bluuebunny/crossref_metadata_2025 huggingface dataset:
Contact lens fitting post‐refractive surgery
Authors: Astin Christine
Published: February 2006

Purpose:  A number of patients who had undergone refractive surgery still required contact lens fitting. Indications for fitting included the correction of residual ametropia, anisometropia, and regular and irregular astigmatism. In some cases, a post‐treatment therapeutic bandage soft contact lens was used to protect the treated eye and to promote regular epithelial healing. Lens fitting was reviewed to give recommendations for problem solving and fitting this category of patient.

Methods:  Before lens fitting, a full history and symptoms and refraction were obtained. The practitioner explained the results of the refractive surgery, advised on advantages and limitations of lens wear and described the choices available. The fitting procedure involved anterior segment assessment and measurement of ocular parameters. Several steps were often required to achieve a successful lens fit and tolerance.

Three main categories of refractive surgery were outlined:

(1) Internal procedure, e.g. implantation of an intra‐ocular lens or a special soft lens draped over the crystalline lens.

(2) Corneal incision, e.g. penetrating and lamellar keratoplasty, radial keratotomy (RK), transverse incision for astigmatism reduction, and stromal lens insertion.

(3) Laser techniques, e.g. PRK, LASIK, LASEK, Holmium laser and thermo‐keratoplasty.

Results:  Contact lenses were fitted aiming to cause least disturbance to the cornea which had already been compromised by previous surgery. Good oxygen transmission, surface wettability and lens design were important features. A rigid gas permeable (RGP) lens could support and protect the cornea, provide a corrective tear lens between the lens and the new corneal contour, and help to stabilise visual acuity. Often a RGP lens of large diameter was required to bridge over the contours of the central cornea region and assist lens centration. Good visual acuity was usually achieved unless residual stromal haze prohibited this. A soft lens draped over the cornea gave good comfort and lens centration. However, it was less effective on irregular astigmatism and led to variable visual acuity on RK or over wide laser ablation zones.

Conclusion:  Fitting the post‐refractive surgery cornea was challenging. Extra time and assessment were recommended as the new corneal topography could lead to problems with contact lens centration and stability of visual acuity. Waiting 3 months post‐treatment to allow the corneal topography to stabilise before commencing fitting is particularly recommended for RK and PRK. Lens aftercare included management of the patients’ high expectations.
The challenges of the corneal graft
Authors: Rubinstein Martin
Published: February 2006

Indications for post‐graft contact lens fitting are primarily therapeutic (healing/suture problems, leaking wound, graft dehiscence) or optical (high/irregular astigmatism, anisometropia, poor vision with spectacles, lens worn on fellow eye). In therapeutic application, ‘soft’ lenses of varying thickness and water content are generally indicated and for relatively short‐term use. For optical management, rigid gas permeable corneal lenses are the mainstay although scleral lenses may be required in certain situations such as the highly irregular cornea where retention of smaller devices is problematic . There are numerous variations from the normal when considering contact lenses for the grafted cornea including physiological/metabolic (thickness variations, reduction in sensitivity, endothelial changes) and topographical (astigmatism, profile, position of graft). For example, in a patient with reduced corneal sensitivity where keratitis is a potential problem, optimising corneal oxygenation and reducing lens wear is recommended. Topographic peculiarities of the cornea can make the fitting of contact lenses a challenge – in extreme cases at best a compromise with the likelihood of limited wearing time and comfort, at worst potentially dangerous with the risk of corneal trauma and graft rejection. Liaison with the corneal surgeon in improving corneal topography by suture manipulation is essential.The practitioner must have access to a wide range of contact lens options and be mindful of lens dimensions and geometry and also material characteristics – this will give the optimal chance of success in dealing with the challenges posed.
Moving towards improved evidence for the effectiveness of low vision interventions
Authors: Rubin Gary , Harper Robert
Published: February 2006

Background:  Two recently published Manchester trials have provided evidence on the effectiveness of specific low vision rehabilitation (LVR) interventions.

Methods:  In RCT 1, we compared enhanced LVR (supplementary home visits) and conventional LVR for people with AMD. In RCT 2, we evaluated the effectiveness of prism relocation spectacles in people with central scotomas due to AMD. RCT methodology was employed in each trial on large samples of subjects (n > 200), using a wide range of outcomes.

Results:  For RCT 1, arms did not differ significantly for any outcome. At 12 months, 94% of participants reported using at least one LVA. For RCT 2, there was no significant effect of treatment group (prism or placebo) on any of the outcomes.

Conclusions:  While these specific LVR interventions did not prove to be effective, they were not designed to address the effectiveness of LVR in general. A LVR vs no‐LVR trial is proposed.

References:  Reeves, B.C., Harper, R.A. and Russell, W.B. (2004) Enhanced low vision rehabilitation for people with age‐related macular degeneration: a randomised controlled trial. Br J Ophthalmol88, 1443–1449.

Smith, H.J., Dickinson, C.M., Cacho, I., Reeves, B.C., Harper, R.A. (2005) A randomized controlled trial to determine the effectiveness of prism spectacles for patients with age‐related macular degeneration. Arch Ophthalmol123, 1042–1050.
Current trends in photodynamic therapy
Authors: Culham Louise
Published: February 2006

Background:  Patients with wet age‐related macular disease (AMD) and subfoveal choroidal neovascular membrane (CNV) may be offered photodynamic therapy (PDT). Currently, Visudyne (Verteporfin) is the only photosensitizer approved by the FDA and randomized trials have shown that treatment can prevent severe vision loss. Combination therapy with Visudyne PDT and intravitreal triamcinolone may be additionally beneficial. In an effort to develop a more effective therapy, we have undertaken studies in primates and in patients with advanced AMD using a new photosensitizer, talaporfin sodium. Following dose‐ranging work in the normal primate retina, a study in humans investigated the safety and effectiveness of this drug.

Methods:  Eleven patients with vision of <6/60 and persistent leakage from CNV were recruited. Following talaporfin sodium injection of 0.5 mg kg−1 bodyweight, a light dose of between 24 and 48 J cm−2 was given with a 664 nm laser. Fluorescein angiography and visual acuity (VA) were performed before and after therapy. Adverse events were recorded. Follow‐up was for 14 days, but informal review was longer (in some cases ≥ 40 weeks).

Results:  All patients showed evidence of decreased leakage from CNV. No re‐opening of closed choroidal vessels was observed during extended follow‐up. At the last follow‐up, VA was stable in seven patients, improved in three and decreased in one (using >0.1 logMAR). Three adverse events were reported; two related to photosensitivity of the skin and one patient had closure of a branch retinal vein.

Conclusion:  Talaporfin sodium PDT showed extended closure of CNVs and therefore has potential for treating exudative AMD and other choroidal vascular anomalies.
The creation of longitudinal cracks in shrinking soils to enhance seedling emergence. Part I. The effect of soil structure
Authors: Taki O. , Godwin R. J. , Leeds‐Harrison P. B.
Published: February 2006

Stand establishment in crusting soils is one of the most critical stages in the production of crops with delicate seedlings. This becomes more difficult in hard‐setting soils of arid lands where dispersion of aggregates due to irrigation results in the formation of a hard layer as the soil dries from the surface downwards and impedes seedling emergence. However, seeds planted near to natural cracks manage to emerge through them. The aim of this study was to improve seedling emergence of irrigated crops in arid and semi‐arid conditions by devising methods to create longitudinal cracks in the vicinity of the seed rows during the subsequent drying phase. Laboratory experiments were conducted in soil boxes containing air‐dried clay soils to investigate the influence of different mechanical effects on the cracking pattern after flooding. Promising results were achieved by compacting a 7–15‐mm wide strip along the seed row. Monitoring the effect of compaction on water release characteristics and tensile strength of soil revealed that the greater water loss of the surrounding non‐compacted soil caused a suction gradient towards the points of lower water content resulting in movement of water and particles towards the drier zones. The compacted soil with a greater tensile strength did not permit the flow of water and particles to the loose soil and a discontinuity occurred. A field experiment in central Iran proved the feasibility of the technique in a semi‐arid area. This was achieved by lightly compacting a narrow strip of soil by applying 17–35 kg on a 22‐mm wide, 558‐mm diameter wheel covered by a layer of flexible rubber which ran over the pre‐compacted soil.
Long‐term effects of recommended management practices on soil carbon changes and sequestration in north‐eastern Italy
Authors: Morari F. , Lugato E. , Berti A. , Giardini L.
Published: February 2006

Management practices can have significant implications for both soil quality and carbon (C) sequestration potential in agricultural soils. Data from two long‐term trials (one at field scale and the other at lysimeter scale), underway in north‐eastern Italy, were used to evaluate the dynamics of soil organic carbon (SOC) and estimate the impact of recommended management practices (RMPs) on soil carbon sequestration. Potential SOC sequestration was calculated as the differences between the change in SOC of treatments differing only for the specified RMP for a period of at least 25 years. The trials compared the following situations: (a) improved crop rotations versus monoculture; (b) grass versus improved crop rotations; (c) residue incorporation versus residue removal; (d) high versus low rates of inorganic fertilizers; (e) integrated nutrient management/organic manures versus inorganic fertilizers. At the lysimeter scale, some of these treatments were evaluated in different soils. A general decrease in SOC (1.1 t C ha−1 year−1) was observed after the introduction of intensive soil tillage, evidencing both the worsening of soil quality and the contribution towards global CO2emissions. Initial SOC content was maintained only in permanent grassland, complex rotations and/or with the use of large quantities of livestock manure. SOC sequestration reached a maximum rate of 0.4 t C ha−1 year−1comparing permanent grassland with an improved crop rotation. Crop residue incorporation and rates of inorganic fertilizer had less effect on SOC sequestration (0.10 and 0.038 t C ha−1 year−1, respectively). The lysimeter experiment highlighted also the interaction between RMPs and soil type. Peaty soil tended to be a source of C independent of the amount and quality of C input, whereas a proper choice of tillage practices and organic manures enhanced SOC sequestration in a sandy soil. The most promising RMPs in the Veneto region are, therefore, conversion to grassland and use of organic manures. Although some of these RMPs are already supported by the Veneto Region Rural Development Plan, their more intensive and widespread implementation requires additional incentives to become economically feasible.
The transferability of Australian pedotransfer functions for predicting water retention characteristics of French soils
Authors: Cresswell H. P. , Coquet Y. , Bruand A. , McKenzie N. J.
Published: February 2006

A French data set was used to evaluate how well two widely used analytical functions describe measured soil water characteristic (SWC) data. Both the van Genuchten (sigmoidal) and Campbell (power‐law) equations gave good descriptions of the data (mean R2 of 98.1 and 97.1% respectively). Methods of predicting SWC data were also evaluated. When a power‐law equation was parameterised using just two measured SWC points and bulk density (the ‘two‐point’ method), a very good SWC prediction was obtained for the French data (mean R2 of 94.8%). An empirical equation for prediction of the SWC was also assessed using the French data set. This method was developed using multiple regression analysis from Australian soil data and requires soil texture and bulk density as input. The predictions (mean R2 of 85.2%) lacked accuracy and precision in comparison with the two‐point method but the empirical approach uses more readily available input data. The accuracy of prediction from both methods was similar to that observed previously for Australian data sets. The empirical approach developed from Australian soil data has reasonable applicability to French soils. The approach of assuming a power‐law model and empirically predicting slope and air entry potential is shown to have merit. A strategy for achieving adequate coverage of soil hydraulic property data for France is suggested incorporating hydraulic prediction methods such as those evaluated here.
The isolation and characterisation of antiplatelet antibodies
Authors: Hamidpour Mohsen , Behrendt Mark , Griffiths Bridget , Partridge Lynda , Lindsey Nigel
Published: February 2006

Abstract:  The isolation and characterisation of antiplatelet antibodies in autoimmune thrombocytopenia purpura patients (ITP) is described. Autoimmune thrombocytopenia purpura is an autoimmune disease, clinically defined by low platelet counts, normal or increased megakaryocytopoiesis and antiplatelet antibodies in serum. This study used phage display to isolate Fab antiplatelet antibodies to study the structure–function relationships of pathogenic antibodies in ITP. Out of six randomly selected colonies, four colonies reacted strongly with whole platelets in enzyme‐linked immunosorbent assay (ELISA). Sequence analysis showed that all four colonies had the same DNA sequence and were the same antibody. Results of Western blotting against non‐reduced human platelet lysate showed that the Fab reacted with platelet proteins with apparent molecular weights of 116, 92 and 39 kD. Furthermore, Western blotting assay against purified membrane glycoprotein IIIa demonstrated reactivity against a band with a molecular weight of 92 kD. Results from Western blotting against platelet lysate and pure platelet glycoprotein confirmed the Fab fragment recognised the platelet glycoprotein IIIa. Three out of the four phage colonies produced soluble Fab, which demonstrated reactivity against platelet autoantigens in ELISA. Further sequence analysis showed that the Fab was somatically mutated suggesting antigen drive and therefore T‐cell assistance was important in the development of this antibody. One of the somatic mutations introduced an RSD amino acid sequence in the complementary determining region 1 (CDR1) of the light chain, which may mimic the RGD motif of fibrinogen which binds integrin GPIIb/IIIa. This raises the possibility that somatic mutation and antigen drive have produced a pathogenic autoantibody.
Genotypic heterogeneity and correlation to intergenic haplotype within high HbF β‐thalassemia intermedia
Authors: Papachatzopoulou Adamantia , Kourakli Alexandra , Makropoulou Panagiota , Kakagianne Theodora , Sgourou Argyro , Papadakis Manousos , Athanassiadou Aglaia
Published: February 2006

Abstract:  Objectives: A molecular study was carried out of β‐thalassemia intermedia patients, compound heterozygotes for mutations usually found in β‐thalassemia major, with high levels of HbF in the absence of hereditary persistence of fetal hemoglobin (HPFH) syndrome. Our objective was to locate cis‐DNA structures, DNA haplotypes, motifs, or polymorphisms that may correlate with the presence of high HbF. Methods: Allele‐specific oligonucleotide (ASO) hybridization was used for the detection of mutations and restriction fragment length polymorphism (RFLP) analysis and automated sequencing for motifs, haplotypes, and polymorphisms. Southern blot was used for investigating α‐thalassemia and/or α‐ or γ‐globin genes triplications. RNA extracted from burst forming unit‐erythroid (BFU‐e) colonies of peripheral blood mononuclear cell cultures was used in reverse transcriptase‐polymerase chain reaction (RT‐PCR) to investigate intergenic transcription. Results: We established that (i) the combination: T haplotype of the Aγ‐δ‐globin intergenic region, the motif (TA)9N10(TA)10 in the HS2 site of locus control region (LCR), and TAG pre‐Gγ haplotype is sufficient but not necessary for high HbF, (ii) the genetic determinant(s) for high HbF involves an element associated with this combination and must be present in the specific R haplotype occurring in β‐thalassemia intermedia and (iii) the genetic determinant(s) for high HbF does not involve the abolition of intergenic transcription in the Aγ‐δ‐globin intergenic region. Conclusions: The genetic determinant(s) of high HbF in the absence of HPFH is linked to intergenic haplotype T and does not disrupt intergenic transcription.
Odontoblast responses to GaAlAs laser irradiation in rat molars: an experimental study using heat‐shock protein‐25 immunohistochemistry
Authors: Tate Yasuaki , Yoshiba Kunihiko , Yoshiba Nagako , Iwaku Masaaki , Okiji Takashi , Ohshima Hayato
Published: February 2006

Pulpal responses to gallium–aluminum–arsenide (GaAlAs) laser irradiation applied to the tooth remains to be elucidated. This study aimed to evaluate the effect of the GaAlAs laser on odontoblasts using immunohistochemistry for heat‐shock protein (HSP)‐25, which labels mature and newly differentiated odontoblasts. The mesial surface of the upper right first molar of 8‐wk‐old Wistar rats was lased at an output power of 0.5–1.5 W for 180 s. The animals were perfusion‐fixed at intervals of 6 h to 30 d after irradiation. At 6 h to 7 d, the intensity of HSP‐25‐immunoreactivity was found to be disturbed in the coronal odontoblast‐layer in an energy‐dependent manner. At 30 d, tertiary dentin with/without bone‐like tissue was formed abundantly in the dental pulp. Statistical analysis revealed that the area occupied by the new hard tissues was significantly wider in 1.5 W‐lased specimens than in 0.5 W‐lased specimens. An intense HSP‐25 immunoreactivity was seen in the odontoblasts underlying the tertiary dentin, whereas immunoreactivity was weak around the bone‐like tissue. It was concluded that the GaAlAs laser may induce the formation of tertiary dentin by influencing the secretory activity of odontoblasts. However, higher energies may cause irreversible changes to the pulp, often leading to the formation of an intrapulpal bone‐like tissue.
Plasminogen activators and their inhibitors in human saliva and salivary gland tissue
Authors: Virtanen Oskari J. , Sirén Vappu , Multanen Juha , Färkkilä Markus , Leivo Ilmo , Vaheri Antti , Koskiniemi Marjaleena
Published: February 2006

The purpose of this study was to identify plasminogen activators (PA) and their specific inhibitors in human cell‐free saliva and to investigate their expression in salivary gland tissue. Saliva samples were obtained from 34 patients visiting a neurological out‐patient department. The activities of tissue and urokinase plasminogen activators (tPA and uPA, respectively), the relative inhibition of tPA, and the amounts of plasminogen activator inhibitors 1 and 2 (PAI‐1 and PAI‐2, respectively) in cell‐free saliva were studied. The activities of tPA and uPA, and tPA inhibition, were measured using in‐house microtiter plate assays, and PAI‐1 and PAI‐2 levels were measured using commercial enzyme‐linked immunosorbent assay (ELISA) kits. Immunohistochemistry was used to evaluate the expression of PAs and PAIs in the salivary gland. Tissue plasminogen activator activity was found in most samples, with a mean activity of 0.63 IU ml−1. uPA was observed in only a few samples. PAI‐1 was not detected, but PAI‐2 was present in all samples (with a mean value of 11.1 ng ml−1). The mean PAI‐2 level in women was 12.4 and in men was 7.6 ngml−1. The activity of tPA and the relative inhibition of tPA seemed to be inversely associated. Tissue plasminogen activator, PAI‐1, and PAI‐2 were evident in salivary gland tissue, whereas the expression of uPA was low. The tPA activity in saliva suggests an active proteolysis. Plasminogen activator inhibitor 2 was found to be the main inhibitor of PAs in saliva.
Age‐associated changes in viscoelastic properties of the bovine temporomandibular joint disc
Authors: Tanaka Eiji , Hirose Miho , Yamano Eizo , Dalla‐Bona Diego A. , Fujita Reiji , Tanaka Masao , Van Eijden Theo , Tanne Kazuo
Published: February 2006

To test the hypothesis that compressive properties of the temporomandibular joint (TMJ) disc change with age, we investigated its viscoelastic properties and stress‐relaxation behavior under compression. Compressive stress‐relaxation tests were performed in different regions of bovine discs of various ages. For each disc, specimens were derived from three different regions (anterior, central, and posterior). For four strain levels (5, 10, 15, and 20%), a stress‐relaxation test was conducted over a 5‐min period. Values of the instantaneous modulus, E0, appeared to be larger in the anterior than in the posterior region of the disc, irrespective of age. The E0 value increased with age, especially in the central region. Values of the relaxed modulus, ER, also increased significantly with age. There were no regional differences in values of the relaxed modulus. Under stress‐relaxation, the relaxation time became longer with age, especially in the posterior region. The results suggest that the compressive properties, instantaneous and relaxed moduli, increase with age, while the relaxation time becomes longer. This implies that the TMJ disc becomes harder with age. Furthermore, the compressive properties of the TMJ disc are region‐specific. As a result of the harder disc, it is likely that the TMJ becomes more vulnerable to secondary damage, such as fracture and tissue degradation.
Cessation of periodontal care during pregnancy: effect on infant birthweight
Authors: Hujoel Philippe P. , Lydon‐Rochelle Mona , Robertson Paul B. , Del Aguila Michael A.
Published: February 2006

The goal of this study was to assess whether interruption of care for chronic periodontitis during pregnancy increased the risk of low‐birthweight infants. A population‐based case‐control study was designed with 793 cases (infants < 2,500 g) and a random sample of 3,172 controls (infants ≥ 2,500 g). Generalized estimating equation models were used to relate periodontal treatment history to low birthweight risk and to common risk factors. The results indicate that periodontal care utilization was associated with a 2.35‐fold increased odds of self‐reported smoking during pregnancy (95% confidence interval: 1.48–3.71), a 2.19‐fold increased odds for diabetes (95% confidence interval: 1.21–3.98), a 3.90‐fold increased odds for black race (95% confidence interval: 2.31–6.61), and higher maternal age. After adjustment for these factors, interruption of periodontal care during pregnancy did not lead to an increased risk for a low‐birthweight infant when compared to women with no history of periodontal care (odds ratio, 0.96; 95% confidence interval, 0.60–1.52). In conclusion, women receiving periodontal care had genetic and environmental characteristics, such as smoking, diabetes and race, that were associated with an increased risk for low‐birthweight infants. Periodontal care patterns, in and of themselves, were unrelated to low‐birthweight risk.
Immunohistochemical localization of transcription factor Sp3 during dental enamel development in rat tooth germ
Authors: Lv Ping , Jia Hong T. , Gao Xue J.
Published: February 2006

Sp3, a member of the Sp family of transcription factors, has previously been thought to be ubiquitously expressed, and its expression pattern in tooth development is not clear. This study was carried out to investigate the immunolocalization of Sp3 during the development of rat tooth germs. Sprague–Dawley rats at ages of 1, 3, 7, 10, and 14 d were used to represent different stages of tooth development. First mandibular molar tooth germs were sectioned and studied by immunohistochemistry. Sp3 was found to be localized within the nuclei of cells in developing tooth germs; however, ameloblast nuclei showed variable intensities at different developmental stages. At the same time, the positive signals in odontoblast nuclei remained stable. The results suggest that Sp3 may play a role in the development of teeth, specifically in the transcription of enamel‐specific genes.
Effects of regional anesthesia with ropivacaine on arterial pressure and heart rate in healthy subjects
Authors: Oliveira Nilton E. , Lima Filho Nelson S. , Lima Eliudem G. , Vasquez Elisardo C.
Published: February 2006

The anesthetic, ropivacaine, has been used extensively in clinical practice, but few studies have evaluated this long‐acting local anesthetic in dentistry. In this study we evaluated the effects of ropivacaine alone and ropivacaine + vasoconstrictor on the cardiovascular system when used as a dental anesthetic in volunteers. Thirty‐two healthy subjects received two consecutive infiltrations of 1.8 ml of either 0.75% ropivacaine or ropivacaine + epinephrine into the pterygomandibular region. Pain sensation, numbness of the lip, arterial pressure, heart rate, and electrocardiogram changes were monitored for 2 h. The onset of anesthesia was 10 min after the injection and lasted for more than 2 h, and numbness of the lip lasted for ≈ 8 h. Ropivacaine alone did not cause significant changes in the cardiovascular parameters, but ropivacaine + epinephrine caused a transient increase in arterial pressure and heart rate 2 min postinjection. We conclude that ropivacaine alone injected into the pterygomandibular region does not affect the cardiovascular system and that the addition of epinephrine has no beneficial effect. This finding may be relevant to dentists endeavoring to find an anesthetic of minimal cardiovascular risk to produce regional anesthesia for long‐lasting procedures without the need of a vasoconstrictor.
Dental caries and salivary status in children with type 1 diabetes mellitus, related to the metabolic control of the disease
Authors: Siudikiene Jolanta , Machiulskiene Vita , Nyvad Bente , Tenovuo Jorma , Nedzelskiene Irena
Published: February 2006

The aim of this study was to investigate the relationship among type 1 diabetes mellitus, dental caries, and salivary status in children. The study comprised 68, 10–15‐yr‐old diabetics, and 68, age‐ and gender‐matched non‐diabetic controls. Diabetics were categorized into well‐to‐moderately controlled (HbA1c < 9.0%) and poorly controlled (HbA1c ≥ 9.0%) groups. Caries was recorded by assessing lesion activity at non‐cavitated and cavity levels. Teeth were examined visually for the presence of dental plaque. Saliva was analyzed for unstimulated and stimulated flow rates, buffer effect, mutans streptococci, lactobacilli, and yeasts. Diabetics had fewer caries and plaque, lower salivary flow rates and buffer effect, and more frequent growth of yeasts than their non‐diabetic controls. Well‐to‐moderately controlled diabetics had fewer decayed surfaces and lower counts of mutans streptococci and yeasts than poorly controlled diabetics, but the level of metabolic control of diabetes had no influence on salivary flow rates and buffer effect. High caries levels in diabetics were significantly associated with age, plaque score, and decreased unstimulated salivary flow rate, but were not associated with the level of metabolic control of diabetes. High caries experience in this study population could be related to plaque accumulation and/or to changes in saliva induced by diabetes mellitus.
Differential Properties of GTP‐ and Ca2+‐Stimulated Exocytosis from Large Dense Core Vesicles
Authors: Bai Li , Zhu Dan , Zhou Keming , Zhou Wei , Li Dongdong , Wang Yan , Zhang Rongying , Xu Tao
Published: February 2006

Many cells utilize a GTP‐dependent pathway to trigger exocytosis in addition to Ca2+‐triggered exocytosis. However, little is known about the mechanism by which GTP triggers exocytosis independent of Ca2+. We used dual‐color evanescent field microscopy to compare the motion and fusion of large dense core vesicles stimulated by either mastoparan (Mas) in Ca2+‐free conditions or high K+ in the presence of Ca2+. We demonstrate that Mas is hardly effective in triggering the fusion of the predocked vesicles but predominantly mobilizes cytosolic vesicles. In contrast, Ca2+‐dependent exocytosis is largely due to predocked vesicles. Fusion kinetics analysis and carbon‐fiber amperometry reveal that Mas induces a brief ‘kiss‐and‐run’ fusion and releases only a small amount of the cargo, whereas Ca2+ stimulates a more persistent opening of the fusion pore and larger release of the contents. Furthermore, we show that Mas‐released vesicles require a much shorter time to reach fusion competence once they approach the plasma membrane. Our data suggest the involvement of different mechanisms not only in triggering and fusion but also in the docking and priming process for Ca2+‐ and GTP‐dependent exocytosis.
Hairy Root and Its Application in Plant Genetic Engineering
Authors: Hu Zhi‐Bi , Du Min
Published: February 2006

Agrobacterium rhizogenes Conn. causes hairy root disease in plants. Hairy root‐infected A. rhizogenes is characterized by a high growth rate and genetic stability. Hairy root cultures have been proven to be an efficient means of producing secondary metabolites that are normally biosynthesized in roots of differentiated plants. Furthermore, a transgenic root system offers tremendous potential for introducing additional genes along with the Ri plasmid, especially with modified genes, into medicinal plant cells with A. rhizogenes vector systems. The cultures have turned out to be a valuable tool with which to study the biochemical properties and the gene expression profile of metabolic pathways. Moreover, the cultures can be used to elucidate the intermediates and key enzymes involved in the biosynthesis of secondary metabolites. The present article discusses various applications of hairy root cultures in plant genetic engineering and potential problems associated with them.

(Managing editor: Wei Wang)
Positive Interactions: Crucial Organizers in a Plant Community
Authors: Cheng Dong‐Liang , Wang Gen‐Xuan , Chen Bao‐Ming , Wei Xiao‐Ping
Published: February 2006

For more than a century, ecologists have concentrated on competition as a crucial process for community organization. However, more recent experimental investigations have uncovered the striking influence of positive interactions on the organization of plant communities. Complex combinations of competition and positive interactions operating simultaneously among plant species seem to be widespread in nature. In the present paper, we reviewed the mechanism and ecological importance of positive interactions in plant communities, emphasizing the certainties and uncertainties that have made it an attractive area of research. Positive interactions, or facilitation, occur when one species enhances the survival, growth, or richness of another. The importance of facilitation in plant organization increases with abiotic stress and the relative importance of competition decreases. Only by combining plant interactions and the many fields of biology can we fully understand how and when the positive interactions occur.

(Managing editor: Ya‐Qin Han)
Plants of Leptostrobus Heer (Czekanowskiales) from the Early Cretaceous and Late Triassic of China, with Discussion of the Genus
Authors: Liu Xiu‐Qun , Li Cheng‐Sen , Wang Yu‐Fei
Published: February 2006

Investigation of the Mesozoic seed plant Leptostrobus Heer from the Yangcaogou Formation of the Late Triassic and the Yixian Formation of the Early Cretaceous, Liaoning Province, China, provides new insight into its general morphology and geographical distribution. The materials of L. cancer from the Yixian Formation described herein are later than all the past findings of this species and add to the record of L. cancer during the Early Cretaceous. Based on well‐preserved specimens, the specific diagnosis is slightly emended and the reconstruction of L. cancer is perfected. The materials from the Yangcaogou Formation of the Late Triassic are placed in L. sphaericus. In addition, we review the history of investigation of the genus Leptostrobus since its establishment in 1876 and discuss the main characteristics of each species.

(Managing editor: Ya‐Qin Han)
Identification and Preliminary Analysis of Several Centromere‐associated Bacterial Artificial Chromosome Clones from a Diploid Wheat Library
Authors: Liu Zhao , Yue Wei , Dong Yu‐Shen , Zhang Xue‐Yong
Published: February 2006

Although the centromeres of some plants have been investigated previously, our knowledge of the wheat centromere is still very limited. To understand the structure and function of the wheat centromere, we used two centromeric repeats (RCS1 and CCS1‐5ab) to obtain some centromere‐associated bacterial artificial chromosome (BAC) clones in 32 RCS1‐related BAC clones that had been screened out from a diploid wheat (Triticum boeoticum Boiss.; 2n=2x=14) BAC library. Southern hybridization results indicated that, of the 32 candidates, there were 28 RCS1‐positive clones. Based on gel blot patterns, the frequency of RCS1 was approximately one copy every 69.4 kb in these 28 RCS1‐positive BAC clones. More bands were detected when the same filter was probed with CCS1‐5ab. Furthermore, the CCS1 bands covered all the bands detected by RCS1, which suggests that some CCS1 repeats were distributed together with RCS1. The frequency of CCS1 families was once every 35.8 kb, nearly twice that of RCS1. Fluorescence in situ hybridization (FISH) analysis indicated that the five BAC clones containing RCS1 and CCS1 sequences all detected signals at the centromeric regions in hexaploid wheat, but the signal intensities on the A‐genome chromosomes were stronger than those on the B‐ and/or D‐genome chromosomes. The FISH analysis among nine Triticeae cereals indicated that there were A‐genome‐specific (or rich) sequences dispersing on chromosome arms in the BAC clone TbBAC5. In addition, at the interphase cells, the centromeres of diploid species usually clustered at one pole and formed a ring‐like allocation in the period before metaphase.

(Managing editor: Li‐Hui Zhao)
A survey of female nursing students’ knowledge, health beliefs, perceptions of risk, and risk behaviors regarding human papillomavirus and cervical cancer
Authors: Denny‐Smith T. , Bairan A. , Page M. C.
Published: February 2006

Purpose: The purpose of the study was to assess knowledge of, perceived susceptibility to, perceived seriousness of, and risk behaviors regarding human papillomavirus (HPV) and cervical cancer among female nursing students.

Data sources: A 40‐item survey of HPV and cervical cancer was distributed to a convenience sample of 240 female nursing students enrolled in a baccalaureate nursing program.

Conclusions: Female nursing students participate in high‐risk sexual behaviors and have a fairly low knowledge level, low perceived susceptibility, and low perceived seriousness regarding HPV and cervical cancer. Knowledge and perceived susceptibility were positively related to number of sexual partners. This may indicate that the women who engage in riskier behavior are more knowledgeable about HPV and their risk of contracting the disease.

Implications for practice: Results indicate that all practitioners involved in the care of women should educate them about HPV and its relationship to cervical cancer. Education should include the need to use condoms to prevent HPV and other sexually transmitted diseases.
Syphilis: An old enemy still lurks
Authors: Ferguson L. A. , Varnado J. W.
Published: February 2006

Purpose: To review the problem of increasing cases of syphilis as a communicable disease and to review different presentations of syphilis and to discuss treatment guidelines.

Data sources: Extensive review of worldwide scientific literature on the epidemiology, diagnosis, and treatment of syphilis.

Conclusions: Syphilis is an infectious sexually transmitted disease, which may have devastating consequences. Previously declining rates have led to complacency in prevention and diagnosis. Primary prevention includes education regarding safer sexual practices. Secondary prevention includes early identification via screening and treatment.

Implications for practice: Syphilis is a contagious disease that has devastating consequences if not diagnosed and treated. Providers should keep ever vigilant in its identification. Specifically, it should be considered when evaluating all symptom‐less dermatological lesions.
Stress, Corticotropin‐Releasing Hormone, Glucocorticoids, and the Immune/Inflammatory Response: Acute and Chronic Effectsa
Authors: ELENKOV ILIA J. , WEBSTER ELIZABETH L. , TORPY DAVID J. , CHROUSOS GEORGE P.
Published: February 2006

Abstract: Corticotropin‐releasing hormone (CRH) influences the immune system indirectly, through activation of the hypothalamic‐pituitary‐adrenal axis and sympathetic system, and directly, through local modulatory actions of peripheral (immune) CRH. We recently demonstrated that catecholamines and histamine potently inhibited interleukin (IL)‐12 and stimulated IL‐10, whereas glucocorticoids suppressed IL‐12, but did not affect IL‐10 production ex vivo. Thus, both glucocorticoids and catecholamines, the end products of the stress system, and histamine, a product of activated mast cells, may selectively suppress cellular immunity and favor humoral immune responses. We localized immunoreactive CRH in experimental carrageenin‐induced aseptic inflammation and, in humans, in inflamed tissues from patients with several autoimmune diseases. In addition, we demonstrated that CRH activated mast cells via a CRH receptor type 1‐dependent mechanism, leading to release of histamine and hence vasodilatation and increased vascular permeability. Thus, activation of the stress system, through direct and indirect effects of CRH, may influence the susceptibility of an individual to certain autoimmune, allergic, infectious or neoplastic diseases. Antalarmin, a novel nonpeptide CRH antagonist, prevented several proinflammatory effects of CRH, thus revealing its therapeutic potential in some forms of inflammation.
Hormonal Regulation of Tumor Necrosis Factor‐α, Interleukin‐12 and Interleukin‐10 Production by Activated Macrophages: A Disease‐modifying Mechanism in Rheumatoid Arthritis and Systemic Lupus Erythematosus?
Authors: WILDER RONALD L. , ELENKOV ILIA J.
Published: February 2006

ABSTRACT:Rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) frequently develop and progress in settings in which sympathoadrenomedullary and gonadal hormone levels are changing, e.g., during pregnancy, postpartum period, menopause, estrogen administration. This paper addresses the view that adrenal and gonadal hormonal deficiency facilitates excessive macrophage production of TNF‐α and IL‐12 that characterizes RA, whereas excessive estrogen action is suggested to play an essential role in the production of IL‐10 in patients with SLE. Disease activity in SLE, in contrast to RA, appears to be associated with high‐level production of IL‐10, relative to the proinflammatory cytokines, TNF‐α and IL‐12. Accumulating data suggest that novel therapeutic approaches may ultimately be developed from continued investigation of the role of the neuroendocrine factors in RA and SLE.
Macrophages as Effectors of the Immunoendocrinologic Interactions in Autoimmune Rheumatic Diseasesa
Authors: CUTOLO MAURIZIO
Published: February 2006

ABSTRACT: An intricate balance between soluble mediators, released by activated cells of the immune/inflammatory system, and products of the neuroendocrine system is implicated in the presence of an autoimmune rheumatic disease. Monocytes/macrophages contribute to autoimmune events in rheumatic diseases, such as rheumatoid arthritis (RA) or systemic lupus erythematosus (SLE), mainly acting as antigen‐processing and presenting cells in the presence of an autoimmune rheumatic disease. Clinical symptoms such as morning stiffness and gelling, at least in RA, that peak during the late night and early morning, are consistent with the hypothesis that the immune function of activated cells (i.e., Th1 cells and monocytes/macrophages) and their mediators (cytokines and reactive oxygen intermediates) is increased at these times in relation to neuroendocrine pathway rhythmicity. Therefore, monocytes/macrophages seem to be the “link” between the steroid hormone environment (i.e., gonadal hormones) and the immune response effectors. If gonadal hormones, along with cytotoxic agents, do modulate macrophage apoptosis, such an approach might offer an important pathway to the control of autoimmune diseases. In conclusion, on the basis of a more complete understanding of macrophage effector and immunoregulatory activities, on both a local and systemic level, new hopes arise from the possible development of more sophisticated antimacrophage treatments for the management of autoimmune rheumatic diseases.
Neuroendocrine Immune Features of Pediatric Inflammatory Rheumatic Diseases
Authors: CHIKANZA I. C.
Published: February 2006

ABSTRACT: Juvenile rheumatoid arthritis (JRA) and juvenile systemic lupus erythematosus (JSLE) are the most common autoimmune rheumatic diseases in children associated with high levels of autoantibodies and immune reactivity. JRA and JSLE are more common in girls. Disease activity is worse in the morning, improves during the daytime and worsens at night suggesting that neuroendocrine immune mechanisms are involved in disease pathophysiology. Adult patients with RA and SLE have excessive levels of prolactin (PL) while cortisol (CS) production is down‐regulated for the degree of ongoing inflammation. PL has potent proinflammatory properties.

Normal to low levels of cortisol have been observed in children with active JRA despite the high serum levels of IL‐6, IL‐1β, and TNF‐α, which activate the hypothalamic‐pituitary‐adrenal axis (HPA). The CS levels are in fact subnormal because inflammatory stress activates the HPA. Normal serum PL levels were seen in children with JRA, most of whom were not active with higher levels in those with active ANA + ve JRA complicated by uveitis. A trend toward high PL levels was seen in 33 children with JSLE. High serum PL levels are seen in patients with active juvenile ankylosing spondylitis (JAS) only.

Growth retardation is a feature of JRA. Patients with JRA have low to normal levels of growth hormone (GH) and low levels of insulin‐like growth factor 1 (IGF‐1). IGF‐1 mediates the effects of GH. The observation of low IGF‐1 in JRA raises the therapeutic possibility with IGF‐1. Overall, high levels of follicle stimulating hormone and luteinizing hormone are found in children with JSLE while the levels in JRA tend to be normal. Testosterone levels are low in patients with JRA. No significant differences in estrogen levels have been found between patients with JRA and those with JSLE and matched controls. There is evidence that the autonomic nervous function is defective in patients with JRA.
Immunological Properties of Dehydroepiandrosterone, Its Conjugates, and Metabolites
Authors: BRADLOW H. LEON , MURPHY JUSTIN , BYRNE JAMES J.
Published: February 2006

ABSTRACT: The immunological response to the administration of various C‐19 steroids has been of increasing interest. Although the action of dehydroepiandrosterone has been studied, the responses to its metabolites have not been explored. In the present study the ability of dehydroepiandrosterone, its conjugates, and metabolites to oppose the anti‐inflammatory action of glucocorticoids on the inflammatory response to 2,4‐dinitrochlorobenzene in the sensitized mouse was examined. A clear difference was seen between the antiglucocorticoid activity of dehydroepiandrosterone, its conjugates, and its 5β‐metabolites on the one hand and the planar 5α‐ and Δ4‐metabolites, which were devoid of antiglucocorticoid activity. The mechanism of this antiglucocorticoid activity remains to be established.
Sex Hormones and Pregnancy in Rheumatoid Arthritis and Systemic Lupus Erythematosus
Authors: ØSTENSEN MONICA
Published: February 2006

ABSTRACT: Rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) are autoimmune disorders with a preponderance in females. RA and SLE differ in their response to sex hormones. Disease development of RA is mitigated by estrogen and pregnancy whereas SLE tends to flare during pregnancy and in response to estrogen. Pregnancy improves the symptoms of RA in about 75% of pregnant patients, but relapses within six months postpartum in 90% of cases. RA is regarded as a T cell‐mediated and TH1 immune response‐driven disease. Pregnancy induces a shift from TH1 to TH2 immune response, increasing the anti‐inflammatory cytokines IL‐4 and IL‐10, which may contribute to gestational amelioration of RA. Prospective studies of SLE pregnancies indicate that about 50% of patients experience a flare, however, with no permanent aggravation of the disease. Lupus nephritis, presence of antiphospholipid antibodies, and a previous history of pregnancy loss increase the risk of complications during pregnancy and fetal loss. The marked increase of estrogen and progesterone during pregnancy seems to enhance some of the manifestations of SLE. The shift to a TH2 immune response may trigger SLE manifestations that are dependent on humoral immune responses such as lupus nephritis. Another factor stimulating immune responses is the pituitary hormone prolactin, which has been found elevated in SLE patients of both sexes and correlated to disease activity in several studies. The hyperprolactinemia of lactation seems to influence postpartum behavior of SLE as well as RA.
Immune Regulatory Properties of Corticosteroids: Prednisone Induces Apoptosis of Human T Lymphocytes following the CD3 Down‐regulation
Authors: SCUDELETTI M. , LANZA L. , MONACO E. , MONETTI M. , PUPPO F. , FILACI G. , INDIVERI F.
Published: February 2006

ABSTRACT:Glucocorticoid hormones (GCH) induce apoptosis in PHA‐primed peripheral blood T lymphocytes (PBL) and down‐regulate membrane‐bound proteins involved in the immune response. We have analyzed whether GCH are able to affect the expression of the TCR‐associated molecules CD3, CD4, and CD8 on PBL‐PHA, and whether the modulation of those receptors is related to the GCH‐driven apoptosis of the PBL‐PHA. Lymphocytes were cultured with PHA or with PHA plus prednisone (PDN) 10−3, 10−6, and 10−9M. Then expression of CD2, CD3, CD4, CD8, and CD56 antigens was studied by cytofluorimetric assay using propidium iodide (PI) staining and annexin procedure, and by gel electrophoresis of low molecular weight DNA. PDN, at a pharmacological concentration (10−6M), was able to inhibit the CD3 expression on T cells. The kinetics of CD3 decrement and of apoptosis show that the down‐regulation of CD3 molecules precedes DNA fragmentation and that the cells lacking CD3 are those prone to PDN‐induced apoptosis. The inhibition of CD3 is not related to a transcriptional or posttranscriptional phenomenon, because both PBL‐PHA and PBL‐PHA‐PDN expressed the same amount of intracytoplasmic CD3 molecule. PDN also induced a down‐regulation of the CD4 and CD8 molecules that resulted sooner in more intense CD8.In vitroPDN is able to induce apoptosis in PBL‐PHA through a down‐regulation of CD3 molecules.