bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of analogues of plant growth regulators on in vitro growth of eukaryotic plant pathogens
Authors: Flors V. , Miralles M. C. , Varas E. , Company P. , González‐Bosch C. , García‐Agustín P.
Published: December 2004

FGA (furfurylamine; 1,2,3,4 tetra‐O‐acetyl‐β‐d‐glucose; adipic acid monoethyl ester), a chemical mixture of three analogues of plant growth regulators that increases the protection of tomato plants against phytopathogens, was demonstrated to have direct antimicrobial activity. It reduced the growth in vitro of the filamentous fungi Alternaria solani and Botrytis cinerea, and the oomycetes Phytophthora capsici and Phytophthora citrophthora (ED50 0·18–0·26% w/v, depending on species). The components of this mixture were also active against these phytopathogens, but sensitivity to the compounds was different for each pathogen. Adipic acid monoethyl ester (E) showed the highest and widest range of activity. Experiments on B. cinerea and A. solani indicated that this compound prevented spore germination in addition to mycelial growth and at high concentrations (0·5% w/v), inhibiting both the yeast Saccharomyces cerevisiae and the bacterium Escherichia coli. This ester retarded A. solani infection of tomato leaves, providing evidence for its efficacy in a biological context and its potential use in plant disease prevention.
The salicylic acid‐dependent defence pathway is effective against different pathogens in tomato and tobacco
Authors: Achuo E. A. , Audenaert K. , Meziane H. , Höfte M.
Published: December 2004

The role of salicylic acid (SA) was investigated in basal defence and induced resistance to powdery mildew (Oidium neolycopersici) and grey mould (Botrytis cinerea) in tomato (Lycopersicon esculentum) and tobacco (Nicotiana tabacum). A comparison of NahG transgenic tomato and tobacco (unable to accumulate SA) to their respective wild types revealed that in tomato, SA was not involved in basal defence against O. neolycopersici but NahG tobacco showed an enhanced susceptibility to O. neolycopersici infection, the effect becoming more obvious as the plants grew older. In contrast, SA played no role in the basal defence of tobacco against B. cinerea, but seemed to contribute to basal defence of tomato against B. cinerea. Activation of the SA‐dependent defence pathway via benzothiadiazole (BTH) resulted in induced resistance against O. neolycopersici in tobacco but not in tomato. Microscopic analysis revealed that BTH treatment could prevent penetration of the Oidium germ tube through tobacco leaves, whereas penetration was successful on tomato leaves irrespective of BTH treatment. In contrast, soil or leaf treatment with BTH induced resistance against B. cinerea in tomato but not in tobacco. It is concluded that the SA‐dependent defence pathway is effective against different pathogens in tomato and tobacco.
Small Area Estimates for Cross-Classifications
Authors: Zhang Li-Chun , Chambers Raymond L.
Published: December 2004

We develop a class of log-linear structural models that is suited to estimation of small area cross-classified counts based on survey data. This allows us to account for various associ- ation structures within the data and includes as a special case the restricted log-linear model underlying structure preserving estimation. The effect of survey design can be incorporated into estimation through the specification of an unbiased direct estimator and its associated covariance structure. We illustrate our approach by applying it to estimation of small area labour force characteristics in Norway.
Semiparametric Non-Linear Time Series Model Selection
Authors: Gao Jiti , Tong Howell
Published: December 2004

Semiparametric time series regression is often used without checking its suitability, resulting in an unnecessarily complicated model. In practice, one may encounter computational difficulties caused by the curse of dimensionality. The paper suggests that to provide more precise predictions we need to choose the most significant regressors for both the parametric and the nonparametric time series components. We develop a novel cross-validation-based model selection procedure for the simultaneous choice of both the parametric and the nonparametric time series components, and we establish some asymptotic properties of the model selection procedure proposed. In addition, we demonstrate how to implement it by using both simulated and real examples. Our empirical studies show that the procedure works well.
A Simple Procedure for the Selection of Significant Effects
Authors: Cox D. R. , Wong Man Yu
Published: December 2004

Given a large number of test statistics, a small proportion of which represent departures from the relevant null hypothesis, a simple rule is given for choosing those statistics that are indicative of departure. It is based on fitting by moments a mixture model to the set of test statistics and then deriving an estimated likelihood ratio. Simulation suggests that the procedure has good properties when the departure from an overall null hypothesis is not too small.
Transplanting patients with a positive donor‐specific crossmatch: A single center's perspective
Authors: Montgomery Robert A. , Zachary Andrea A.
Published: December 2004

Abstract: An increasing number of individuals with end‐stage renal disease have become sensitized to human leukocyte antigens (HLA). Sensitization can have a profound impact on the likelihood of obtaining a requisite negative crossmatch (‐XM) with a potential donor. Technologic breakthroughs in our ability to diagnose antibody‐mediated rejection (AMR) and monitor anti‐HLA antibodies has set the stage for a renascence in the understanding and treatment of individuals who harbor donor‐specific antibody (DSA). Promising early results from single institutions that have developed preconditioning protocols allowing successful transplantation of XM (+) patients have encouraged other centers to adopt these protocols. Sensitized patients represent a great challenge for the clinician and there is much that remains unknown about the assessment and treatment of these patients. We have successfully preconditioned and transplanted more than 80 patients over a 5‐yr period. As our understanding of these patients has increased, we have progressed from a ‘one size fits all’ approach to therapy to more rational, individualized treatment plans that take into account the varying immunologic risk that each patient possesses. In this article we have summarized our evolving experience with the assessment, treatment, transplantation, and monitoring of patients who undergo preconditioning for a (+) XM with a live donor.
Renal transplant nephrectomy in children: Can an aggressive approach be recommended?
Authors: Zerouali F. , Levtchenko E. N. , Feitz W. F. J. , Cornelissen E. A. M. , Monnens L. A. H.
Published: December 2004

Abstract:  Background:  A patient with a failed renal graft is generally approached conservatively, especially when graft failure occurs more than 1 month after transplantation. This approach was the cause of extensive morbidity in our institution and therefore we evaluated the correctness of our approach towards transplanted children.

Patients and methods:  Case histories of 182 renal transplants in 145 patients, performed between 1977 and 1999 were reviewed.

Results:  A total of 63 renal grafts failed: 19 between 0–1 month (group 1), 22 between 1 month and 1 yr (group 2) and 22 later than 1 yr after transplantation (group 3). Fifty‐three grafts (84%) were removed: 100% of group 1, 86% of group 2 and 68% of group 3. The symptoms that indicated the need for graft removal were fever without a clear infection focus (n = 12), abdominal pain in the transplant area (n = 14), macroscopic hematuria (n = 10) and severe hypertension (n = 22). After transplant nephrectomy pain, fever and macroscopic hematuria completely resolved in all and hypertension resolved in 36% of patients. Transplant nephrectomy‐associated morbidity was observed in 38% of the patients with 100% recovery.

Conclusion:  The clinical outcome confirmed the indications for transplant nephrectomy. Our future approach will be more aggressive: as soon as symptoms such as unexplained fever, local pain or macroscopic hematuria appear, graft removal will be performed without delay.
Utility of azathioprine metabolite measurements in post‐transplant recurrent autoimmune and immune‐mediated hepatitis
Authors: Rumbo Carolina , Shneider Benjamin L. , Emre Sukru H.
Published: December 2004

Abstract:  Patients with post‐transplant immune‐mediated hepatitis (IMH) and recurrent autoimmune hepatitis (RAIH) have a poor outcome and a higher need for retransplantation. Azathioprine (AZA) is used as adjunctive immunosuppression after transplantation; optimizing its dose may be a key point in preserving graft function. Complications of high AZA dosing make dose escalation potentially problematic. Our aim was to correlate AZA metabolite levels with therapeutic effects, toxicity, and adherence to medication in children with IMH and RAIH. Charts of 14 patients were retrospectively reviewed. The post‐transplant diagnosis was based on liver biopsy and autoimmune markers. AZA was prescribed after establishing the post‐transplant diagnosis. AZA was started at 1.1 (1.0–1.8) mg/kg/day. Routine biochemical studies, tacrolimus levels, 6‐thioguanine (6‐TG) and 6‐methylmercaptopurine levels were assessed every 8 wk. AZA dose was routinely adjusted to achieve 6‐TG levels between 235 and 450 pmol per 8 × 108 RBC. A total of 92 samples from 14 patients were reviewed. Four patients were excluded because of non‐adherence. AZA dose was increased by 245% resulting in eight of 10 patients in the target range; no hepatic or bone marrow toxicity was observed. ALT levels and steroid requirements were significantly reduced (p < 0.05). The AZA dose required to achieve target 6‐TG levels was significantly greater in children <10 yr. AZA metabolite testing in children post‐liver transplant is useful in assessing adherence to medication and it is potentially helpful in optimizing medication dosing. In younger children the AZA dose requirements were two to four times higher than previously reported standard doses.
Non‐alcoholic steatohepatitis in children
Authors: Nanda Kerkar
Published: December 2004

Abstract: Obesity has emerged as a significant new health problem in the pediatric population. Non‐alcoholic steatohepatitis (NASH) is an entity in the spectrum of non‐alcoholic fatty liver disease (NAFLD) ranges from fat in the liver – simple steatosis, NASH/ steatohepatitis – fat with inflammation and/or fibrosis to advanced fibrosis and cirrhosis when fat may no longer be present. NASH is associated with obesity, diabetes, insulin resistance (IR), and hypertriglyceridemia. While majority of individuals with risk factors like obesity and IR have steatosis only a minority develop steatohepatitis, possible mechanisms have been discussed. Clinical experience with pediatric NASH is limited. Children generally present in the prepubertal age group, have a male predominance with a higher incidence in children of Hispanic origin. Body mass index (BMI) of 25–29.9 is considered to be overweight and that ≥30 obese. Acanthosis nigricans as a marker of IR should be looked for. As NASH is a diagnosis of exclusion, other causes of chronic liver disease must be excluded. Increased echogenicity in the liver is noted on ultrasound. Liver biopsy is considered the gold standard in establishing the diagnosis. Histopathological lesions thought to be necessary for diagnosis of NASH include steatosis (macrovesicular > microvesicular), mixed mild lobular inflammation and hepatocyte ballooning. A system of grading depending on degree of steatosis and/or inflammation and staging depending on the extent of fibrosis has also been proposed. Although there is no consensus for the treatment for NASH, effort needs to be made to prevent development of fibrosis, which results in cirrhosis and portal hypertension. Slow, consistent weight loss has been shown to be effective in childhood NAFLD, based on improvement of serum aminotransferases or liver sonogram. A low glycemic index diet has been shown to be more effective than a low fat diet in lowering BMI. Family based behavioral intervention may also enhance success with diet. Several pharmacological agents have been used including ursodeoxycholic acid, vitamin E, betaine, n‐acetyl cysteine, and insulin sensitizing agents like metformin, rosiglitazone, and pioglitazone. Transplantation for overt NASH is rare, accounting for <1% of liver transplantations in the USA. The disease can recur after liver transplantation. A strong association exists between the presence of steatosis in a donor liver and poor graft function. As a result, cadaveric donor livers with macrovesicular steatosis >40% are not used routinely. Prognosis in NASH is dependent not only on severity and number of risk factors but also on the degree of histological damage. Clinical trials are needed to identify an effective treatment that halts the progression of NAFLD to NASH in both pretransplantation and post‐transplantation patients.
Mechanisms of autoimmune hepatitis
Authors: Vergani Diego , Mieli‐Vergani Giorgina
Published: December 2004

Abstract:  Autoimmune hepatitis (AIH) is a progressive inflammatory liver disease with a female preponderance, responsive to immunosuppressive treatment. Two types of AIH are described: type 1 AIH is characterized by positivity for smooth muscle and/or antinuclear antibody, while type 2 AIH is positive for liver kidney microsomal type 1 antibody. The putative mechanisms leading to the development of this condition include genetic predisposition to autoimmunity through possession of specific human leukocyte antigen alleles, immune reactions to liver cell antigens, possibly triggered by a mechanism of molecular mimicry, where immune responses to external pathogens, e.g. viruses, become directed toward structurally similar self‐components, and an impairment in immune regulation. AIH has been described to arise de novo after liver transplantation. The mechanisms leading to post‐transplant autoimmunity remain to be defined.
Recognition of facial expression and visual P300 in schizophrenic patients: Differences between paranoid type patients and non‐paranoid patients
Authors: UENO TAKEFUMI , MORITA KIICHIRO , SHOJI YOSHIHISA , YAMAMOTO MASASHI , YAMAMOTO HIROKO , MAEDA HISAO
Published: December 2004

Abstract  This study compared the effects of facial affective stimuli on visual event‐related potentials (ERP) in schizophrenic patients and healthy subjects using photographs of babies depicting sadness (crying face), neutrality (neutral face), and pleasure (smiling face). Visual ERP were recorded using an oddball paradigm in 32 schizophrenic patients (16 paranoid type and 16 non‐paranoid patients) and 32 age‐matched healthy subjects. The P300 amplitude, latency, and the subject's reaction time were recorded. The P300 amplitude when viewing a photograph of a smiling baby was the smallest registered of three photographs for healthy subjects and paranoid type patients with successively greater amplitudes for neutrality and sadness. However, the P300 amplitude was the smallest while viewing crying photographs and was the largest while viewing a smiling photograph for non‐paranoid patients. These results suggest that the P300 amplitude is influenced by viewing emotionally moving facial expressions and that the effect is different for different subtypes of schizophrenia. These differences may reflect differences in information processing resulted from emotional influences caused by visual‐affective stimuli.
Effects of donepezil on Alzheimer's disease: The relationship between cognitive function and rapid eye movement sleep
Authors: MIZUNO SOICHI , KAMEDA ATSUKO , INAGAKI TAKUJI , HORIGUCHI JUN
Published: December 2004

Abstract  The aim of this study was to observe the effects of donepezil on both the cognitive function and sleep patterns in patients of Alzheimer's Type Dementia (ATD), especially to determine the relationship between the improvement of cognitive function and the amount of rapid eye movement (REM) sleep. A total of 12 patients (7 females, 5 males; age, 73.0 ± 6.8) meeting the NINCDS‐ADRDA (National Institute of Neurological and Communicative Disorders and Stroke‐Alzheimer's Disease and Related Disorders Association) criteria of probable AD were studied. These patients presented with mild to moderate dementia, which was confirmed by a Clinical Dementia Rating score of 1 or 2. Following baseline examinations consisting of the Alzheimer's Disease Assessment Scale‐cognitive component‐Japanese version (ADAS‐Jcog) and polysomnography (PSG), 5 mg of donepezil was administered to the patients at breakfast every day. All patients were reassessed 6 weeks later using the same examinations. With sleep patterns, the percentage of REM sleep to total sleep time increased after the administration of donepezil. In addition, it was also found that sleep efficiency was increased and sleep latency was shortened by this administration. Although the ADAS‐Jcog score did not decrease significantly, there was significant positive correlation between the decrease of the ADAS‐Jcog score and the increase in the percentage of REM sleep. These results indicate the increase action of REM sleep due to activate central cholinergic systems and the possibility to improve sleep conditions due to one‐time administration after breakfast of donepezil in mild to moderate ATD. It is concluded that the increase in REM sleep may reflect the improvement of cognitive function in ATD patients.
Inactivation of the PTEN gene protein product is associated with the invasiveness and metastasis, but not angiogenesis, of breast cancer
Authors: Chung Myoung Ja , Jung Sung Hoo , Lee Bong Ju , Kang Myoung Jae , Lee Dong Geun
Published: December 2004

PTEN is a novel tumor‐suppressor gene located on chromosomal band 10q23. Loss of PTEN function has been implicated  in  the  progression  of  several  types  of  cancer, but the correlation between loss of PTEN expression and advanced carcinomas is not well established. The capacity for angiogenesis of a tumor is known to play a very important role in growth and metastasis, and there have been reports that PTEN relates to angiogenesis. In the present study, formalin‐fixed and paraffin embedded tissues from 101 patients with breast carcinomas, including 88 cases of invasive ductal carcinomas and 13 cases of ductal carcinoma in situ (DCIS), were evaluated by immunohistochemical methods for the expression of PTEN and vascular endothelial growth factor (VEGF), as well as microvessel density (MVD). The results were compared with the clinicopathologic parameters. There was no loss of PTEN expression in any of the cases of DCIS, but 28 (32%) of the 88 invasive cases did not express PTEN. Loss of PTEN expression was associated with lymph node metastasis (P = 0.03), but  did  not  correlate  with  tumor  size,  tumor  grade,  MVD or recurrence. VEGF expression significantly correlated with lymph node metastasis in invasive ductal carcinoma (P = 0.01). There was no correlation between the expression of PTEN and that of VEGF (P = 0.63). The present study suggests that loss of PTEN expression is common and correlates with tumor progression and lymph node metastasis  in  breast  carcinoma.  The  relationship  between  loss of PTEN and progression of breast cancer may not be explained by modulation of angiogenesis.
Human DNA damage checkpoints and their relevance to soft tissue sarcoma
Authors: Hattori Hiroyuki , Kuroda Masahiko , Ishida Tsuyoshi , Shinmura Koutarou , Nagai Shuzou , Mukai Kiyoshi , Imakiire Atsuhiro
Published: December 2004

Soft tissue sarcoma (STS) is a malignant neoplasm, arising in mesenchymal tissues, that is difficult to treat clinically because it can be highly resistant to chemo‐radiotherapy. At present, the mechanism of that resistance remains unclear. Cell cycle checkpoints engender strict control of cell proliferation, arresting the cell cycle to provide time for repair or apoptosis when DNA damage is induced by unprogrammed extrinsic events. These pathways involve at least two checkpoints: one at the G1/S transition and one at the G2/M transition. The p53 gene, which is mutated in several malignant tumors, plays an important role in DNA repair at the G1/S transition; however, there is little information on the G2/M checkpoint in STS. In the present study, several proteins (phospho‐p53, ‐cdc25, ‐cdc2, ‐Chk1 and ‐Chk2) involved in checkpoint pathways were investigated using immunohistochemistry in STS specimens. Most STSs maintain a well‐preserved G2/M checkpoint despite the loss of the G1/S checkpoint (phospho‐p53: 4.9% (2/41); ‐cdc25: 41% (17/41); ‐cdc2: 61% (25/41); ‐Chk1: 29% (12/41); ‐Chk2: 46% (19/41)). Furthermore, in a postoperative chemotherapy case  the  number  of  cells  positive  for  phospho‐cdc25  and ‐Chk2 was higher in a recurrent tumor than in the primary tumor (n = 7, P = 0.046 < 0.05, Wilcoxon signed‐ranks test). These findings indicate that the G2/M checkpoint pathway is well preserved and might contribute to the chemotherapeutic resistance associated with STS.
Distribution of myofibroblastic cells in the liver and kidney of Meckel–Gruber syndrome
Authors: Kuroda Naoto , Ishiura Yoshihito , Kawashima Masaaki , Miyazaki Eriko , Hayashi Yoshihiro , Enzan Hideaki
Published: December 2004

Meckel–Gruber syndrome (MGS) is a rare disorder characterized by occipital encephalocele, polydactyly and polycystic kidney. Early diagnosis is very important because MGS has a high risk of recurrence and infants with MGS are frequently stillborn or die soon after birth. An autopsy case of MGS is presented and the focus is specifically on the myofibroblastic cells of the liver and polycystic kidney. Although routine histological examination did not reveal hepatic fibrosis, a specific distribution of alpha smooth muscle actin (α‐SMA)‐positive and h‐caldesmon (h‐CD)‐negative stromal cells (myofibroblastic cells) was observed along the limiting plate of the portal area. Furthermore, myofibroblastic cells were focally distributed along the sinusoidal wall and around the bile ducts in the portal area. In the polycystic kidney, the presence of myofibroblastic cells in the stroma between the cystic lesions was also confirmed by electron microscopy. In conclusion, myofibroblastic cells were distributed in the liver and kidney of a patient with MGS and their specific distribution in the liver may be indicative of prestage hepatic fibrosis.
Analgesia for adenotonsillectomy in children: a comparison of morphine, ketamine and tramadol
Authors: Umuroğlu Tümay , Eti Zeynep , Çiftçi Hatice , Yılmaz Göğüş F.
Published: December 2004

Background : Establishment of good analgesia is of major concern in the postoperative period following adenotonsillectomy. The aim of this study was to compare the effects of ketamine, morphine and tramadol on postoperative pain after adenotonsillectomy in children.

Methods : Sixty children (age 5–12 years) scheduled for adenotonsillectomy were randomized into four groups to receive intravenously (i.v.) either 0.5 mg·kg−1 ketamine hydrochloride (K), 0.1 mg·kg−1 morphine hydrochloride (M), 1.5 mg·kg−1 tramadol hydrochloride (T) or normal saline (S) in a volume of 4 ml during induction. After tracheal intubation 10 μg·kg−1·min−1 ketamine hydrochloride in group K and 0.6 ml·kg−1·h−1 saline i.v. in groups M, K and S were infused peroperatively. Postoperative analgesic requirements and side‐effects were recorded. Pain was assessed by the Numeric Rating Scale (NRS) and the Children's Hospital of Eastern Ontario Pain Scale (CHEOPS) scores.

Results : Heart rate increased significantly peroperatively only in group K. NRS at first and fifth minute in group M and at first minute in group T and K and CHEOPS score at first, fifth, 15th and 60th min in group M were found to be significantly lower than in the control group. The time to first analgesic requirement was significantly longer in group M compared with ketamine and the control group. Six children in group M, nine in group T, 11 in group K and 15 in group S needed additional analgesics.

Conclusions : Morphine hydrochloride 0.1 mg·kg−1 i.v. administered during induction of anaesthesia provides efficient pain relief in children undergoing adenotonsillectomy.
Offenders as Victims of Crime?: An Investigation into the Relationship Between Criminal Behaviour and Victimization
Authors: Deadman Derek , MacDonald Ziggy
Published: December 2004

We consider the association between victimization and offending behaviour by using data from the Youth Lifestyles Survey. We consider the effect of violent and non-violent offending on the probability of being a victim of violent and non-violent crime and find a positive association between these by using univariate probit estimates. However, taking into account the endog- enous nature of offending and victimization via a bivariate probit model, we find that univariate estimates understate the association. We suggest that policy recommendations should only be informed by the bivariate analysis of the association between offending and victimization.
The Validation of Surrogate End Points by using Data from Randomized Clinical Trials: A Case-Study in Advanced Colorectal Cancer
Authors: Burzykowski Tomasz , Molenberghs Geert , Buyse Marc
Published: December 2004

In many therapeutic areas, the identification and validation of surrogate end points is of prime interest to reduce the duration and/or size of clinical trials. Buyse and co-workers and Burzykowski and co-workers have proposed a validation strategy for end points that are either normally distributed or (possibly censored) failure times. In this paper, we address the problem of validating an ordinal categorical or binary end point as a surrogate for a failure time true end point. In particular, we investigate the validity of tumour response as a surrogate for survival time in evaluating fluoropyrimidine-based experimental therapies for advanced colorectal cancer. Our analysis is performed on data from 28 randomized trials in advanced colorectal cancer, which are available through the Meta-Analysis Group in Cancer.
An Invitation to Quantum Tomography
Authors: Artiles L. M. , Gill R. D. , Gut¸ă M. I.
Published: December 2004

We describe quantum tomography as an inverse statistical problem in which the quantum state of a light beam is the unknown parameter and the data are given by results of measurements performed on identical quantum systems. The state can be represented as an infinite dimensional density matrix or equivalently as a density on the plane called the Wigner function. We present consistency results for pattern function projection estimators and for sieve maximum likelihood estimators for both the density matrix of the quantum state and its Wigner function. We illustrate the performance of the estimators on simulated data. An EM algorithm is proposed for practical implementation. There remain many open problems, e.g. rates of convergence, adaptation and studying other estimators; a main purpose of the paper is to bring these to the attention of the statistical community.
An introduction to plant sphingolipids and a review of recent advances in understanding their metabolism and function
Authors: Lynch Daniel V. , Dunn Teresa M.
Published: December 2004

Sphingolipids are ubiquitous constituents of eukaryotic cells, and have been intensively investigated in mammals and yeast for decades. Aspects of sphingolipid biochemistry in plants have been explored only recently. To date, progress has been made in determining the structure and occurrence of sphingolipids in plant tissues; in characterizing the enzymatic steps involved in production and turnover of sphingolipids (and, in some cases, the genes encoding the relevant enzymes); and in identifying a variety of biological functions for sphingolipids in plants. Given that these efforts are far from complete and much remains to be learned, this review represents a status report on the burgeoning field of plant sphingolipid biochemistry.

Contents

Summary
677

I.
Introduction
678

II.
Plant sphingolipid structure
678

III.
Sphingolipid metabolism in plants
683

IV.
Sphingolipid functions in plants
693

V.
Conclusions
696

Acknowledgements
696

References
696
The plastic plant: root responses to heterogeneous supplies of nutrients
Authors: Hodge Angela
Published: December 2004

When roots encounter a nutrient‐rich zone or patch they often proliferate within it. Roots experiencing nutrient‐rich patches can also enhance their physiological ion‐uptake capacities compared with roots of the same plant outside the patch zone. These plastic responses by the root system have been proposed as the major mechanism by which plants cope with the naturally occurring heterogeneous supplies of nutrients in soil. Various attempts to predict how contrasting species will respond to patches have been made based on specific root length (SRL), root demography and biomass allocation within the patch zone. No one criterion has proved definitive. Actually demonstrating that root proliferation is beneficial to the plant, especially in terms of nitrogen capture from patches, has also proved troublesome. Yet by growing plants under more realistic conditions, such as in interspecific plant competition, and with a complex organic patch, a direct benefit can be demonstrated. Thus, as highlighted in this review, the environmental context in which the root response is expressed is as important as the magnitude of the response itself.

Contents

I.
Introduction
9

II.
Morphological responses
10

III.
Root demography
14

IV.
Physiological plasticity
14

V.
Root plasticity in patches in competition and symbiosis with microorganisms
16

VI.
Influence of patch attributes
17

VII.
Control of root proliferation
19

VIII.
Conclusions
20

Acknowledgements
20

References
20
Evolution under tight linkage to mating type
Authors: Uyenoyama Marcy K.
Published: December 2004

Recent large‐scale sequencing studies of mating type loci in a number of organisms offer insight into the origin and evolution of these genomic regions. Extensive tracts containing genes with a wide diversity of functions typically cosegregate with mating type. Cases in which mating type determination entails complementarity between distinct transcription units may descend from systems in which close physical linkage facilitated the coordinated expression and cosegregation of the interacting genes. In response to the particular selection pressures associated with the maintenance of more than one mating type, this nucleus of low recombination may expand over evolutionary time, engulfing neighboring tracts bearing genes with no direct role in reproduction. This scenario is consistent with the present‐day structure of some mating type loci, including regulators of homomorphic self‐incompatibility in angiosperms (S‐loci). Recombination suppression and enforced S‐locus heterozygosity accelerate the accumulation of genetic load and promote genetic associations between S‐alleles and degenerating genes in cosegregating tracts. This S‐allele‐specific load may influence the evolution of self‐incompatibility systems.
Attentional blink reflex modulation in a continuous performance task is modality specific
Authors: Lipp Ottmar V. , Neumann David L.
Published: December 2004

Four experiments investigated the attentional modulation of acoustic blinks during continuous spatial tracking tasks. Experiment 1 found blink magnitude inhibition in a visual tracking task. Experiment 2 replicated this finding and also found blink latency slowing. Experiment 3 varied the difficulty of the task and found larger blink inhibition in the easy condition. Blink latency slowing did not differ and was significant at both difficulty levels. Experiment 4 employed less difficult visual and acoustic tracking tasks at two levels of task load. Blink magnitude inhibition during the visual and facilitation during the acoustic task was significant during high load in both modality groups. Blink latency was slowed in all visual task conditions and shortened in the difficult acoustic task. These results indicate that attentional blink modulation in a continuous spatial tracking task is modality specific.
The sequential processing of visual feature conjunction mismatches in the human brain
Authors: Wang Yuping , Cui Lili , Wang Huijun , Tian Shujuan , Zhang Xi
Published: December 2004

To clarify the brain mechanism for multifeature stimulus comparison, subjects matched the features of two serial visual stimuli in pairs. Stimulus pairs were of four categories: C−S−, color same, shape same (match); C−S+, color same, shape different (shape mismatch); C+S−, color different, shape same (color mismatch); C+S+, color different, shape different (conjunction mismatches). Subjects matched the stimuli in three different sessions according to different attention tasks: attending to color (Ac), attending to shape (As), or attending to both color and shape (Acs). A negative one‐peak brain potential, N270, was elicited in all the mismatch conditions with amplitude enhanced in the task‐relevant mismatch. Negative potential with two peaks, N270 and N400, appeared when attending to the conjunction mismatches concurrently. The two serial negativities in response to attended feature conjunctions might reflect the temporal different stages for processing conjunction mismatches or conflicts.
ERP indices of emotionality and semantic cohesiveness during recognition judgments
Authors: Mcneely Heather E. , Dywan Jane , Segalowitz Sidney J.
Published: December 2004

Event‐related potentials (ERPs) were used to examine the impact of emotionality on false recognition. In Experiment 1, participants discriminated previously studied words from neutral and negatively valenced emotional foils. Emotional words elicited a more positive ERP than did neutral words and emotional foils were falsely recognized more often than neutral foils. In Experiment 2, the hypothesis that emotionality‐based false recognition is due to the semantic cohesiveness of emotional words was tested by including a highly associated but emotionally neutral category (animals). It was emotional and not animal foils that elicited greater positivity in the ERP and increased false positive response. These data provide little support for semantic cohesiveness as the basis for false recognition effects, but are consistent with the view that the salience of emotional words can be falsely attributed to familiarity in the context of a recognition task.
Event‐related potentials associated with sound discrimination versus novelty detection in children
Authors: Čeponienė R. , Lepistö T. , Soininen M. , Aronen E. , Alku P. , Näätänen R.
Published: December 2004

In children, deviant sounds in an oddball paradigm elicit a mismatch negativity (MMN) indexing discrimination of sound change and late difference negativity (LDN) with unknown functional significance. Salient sounds elicit an ERP index if orienting, P3a, and a late negative component, Nc. We compared children's responses elicited by moderate sound changes and novel sounds to examine the relationships between MMN and LDN, and LDN and Nc. Two components of the Nc, the Nc1 and Nc2, were identified. The scalp topography of LDN differed from those of the MMN and Nc1. Children's early P3a appeared mature but late P3a lacked frontal predominance. The findings suggested that LDN is not linked with either the sensory or attentional processing. It might reflect cognitive, albeit preattentive, processing of sound change. The Nc1 appears to reflect cognitive attentive processing of salient stimuli and the Nc2 might reflect reorienting after distraction.
Left‐hemispheric abnormal EEG activity in relation to impairment and recovery in aphasic patients
Authors: Hensel Sandra , Rockstroh Brigitte , Berg Patrick , Elbert Thomas , Schönle Paul Walter
Published: December 2004

Focal electromagnetic slow‐wave activity is generated in the vicinity of brain lesions. The present study confirmed this for the EEG delta band (1–4 Hz): Activity in the waking state was pronounced over the hemisphere of the lesion in 11 stroke patients suffering from aphasia, but not in 10 healthy controls. Changes of abnormal slow waves patterns were tracked from 1–3 months to 2 years poststroke by recording the EEG five times at 4‐month intervals. Across the first year poststroke, mean left‐hemispheric delta amplitude and equivalent current dipole strength decreased in parallel with the spontaneous recovery of language function, whereas the regional distribution of delta activity sources was stabile across time. No changes were observed during the second year poststroke. Results suggest that abnormal slow waves in the vicinity of brain lesions may be related to impairment in brain function, and that their measurement may assist in depicting the course of functional recovery.
Feature versus gestalt representation of stimuli in the mismatch negativity system of 7‐ to 9‐year‐old children
Authors: Molholm Sophie , Gomes Hilary , Lobosco Jacqueline , Deacon Diana , Ritter Walter
Published: December 2004

We examined preattentive auditory change detection in 7‐ to 9‐year‐old children. The question of interest was whether the preattentive comparison of stimuli indexed by the scalp‐recorded mismatch negativity (MMN) was performed on representations of individual stimulus features or on gestalt representations of their combined attributes. The design of the study, based on a work byD. Deacon, J. Nousak, M. Pilotti, W. Ritter, and C. Yang (Psychophysiology, 1998), was such that both feature and gestalt representations could have been available to the comparator mechanism generating the MMN. The data indicated that for the majority of the children—those that exhibited an inverse relationship between the amplitude of the MMN and the probability of the deviant—the MMN was based on feature‐specific information. This study also provides a method to obtain MMNs to deviants in three different features in the time usually required to obtain an MMN to a single acoustic feature.
Program running versus problem solving: Mental task effect on tonic heart rate
Authors: Sosnowski Tytus , Krzywosz‐Rynkiewicz Beata , Roguska Joanna
Published: December 2004

It was hypothesized that mental tasks that involve program running (RUN tasks) would cause a greater tonic heart rate (HR) increase than tasks that require the search for problem solutions (EDIT tasks). Three experiments using verbal, numeric, and graphic material were run to compare tasks matched for difficulty but differing in qualitative demands (RUN vs. EDIT tasks). As predicted, filling in missing letters in words caused a larger HR increase than finding words that were logical continuations of a series of words (Experiment 1) and performing arithmetic operations caused a greater HR increase than logical completion of a series of digits (Experiment 2). In Experiment 3, two of three tasks that demanded counting of graphic elements caused a larger HR increase than a task that required logical completion of a series of graphic elements. Experiments 1 and 2 also showed that RUN tasks evoked greater phasic HR acceleration than EDIT tasks.
Domestic Violence and Women's Mental Health in Chile
Authors: Ceballo Rosario , Ramirez Cynthia , Castillo Marcela , Caballero Gabriela Alejandra , Lozoff Betsy
Published: December 2004

Domestic violence against women is a pervasive, global health problem. This study investigates the correlates and psychological outcomes of domestic abuse among women in a semi-industrial country. The participants included 215 mothers residing in working-class communities located on the outskirts of Santiago, Chile. We utilized structural equation modeling to test the hypothesis that poverty and other structural inequalities would be related to incidents of domestic abuse in Chile, as they are in the United States. Our results suggest that lower socioeconomic status, even within poor communities, and stressful life events have a direct relationship to domestic conflict. Domestic abuse was, in turn, associated with women's mental health such that greater domestic conflict was related to higher reports of depressive affect and symptoms of posttraumatic stress disorder. The importance of identifying similarities and differences in the occurrence of domestic violence in developing countries as compared to industrialized countries is discussed.
Association of HLA Class I Antigens and HLA Class II Alleles with Vitiligo in a Turkish Population
Authors: Taştan Halİs Bülent , Akar Ahmet , Orkunoğlu Funda Eli̇f , Arca Ercan , İnal Ali̇
Published: December 2004

As is the case with many other autoimmune diseases, there is an association between vitiligo and HLA complex. HLA subtypes vary with racial/ethnic background. The purpose of this study was to determine which HLA class I antigens and HLA class II alleles are associated with Turkish vitiligo patients. Forty‐one patients with vitiligo and 61 healthy control subjects were typed for HLA class II alleles. Thirty‐three out of 41 patients with vitiligo and 100 healthy transplant donors were typed for HLA class I antigens. HLA DNA typing was performed by polymerase chain reaction/sequence specific primer method for class II. HLA typing for class I was performed by serological method. The frequency of HLA DRB1*03 was 0.6340 in patients compared to 0.2950 in controls (P = 0.0014). The frequency of HLA DRB1*04 was found to be 0.6830 in patients compared to 0.2950 in controls (P = 0.00026). The allele HLA DRB1*07 was present in 0.390 of patients compared to 0.0820 of the controls (P = 0.0004). A preventive antigen for the manifestation of vitiligo has not been identified in this study. Our findings suggest that DRB1*03, DRB1*04 and DRB1*07 alleles are genetic markers for general susceptibility to vitiligo in a Turkish population.
Extremely high maternal alkaline phosphatase serum concentration with syncytiotrophoblastic origin
Authors: Boronkai A , Than N G , Magenheim R , Bellyei S , Szigeti A , Deres P , Hargitai B , Sumegi B , Papp Z , Rigo J
Published: December 2004

An extremely high alkaline phosphatase (AP) concentration (3609 IU/litre) was found in a 20 year old primigravida at 37 week’s gestation, prompting an examination of its histological and cellular origin. Immunohistochemistry and western blots using antibodies against AP, Ki-67, phospho-protein kinase B (Akt), phospho-p44/42 mitogen activated protein kinase/extracellular signal regulated kinase 1/2 (MAPK/Erk1/2), phospho-glycogen synthase kinase-3β (GSK-3β), phospho-stress activated protein kinase/c-Jun N-terminal kinase, total-Akt, total-GSK-3β, and phospho-p38-MAPK were carried out on index and control placental samples of the same gestational age. Compared with controls, staining of the index placenta showed minimal AP labelling of the brush border and remarkable positivity of the intervillous space. Cytotrophoblastic proliferation was 8–10% in the index placenta compared with 1–2% in controls. The index placenta also had raised concentrations of protein kinases with important roles in cell differentiation. The proliferation and differentiation rates of the cytotrophoblasts were found to be five times higher in index samples than in controls. It is hypothesised that loss of syncytial membranes in immature villi led to increased AP concentrations in the maternal circulation and decreased AP staining of the placenta. Loss of the syncytium might also stimulate increased proliferation of villous cytotrophoblasts, which would then fuse and maintain the syncytium.
The characteristics of human papillomavirus DNA in head and neck cancers and papillomas
Authors: Major T , Szarka K , Sziklai I , Gergely L , Czeglédy J
Published: December 2004

Aim:To determine the prevalence, type, physical state, and viral load of human papillomavirus (HPV) DNA in cases of head and neck cancer and recurrent respiratory papillomatosis (RRP).

Methods:The prevalence and type of HPV DNA was determined in 27 fresh frozen tissue specimens from patients with head and neck cancers and 16 specimens from 10 patients with RRP by MY09/MY11 and GP5+/GP6+ nested polymerase chain reaction (PCR) and subsequent restriction enzyme cleavage. The physical state of HPV DNA was analysed by E1, E2, and E1E2 specific PCRs and Southern blot hybridisation (SBH).

Results:HPV DNA was detected in 13 of 27 cancers and 10 of 10 papillomas. Both low risk HPV-6 and HPV-11 and high risk HPV-16 were present in cancers in low copy numbers, whereas papillomas exclusively harboured low risk HPV-6 and HPV-11. E1E2 PCRs failed to determine the physical state of HPV in cancers except one case where HPV-6 DNA was integrated. In contrast to cancers, all papillomas showed the episomal state of HPV DNA and a relatively higher viral load.

Conclusions:Based on the prevalence, type, physical state, and copy number of HPV DNA, cancers and papillomas tend to show a different HPV DNA profile. The 100% positivity rate of low risk HPV types confirms the role of HPV-6 and HPV-11 in the aetiology of RRP.
Mitochondrial DNA haplotyping revealed the presence of mixed up benign and neoplastic tissue sections from two individuals on the same prostatic biopsy slide
Authors: Alonso A , Alves C , Suárez-Mier M P , Albarrán C , Pereira L , Fernández de Simón L , Martín P , García O , Gusmão L , Sancho M , Amorim A
Published: December 2004

DNA typing was requested to investigate a presumptive cancer diagnosis error by confirming whether benign and cancerous prostatic tissue in the same presurgical haematoxylin and eosin stained slide belonged to the same person. After independent histological re-examination of the slide by a pathologist, manual slide dissection was used to guarantee independent and high recovery DNA isolation from each tissue section, avoiding carryover and background contamination. Nuclear DNA quantification performed by real time polymerase chain reaction (PCR) revealed the absence of human DNA for short tandem repeat (STR) typing. Mitochondrial DNA was only obtained by performing PCR of very short fragments (∼100 bp), indicating high DNA degradation. Different low frequency hypervariable region I haplotypes were obtained from each tissue section (normal tissue section haplotype: 16224C, 16234T, 16311C, 16356C; cancer tissue section haplotype: 16256T, 16270T, 16293G). Only the normal tissue section haplotype matched that obtained from the patient’s blood sample, indicating that the cancer tissue section originated from an unknown patient. These results supported the hypothesis of sample mix up during block processing or slide preparation by a carryover mechanism. Mitochondrial genetic typing is recommended to exclude the possibility of carryover artefacts when low DNA content and high degradation compromise conventional STR typing.
Efficacy of screening the intermediate cluster region of the bcl2 gene in follicular lymphomas by PCR
Authors: Batstone P J , Goodlad J R
Published: December 2004

Background:The t(14;18) translocation is a common finding in nodal follicular B cell lymphomas and diffuse large B cell lymphomas, and results in the overexpression of the antiapoptotic bcl2 protein. This chromosome rearrangement can be detected by the polymerase chain reaction (PCR), with most breakpoints in the bcl2 gene occurring within either the major breakpoint region (mbr) or the minor cluster region (mcr). However, recent investigations have revealed several breakpoints between these two regions, which cluster 19 kb 3′ of mbr in the “intermediate cluster region” (icr).

Aims/Methods:To analyse a series of 57 B cell follicular lymphomas known to carry the t(14;18) by PCR with primers directed against all three cluster regions to determine the efficacy of screening the icr site.

Results:Twenty six samples had an mbr rearrangement, four an mcr rearrangement, and three an icr rearrangement.

Conclusions:These results suggest that screening for icr is at least as efficacious as screening for mcr rearrangements.