fatal asthma in an 8‐year‐old boy, followed by complete recovery. After admission to the intensive care unit, despite treatment with maximal conventional bronchodilatative therapy, the clinical picture deteriorated with evident signs of respiratory muscle fatigue. The child was sedated, intubated and mechanically ventilated. Magnesium sulphate, ketamine and sevoflurane were gradually introduced together with deep sedation, curarization and continuous bronchodilatative therapy. Ten hours after admission, arterial pCO2 reached 39 kPa (293 mmHg), pH was 6.77 and pO2 8.6 kPa (65 mmHg). Chest radiograph showed severe neck subcutaneous emphysema, with signs of mediastinal emphysema. No episode of haemodynamic instability was seen despite severe prolonged hypercapnia lasting more than 14 h. Oxygenation was maintained and successful recovery followed without neurological or cardiovascular sequelae. This case shows the cardiovascular and neurological tolerance of a prolonged period of supercarbia in a paediatric patient. The most important lesson to be learned is the extreme importance of maintaining adequate tissue perfusion and oxygenation during an asthma attack. The second lesson is that when conventional bronchodilators fail, the intensivist may resort to the use of drugs such as ketamine, magnesium sulphate and inhalation anaesthesia. In this context deep sedation and curarization are important not only to improve oxygenation, but also to reduce cerebral metabolic requirements.
Cre‐mediated site‐specific gene integration for consistent transgene expression in rice
Authors: Srivastava Vibha , Ariza‐Nieto Magnolia , Wilson Andrea J.
Published: December 2004

To minimize expression variability amongst transgenic lines, we have utilized the strategy of Cre/lox‐mediated site‐specific gene integration. This method allows the precise integration of a transgene in a lox site previously placed in the genome. Using the biolistic method for DNA delivery, we have generated several site‐specific integrant lines, derived from three different target lines. About 80% of the selected lines contain precise integration of the gusA reporter gene and fall into two categories: single‐copy (SC) lines that contain site‐specific integration without additional random integrations, and multicopy (MC) lines that contain random integrations in addition to the site‐specific integration. The expression of the gusA gene was studied in callus cells and regenerated plants. The isogenic SC lines displayed significantly lower expression variation, whereas much higher expression variation was observed in MC lines. Furthermore, stable inheritance of the gusA gene was observed in T1 plants derived from a subset of SC lines. This demonstrates that consistent gene expression can be obtained in rice by Cre‐mediated site‐specific integration.
The evolution of silicification in diatoms: inescapable sinking and sinking as escape?
Authors: Raven J. A. , Waite A. M.
Published: December 2004

The silicified bipartite cell walls of diatoms (Bacillariophyceae) are produced in intracellular compartments by precipitation from supersaturated Si(OH)4and are then externalized. Fossil evidence of silicification is for marine, probably neritic, centric diatoms from approx. 120 Mya. Regardless of the initial selective significance of silicification, and of other current roles of silicification, the increased density resulting from silicification increases the sinking rate of cells; this can be partly or wholly offset by regulation of the protoplast solute content. Acclimatory and regulatory changes in silicification (relatively slow), and intracellular solute composition (relatively rapid), and intracellular solute composition (relatively rapid) of marine diatoms alter cell density over periods of hours to days. Density changes via changes in resource supply and, probably, parasitism, would move cells into optimal resource supply conditions, and remove parasitized, infective cells from surface populations of uninfected cells. Regulation of sinking rate could have been the first function of external or internal silica if the earliest silicified diatoms were planktonic.

ContentsI.Introduction46II.Phylogeny of diatoms and the habitat of the earliest diatoms46III.Origin of the silicon requirement in diatoms46IV.The phylogeny and ontogeny of turgor‐ resistant silicified walls47V.Possible selective advantages of silicified walls49VI.Conclusions57Acknowledgements57References57
Cell biology of the plant Golgi apparatus
Authors: Hawes Chris
Published: December 2004

The higher plant Golgi apparatus, comprising many individual stacks of membrane bounded cisternae, is one of the most enigmatic of the cytoplasmic organelles. Not only can the stacks receive material from the endoplasmic reticulum, process it and target it to the correct cellular destination, but they can also synthesise and export complex carbohydrates and lipids and most likely act as one end point of the endocytic pathway. In many cells such processing and sorting can take place while the stacks are moving within the cytoplasm and, remarkably, the organelle manages to retain its structural integrity. This review considers some of the latest data and views on transport both to and from the Golgi and the mechanisms by which such activity is regulated.

Contents

Summary
29

I.
Introduction
29

II.
What is the plant Golgi apparatus?
30

III.
Out of the ER
31

IV.
Regulation of ER to Golgi transport
32

V.
Retrograde transport – Golgi to ER – the role of ARF and COPI
35

VI.
Transport down the stack
37

VII.
Targeting within the Golgi
37

VIII.
Holding it all together
38

IX.
Exit from the stack
39

X.
Roles for lipids
40

XI.
Conclusions
40

Acknowledgements
40

Note added in proof
41

References
41
Ethnicity, gender, and age effects on adrenoceptors and physiological responses to emotional stress
Authors: Suarez Edward C. , Saab Patrice G. , Llabre Maria M. , Kuhn Cynthia M. , Zimmerman Eugene
Published: December 2004

We examined the unique and joint effects of ethnicity, gender, and age on cardiovascular and catecholamine responses to the anger recall interview, and β2‐adrenergic receptor density and function on peripheral blood mononuclear cells. Participants were 179 nonsmoking, normotensive men and women aged 18–49 years. All subjects showed similar blood pressure increases during the anger recall interview. Black men, however, showed the smallest increases in heart rate in conjunction with an attenuated peripheral vasodilatation. Black women and Whites showed similar increases in heart rate and peripheral vasodilatation. Increasing age was associated with greater norepinephrine increases to anger recall in Black males. Black men also exhibited higher epinephrine levels throughout the protocol, higher dissociation constant to 125I‐pindolol, and age‐dependent increases in β2‐receptor density. Relative to Whites and Black females, arousal of negative affect in Black males led to a pattern of sympathetic nervous system activity that may help explain the higher prevalence of hypertension in this population.
Autonomic and behavioral responding to concealed information: Differentiating orienting and defensive responses
Authors: Verschuere Bruno , Crombez Geert , De Clercq Armand , Koster Ernst H. W.
Published: December 2004

A mock crime experiment was conducted to examine whether enhanced responding to concealed information during a polygraph examination is due to orienting or defensive responding. Thirty‐six undergraduate students enacted one of two mock crimes. Pictures related to both crimes were presented while heart rate, magnitude of the skin conductance response, and reaction times to a secondary probe were measured. Compared to control pictures, participants showed heart rate deceleration and enhanced electrodermal responding to pictures of the crime they had committed. Probe reaction times did not differ significantly between crime and control pictures. The present findings support the idea that the orienting reflex accounts for the enhanced responding to concealed information. Theoretical and practical implications of the orienting account are discussed.
Word‐specific cortical activity as revealed by the mismatch negativity
Authors: Pulvermüller Friedemann , Shtyrov Yury , Kujala Teija , Näätänen Risto
Published: December 2004

Neurophysiological brain activity evoked by individual spoken words and pseudowords was recorded and the mismatch negativity (MMN), an automatic index of experience‐dependent auditory memory traces, was calculated. Consistent with earlier reported results, the MMN response to word‐final syllables was enhanced compared with that elicited by the same syllables placed in a pseudoword context. Here we now demonstrate that the enhancement of the MMN elicited by two individual words showed different scalp topographies. The early word‐specific brain activity is consistent with the assumption that the memory traces activated by individual words are carried by large neuronal ensembles that differ in their distributions over the cortex. Current source estimates localized the between‐word differences in the right hemisphere and in parieto‐occipital left‐hemispheric areas. The differential brain responses to individual words appeared as early as ∼100 ms after the recognition points of the words, suggesting that their specific memory traces become active almost immediately after the information in the acoustic input is sufficient for word identification.
Differential analysis in the time domain of the baroreceptor cardiac reflex sensitivity as a function of sequence length
Authors: Reyes del Paso Gustavo A. , Hernández José A. , González M. Isabel
Published: December 2004

Analysis of baroreceptor sensitivity (BRS) in the time domain through the spontaneous sequence method used a measure of BRS based on the average of all sequences detected, without making any distinction in cardiac cycle length. In this article, we study differentially the functioning of the baroreflex as a function of the length of the cardiac sequences (3, 4, 5, or 6 cardiac cycles). One hundred and four students performed three mental stress tasks: mental arithmetic, memory, and visual attention. The results show that (1) as sequence length decreases, the relationships between BRS and indexes of vagal cardiac control increase, (2) the BRS associated with the more short sequences (3 and 4 beats) is the most vulnerable to mental stress, particularly the mental arithmetic task, and (3) BRS increases progressively as sequence length decreases. These results suggest that the nature and functioning of the baroreflex differ as a function of the length of the cardiac sequences.
The Role of Sexual Precedence in Verbal Sexual Coercion
Authors: Livingston Jennifer A. , Buddie Amy M. , Testa Maria , VanZile-Tamsen Carol
Published: December 2004

Experiences of verbal sexual coercion are common and have potential for negative consequences, yet are not well understood. This study used qualitative and descriptive statistics to examine verbal sexual coercion experiences among a community sample of 114 women and explored the role of sexual precedence in these experiences. Analyses revealed that sexual precedence plays an important role in determining how these experiences come about and why women acquiesce to unwanted intercourse. Verbal persuasion and persistence were the most commonly reported tactics. The valence of this verbal persuasion differed qualitatively according to precedence status, with those having a history of sexual precedence using negative persuasion (e.g., threats to relationship) and those with no precedence relying on positive messages (e.g., sweet talk). Most women used direct verbal resistance to indicate their unwillingness to have sex, regardless of precedence status. Women's reasons for compliance and consequences differed qualitatively according to sexual precedence status.
Sociocultural, Feminist, and Psychological Influences on Women's Body Satisfaction: A Structural Modeling Analysis
Authors: Fingeret Michelle Cororve , Gleaves David H.
Published: December 2004

We explored sociocultural, feminist, and psychological influences on women's body dissatisfaction by examining the manner in which awareness and internalization of appearance standards, feminist ideology, and self-esteem affect body dissatisfaction. A main goal of the study was to test a model of potential protective mechanisms against internalization of appearance standards. The LISREL 8.5 program was used to perform structural modeling analyses on the proposed theoretical models. The results supported previous findings regarding the influential role of sociocultural variables on women's body dissatisfaction. In particular, internalization was found to mediate the relationship between awareness and body dissatisfaction. Feminist ideology and self-esteem were not found to serve as protective mechanisms against internalization. However, self-esteem appeared to directly affect body dissatisfaction.
Team Sports Achievement and Self-Esteem Development Among Urban Adolescent Girls
Authors: Pedersen Sara , Seidman Edward
Published: December 2004

In this study we investigate the contribution of achievement in team sports to adolescent girls' self-esteem development. Adolescent girls ( N = 247) from racially and ethnically diverse backgrounds were surveyed as part of a larger study investigating the development of poor urban youth. Participants responded to items tapping global self-esteem, team sports achievement, and athletic self-evaluations. The results of hierarchical regression analyses indicate that girls' team sports achievement experiences in early adolescence are positively associated with self-esteem in middle adolescence. This relationship is partially mediated by team sports self-evaluations. Applications of these findings to the development of interventions designed to enhance the self-esteem of young women and girls are discussed.
The Melanosome as a Model to Study Organelle Motility in Mammals
Authors: Barral Duarte C. , Seabra Miguel C.
Published: December 2004

Melanosomes are lysosome‐related organelles within which melanin pigment is synthesized. The molecular motors that allow these organelles to move within melanocytes have been the subject of intense study in several organisms. In mammals, melanosomes travel bi‐directionally along microtubule tracks. The anterograde movement, i.e., towards microtubule plus‐ends at the periphery, is accomplished by proteins of the kinesin superfamily, whereas the retrograde movement, i.e., towards microtubule minus‐ends at the cell center, is achieved by dynein and dynein‐associated proteins. At the periphery, melanosomes interact with the actin cytoskeleton via a tripartite complex formed by the small GTPase Rab27a, melanophilin and myosin Va, an actin‐based motor. This interaction is essential for the maintenance of a dispersed state of the melanosomes, as shown by the perinuclear clustering of organelles in mutants in any of the referred proteins. In the retinal pigment epithelium, a similar complex formed by Rab27a, a melanophilin homolog called MyRIP and myosin VIIa is probably responsible for the tethering of melanosomes to the actin cytoskeleton. The coordination of motor activities is still poorly characterized, although some models have emerged in recent years and are discussed here. Unraveling regulatory mechanisms responsible for melanosome motility in pigmented cells will provide general insights into organelles dynamics within eukaryotic cells.
The Contemporary Presidency: The Presidency and Image Management: Discipline in Pursuit of Illusion
Authors: MAYER JEREMY D.
Published: December 2004

The exigencies of the modern media age require that presidents put great effort into the crafting and maintenance of a positive image with the American people. The power of the president to realize his agenda in Washington and indeed around the world is directly affected by his standing with the public. The presidential image has become more contested, personal, and malleable as it has become more central and puissant. The Bush administration has shown a particular talent for disciplined management of presidential image, which has led to notable successes in public approval of the president's character.
Langerhans cell histiocytosis in sequential discordant lymphoma
Authors: Adu-Poku K , Thomas D W , Khan M K , Holgate C S , Smith M E F
Published: December 2004

B cell non-Hodgkin lymphoma of the follicular subtype (grade 3/3) affecting the nasopharynx and breast, and containing foci of Langerhans cell histiocytosis, was diagnosed in a 56 year old white woman who was a longstanding heavy smoker. Four years before this she had developed stage 1a mixed cellularity Hodgkin lymphoma affecting the right inguinal region, which was treated by irradiation and chemotherapy without recurrence. Review of the original Hodgkin lymphoma histology demonstrated a small focus of Langerhans cell histiocytosis. This is thought to be the first recorded case of Langerhans cell histiocytosis occurring in a sequential discordant lymphoma. Its importance is discussed.
Expression of prostate specific antigen in male breast cancer
Authors: Carder P J , Speirs V , Ramsdale J , Lansdown M R J
Published: December 2004

Male breast cancer is uncommon, accounting for less than 1% of all breast cancers. Carcinoma metastatic to the male breast is also unusual, with metastatic prostatic carcinoma being among the most common primary sites from which such tumours derive. Metastatic prostatic cancer and primary breast cancer may be histologically indistinguishable without immunohistochemistry because both often infiltrate with a cribriform architecture. Distinguishing between primary and metastatic disease within the breast is important because the treatment options for each are radically different. Following a case in which metastatic prostatic disease was initially wrongly diagnosed as primary breast cancer, a small series of male breast cancers was examined for expression of prostate specific antigen (PSA) and prostatic acid phosphatase to assess the usefulness of these markers in making this distinction. Focal expression of PSA was found in one of 11 cases of male breast cancer. These results indicate that PSA should be used with caution in this context.
Plasma nitrotyrosine in reversible myocardial ischaemia: Table 1
Authors: Elfatih A , Anderson N R , Mansoor S , Ahmed S , Horton R , Holland M R , Gama R
Published: December 2004

Background:Nitric oxide (NO) plays a vital role in vascular homeostasis and in the pathophysiology of coronary heart disease. Its metabolites, nitrite and nitrate, have vasculoprotective properties, whereas peroxynitrite, an oxidant metabolite of NO, is cytotoxic and can aggravate myocardial damage during ischaemic reperfusion injury. Peroxynitrite nitrates free and protein bound tyrosine residues to produce nitrotyrosine. The measurement of nitrotyrosine provides an indirect estimation of plasma peroxynitrite concentrations.

Aims:To measure plasma nitrotyrosine concentrations to see whether peroxynitrite could contribute to myocardial dysfunction during myocardial ischaemia induced by an exercise tolerance test (ETT).

Materials/Methods:Plasma free nitrotyrosine concentrations were compared before and after exercise in 29 subjects with a positive ETT and 34 subjects with a negative ETT.

Results:Plasma nitrotyrosine concentrations were similar in patients with exercise induced myocardial ischaemia and controls.

Conclusion:Peroxynitrite does not contribute to the myocardial dysfunction in reversible myocardial ischaemia.
Primary pleural epithelioid haemangioendothelioma with metastases to the skin. A case report and literature review
Authors: Al-Shraim M , Mahboub B , Neligan P C , Chamberlain D , Ghazarian D
Published: December 2004

Epithelioid haemangioendothelioma (EHE) is a rare vascular tumour of intermediate behaviour. It can arise from various sites including the liver, spleen, pleura, or lung. Cutaneous EHE can be primary or secondary. This report describes the case of a 51 year old man who presented with a history of dry cough, shortness of breath, and pleural effusion, and who developed two cutaneous nodules in the anterior abdominal wall a few weeks later. He had a previous history of asbestos exposure. Computed tomography scan showed a left sided pleural effusion and nodular pleural mass. Histology of both the pleural and cutaneous lesions was compatible with EHE. Electron microscopic examination demonstrated the presence of Weibel-Palade bodies. The patient underwent elliptical excision of the metastatic cutaneous nodules after decortication of the primary pleural tumour and adjuvant treatment. A few reports have described metastasis of intrathoracic EHE to the skin. Despite treatment with interferon, the patient developed more cutaneous lesions two years after the initial diagnosis. Even though the tumour has the classic light histological and ultrastructural features of EHE, it behaved in an aggressive manner.