bluuebunny/crossref_metadata_2025 huggingface dataset:
The influence of STAT5 antisense oligonucleotides on the proliferation and apoptosis of selected human leukaemic cell lines
Authors: Baśkiewicz‐Masiuk M. , Masiuk M. , Machaliński B.
Published: October 2003

Abstract.  The signal transducers and activators of transcription – STAT5A and STAT5B – take part in the regulation of many essential physiopathological processes. They influence the cell cycle, apoptosis and the proliferation of different types of cell lines. The STAT5 proteins are induced in response to multiple haematopoietic cytokines. Because they are constitutively active in certain haemato‐oncologic diseases, it is also suggested that they play an important role in leukaemogenesis. However, function of these proteins in haematopoietic cell transformation and proliferation is not clear. The aim of this study was to evaluate the impact of perturbation of STAT5 expression [using oligodeoxynucleotide (ODN) against STAT5 mRNA], on the clonogenicity and survival of selected human leukaemic cell lines, HEL, HL‐60, K562, TF‐1. We analysed the effect of ODN pre‐treatment on the cell clonogenicity in methylcellulose cultures according to the time and the temperature of exposure. Moreover, we attempted to estimate apoptosis induced in examined cells, by flow cytometry using combined Annexin V‐PI staining and the TUNEL method. We also applied the RT‐PCR method to analyse Bax and Bcl‐xL gene expression. We found that the perturbation of STAT5 expression with antisense oligonucleotides caused a decrease in the proliferative potential of human K562 and TF‐1 cell lines. Also, we observed higher induction of apoptotic cell death in the K562 and TF‐1 cells incubated with the antisense STAT5A ODNs. We did not notice any impact of ODNs on the HL‐60 and HEL cells. Our studies using STAT5 antisense oligonucleotides showed that these proteins may be critical in the regulation of growth and apoptosis of some types of leukaemic blasts.
Epithelial progenitor cell lines as models of normal breast morphogenesis and neoplasia
Authors: Petersen Ole William , Gudjonsson Thorarinn , Villadsen René , Bissell Mina J. , Rønnov‐Jessen Lone
Published: October 2003

Abstract.  The majority of human breast carcinomas exhibit luminal characteristics and as such, are most probably derived from progenitor cells within the luminal epithelial compartment. This has been subdivided recently into at least three luminal subtypes based on gene expression patterns. The value of knowing the cellular origin of individual tumours is clear and should aid in designing effective therapies. To do this, however, we need strategies aimed at defining the nature of stem and progenitor cell populations in the normal breast. In this review, we will discuss our technical approach for delineating the origin of the epithelial cell types. A major step forward was the purification of each cell type by the application of immunomagnetic cell sorting based on expression of lineage‐specific surface antigens. We then developed chemically defined media that could support either the luminal epithelial or the myoepithelial cell phenotype in primary cultures. Having succeeded in continuous propagation presumably without loss of markers, we could show that a subset of the luminal epithelial cells could convert to myoepithelial cells, signifying the possible existence of a progenitor cell population. By combining the information on marker expression and in situ localization with immunomagnetic sorting and subsequent immortalization, we have identifed and isolated a cytokeratin 19‐positive suprabasal putative precursor cell in the luminal epithelial compartment and established representative cell lines. This suprabasal‐derived epithelial cell line is able to generate both itself and differentiated luminal epithelial and myoepithelial cells, and in addition, is able to form elaborate terminal duct lobular unit (TDLU)‐like structures within a reconstituted basement membrane. As more than 90% of breast cancers arise in TDLUs and more than 90% are also cytokeratin 19‐positive, we suggest that this cell population contains a breast‐cancer progenitor.
Evidence of progenitor cells of glandular and myoepithelial cell lineages in the human adult female breast epithelium: a new progenitor (adult stem) cell concept
Authors: Boecker Werner , Buerger Horst
Published: October 2003

Abstract.  Although experimental data clearly confirm the existence of self‐renewing mammary stem cells, the characteristics of such progenitor cells have never been satisfactorily defined. Using a double immunofluorescence technique for simultaneous detection of the basal cytokeratin 5, the glandular cytokeratins 8/18 and the myoepithelial differentiation marker smooth muscle actin (SMA), we were able to demonstrate the presence of CK5+ cells in human adult breast epithelium. These cells have the potential to differentiate to either glandular (CK8/18+) or myoepithelial cells (SMA+) through intermediary cells (CK5+ and CK8/18+ or SMA+). We therefore proceeded on the assumption that the CK5+ cells are phenotypically and behaviourally progenitor (committed adult stem) cells of human breast epithelium. Furthermore, we furnish evidence that most of these progenitor cells are located in the luminal epithelium of the ductal lobular tree. Based on data obtained in extensive analyses of proliferative breast disease lesions, we have come to regard usual ductal hyperplasia as a progenitor cell‐derived lesion, whereas most breast cancers seem to evolve from differentiated glandular cells. Double immunofluorescence experiments provide a new tool to characterize phenotypically progenitor (adult stem) cells and their progenies. This model has been shown to be of great value for a better understanding not only of normal tissue regeneration but also of proliferative breast disease. Furthermore, this model provides a new tool for unravelling further the regulatory mechanisms that govern normal and pathological cell growth.
Identification of novel expressed sequences, up‐regulated in the leucocytes of chronic fatigue syndrome patients
Authors: Powell R. , Ren J. , Lewith G. , Barclay W. , Holgate S. , Almond J.
Published: October 2003

Background
Chronic fatigue syndrome (CFS) is an increasing medical phenomenon of unknown aetiology leading to high levels of chronic morbidity. Of the many hypotheses that purport to explain this disease, immune system activation, as a central feature, has remained prominent but unsubstantiated. Supporting this, a number of important cytokines have previously been shown to be over‐expressed in disease subjects. The diagnosis of CFS is highly problematic since no biological markers specific to this disease have been identified. The discovery of genes relating to this condition is an important goal in seeking to correctly categorize and understand this complex syndrome.

Objective
The aim of this study was to screen for changes in gene expression in the lymphocytes of CFS patients.

Methods
‘Differential Display’ is a method for comparing mRNA populations for the induction or suppression of genes. In this technique, mRNA populations from control and test subjects can be ‘displayed’ by gel electrophoresis and screened for differing banding patterns. These differences are indicative of altered gene expression between samples, and the genes that correspond to these bands can be cloned and identified. Differential display has been used to compare expression levels between four control subjects and seven CFS patients.

Results
Twelve short expressed sequence tags have been identified that were over‐expressed in lymphocytes from CFS patients. Two of these correspond to cathepsin C and MAIL1 – genes known to be upregulated in activated lymphocytes. The expression level of seven of the differentially displayed sequences have been verified by quantifying relative level of these transcripts using TAQman quantitative PCR.

Conclusion
Taken as a whole, the identification of novel gene tags up‐regulated in CFS patients adds weight to the idea that CFS is a disease characterized by subtle changes in the immune system.
Oral magnesium and vitamin C supplements in asthma: a parallel group randomized placebo‐controlled trial
Authors: Fogarty A. , Lewis S. A. , Scrivener S. L. , Antoniak M. , Pacey S. , Pringle M. , Britton J.
Published: October 2003

Background
Epidemiological studies suggest that higher intakes of dietary vitamin C and magnesium may be associated with a reduced risk of asthma.

Objective
To determine whether vitamin C or magnesium supplements improve the clinical control of asthma in primary care patients.

Methods
A randomized, placebo‐controlled, double‐blind parallel group trial of 16 weeks supplementation with 1 g/day vitamin C, 450 mg/day magnesium chelate or matched placebo. Three hundred patients aged 18–60 years with physician‐diagnosed asthma, controlled with at least one dose of an inhaled corticosteroid daily, were recruited from 24 primary care practices in Nottingham, UK. The main outcome measures were change in forced expiratory volume in 1 s, forced vital capacity, airway responsiveness to methacholine, mean morning and evening peak flow, symptom scores and bronchodilator use, both individually and as a combined summary statistic.

Results
There was no evidence of any beneficial effect of either supplement on any outcome measure of asthma control in the primary intention‐to‐treat analysis, or in an analysis restricted to participants who completed the study.

Conclusions
Regular dietary supplementation with vitamin C or magnesium adds no clinical benefit to current standard therapy of asthma in primary care patients.
Nursing interventions for patients with chronic conditions
Authors: Frich Liv Merete Holm
Published: October 2003

Background. Maintaining independence in older people or restoring and encouraging self‐management in those with chronic conditions are ways of increasing health‐related quality of life and at the same time may achieve cost savings. Nurses often carry out these types of interventions in follow‐up home visits.

Aims. To describe nursing interventions during home visits and their effects on people suffering from a range of chronic conditions.

Method. A structured descriptive review was carried out using the Medline, Embase, PsycINFO, CINAHL and Cochrane databases and the terms chronic or diabetic or arthrit* or pain and randomi* and [(nurs* and care) or (nurs* and interventions)].

Findings. In older people the best outcomes are reached if the target population is ‘the younger‐old’, or if intervention is tailored to elders who have stated health problems. The effect depends on the duration of the follow‐up period, number of follow‐up visits and personality of the nurse. Follow‐up nursing interventions for patients with diabetes can improve psychosocial and health outcomes.

Education of health providers and amount of time spent with patients seem to be important for positive outcome. A rheumatology nurse specialist seems to provide equally good clinical results as a rheumatologist and produces better patient‐related outcomes. Compared with a multidisciplinary team treating patients in day care or inpatient settings, a rheumatology nurse specialist provides less patient satisfaction, but equally good clinical outcomes.

Conclusions. Patients with chronic conditions often benefited from follow‐up visits by nurses. Visits should be multiple, extended over a long‐term, and interventions should be individualized. The outcomes may be described as patient satisfaction, good clinical outcomes and cost savings. Future randomized controlled trials should describe nurses’ interventions and educational background to enable replication. Randomized controlled trials using the Health Technology Assessment method would permit comparison between studies and be a good foundation for future decision‐making.
Wandering behaviour in people with dementia
Authors: Lai Claudia K.Y. , Arthur David G.
Published: October 2003

Background. Wandering has been described as one of the most challenging behaviours to manage and yet a search of the literature in the last two decades yields only a limited number of papers that specifically studied wandering.

Aim. This paper reviews the current literature on wandering in relation to the nature of the phenomenon, attempts to classify the behaviour, the extent of the problem, the profile of those who wander, postulations about its aetiology, and intervention strategies being employed.

Method. Eight literature databases were searched for the last 40 years up to February 2003 using ‘wandering’ and ‘dementia’ as combined keywords. A total of 133 articles was included in the review.

Findings. The prevalence of wandering behaviour was difficult to assess and no conclusions could be reached. The typical wanderer depicted in the literature was relatively young in the older population, more cognitively impaired, more likely to be a man, might have experienced sleep problems, had a more active premorbid lifestyle, and used more psychotropic medications. While studies agreed that wanderers are more cognitively impaired, their findings did not necessarily agree on other attributes. Three major approaches, namely the biomedical, psychosocial and person–environment interaction perspectives, in conceptualizing wandering behaviour can be identified from the literature. Medications, activity programmes, behavioural modification and environmental manipulation have been used as interventions but none has so far demonstrated unequivocal effectiveness.

Conclusion. Knowledge generated through research remains insufficient to explain fully why and when wandering occurs. Variability in how the phenomenon was defined and studied, and the small size of the samples made generalizability of findings difficult. Future research should incorporate a clearer definition of wandering; a specific targeted population with representative sample size; appropriate subject identification strategies; focussed interventions, and better control conditions.
Early recognition of dementia by nurses
Authors: Manthorpe Jill , Iliffe Steve , Eden Alison
Published: October 2003

Background. Early recognition of dementia is a key policy objective designed to maximize the efficacy of treatment and to provide timely and appropriate support before crisis occurs. The impact of early recognition of dementia is under‐researched in primary care nursing.

Aim. To explore whether community mental health nurses (CMHNs), community nurses (CNs) and practice nurses (PNs) have different perspectives on early diagnosis of dementia and to consider the possible effects of any variation.

Method. Data are drawn from questionnaires completed by CMHNs (79), CNs (153) and PNs (36) who attended workshops offered on 24 occasions in 21 settings across the United Kingdom. The workshops attracted a range of primary care practitioners and were part of a training programme on early diagnosis of dementia.

Results. Analysis of the data shows some differences in knowledge, experience and confidence between the three nurse groups. CMHNs were more confident in their abilities to recognize dementia and found providing support less difficult than CNs and PNs. CMHNs considered that they were best placed to co‐ordinate services for people with newly recognized dementia. CNs and PNs, however, reported experience of working with people with dementia and many appeared able to respond to early signs and to identify potential sources of support.

Conclusions. While CMHNs may have a key role in responding effectively to the newly identified needs of people with early dementia, other nurses working in the community are likely to encounter people with early dementia. In the context of a policy objective to identify people with dementia earlier, all community‐based nurses should be able to recognize the possibility of dementia and support those undergoing referral or assessment. Their confidence in doing so should be enhanced by continued professional development. Training in dementia recognition, involvement in and membership of primary care teams supporting people with dementia should not be confined to CMHNs. Nurses who regularly encounter the general population of older people may be well placed to provide continuity of support for those who may, or may not, have cause to suspect that they or their relatives have early dementia.
Nursing and health care in Indonesia
Authors: Shields Linda , Hartati Lucia Endang
Published: October 2003

Aim. Indonesia, with its population of over 220 million, has health problems similar to those of other developing countries. In an attempt to provide nurses throughout the world with knowledge about Indonesia, we describe the country, its health system, and problems encountered by nurses and other health professionals.

Method. We explain the way the health system works within Indonesian culture, discuss the effects of the international nursing shortage and outline the role of aid agencies. The ethical dilemmas faced by health professionals who care for patients within a poorly resourced system are examined. While the information pertains to the whole country, we focus on the main island of Java, as that is where we have worked and resided.

Findings. Nursing education is primarily conducted at senior high school, while medical education is similar to the university education offered in many countries, and allied health professionals are educated to varying standards. Indonesian health officials recognize that the low standard of nursing education contributes to poor health statistics, and they are working hard to improve this. There has been strong support from the government for the implementation of university education for nurses, and for courses within academies that bridge the gap between current standards and the levels of education required for the delivery of optimum health care.

Discussion. We both are nurses. One of us is an Indonesian and the other has worked for many years in Indonesia and coordinated a programme that organized exchanges of health professionals working in large tertiary referral hospitals and health departments in Indonesia and Australia. The information presented here is the result of many collaborative projects and gives information not available in published works.
Nutrient intakes of an adult Pakistani, European and African‐Caribbean community in inner city Britain
Authors: Vyas Avni , Greenhalgh Alyson , Cade Janet , Sanghera Baljit , Riste Lisa , Sharma Sangita , Cruickshank Kennedy
Published: October 2003

Objectives  To report nutrient intakes for three different ethnic groups living in inner city Manchester and explore under‐reporting in each group.

Design  Cross‐sectional survey. All participants completed one of three food frequency questionnaires, specifically developed for each ethnic group, and took part in a larger international survey of risk factors for diabetes and hypertension.

Setting  Participants were drawn randomly from seven GP registers in inner city Manchester, UK.

Participants  Men and women aged 25–79 years, 86 European, 246 African‐Caribbean origin and 84 Pakistani origin participants were included in the analysis.

Results  Body mass index was highest in the Pakistani women, 30.2 kg m−2. European participants had the highest reported energy intakes (EIs) for men and women (10.9 and 9.6 MJ, respectively). Pakistani men and women had the highest percentage of energy from fat (36.7 and 36.6%, respectively). Iron intakes were low in the African‐Caribbean group and calcium intakes were low in the Pakistani group. Under‐reporting [assessed as EI : basal metabolic rate (BMR) ratio <1.2] appeared to be high and occurred across all ethnic groups, with those apparently under‐reporting having higher BMIs in all groups.

Conclusion  The data provide nutrient intake estimates in three different ethnic groups using a similar method. Limitations include under‐reporting across all ethnic groups in a similar pattern with under‐reporters having higher BMIs in all groups, as found elsewhere.
Knowledge and use of evidence‐based nutrition: a survey of paediatric dietitians
Authors: Thomas D. E. , Kukuruzovic R. , Martino B. , Chauhan S. S. , Elliott E. J.
Published: October 2003

Objective  To survey paediatric dietitians’ knowledge and use of evidence‐based nutrition (EBN).

Design  Cross‐sectional survey using reply‐paid questionnaires.

Subjects  Paediatric dietitians in Australian teaching hospitals.

Main outcome measures  Age, sex, appointment, clinical practice, research activities; attitudes to, training in and use of EBN; and perceived barriers to use of EBN.

Statistical analysis  Data were analysed using descriptive statistics (SPSS).

Results  Fifty‐nine (86%) of 69 questionnaires were returned. Most (97%) dietitians were women working full‐time (63%), mean age 37 years (±9 SD). Most (75%) dietitians encountered knowledge gaps less than five times per week and most (87%) questions related to therapy. The majority (95%) performed their own literature searches, less than five times per month. All had access to ≥1 electronic literature databases including Medline (n = 58, 98%), Cochrane Library (n = 44, 75%) and CINAHL (n = 35, 59%). Information sources used most often were Medline and consultation with colleagues. Reported barriers to using EBN were lack of time (n = 53, 90%) or lack of skills for critical appraisal of published articles (n = 51, 86%) or literature searching (n = 48, 81%). While 53 (90%) believed in an evidence‐based approach, 43 (73%) either did not practise EBN or rated themselves as beginners.

Conclusion  Most dietitians favoured evidence‐based practice, but reported lack of time, skills or rapid access to electronic databases as barriers to its practice.
The prevalence of malnutrition in patients with human immunodeficiency virus on admission to hospital
Authors: Martin S.A. , Phillpot M. , Baldwin C. , Madden A.M.
Published: October 2003

Introduction: The prevalence of malnutrition in new hospital admissions is between 9 and 60% but it is widely acknowledged that malnutrition is often unrecognized (Lennard‐Jones, 1992; McWhirter & Pennington, 1994; Karlsson & Nordstrom, 2001). In patients with human immunodeficiency virus (HIV), weight loss and wasting are common features, which have been extensively studied and shown to have significant clinical implications. Loss of 5–10% of body weight has been demonstrated to be highly predictive of the development of opportunistic infections and death (Wheeler et al., 1998). However, few studies have examined the frequency of undernutrition in these patients. The aim of the study was to determine the prevalence of malnutrition in HIV patients admitted to a dedicated ward at the Chelsea and Westminster Hospital.

Method: Data on height, weight and weight change were collected from patients admitted consecutively between January and April 2002. Body mass index (BMI) and, where a reliable weight history was available, percentage weight loss was calculated. Patients at high risk of malnutrition were identified using the screening tool for adults at risk of malnutrition (BAPEN, 2000), which uses a combination of BMI and percentage body weight loss to determine overall risk. Patients with BMI <18.5 kg m−2 and with weight loss >10% were considered to be at high risk of malnutrition.

Results: Data were collected on 120 admissions, of which 100 were eligible for inclusion. Thirty seven patients were found to be at high risk of malnutrition, 19 of whom had a BMI <18.5 kg m−2 and 18 of whom had reported a body weight loss greater than 10% (Table 1). Only six patients of 32 patients in the high‐risk group were identified in both the BMI and weight loss categories.

Classification of patients by BMI and weight loss category

Weight loss category

<5%
5–10%
>10%
Unavailable

BMI category (kg m−2)

 >20
30
18
9
12

 18.5–20
1
6
3
2

 <18.5
4
6
6
3

Values in bold indicate patients at high risk of malnutrition.

Discussion: The results show that a substantial proportion of HIV patients admitted to hospital are malnourished. Using a single measure of identifying patients at greatest risk of malnutrition (either BMI <18.5 kg m−2 or weight loss >10%) can underestimate the number of patients who may be at nutritional risk and require further nutritional assessment and possibly nutritional support.
Direct attachment of cell suspensions to high‐pressure freezing specimen planchettes
Authors: Sawaguchi A. , Yao X. , Forte J. G. , Mcdonald K. L.
Published: October 2003

We describe a procedure for high‐pressure freezing (HPF) of cultured cells using the HPF aluminium planchettes as a substrate. Cells are either grown directly on planchettes covered with Matrigel or allowed to attach to poly‐l‐lysine‐coated planchettes. This method allows for rapid transfer of the cells into the HPF and minimizes physical and physiological trauma to the cells. Furthermore, the yield of well‐frozen cells approaches 100% for every cell type we have tried so far. In this report, we show well‐preserved ultrastructure in mitotic and interphase HeLa cells, isolated gastric parietal cells and isolated gastric glands. Immunogold labelling of H+/K+‐ATPase is shown in parietal cells of isolated gastric glands embedded in LR White resin. The aluminium planchettes appear to have little effect on cell physiology, as demonstrated by the fact that parietal cells cultured for 24–28 h on the planchettes retain their responsiveness to stimulation with histamine.
Freeze‐substitution protocols for improved visualization of membranes in high‐pressure frozen samples
Authors: Giddings T. H.
Published: October 2003

Specimen preparation methods based on high‐pressure freezing and freeze‐substitution have enabled significant advances in the quality of morphological preservation of biological samples for electron microscopy. However, visualization of a subset of cellular membranes, particularly the endoplasmic reticulum and cis Golgi, is often impaired by a lack of contrast. By contrast, some efforts to increase membrane staining may lead to excessively granular staining. No one freeze‐substitution method has emerged that both overcomes these limitations and is suitable for all types of analysis. However, one or more of the following protocols, perhaps with minor modifica‐tions, should yield satisfactory results in most cases. Freeze‐substitution in glutaraldehyde and uranyl acetate in acetone, followed by embedding in Lowicryl HM20, generates samples suitable for both immunolocalization and high‐resolution structural studies. Membranes are typically lightly stained but very well defined. Initial freeze‐substitution in tannic acid and glutaraldehyde in acetone prior to exposure to osmium tetroxide significantly enhanced contrast on mammalian cellular membranes. Finally, initial trials indicate that freeze‐substitution in potassium permanganate in acetone can provide strong contrast on endoplasmic reticulum and Golgi as well as other membranes. The tendency of permanganate to degrade cytoskeletal elements and other proteins when employed in aqueous solutions at room temperature is apparently curtailed when it is used as a freeze‐substitution reagent.
The use of filter membranes for high‐pressure freezing of cell monolayers
Authors: Morphew M. K. , Mcintosh J. R.
Published: October 2003

Rapid freezing of cells and tissues, followed by freeze‐substitution fixation and plastic embedding, has become a highly reliable method for preparing samples for imaging in the electron microscope. High‐pressure freezing is an efficient means of immobilizing suspensions of yeasts, thick pellets of mammalian cells, or small (< 0.5 mm) pieces of plant or animal tissue. Monolayers of cultured mammalian cells that are too thick for efficient immobilization by other modes of rapid freezing have also been successfully preserved by this method. Monolayer cultures are often important because they can be imaged by light microscopy (LM) both before and after their preparation for electron microscopy (EM). Additionally, some monolayer cultures serve as model systems for physiological processes, so it is important that cells under study can grow on a substrate that is both physiologically appropriate and convenient for EM processing. Here we describe a reliable method for preparing mammalian cell monolayers (PtK1 and polarized MDCK) for EM. Our protocol results in good preservation of cellular ultrastructure, it is a useful companion to studies of cell physioloy and, with some limitation, is suitable for correlative LM and EM.
Recent progress in freeze‐fracturing of high‐pressure frozen samples
Authors: Walther P.
Published: October 2003

Pancreatic tissue, bacteria and lipid vesicles were high‐pressure frozen and freeze‐fractured. In addition to the normal holder, a new type of high‐pressure freezing holder was used that is particularly suitable for suspensions. This holder can take up an EM grid that has been dipped in the suspension and clamped in between two low‐mass copper platelets, as used for propane‐jet freezing. Both the standard and the new suspension holder allowed us to make cryo‐fractures without visible ice crystal damage. High‐pressure frozen rat pancreas tissue samples were cryo‐fractured and cryo‐sectioned with a new type diamond knife in the microtome of a freeze‐etching device. The bulk fracture faces and blockfaces were investigated in the frozen‐hydrated state by use of a cryo‐stage in an in‐lens SEM. Additional structures can be made visible by controlled sublimation of ice (‘etching’), leading to a better understanding of the three‐dimensional organization of organelles, such as the endoplasmic reticulum. With this approach, relevant biological structures can be investigated with a few nanometre resolution in a near life‐like state, preventing the artefacts associated with conventional fixation techniques.
Influence of aldehyde fixation on the morphology of endosomes and lysosomes: quantitative analysis and electron tomography
Authors: Murk J. L. A. N. , Posthuma G. , Koster A. J. , Geuze H. J. , Verkleij A. J. , Kleijmeer M. J. , Humbel B. M.
Published: October 2003

Cryoimmobilization is regarded as the most reliable method to preserve cellular ultrastructure for electron microscopic analysis, because it is both fast (milliseconds) and avoids the use of harmful chemicals on living cells. For immunolabelling studies samples have to be dehydrated by freeze‐substitution and embedded in a resin. Strangely, although most of the lipids are maintained, intracellular membranes such as endoplasmic reticulum, Golgi and mitochondrial membranes are often poorly contrasted and hardly visible. By contrast, Tokuyasu cryosectioning, based on chemical fixation with aldehydes is the best established and generally most efficient method for localization of proteins by immunogold labelling. Despite the invasive character of the aldehyde fixation, the Tokuyasu method yields a reasonably good ultrastructural preservation in combination with excellent membrane contrast. In some cases, however, dramatic differences in cellular ultrastructure, especially of membranous structures, could be revealed by comparison of the chemical with the cryofixation method. To make use of the advantages of the two different approaches a more general and quantitative knowledge of the influence of aldehyde fixation on ultrastructure is needed. Therefore, we have measured the size and shape of endosomes and lysosomes in high‐pressure frozen and aldehyde‐fixed cells and found that aldehyde fixation causes a significant deformation and reduction of endosomal volume without affecting the membrane length. There was no considerable influence on the lysosomes. Ultrastructural changes caused by aldehyde fixation are most dramatic for endosomes with tubular extensions, as could be visualized with electron tomography. The implications for the interpretation of immunogold localization studies on chemically fixed cells are discussed.
Lafoensia pacari extract inhibits IL‐5 production in toxocariasis
Authors: Rogerio A. P. , Sá‐Nunes A. , Albuquerque D. A. , Anibal F. F. , Medeiros A. I. , Machado E. R. , Souza A. O. , Prado J. C. , Faccioli L. H.
Published: October 2003

Toxocariasis is an infection induced by Toxocara canis, an intestinal parasite of dogs. In this study, an experimental murine model of toxocariasis was used to evaluate the anti‐inflammatory activity of an ethanolic extract of Lafoensia pacari stem bark. Mice infected with T. canis were treated with L. pacari extract (200 mg/kg, p.o.). Subsequently, we observed a reduction in the number of eosinophils in the peritoneal cavity, bronchoalveolar fluid, blood and bone marrow. Production of interleukin (IL)‐5, a major cytokine involved in eosinophilic differentiation, proliferation and activation, is also an important marker for infection. The reduced levels of IL‐5 observed in serum, lung homogenates and bronchoalveolar fluid demonstrated the anti‐inflammatory mechanisms of L. pacari. Larvae recovery from infected mice treated with L. pacari was comparable with that from untreated mice, suggesting that L. pacari is not toxic to the parasite. Nonetheless, our results demonstrate a potential therapeutic effect of L. pacari extract in IL‐5‐mediated inflammatory diseases and provide new prospects for the development of drugs to treat IL‐5‐dependent allergic diseases such as parasite infection and asthma.
Epidemic (human immunodeficiency virus‐related) Kaposi's sarcoma in West African women
Authors: Nnoruka Edith N.
Published: October 2003

Background  Most patients infected with human immunodeficiency virus (HIV) experience skin disease at some stage of their illness, either as a presenting feature or as a later manifestation. Different dermatoses may coexist during the course of the infection, and the unusual nature of the skin lesions can make an accurate diagnosis difficult. Kaposi's sarcoma is one of the acquired immunodeficiency syndrome (AIDS)‐defining skin diseases and may coexist with other lesions in AIDS patients. Kaposi's sarcoma is caused by human herpesvirus 8 (HHV8), which is mainly transmitted through male homosexual behavior, and is less common in women than in men.

Methods  The clinical, histopathologic, and therapeutic aspects of AIDS‐related Kaposi's sarcoma in three women (age, 18–34 years) who presented to the dermatology clinic of the University of Nigeria Teaching Hospital, Enugu, Nigeria, were studied over 18 months, beginning in August and September 1998.

Results  At presentation, the condition of the three patients was generally poor, with severe anemia and extensive dark‐brown papules, plaques, and nodules. Mucosal involvement was extensive. Generalized lymphadenopathy was found in two patients, one of whom had extensive coexisting dermatophytosis. All three women were in stage III/IV of the disease at the time of initial presentation. Death occurred within days in one and within 7–8 months in two.

Conclusions  Because these female patients with epidemic Kaposi's sarcoma lived in an almost entirely heterosexual population, the mode of contamination with HHV8 was obscure. The course of the disease was pervasive, aggressive, and devastating.
Comparison of trichloroacetic acid solution and cryosurgery in the treatment of solar lentigines
Authors: Lugo‐Janer Alexander , Lugo‐Somolinos Aida , Sanchez Jorge L.
Published: October 2003

Background  Solar lentigines are benign keratinocytic proliferations resulting from prolonged and cumulative sun exposure. The newer photoselective lasers have become the mainstay of treatment. However, cryosurgery and trichloroacetic acid (TCA) solution are cost‐effective alternatives in the treatment of solar lentigines.

Methods  Twenty‐five patients with multiple solar lentigines over the dorsa of their hands were included. Each hand was treated randomly with either 30% TCA solution or liquid nitrogen spray. The efficacy of treatment was evaluated at 8 weeks.

Results  Cryosurgery was more likely to produce significant lightening of the lentigines than 30% TCA solution (P < 0.05) but was more painful and took longer to heal.

Conclusion  Cryosurgery was found to be superior to TCA 30% solution in the treatment of solar lentigines. This study demonstrates that old‐fashioned treatments for solar lentigines are still excellent and cost‐effective therapeutic choices.
RNA‐binding properties of HCF152, an Arabidopsis PPR protein involved in the processing of chloroplast RNA
Authors: Nakamura Takahiro , Meierhoff Karin , Westhoff Peter , Schuster Gadi
Published: October 2003

The nonphotosynthetic mutant of Arabidopsis hcf152 is impaired in the processing of the chloroplast polycistronic transcript, psbB‐psbT‐psbH‐petB‐petD, resulting in nonproduction of the essential photosynthetic cytochrome b6f complex. The nucleus‐encoded HCF152gene was identified to encode a pentatricopeptide repeat (PPR) protein composed primarily of 12 PPR motifs, similar to other proteins of this family that were identified in mutants defected in chloroplast gene expression. To understand the molecular mechanism of how HCF152 modulates chloroplast gene expression, the molecular and biochemical properties should be revealed. To this end, HCF152 and several truncated versions were produced in bacteria and analyzed for RNA‐binding and protein–protein interaction. It was found that two HCF152 polypeptides bind to form a homodimer, and that this binding is impaired by a single amino acid substitute near the carboxyl terminus, replacing leucine with proline. Recombinant HCF152 bound with higher affinity RNA molecules, resembling the petB exon–intron junctions, as well as several other molecules. The highest affinity was found to RNA composed of the poly(A) sequence. When truncated proteins composed of different numbers of PPR motifs were analyzed for RNA‐binding, it was found that two PPR motifs were required for RNA‐binding, but had very low affinity. The affinity to RNA increased significantly when proteins composed of more PPR motifs were analyzed, displaying the highest affinity with the full‐length protein composed of 12 PPR motifs. Together, our data characterized the nuclear‐encoded HCF152 to be a chloroplast RNA‐binding protein that may be involved in the processing or stabilization of the petB transcript by binding to the exon–intron junctions.
Binding affinity of nonsteroidal ecdysone agonists against the ecdysone receptor complex determines the strength of their molting hormonal activity
Authors: Minakuchi Chieka , Nakagawa Yoshiaki , Kamimura Manabu , Miyagawa Hisashi
Published: October 2003

N‐tert‐Butyl‐N,N′‐dibenzoylhydrazine and its analogs are nonsteroidal ecdysone agonists that exhibit insect molting hormonal and larvicidal activities. The interaction mode of those ecdysone agonists with the heterodimer of the ecdysone receptor and ultraspiracle has not been fully elucidated. We expressed the ecdysone receptor B1 and the ultraspiracle of the lepidopteran, Chilo suppressalis, using an in vitro transcription/translation system and confirmed, using gel‐shift assays, that the proteins function as ecdysone receptors. We also analyzed their ligand‐binding affinity. A potent ecdysteroid, ponasterone A, specifically bound to the ecdysone receptor with low affinity (KD = 55 nm), and the specific binding was dramatically increased (KD = 1.2 nm) in the presence of the ultraspiracle. For seven nonsteroidal ecdysone agonists and five ecdysteroids, the binding activity to the in vitro‐translated ecdysone receptor–ultraspiracle complex was linearly correlated with the binding activity to the inherent receptor protein in the cell‐free preparation of C. suppressalis integument. The binding to the ecdysone receptor–ultraspiracle complex for a series of compounds was highly correlated with their molting hormonal activity, indicating that the binding affinity of nonsteroidal ecdysone agonists to the ecdysone receptor–ultraspiracle complex primarily determines the strength of their molting hormonal activity.
Fine‐scale habitat preferences and habitat partitioning by three mycophagous mammals in tropical wet sclerophyll forest, north‐eastern Australia
Authors: VERNES KARL
Published: October 2003

Abstract  Fine‐scale habitat preferences of three co‐occurring mycophagous mammals were examined in a tropical wet sclerophyll forest community in north‐eastern Australia. Two of the three mammal species responded to fine‐scale variation in vegetation and landform around individual trap locations. At a broad scale, the northern bettong (Bettongia tropica), an endangered marsupial endemic to the Australian wet tropics region, showed a preference for ridges over mid‐slopes and gullies, irrespective of forest type. In contrast, the northern brown bandicoot (Isoodon macrourus), a widespread marsupial, displayed a preference for Eucalyptus woodland over adjacent Allocasuarina forest, irrespective of topographic category. The giant white‐tailed rat (Uromys caudimaculatus), a rodent endemic to the wet tropics, showed no particular preference for either forest type or topographic category. A multiple regression model of mammal capture success against three principal habitat gradients constructed from 21 habitat variables using principal component analysis indicated strong species‐specific preferences for fine‐scale vegetation assemblages. Bettongs preferred areas of Eucalyptus woodland with sparse ground cover, low densities of certain grass species, high density of tree stems and few pig diggings. Bandicoots, in contrast, favoured areas in both forest types with dense ground cover, fewer tree stems and greater numbers of pig diggings; that is, characteristics least favoured by bettongs. The striking differences in fine‐scale habitat preferences of these two mammals of similar body size and broad habitat requirements suggest a high degree of fine‐scale habitat partitioning. White‐tailed rats did not show preference for any of the habitat gradients examined.
Patterns of resource allocation in the dioecious alpine herb Aciphylla simplicifolia (Apiaceae)
Authors: PICKERING CATHERINE MARINA , ARTHUR JAMES MICHAEL
Published: October 2003

Abstract Patterns of reproductive and vegetative biomass allocation were compared in male and female plants of the alpine herb Aciphylla simplicifolia. Male and female plants had similar vegetative biomass but differed in the pattern of resource allocation. Inflorescences of males and females were similar in weight at the time of flowering, but differed in biomass allocation to some structures within the inflorescences, particularly those associated with ovule production and pollinator attraction (number and size of flowers). At the time of fruit production, female inflorescences were 2.6 times heavier than at flowering with developing fruit six times heavier than flowers. In addition to the increase in biomass allocated to structures associated with the provisioning and dissemination of seed, support structures (main and side stalks) were also heavier. As a result of this additional investment of resources at the time of fruit production, the reproductive effort (RE) of female plants was much higher than that of males: 37% of above ground biomass compared with 21% for males. Differences in RE did not change with plant size; however, allocation to reproduction appeared to be a constant proportion of biomass over nearly all plant sizes sampled. These results show that sex‐specific resource allocation can be a complex of temporal and morphological patterns.
Combined Use of Transesophageal ECHO and Fluoroscopy for the Placement of Left Ventricular Pacing Leads via the Coronary Sinus
Authors: BASHIR JAMIL G. , FRANK G. , TYERS O. , LAMPA MARTIN , YAMAOKA RANDI
Published: October 2003

Biventricular pacing is an emerging technology for treatment of congestive heart failure. Left ventricular leads are most commonly placed through the coronary sinus (CS) into an epicardial coronary vein. Cannulation of the CS can be difficult and standard guiding catheters have a tendency to displace during lead advancement. This study found that transesophageal echocardiography facilitated CS cannulation in complex cases requiring antecedent lead extraction. (PACE 2003; 26:1951–1954)
Filtered QRS Duration on Signal‐Averaged Electrocardiography Predicts Inducibility of Ventricular Tachycardia in Arrhythmogenic Right Ventricle Dysplasia
Authors: NASIR KHURRAM , TANDRI HARIKRISHNA , RUTBERG JULIE , TICHNELL CRYSTAL , SPEVAK PHIL , CROSSAN JANE , BAUGHMAN KENNETH L. , KASPER EDWARD K. , TOMASELLI GORDON F. , BERGER RONALD , CALKINS HUGH
Published: October 2003

Treatment of arrhythmogenic right ventricular dysplasia (ARVD) is mostly based on the prevention of sudden cardiac death that results from arrhythmias. A clinical history suggestive of ARVD requires careful evaluation including electrophysiological study. The potential ability to identify those patients who will have inducible VT with electrophysiological study will enable better risk stratification and selection of vulnerable patients for electrophysiologically guided therapy. The purpose of the study was to evaluate the predictive ability of signal‐averaged electrocardiography (SAECG) to predict inducibility of VT in patients with ARVD. The patient population consisted of 31 ARVD patients diagnosed with McKenna's criteria who underwent electrophysiological study. Electrophysiological study was considered positive if sustained monomorphic VT was induced. The sensitivity, specificity, and predictive accuracy of various SAECG criteria for inducibility of sustained monomorphic VT were also calculated. Twenty‐one patients had inducible VT. The filtered QRS duration (fQRS), duration of signal <40 uV (LAS40), and root mean square voltage in the last 40 ms of QRS duration (RMS40) in ARVD patients induced versus noninduced were 122 ± 21 and 103 ± 8 ms (P = 0.007), 45 ± 20 and 28 ± 14 ms (P = 0.02), 19 ± 19 and 32 ± 22 uV (0.03), respectively. The ejection fractions were comparable in both groups. fQRS duration ≥110 ms had sensitivity of 91%, specificity of 90%, and a total predictive accuracy of 90% in predicting inducibility of VT in these patients. Filtered QRS duration on SAECG is predictive of electrophysiological study outcome in ARVD. Further studies will be needed to determine if SAECG results can predict the development of ventricular arrhythmias during follow‐up. (PACE 2003; 26:1955–1960)