bluuebunny/crossref_metadata_2025 huggingface dataset:
Cyclooxygenase expression in splanchnic hyposensitivity to glypressin of bleeding portal hypertensive rats
Authors: Huang H.‐C. , Wang S.‐S. , Chen Y.‐C. , Lee F.‐Y. , Chang F.‐Y. , Lin H.‐C. , Hou M.‐C. , Chan C.‐C. , Chen C.‐T. , Wu S.‐L. , Lee S.‐D.
Published: June 2003

Background Prostacyclin mediates, at least partly, the splanchnic vascular hyporesponsiveness to glypressin in bleeding portal hypertensive rats. This study investigated the relative contribution of cyclooxygenase‐1 (COX‐1) and cyclooxygenase‐2 (COX‐2) in the splanchnic hyposensitivity to glypressin in rats with portal hypertension induced by partial portal vein ligation (PVL).

Methods Fourteen days after the operation, the rats were divided into without‐ and with‐bleeding groups. Three series of PVL rats were used to investigate (i) the haemodynamic effects of glypressin (0·07 mg kg−1 intravenously), (ii) COX‐1/COX‐2 mRNA expression over abdominal aorta and superior mesenteric artery and (iii) plasma levels of 6‐keto‐prostaglandin‐F1α. In rats with a hypotensive haemorrhage, 4·5 mL of blood was withdrawn and 50% of the withdrawn blood was re‐infused before blood and vessel sampling or the administration of glypressin.

Results Splanchnic hyposensitivity to glypressin was demonstrated in the haemorrhage‐transfused PVL rats with enhanced COX‐1 expression of superior mesenteric artery and increased plasma levels of 6‐keto‐prostaglandin‐F1α. There were no differences in the COX‐2 expression of superior mesenteric artery and COX‐1 and COX‐2 expressions of abdominal aorta between without‐ and with‐bleeding groups.

Conclusion In portal hypertensive rats with acute haemorrhage, COX‐1 over‐expression in the superior mesenteric artery plays a role in mediating the splanchnic hyposensitivity to glypressin.
Fatty acids modulate the effect of darglitazone on macrophage CD36 expression
Authors: Svensson L. , Camejo G. , Cabré A. , Vallvé J.‐C. , Pedreño J. , Norén K. , Wiklund O. , Hultén L. M.
Published: June 2003

Background Scavenger receptor‐mediated uptake of cholesterol by macrophages in the arterial wall is believed to be proatherogenic. Thiazolidinediones are peroxisome proliferator‐activated receptor γ (PPARγ)‐agonists, which are used in the treatment of type II diabetes. They reduce atherogenesis in LDL receptor deficient and ApoE knockout mice, but up‐regulate CD36, which may contribute to foam cell formation. The dyslipidaemia in type II diabetes is characterized by high levels of nonesterified fatty acids. Therefore we tested the effect of fatty acids and how fatty acids and the thiazolidinedione darglitazone interact in their effect on CD36 expression in human monocytes and macrophages.

Materials and methods Flow cytometry and reverse transcription‐polymerase chain reaction were used to study CD36 expression. Cellular lipids were analyzed with high performance liquid chromatography.

Results Darglitazone increased CD36 mRNA and protein expression in human macrophage cells. In the presence of 5% human serum, darglitazone increased the accumulation of triglycerides, but did not affect cholesterol ester levels. In the presence of albumin‐bound oleic or linoleic acid, darglitazone did not increase CD36 mRNA, cell‐surface CD36 protein or triglyceride content. Fatty acids per se increased CD36 mRNA and protein.

Discussion The increase in CD36 in macrophages suggests a role for fatty acids in the regulation of foam cell formation. The results also suggest that the potentially proatherogenic CD36 up‐regulating effect of thiazolidinediones in macrophages might not be present when the cells have access to physiological levels of albumin‐bound fatty acids.
Natural killer receptor repertoires in transplantation
Authors: Jones D. C. , Young N. T.
Published: June 2003

Natural killer (NK) lymphocytes are potent effector cells that are controlled by the expression of a variety of cell surface receptors with either inhibitory or activating functions. The genetic and functional diversity of this receptor repertoire and the role of HLA class I molecules as a major group of NK receptor ligands create an innate alloreactive capacity in this cell type. Both animal models and in vitro studies have implicated NK cells as contributors to the pathology of clinical transplantation. However, recent clinical studies have indicated the potential benefit of exploiting NK cell alloreactivity in mismatched haematopoietic stem cell transplantation. Further investigations of NK cell alloreactivity will undoubtedly reveal additional applications of this fundamental cell type in clinical transplantation.
Association of ABO histo‐blood group B allele with myocardial infarction
Authors: Nydegger U. E. , Wuillemin W. A. , Julmy F. , Meyer B. J. , Carrel T. P.
Published: June 2003

To investigate a possible association of ABO blood group alleles with myocardial infarction, a case–control study comprising 177 patients (median age 57.0 years; range 32–72 years) and 89 controls was performed. The distributions of the ABO blood‐genotype O1, O2, A1, A2 and B alleles were assessed by analysis of genomic DNA, using the sequence‐specific primer–polymerase chain reaction (PCR‐SSP) technique to investigate exons VI and VII on chromosome 9. The prevalence of the B allele was 2.5 times higher amongst patients with a history of myocardial infarction than amongst controls (16.3 vs. 6.7%; P = 0.034, Fisher's exact test). There was an association between patients carrying the B allele and myocardial infarction, with an odds ratio (OR) of 2.7 (95% confidence interval 1.1–6.8). The B allele remained an independent risk factor for myocardial infarction (P = 0.038) when classical risk factors were adjusted for by unconditional logistic regression. In conclusion, the ABO blood group B allele was found to be an independent risk factor for myocardial infarction.
Different roles of proteolipids and 70‐kDa subunits of V‐ATPase in growth and death of cultured human cells
Authors: Zhan Hong , Yokoyama Ken , Otani Hajime , Tanigaki Keiji , Shirota Naomi , Takano Syuichi , Ohkuma Shoji
Published: June 2003

Background: The vacuolar‐type proton‐translocating adenosine triphosphatase (V‐ATPase) plays important roles in cell growth and tumour progression. V‐ATPase is composed of two distinct structures, a hydrophilic catalytic cytosolic sector (V1) and a hydrophobic transmembrane sector (V0). The V1 sector is composed of 5–8 different subunits with the structure A3B3C1D1E1F1G1H1. The V0 sector is composed of 5 different subunits with the structure 1161381191166. The over‐expression of 16‐kDa proteolipid subunit of V‐ATPase in the perinuclear region of the human adventitial fibroblasts promotes phenotypic modulation that contributes to neointimal formation and medial thickening. A relationship between oncogenicity and the expression of the 16‐kDa proteolipid has also been suggested in human pancreatic carcinoma tissue.

Results: We found that the mRNA levels of the 16‐kDa proteolipid but not of the 70‐kDa subunit of V‐ATPase in human myofibroblasts were more abundant in serum‐containing medium (MF(+) cells) than serum‐free medium (MF(–) cells). In HeLa cells, the levels of mRNA and protein of the 16‐kDa, 21‐kDa or 70‐kDa were clearly suppressed when the corresponding anti‐sense oligonucleotides were administered to the culture medium. The growth rate and viability (mostly due to necrosis) of HeLa cells were reduced markedly by the 16‐kDa and 21‐kDa anti‐sense, but little by the 70‐kDa anti‐sense, and not at all by any sense oligonucleotides. The localization of 16‐kDa/21‐kDa proteolipid subunits was different from that of the 70‐kDa subunit in HeLa cells.

Conclusion: These results suggest that the 16‐kDa and 21‐kDa proteolipid subunits of the V0 sector play crucial roles in growth and death of cultured human cells. Our results may provide new insights into the mechanism and therapeutic implications for vessel wall hyperplasia and tumorigenesis.
Transmembrane topology of sphingoid long‐chain base‐1‐phosphate phosphatase, Lcb3p
Authors: Kihara Akio , Sano Takamitsu , Iwaki Soichiro , Igarashi Yasuyuki
Published: June 2003

Background: Sphingoid long‐chain base‐1‐phosphates (LCBPs) are thought to act as intracellular signalling molecules in yeast. Lcb3p is a member of the LCBPs‐specific phosphatase family (SPP family). Other yeast phosphatases, Lpp1p and Dpp1p, are members of a different lipid phosphatase family (LPP family) known to exhibit broader substrate specificities. Until now, only the membrane topology of mammalian LPP family members has been reported, whereas that of the SPP family has remained unclear.

Results: In our in vitro system, Lcb3p displayed major phosphatase activity against dihydrosphingosine‐1‐phosphate, while Dpp1p and Lpp1p also exhibited activities. Here, we determined that Lpp1p and Dpp1p exhibit the topology common to the LPP family. Moreover, we examined the transmembrane topology of Lcb3p using a C‐terminal reporter approach. From our results we deduced a structural model illustrating that Lcb3p has eight membrane‐spanning domains with its highly conserved phosphatase motifs positioned within the endoplasmic reticulum (ER) lumen. Consistent with this result, Lcb3p collected in low speed pellet fractions was highly resistant to exogenous proteinase K unless the membrane was disrupted.

Conclusion: Our results suggest that the active site of Lcb3p is located in the ER lumen and, thus, the phosphate group of the LCBP is hydrolysed on the lumenal side.
Overlapping omt1+ and omt2+ genes are required for spore wall maturation in Schizosaccharomyces pombe
Authors: Kakihara Yoshito , Nabeshima Kentaro , Hirata Aiko , Nojima Hiroshi
Published: June 2003

Background: Overlapping genes that are transcribed from the same genomic regions are rare in eukaryotes and to date few detailed functional analyses have been reported.

Results: We report here three novel overlapping transcripts that are specifically expressed during meiosis of Schizosaccharomyces pombe. They are denoted as omt1+, omt2+ and omt3+ after overlapping meiotic transcripts. omt1+ encodes a 12‐kDa protein and omt2+ encodes a 11‐kDa protein with homology to the bifunctional mammalian protein DCoH/PCBD. omt3+ does not have a significant open reading frame. The omt2+ transcript overlaps with both the omt1+ and omt3+ transcripts but the latter two transcripts do not overlap. omt1Δ and omt2Δ but not omt3Δ failed to form mature spore walls. The Omt1‐GFP and Omt2‐GFP fusion proteins localized to the outside and the inside of the spore walls, respectively. The sporulation‐specific protein Meu10 and the spore wall components were abnormally localized in the spore walls of omt1Δ and omt2Δ.

Conclusion: The overlapping genes omt1+ and omt2+ express functional proteins that participate in spore wall maturation, indicating that gene overlap does not affect the physiological functions of the proteins encoded by these genes. Generation of overlapped RNA may be due to loose regulation of transcription termination during meiosis of S. pombe.
A novel rabconnectin‐3‐binding protein that directly binds a GDP/GTP exchange protein for Rab3A small G protein implicated in Ca2+‐dependent exocytosis of neurotransmitter
Authors: Kawabe Hiroshi , Sakisaka Toshiaki , Yasumi Masato , Shingai Tatsushi , Izumi Genkichi , Nagano Fumiko , Deguchi‐Tawarada Maki , Takeuchi Masakazu , Nakanishi Hiroyuki , Takai Yoshimi
Published: June 2003

Background: Rab3A, a member of the Rab3 small G protein family, regulates Ca2+‐dependent exocytosis of neurotransmitter. The cyclical activation and inactivation of Rab3A are essential for the Rab3A action in exocytosis. GDP‐Rab3A is activated to GTP‐Rab3A by Rab3 GDP/GTP exchange protein (Rab3 GEP) and GTP‐Rab3A is inactivated to GDP‐Rab3A by Rab3 GTPase‐activating protein (Rab3 GAP). We have recently found a novel protein, named rabconnectin‐3, which is co‐immunoprecipitated with Rab3 GEP or GAP from the extract of the crude synaptic vesicle (CSV) fraction of rat brain. Rabconnectin‐3 is abundantly expressed in the brain where it is associated with synaptic vesicles. We have found that two more proteins are co‐immunoprecipitated with Rab3 GEP from the CSV fraction of rat brain. We attempted here to isolate and characterize one of them.

Results: We determined its partial amino acid sequence, cloned its cDNA from a human cDNA library, and determined its primary structure. The protein consisted of 1490 amino acids (aa) and showed a calculated molecular weight of 163 808. The protein had 7 WD domains. The protein was abundantly expressed in the brain where it co‐localized with rabconnectin‐3 on synaptic vesicles. The protein formed a stable complex with rabconnectin‐3. We named this protein rabconnectin‐3β and renamed rabconnectin‐3 rabconnectin‐3α. Rabconnectin‐3β, but not rabconnectin‐3α, directly bound Rab3 GEP. Neither rabconnectin‐3α nor ‐3β directly bound Rab3 GAP.

Conclusion: These results indicate that rabconnectin‐3 consists of the α and β subunits and binds directly Rab3 GEP through the β subunit and indirectly Rab3 GAP through an unidentified molecule(s).
Thai nurses' beliefs about breastfeeding and postpartum practices
Authors: Kaewsarn Pattaya , Moyle Wendy , Creedy Debra
Published: June 2003

• Cultural beliefs are important determinants of health care behaviours. Nurses have an important influence on infant feeding decisions and maternal postpartum care, but little is known about the extent to which their practice is influenced by traditional beliefs and/or recent innovations driven by evidence‐based research.

• The aim of this study was to investigate Thai nurses' traditional beliefs about breastfeeding and related postpartum care, and their impact on nursing practice.

• A survey of 372 nurses working in hospitals and health services in Ubon Ratchathani, Thailand was undertaken. Questionnaire items were developed from a review of the literature and exploratory interviews with Thai women. Descriptive statistics were used to represent the incidence of particular beliefs and behaviours. Chi‐square analyses were conducted to determine relationships between demographic characteristics and traditional beliefs and practices.

• There were discrepancies between nurses' beliefs and contemporary evidence‐based practices. Many nurses supported traditional Thai postpartum practices such as food restrictions and encouraging hot baths. Some traditional beliefs supported by nurses may be detrimental to women and babies such as ‘lying by fire’, discarding of colostrum, and giving boiled water to neonates. Only half the nurses reported that they encouraged mothers to breastfeed immediately following birth.

• The study was undertaken in the North‐East of Thailand, where the population is known to have strong belief systems. Reliability and content validity of the tool would be enhanced through replication studies and qualitative investigations of other breastfeeding issues.

• There is a need for professional development strategies such as peer review and mentoring to address inadequate knowledge and outdated practices of some health professionals, as well as continuity of care models to assess quality care outcomes that are culturally appropriate.
Immediate needs of adult family members of adult intensive care patients in Hong Kong
Authors: Yin King Lee Linda , Lau Yee Ling
Published: June 2003

• Having a family member admitted to Intensive Care Unit (ICU) is stressful for the whole family. Stress can hinder family members' coping and thus affect the support that is given to patient. In order to lessen the effect of stress, family members' immediate needs must be identified and met.

• The aim of this study was to explore the immediate needs of adult family members of adult intensive care patients in Hong Kong.

• The study adopted a descriptive cross‐sectional design. The Chinese version of Critical Care Family Need Inventory (CCFNI) was used to investigate the immediate needs of a convenience sample of 40 adult family members of patients in an adult ICU. Data were collected through personal interviews within 24–72 hours of patients' admission.

• Findings revealed that 25 out of 45 need items on the CCFNI that were rated as important or very important. The need ‘to know the expected outcome’ was ranked as the most important.

• All the needs related to reassurance were ranked within the top 10 important needs. The top 10 important needs were met by doctors and nurses.

• There were significant differences in needs between family members with different gender, experience of visiting ICUs, religious background and characteristics of patients.

• The findings suggest that family members perceived reassurance and information support as important. Although this study was limited by using a small convenience sample, the findings could still provide insight for nurses working in ICUs.
Nurses' attitudes towards perinatal bereavement support in Hong Kong: a pilot study
Authors: Chan Moon Fai , Chan Suk Hing , Day Mary Christine
Published: June 2003

• The purpose of this study is to explore nurses' attitudes towards perinatal bereavement care and to identify required support and training needs for nurses on bereavement care in Hong Kong.

• Data were collected through a structured questionnaire, and 110 nurses were recruited from the obstetrics and gynaecology unit in one of the largest public hospitals in Hong Kong.

• The majority of nurses held a positive attitude towards bereavement care. A significant difference in nurses' attitudes towards bereavement support was found in terms of demographics, practical experiences and training factors.

• The results showed that only 25.5% (n = 28) of nurses had bereavement‐related training. In contrast, 90.9% of nurses showed a positive response to grief training and 90.0% would share experiences with colleagues and seek support when feeling under stress.

• The findings also suggest that nurses' attitudes towards bereavement care are positively correlated with bereavement care training needs (r = 0.53) and hospital policy support (r = 0.55).

• Hong Kong nurses' attitudes towards perinatal care emphasized their need for increased knowledge and experience, improved communication skills, and greater support from team members and the hospital. These findings may be used for Hong Kong health care professionals to improve support of nurses, to ensure delivery of sensitive bereavement care in perinatal settings and to enhance nursing school curricula.
A prospective, randomized study of ventilator‐associated pneumonia in patients using a closed vs. open suction system
Authors: Salloum Zeitoun Sandra , Botura Leite De Barros Alba Lúcia , Diccini Solange
Published: June 2003

• The objective of this study was to verify the incidence of nosocomial pneumonia in intubated and extended mechanically ventilated patients having endotracheal suctioning by an open vs. closed suction method aiming to decrease nosocomial pneumonia.

• Twenty‐four (51.1%) patients received open‐tracheal suction and 23 (48.9%) received closed‐tracheal suction. The inclusion criteria were: surgical and medical patients older than 13 years, undergoing mechanical ventilation for more than 48 hours. Additional data were gathered using the Acute Physiology and Chronic Health Evaluation II, and details on smoking, alcoholism, diabetes mellitus, renal failure, previous lung disease, and previous use of antibiotics, steroids, H2 antagonists and antacids.

• Among the 24 patients having open‐tracheal suction, 11 developed nosocomial pneumonia while of the 23 patients undergoing closed‐tracheal suction, seven developed infection (P = 0.278). Risk factors for nosocomial pneumonia were not significantly different between the two groups. In the final logistical regression model the following variables remained: groups (open and closed) [odds ratio (OR) = 0.014; confidence interval (CI) = 0.001–0.416; P = 0.014] and use of prior antibiotics (OR = 2.297; CI = 1.244–4.242; P = 0.008).

• Use of a closed suction system did not decrease the incidence of nosocomial pneumonia when compared with the open system. The exogenous risk factors were the most important for acquiring this infection.
Postoperative cognitive changes among older Taiwanese patients
Authors: Lou Meei‐Fang , Dai Yu‐Tzu , Huang Guey‐Shiun , Yu Po‐Jui
Published: June 2003

• The purpose of the study was to describe variations in cognitive/behavioural changes during the course of delirium among older Taiwanese patients after elective surgery.

• A total of 106 patients assessed four times (admission, onset of delirium, delirium day 3 and delirium day 5) by the Mini Mental State Examination (MMSE) were included in the analysis to understand the neurocognitive/behaviour change during the course of delirium.

• Repeated measures anova was used to analyse within‐subject differences across these four time points for those who became delirious and those who did not.

• The findings showed that patients who experienced delirium had significantly (P < 0.01) lower MMSE scores than non‐delirious patients. Scores for the delirious group were also significantly different across the four assessments (P < 0.01) within the group. The subscales of orientation to time, orientation to place, registration and recall were the major changes from time 1 (admission assessment) to time 2 (onset of delirium) for delirious patients. When scores for time 4 (delirium day 5) and time 1 (admission assessment) were compared, the subscales of orientation to time, orientation to place and visual construction showed the least improvement among the subscales at time 4.

• The findings of the study suggest that mental status assessments are important during the patient's admission and hospital stay. The repeated assessments can be incorporated into routine nursing care so that problems can be detected and appropriate nursing care implemented.
Finnish nurses' views on their research activities
Authors: Kuuppelomäki Merja , Tuomi Jouni
Published: June 2003

• The purpose of the study reported here was to describe Finnish nurses' research and publication activities, as well as their views on the availability and utilization of research results in nursing practice.

• The data were collected using a structured questionnaire in which obstacles to the utilization of research results were measured with a previously developed instrument. A total of 400 nurses from community health centres, a central hospital and a central university hospital took part.

• Most of the nurses had carried out research on their own. Age, experience, training in research and development and other further training, as well as reading the nursing literature, were associated with doing research. Some of the reasons why the nurses had not carried out research were revealed. Publication of results was very rare. There were problems with the availability of research results.

• The most common obstacles to research utilization had to do with the presentation of results and the setting. In research utilization, respondents received most support from the ward manager and least support from doctors.

• If we want to encourage nurses to do research and increase the utilization of research results, greater effort should be invested in teaching research methodology, in introducing more flexible working hours and in developing other support systems.
Power imbalance between nurses and patients: a potential inhibitor of partnership in care
Authors: Henderson Saras
Published: June 2003

• The Patient's Charter identifies the need for nurses to respect patients' rights to influence their care, and contemporary nursing practice advocates that nurses work in partnership with patients. Hence nurses are encouraged to share their power and facilitate empowerment in their patients by giving them information and support.

• However, the literature indicates that nurses are not very successful in making patients feel empowered to make informed decisions. This study, conducted in 1998, provides some answers as to why this may be the case.

• The aim of the study was to explore and describe nurses' and patients' views regarding partnership in care in hospital.

• Using the grounded theory approach, participants were drawn from four hospitals in Western Australia. A purposive sample of 33 nurses and 32 patients were interviewed in‐depth. Participant observation was also conducted and field notes were written. The interviews were transcribed verbatim and analysed using the constant comparative method.

• The findings showed that nurses viewed involving patients in care as requiring them to give patients information and to share their decision‐making powers with them. With the exception of a few, the majority of nurses were unwilling to share their decision‐making powers.

• This created a situation of power imbalance with subsequent little patient input. Factors identified included nurses' beliefs that they ‘know best’, the view that patients lacked medical knowledge and the perceived need for nurses to hold onto their power and maintain control.

• If nurses and patients are to work as partners, it is important that nurses make every effort to equalize the power imbalance. One way to do this is for nurses to share and give information to patients readily and to be open in their communication with them.
Fine‐scale environmental variation and structure of understorey plant communities in two old‐growth pine forests
Authors: Frelich Lee E. , Machado José‐Luis , Reich Peter B.
Published: June 2003

Although it is well established that nitrogen and light play major roles in structuring plant communities across the landscape, it is not as clear how they structure communities within forest stands. Virtually nothing is known about within‐stand structure of understorey communities of herbs and small shrubs in near‐boreal forests.

We tested the hypothesis that fine‐scale (5–20 m) variability in N and light structure forest‐floor plant communities in two old‐growth mixed Pinus resinosa and Pinus strobus forests in north‐eastern Minnesota, USA.

In each forest, all trees > 1.4 m tall were mapped on a 0.75–1.0 ha area. A grid of subplots 5–10 m apart was established (total n = 147), and N mineralization (µg g−1 soil day−1), soil depth (cm), light (% canopy openness), and percentage cover of all herbs and small shrubs were measured on each subplot.

Cluster analysis showed that the dominant understorey species fall into three groups. Group 1 is unrelated to N and light, and is negatively associated with a midstorey of the small tree Acer rubrum and the most abundant tall shrub Corylus cornuta. Group 2 reaches maximum abundance in places (mostly gaps) with relatively high light, but is unrelated to within‐stand variation in N availability. Group 3 consists of a single species, Aster macrophyllus, and reaches maximum abundance in areas with low N availability and low abundance of Corylus, but higher than average abundance of P. strobus and Betula papyrifera overstorey trees.

N and light have a moderate influence on understorey plant community structure. The plant species do arrange themselves along N and light gradients, but the gradients are likely to be too narrow to allow the degree of differentiation seen at the landscape level. Spatial patterning of the species groups is probably influenced by other factors, including disturbance history, chance and neighbourhood effects such as clonal reproduction.
Resprouting of woody saplings following stem snap by wild pigs in a Malaysian rain forest
Authors: Ickes Kalan , Dewalt Saara J. , Thomas Sean C.
Published: June 2003

The lowland rain forest at Pasoh Forest Reserve in Peninsular Malaysia is subject to disturbance by native wild pigs (Sus scrofa). Female pigs snap off woody plants up to 3.5 m tall to construct nests for reproduction, damaging >170 000 saplings km−2 year−2. We investigated the ability of 1808 woody saplings to survive and resprout over a 3‐year period following pig and experimental stem snap.

Most plants resprouted to some degree, but, in understorey conditions, growth of new shoots was slow. More than 90% of stems were alive 3 months after damage, but > 40% had not yet produced a single fully expanded leaf. Mortality at 36 months was higher for resprouting saplings (33%) than for undamaged control saplings (9%). Survival of damaged stems was highly and positively correlated with stump basal diameter. Canopy species consistently showed lower survivorship than midstorey, understorey and treelet species but no differences in survivorship were found for habit (tree vs. liana) or leaf morphology (simple vs. compound).

The number and total length of resprout shoots (TSL) were strongly, positively correlated with stump diameter. Canopy species produced greater TSL but fewer new shoots than did smaller‐stature species. Trees and lianas produced similar TSL at 3 and 6 months, but trees produced more TSL at 12 and 36 months. Simple‐leaved plants consistently had longer TSL than compound‐leaved plants.

Both species and families differed greatly in terms of survival, TSL and number of shoots. Dipterocarpaceae, which comprises 24% of basal area in the forest, and Euphorbiaceae, the most species‐rich family, had especially poor survivorship of damaged individuals.

Our results suggest that elevated pig densities found in small forest reserves such as Pasoh are likely to alter tree community composition as a result of the differential ability of species to regenerate following physical disturbance. Regeneration of canopy tree species, particularly in the silviculturally important and heavily dominant family Dipterocarpaceae, may be particularly susceptible to pig‐related disturbance.
Near‐field Raman spectroscopy using a sharp metal tip
Authors: Hartschuh A. , Anderson N. , Novotny L.
Published: June 2003

Near‐field Raman spectroscopy with a spatial resolution of 20 nm is demonstrated by raster scanning a sharp metal tip over the sample surface. The method is used to image vibrational modes of single‐walled carbon nanotubes. By combining optical and topographical signals rendered by the single‐walled carbon nanotubes, we can separate near‐field and far‐field contributions and quantify the observed Raman enhancement factors.
The effects of probe boundary conditions and propagation on nano‐Raman spectroscopy
Authors: Hallen H. D. , Ayars E. J. , Jahncke C. L.
Published: June 2003

Raman spectra obtained in the near‐field, with collection of the Raman‐shifted light in reflection, show selective enhancement of vibrational modes. We show that the boundary conditions for an electric field near a metal surface affect propagation of the reflected signal and lead to this selection. The enhancement of certain Raman forbidden vibrations is explained by the presence of an electric field gradient near the metal‐apertured fibre probe.
Electrodynamic interaction between two atoms in near‐field contact
Authors: Broe J. , Keller O.
Published: June 2003

A theoretical study of elements of the quantum electrodynamic interaction between two single‐electron atoms in near‐field contact is presented. The framework of the study is an electromagnetic propagator formalism that allows one to describe the near‐field space–time interaction in such a manner that the Einstein causality and lack of photon localizability are manifest. First we set up the atom‐field Hamiltonian in the so‐called G‐gauge, starting from the Coulomb Hamiltonian, and thereafter we show that this leads to a correct propagator description for the retarded part of the transverse electromagnetic field (operator). In the G‐gauge approach, renormalization of the two‐particle energy level structure stemming from the transverse self‐field occurs. The intraparticle renormalization is calculated for a three‐level atom (it is trivial for a two‐level atom), and the interparticle renormalization, which depends on the atomic separation, is determined for two two‐level atoms. The magnitude of the energy renormalization is always finite in our theory because we do not consider the atoms to be point‐like objects from an electromagnetic point of view. Throughout, we relate our G‐gauge formalism to the multipole theory often used in studies of interatomic electrodynamics.
Propagation of surface plasmon polariton in nanometre‐sized metal‐clad optical waveguides
Authors: Onuki T. , Watanabe Y. , Nishio K. , Tsuchiya T. , Tani T. , Tokizaki T.
Published: June 2003

Using a local anodic‐oxidation method with a probe tip of a scanning near‐field optical microscope (SNOM) as the electrode, we have fabricated an oxide core with subwavelength dimensions on metal. The propagation of the surface plasmon polariton (SPP), which is excited at the interface between the oxide core and the metal clad, has been investigated using the same SNOM. Altering the wavelength of input light from 532 nm to 830 nm, the propagation length of the SPP extends from 2 µm to 6 µm. We carried out a simulation of the SPP propagation, and obtained a similar wavelength dependence.
Optical switching due to whispering gallery modes in dielectric microspheres coated by a Kerr material
Authors: Haraguchi M. , Fukui M. , Tamaki Y. , Okamoto T.
Published: June 2003

We numerically evaluated the optical responses of a nonlinear microsphere put on prisms, i.e. in prism‐coupling geometry where the incident light excites the WGM through near‐field coupling. As numerical calculations, we employed the finite‐difference time‐domain method taking into account Kerr nonlinearity. The sphere was coated by a Kerr material with 160 nm thick. The third‐order nonlinear susceptibility of the Kerr material χ(3) was assumed to be 7 × 10−14[m2 V−2]. The diameter of the sphere was assumed to be 1 µm. The numerical results have shown that the control and/or the signal lights can induce the optical switching‐like variation in the reflectance. Such a nonlinear response of the sphere has been interpreted by the variation in the dielectric constant of the sphere due to a Kerr nonlinearity.
Magneto‐optical near‐field microscopy of ultrathin films in ultrahigh vacuum
Authors: MeYer G. , CreCelius T. , BaUer A. , WeGner D. , MaUch I. , KaIndl G.
Published: June 2003

We demonstrate that magnetic domains of ultrathin films can be imaged in situ in ultrahigh vacuum (UHV) by scanning near‐field optical microscopy in combination with a Sagnac interferometer (Sagnac‐SNOM). In the present set‐up, the Sagnac interferometer is not only used for measuring the magneto‐optical Kerr effect but also for tip‐to‐sample distance control. The high sensitivity of the instrument enabled us to study the magnetization reversal processes in externally applied magnetic fields in ultrathin films of Fe and Ni grown on Cu(100) single crystals.
A method for controlling the spins of atoms using optical near‐fields
Authors: Shojiguchi A. , Kitahara K. , Kobayashi K. , Ohtsu M.
Published: June 2003

On the basis of the procedure for controlling the spins of atoms using circularly polarized evanescent light proposed by Hori et al.[(1996) Abstracts of the 1st Asia‐Pacific Workshop on Near‐field Optics] we discuss the influence of boundary conditions on the probability of spontaneous emission and thus on the spin polarization efficiency, which was not considered in the Hori et al. study. Using the Carniglia–Mandel mode expansion of electromagnetic fields, we derive the spontaneous emission and spin polarization probabilities of atoms near a dielectric surface, and show the atom–surface distance dependence and refractive index dependence. Numerical evaluation for the 6P1/2–6S1/2 transition of a Cs atom indicates an increase in the efficiency of spin polarization by 30%.
Apertureless near‐field Raman spectroscopy
Authors: Wang J. J. , Smith D. A. , Batchelder D. N. , Saito Y. , Kirkham J. , Robinson C. , Baldwin K. , LI G , Bennett B.
Published: June 2003

We report on the tip‐enhanced Raman spectra of C60 obtained on a custom‐built apertureless scanning near‐field optical microscope. A commercial atomic force microscope tip coated with 100 nm thickness of gold was used to enhance locally the Raman signal and permit topographic and spectral information to be acquired simultaneously. We present preliminary data which demonstrate the tip enhancement effect using C60 as a test sample.
Systematic variation of polymer jacketed fibres and the effects on tip etching dynamics
Authors: Wei P.‐K. , Chen Y.‐C. , Kuo H.‐L.
Published: June 2003

Using a chemically etched fibre probe through a plastic jacket provides a simple way to smooth a tip's surface. Convection flow in the plastic tube and lateral diffusion with fixed meniscus height has been proposed to explain such improvement. Fibres with additive thin polymer layers and bare fibres with thick untapered/tapered plastic layers have been prepared to verify the dominant mechanism. The additive layers greatly change the tip's geometry and bare‐fibres with untapered plastics cannot form tips. This confirmed that lateral diffusion dominates the etching process. Based on our investigation, we propose a new non‐meniscus end‐etching method by using tapered plastics. Unlike etching methods with meniscus, the end‐etching method can regularly form very smooth tips. It is insensitive to vibrations and temperature drifts and also suitable for most fibres.
Near‐field nano‐ellipsometer for ultrathin film characterization
Authors: Zhan Q. , Leger J. R.
Published: June 2003

We describe a near‐field ellipsometer for accurate characterization of ultrathin dielectric films. Optical tunnelling mimics the absorption in metallic films, enabling accurate measurement of the refractive index of ultrathin dielectric film. A regression model shows that a refractive index resolution of 0.001 for films as thin as 1 nm is possible. A solid‐immersion nano‐ellipsometer that incorporates this near‐field ellipsometric technique with a solid‐immersion lens is constructed to demonstrate the viability of this technique. Such a nano‐ellipsometer can accurately characterize thin films ranging in thickness from subnanometre to micrometres with potential transverse resolution of the order of 100 nm.
Near‐field observation of carrier diffusion in GaAs quantum structures under high magnetic fields
Authors: Tokizaki T. , Onuki T. , Tsuchiya T. , Yokoyama H.
Published: June 2003

Photoluminescence from a two‐dimensional electron‐gas system in GaAs single hetero‐structures was investigated using a scanning near‐field optical microscope (SNOM) operated at cryogenic temperatures under high magnetic fields. The local intensity of the luminescence increased 600‐fold that at 0 T as the magnetic field was increased up to 6 T. The enhancement depended on the spatial resolution of the SNOM. These characteristics are explained by the suppression of the diffusion of photocarriers caused by the Lorentz force in magnetic fields.
Characterization of a 35‐kDa carbohydrate larval antigen (CarLA) fromTrichostrongylus colubriformis; a potential target for host immunity
Authors: Harrison G. B. L. , Pulford H. D. , Hein W. R. , Severn W. B. , Shoemaker C. B.
Published: June 2003

In an accompanying paper we show that antibodies in intestinal mucus that recognize a 35‐kDa antigen from the surface of the L3 stage of the sheep intestinal nematode parasite,Trichostrongylus colubriformis,are strongly associated with immune rejection of L3 in a truncated infection model of immunity in sheep. Monoclonal antibody PAB‐1 was used to immunopurify this antigen fromT. colubriformisL3.The antigen is resistant to digestion with a range of proteases including proteinase K and does not stain on gels or blots treated with protein‐detecting reagents but does stain with carbohydrate‐detecting reagents. The antigen is also resistant to degradation by the action of lipases and is not soluble in organic solvents, suggesting that lipid components are not present or not accessible. Treatment with glycosidases does not affect the antigen, indicating either that sialic acid and N‐linked or O‐linked sugars are not present or that they are not accessible to enzyme attack. The antigen is not destroyed by harsh alkaline degradation with up to 8 mNaOH with or without borohydride reducing agent, or by extensive hydrazinolysis. Strong acid hydrolysis with trifluoroacetic acid or boiling in hydrochloric acid for 20 min does destroy the antigen. The antigen migrates as a poorly defined high molecular weight complex on native electrophoresis gels, but is detected as a major band at 35 kDa on SDS PAGE either by carbohydrate staining or by immunoblotting with antibody from immune sheep intestinal mucus and with mAb PAB‐1. Proteinase K digestion and alkaline degradation of extracts from L3 of 10 other parasitic nematode species revealed that L3 of each species contained a carbohydrate staining molecule which can be detected by mAb PAB‐1 and by mucus antibody from immune sheep. Because antibodies in intestinal mucus are directed against these antigens and may be responsible for protective immunity, carbohydrate larval antigens (CarLA) could represent a new family of molecules with potential as targets for stimulating host immunity.
Prospect for an Entamoeba histolytica Gal‐lectin‐based vaccine
Authors: Gaucher Denis , Chadee Kris
Published: June 2003

Entamoeba histolytica is the aetiological agent of invasive amoebiasis, the third leading parasitic cause of mortality in the world. The disease can be easily cured by chemotherapy; however, prevention, mainly in the form of vaccination, could greatly decrease the incidence of the disease, and possibly help in its eradication. The parasite's surface galactose and N‐acetyl‐d‐galactosamine‐inhibitable adherence lectin (Gal‐lectin) is highly antigenic and is the most promising subunit vaccine candidate. We have generated a Gal‐lectin‐based DNA vaccine and tested its immunogenicity in mice. Although further optimization will probably be required, this vaccine could help in the generation of an amoebiasis DNA vaccine for use in humans.
Chemotherapy‐induced, age‐related changes in antischistosome antibody responses
Authors: Mutapi Francisca , Hagan Paul , Woolhouse Mark E. J. , Mduluza Takafira , Ndhlovu Patricia D.
Published: June 2003

Humoral responses directed against Schistosoma mansoni soluble egg antigen were studied in Zimbabwean children before and after treatment with either praziquantel (PZQ) or oxamniquine (OXAM). Treated children showed a significant increase in the proportion producing IgE and IgG3 and in mean levels of IgE, IgM, IgG3 six weeks post‐treatment. At 18 weeks post‐treatment, the proportion of treated children producing IgA, IgE, and IgG3 increased while the proportion producing IgG1 and IgG4 decreased. Mean levels of IgA, IgE, and IgG3 were higher than pre‐treatment levels while levels of IgG1, IgG4 and IgM were lower. Statistical analyses showed that the magnitude of change in levels of IgE, IgM and IgG3 at 6 weeks post‐treatment and of IgE, IgG3 and IgG4 at 18 weeks post‐treatment was significantly greater in treated compared to untreated children, and there were no significant differences in immune responses between children treated with praziquantel and those treated with oxamniquine. The magnitude of change in IgE at 6 and 18 weeks, IgM at 6 weeks and IgG3 at 18 weeks post‐treatment were significantly associated with age in treated but not in untreated children, with the change being greater in younger children. This suggests that treatment induced a change in the age‐antibody relationship for these isotypes, and that the age‐antibody relationship is not robust to chemotherapy. Pre‐treatment infection levels were significantly associated (positive correlation) with the magnitude of change for IgE and IgG3 at 18 weeks post‐treatment. Taken together, these results indicate that the age‐antibody relationship observed in these children is due, at least in part, to cumulative host experience of parasite antigens and not host age alone.
Abomasal lymph node responses toHaemonchus contortusintestinal antigens established in kid goats by infection or immunization with intestinal antigens
Authors: Jasmer Douglas P. , Karanu Francis , Davis William C. , Mcguire Travis S.
Published: June 2003

Immune responses toHaemonchus contortusintestinal antigens were evaluated using abomasal lymph node (ALN) lymphocytes from kid goats protected against challenge infection by immunization with parasite intestinal antigen, and from kids that were challenged after immunization with ovalbumin. ALN lymphocytes from the intestinal antigen‐immunized group produced significantly higher antibody levels against intestinal antigens than the ovalbumin group, supporting the theory that immunization contributed to that ALN response. In contrast, intestinal lysates and membrane enriched preparations from intestinal cells stimulated significant proliferation of ALN lymphocytes in both groups. The proliferation was antigen‐dependent, since intestinal antigens failed to stimulate proliferation in ALN lymphocytes from unimmunized and uninfected kids. For both the intestinal antigen and ovalbumin immunized groups, CD4+ T lymphocytes predominated in ALN lymphocytes that were stimulated to proliferate by intestinal antigens. The results indicate thatH. contortusinfection alone can induce ALN lymphocyte responses to intestinal antigens. In contrast to ALN lymphocyte responses, serum antibody against intestinal antigens was generally low to undetectable in ovalbumin‐immunized kids following infection. Abomasal mucus from anH. contortusinfected lamb was probed with a monoclonal antibody that binds to a periodate sensitive determinant on numerousH. contortusintestinal membrane and secreted proteins. Numerous bands of reactivity were detected, indicating that multiple parasite intestinal antigens were released into abomasal mucus during infection. The results, challenge the general concept thatH. contortusintestinal antigens are ‘hidden’ from the host immune system during an infection. On the contrary, parasite intestinal proteins may be relatively abundant antigens presented to the host during infection. In addition, ALN T lymphocytes appear to provide a more sensitive measure than serum antibody to detect presentation of these antigens to the host immune system.
Exceptional anoxia resistance in larval tiger beetle, Phaeoxantha klugii (Coleoptera: Cicindelidae)
Authors: Zerm Matthias , Adis Joachim
Published: June 2003

Abstract. The tiger beetle Phaeoxantha klugii inhabits Central Amazonian floodplains, where it survives the annual inundation period in the third‐instar larval stage submerged in the soil at approximately 29 °C for up to 3.5 months. Because flooded soils quickly become anoxic, these larvae should be highly resistant to anoxia. The survival of adult and larval P. klugii was therefore tested during exposure to a pure nitrogen atmosphere in the laboratory at 29 °C. Adult beetles were not resistant (< 6 h). Survival of larvae decreased over time, maximum survival was 15 days, whereas time to 50% mortality was 5.7 days (95% confidence interval 3.8–7.9). Anoxia resistance was additionally tested in third‐instar larvae submerged within sediment for 40 days before anoxia exposure in the laboratory. Anoxia resistance was greatly enhanced in these larvae, showing a survival rate of 50% after 26 days of anoxia exposure. It appears that the gradual flooding process and/or the submersion phase induced a physiological alteration, most probably a strong depression in metabolic rate, which requires some days for induction. The degree of anoxia resistance in larval P. klugii is remarkable among terrestrial arthropods worldwide, even more so considering the high ambient temperatures. The species is well‐suited to serve as a model organism for studying the physiological mechanisms of anoxia and submersion resistance in terrestrial arthropods inhabiting tropical floodplains.