bluuebunny/crossref_metadata_2025 huggingface dataset:
Errors in the visual perception of size in left hemi‐Parkinson's disease
Authors: Harris J. P. , Atkinson E. A. , Fowler M. S. , Lee A. C. , Nithi K.
Published: March 2003

Purpose:  Although Parkinson's disease (PD) has been considered to be primarily a motor disorder, there is increasing evidence for perceptual abnormality in the illness, which might impair the visual control of movements. We investigated how the perceived size of visual stimuli in PD depends on their position in external space, as well as on the involvement of the right hemisphere.

Methods:  Patients with mild/moderate idiopathic PD were allocated to a primarily left‐ or a primarily right‐sided group (LPD, RPD; n = 7 or 8 in different experiments) from the severity of tremor, rigidity, and akinesia in the left and right limbs. The ratio of severity of symptoms between the worse and least affected side averaged more than 3 : 1. In a method of constant stimuli, observers judged whether the width or height of a (variable) rectangle in one region of space was greater than that of a (standard) rectangle in another region. Psychometric functions were fitted to each observer's data by probit analysis, from which the mean (point of subjective equality) and slope were obtained.

Results:  In LPD (but not RPD or controls) rectangles in left space had to be wider than identical rectangles in right space, and rectangles in right space narrower than identical rectangles in left space, to be perceived as of equal width. Similarly, a rectangle in lower space had to be shorter than an identical rectangle in upper space to be perceived as of equal height, whether the rectangles were positioned in right or in left space.

Conclusions:  The results are consistent with a perceptual compression of objects in left and upper space in LPD (but not in RPD), implicating right‐hemisphere dopaminergic mechanisms in the visual perception of size. The effects are small (about 4%) but may be important in the visual control of precise movements in LPD.
Habitual binocular performance and vision‐related quality of life
Authors: Patel R. , Pardhan S. , Hobbiss A. , Gilchrist J.
Published: March 2003

Purpose:  Binocular summation (binocular sensitivity > monocular sensitivity) and binocular inhibition (binocular sensitivity < monocular sensitivity) have been shown in various laboratory and clinical situations. The occurrence of habitual binocular summation/inhibition is unknown. The aim of this study was to investigate binocular performance in 100 ‘ocularly normal’ subjects over the age of 45 years attending an optometric practice. In addition, very little data exist on habitual quality of life (QOL) scores in normal subjects. We aimed to investigate whether binocular performance for different visual tasks affected QOL scores.

Methods:  Right eye, left eye and binocular contrast sensitivity (CS), near and distance logMAR acuity (VA), and face recognition (FR) were measured. Vision‐related quality of life (QOL) scores were measured using the standard NEI–VFQ 25 questionnaire.

Results:  Habitual binocular summation ratios were similar to those reported under laboratory conditions. Binocular summation ratios for visual acuity were 26%, 47% for CS and 11% for FR. Binocular inhibition was shown by 12 subjects with VA, seven people in CS and 31 subjects with FR. No significant associations were shown between the summation ratios of distance VA, near VA, CS & FR and the 13 different QOL categories.

Conclusions:  Face recognition showed the poorest summation as it falls under the complex pattern recognition known to produce lower summation under laboratory conditions. Binocular summation ratios were not significantly associated with either the age of the subject or to the differences between the two eyes. The lack of correlation between binocular summation ratios and QOL was because of the high scores shown by the normal subjects.
Accommodation responses in late‐onset myopia are improved by spatiotopic stimulation
Authors: Gray L. S. , Seidel D. , Heron G.
Published: March 2003

Purpose:  Inaccurate accommodation responses to retinotopic stimuli have been shown in late‐onset myopia (LOM). The aim of this experiment was to determine whether spatiotopic (perceived proximity) and binocular stimulation would improve the quality of accommodation responses in LOM subjects.

Methods:  Ten emmetropic subjects (mean age 22.3 ± 2.3 years) and 10 LOM subjects (mean age 21.8 ± 1.5 years) participated. A specially modified Canon R‐1 infrared optometer was used to measure accommodation responses. Three conditions were presented: (1) Monocular blur‐only stimulus, (2) Monocular free‐space stimulus, and (3) Binocular free‐space stimulus. Each condition was presented on a separate day to avoid fatigue effects.

Results:  Accommodation stimulus–response curves in the LOM group showed improved accuracy with the spatiotopic stimulus. Microfluctuations were significantly (p < 0.01) smaller in magnitude in the LOM group with the spatiotopic stimulus, because of reductions in the low frequency components of the fluctuations. A significant (p < 0.01) increase in the percentage of correct step accommodation responses for the spatiotopic stimulus was found in the LOM group. However, step response times in the LOM group with the spatiotopic stimulus were not significantly different than those found with the retinotopic stimulus, and were significantly (p < 0.01) longer than those found in the emmetropic group.

Conclusions:  (1) Spatiotopic stimulation produces significant improvements in static accommodative accuracy in LOM subjects compared with retinotopic stimulation. (2) The quality of dynamic accommodation responses in LOM subjects was found to improve significantly with spatiotopic stimulation. (3) LOM subjects appear to rely upon proximity driven stimuli to improve accommodative response accuracy.
Does corneal polarisation vary with corneal astigmatism?
Authors: Mamoojee A. , Diaz‐Santana L. , Lara‐Saucedo D.
Published: March 2003

Purpose:  To assess the correlation between the axis of corneal astigmatism and/or corneal thickness with that of corneal birefringence in a small group of observers using a subjective polarimeter and a corneal topographer.

Methods:  The corneal polarisation axis and corneal astigmatism directions were measured in 11 subjects, providing data for 22 eyes. One kerataconic subject was included in the sample. The study utilised subjective ellipsometry using an instrument engineered at Imperial College, London to determine the corneal polarisation axis. An Orbscan (Bausch & Lomb, Rochester, NY, USA) corneal topographer was used to measure corneal astigmatism and corneal thickness.

Results:  It was found that the angle of corneal polarisation axis and the steepest direction of corneal astigmatism were correlated. The correlation coefficient for the RE was −0.49, whilst that for LE was 0.43. A similar relationship was found for the flat axis of the cornea.

Conclusions:  There was a fair correlation between the corneal polarisation direction and both the flat and steep axis of corneal astigmatism. It was also found, in agreement with other studies, that corneal polarisation axis in either eye was symmetrical about the nose, as was corneal astigmatism. The kerataconic cornea followed the trend observed, although nothing conclusive can be stated. A relationship between the corneal polarisation axis and corneal thickness was not established. Analysis of the data provided us with simple equations, which could help to predict a polarisation axis for a known direction of corneal astigmatism.
Ginkgo Biloba: A Review of Quality, Safety, and Efficacy
Authors: Mahady Gail B.
Published: March 2003

Abstract Results from randomized, controlled clinical trials support the use of standardized leaf extracts of Ginkgo biloba for the symptomatic treatment of age‐associated memory impairment, dementia (including Alzheimer's disease), and intermittent claudication. Product selection is extremely important, as much of the published safety and efficacy data are based on 2 standardized extracts, both available in the US. The recommended dose of a Ginkgo biloba leaf extract (standardized to contain 24–26% flavonoid glycosides, 5–7% terpene lactones, and less than 5 parts per million ginkgolic acids) is 40 mg to 60 mg, 3 to 4 times a day. Daily administration of the extract for at least 4 to 6 weeks is required before the full therapeutic effects may be observed. While there are no known contraindications, due to potential platelet‐activating factor antagonism and inhibition of platelet aggregation, Ginkgo extracts should be used cautiously in patients receiving anticoagulant or antiplatelet therapy or having bleeding disorders. A number of bleeding episodes due to co‐administration of aspirin or warfarin have been reported. Other adverse reactions, such as nausea, vomiting, headaches, and dizziness have also been observed in clinical trials. Administration of Ginkgo biloba preparations to children or during pregnancy or nursing is not currently recommended.
An Update: Vitamin E Supplementation and Heart Disease
Authors: Blumberg Jeffrey B.
Published: March 2003

▪ Abstract In vitro studies and experiments in animal models provide a large and compelling body of evidence that oxidation of low‐density lipoprotein (LDL) and/or related oxidative mechanisms play a critical role in the initiation and progression of atherogenesis.1 A corollary to the theory that reactive oxygen and nitrogen species (“free radicals”) are the key molecules in this process is that antioxidants that can protect LDL from peroxidation should decrease the risk of developing atherosclerosis, attenuate its progression, or even reverse established disease.2 However, recently, clinical trials employing the principal lipid‐soluble dietary antioxidant, vitamin E, have provided mixed results indicating either benefit, no effect, or an adverse impact on patients with cardiovascular disease (CVD). Consideration of the design and outcome of these studies together with new reports about the action of antioxidants suggests approaches for new studies as well as a basis for current advice to patients.
Talking to Patients About Food Insecurity
Authors: Messer Ellen , Ross Elizabeth M. , Ldn
Published: March 2003

Food insecurity is highly prevalent in the United States. Even in the best of times, some 10% of the U.S. population self‐reports food insecurity in the U.S. annual census instrument, and some 23.3 million Americans use the community‐based emergency food system. Unemployed or underemployed individuals, the elderly, single parents, substance abusers, and uninsured or underinsured individuals with medical illnesses are at increased risk for food insecurity. This article discusses clinical approaches to food‐insecure individuals. Measurement tools developed to define and document the extent of hunger and food insecurity in the U.S. population are presented as templates for discussion between doctor or dietitian and patient. Information is provided to help clinicians guide patients with food insecurity to appropriate resources.
Probiotics for Urogenital Health
Authors: Reid Gregor
Published: March 2003

Bacterial vaginosis, urinary tract infection, and yeast vaginitis afflict an estimated 1 billion women each year. Once investigation has ruled out complicated underlying causes, the only therapeutic option is antimicrobial agents. In many cases, this is effective at clearing infection. However, recurrences, side effects, and secondary infections are frequent. Coinciding with infection is a disruption of the normal commensal microflora in the vagina, primarily a loss of lactobacilli. The exogenous application of lactobacilli to the host as probiotic agents appears to offer hope as an alternative management regimen to antimicrobial treatment and prophylaxis. Although commercial probiotics specifically selected and proven to be effective for urogenital infections are not yet available, there is growing in vitro and human data to suggest that certain strains could confer health benefits on a large number of women. Given that depleted vaginal lactobacilli and recurrent infection is associated with increased risk of sexually transmitted diseases and preterm labor, multiple antibiotic resistance, and significant reduction in quality of life, the need for probiotic therapeutics has never been greater.
The Obese Patient with Infertility: A Practical Approach to Diagnosis and Treatment
Authors: Moran L. J. , Norman R. J.
Published: March 2003

Overweight and obesity are serious and prevalent conditions in Western countries and carry many health consequences, including reproductive dysfunction. In particular, excess fat in the abdominal area is strongly related to disorders of the reproductive system. Moderate weight loss and reduction of abdominal fat improves menstrual regularity, ovulation, and infertility in women. This may be etiologically related to insulin resistance, particularly in a subset of infertile women with polycystic ovary syndrome. As such, weight loss should be promoted as an initial treatment option for obese women with infertility. However, the most effective method for achieving and maintaining weight loss is unclear. Gradual weight loss is best achieved through a sensible eating plan that can be maintained over long periods of time. The likelihood of maintaining weight loss is increased when diet is combined with regular exercise, cognitive behavior therapy, and a supportive group environment. Adoption of these principles in a primary healthcare setting can therefore aid in treatment of infertility related to obesity.
Growth hormone does not attenuate the inhibitory effects of sepsis on wound healing
Authors: Stamm Jason , Cooney Robert N , Maish George O , Shumate Margaret L , Lang Charles H , Ehrlich H. Paul , Vary Thomas C
Published: March 2003

Chronic abdominal sepsis is associated with impaired tissue repair. Treatment of burn patients with growth hormone results in improved healing of skin graft donor sites. The goal of this study was to determine whether administration of growth hormone could attenuate the inhibitory effects of sepsis on cutaneous wound healing. Four groups of male Sprague Dawley rats were studied: control, control + growth hormone, sepsis, and sepsis + growth hormone. Sepsis was caused by implantation of a bacterial focus in the peritoneal cavity. Control animals underwent sham laparotomy, and polyvinyl alcohol sponge implants were placed in subdermal pockets in all animals. Saline or growth hormone (400 μg) was injected subcutaneously every 12 hours. On day 5, the incisional wounds and polyvinyl alcohol sponge implants were harvested. The breaking strength of abdominal incisions was measured. Granulation tissue penetration and quality were determined by scoring polyvinyl alcohol sponge implant histology from 1 to 4 in a blinded fashion. Collagen deposition in polyvinyl alcohol sponge implants was quantitated by hydroxyproline assay. Septic mortality was not altered by growth hormone administration. Septic animals showed a reduction in food consumption for 2 days after surgery (p < 0.05 vs. controls), which was not affected by growth hormone administration. The breaking strength of incisional wounds and hydroxyproline content of polyvinyl alcohol sponge implants was reduced in septic rats (p < 0.001 vs. controls) but administration of growth hormone for 5 days did not improve breaking strength or collagen deposition in either group. We conclude that the administration of growth hormone for 5 days did not improve collagen deposition or breaking strength in cutaneous wounds from control or septic animals. The results suggest that growth hormone treatment is unlikely to improve tissue repair in sepsis‐induced catabolic illness.
Hypertrophic scar tissues and fibroblasts produce more transforming growth factor‐β1 mRNA and protein than normal skin and cells
Authors: Wang Rijian , Ghahary Aziz , Shen Qiong , Scott Paul G , Roy Kenneth , Tredget Edward E
Published: March 2003

Transforming growth factor‐β1 is a well‐known fibrogenic cytokine produced by many types of cells including dermal fibroblasts. To investigate whether this fibrogenic cytokine is involved in development of hypertrophic scar, transforming growth factor‐β1 gene expression was evaluated in small skin samples. Because a sufficient quantity of normal skin from patients with hypertrophic scar is not readily available, a reverse transcription‐polymerase chain reaction technique was used. Quantitation of gene expression by reverse transcription‐polymerase chain reaction is difficult partly due to the lack of suitable complementary RNA standards. We have established a convenient, reliable procedure to construct an internal standard for transforming growth factor‐β1 starting with a gene specific polymerase chain reaction product. After digestion of the polymerase chain reaction product with endonuclease, a small piece of cDNA from human procollagen α1(I) cDNA with compatible ends was inserted into the polymerase chain reaction‐DNA fragment. The recombinant cDNA was re‐amplified by polymerase chain reaction and subcloned into a plasmid containing bacteriophage T7 and T3 promoters. Complementary RNA was prepared from the recombinant plasmid and amplified by reverse transcription‐polymerase chain reaction together with the tissue or cellular RNA. After amplification, the products were electrophoresed in an agarose gel containing ethidium bromide. The bands for internal standard and transforming growth factor‐β1 mRNA were scanned, digitized, and plotted against the amount of internal standard complementary RNA added in the reverse transcription‐polymerase chain reaction. The number of mRNA molecules/cell was calculated. We examined the transforming growth factor‐β1 mRNA in hypertrophic scar tissue and in normal skin and found that hypertrophic scar tissues expressed five‐fold more transforming growth factor‐β1 mRNA than normal skin per unit of wet weight. We used this procedure to quantitate transforming growth factor‐β1 mRNA expression in 5 pairs of fibroblast cultures derived from hypertrophic scar and normal skin. The results showed that hypertrophic scar fibroblast cultures contain significantly more molecules of mRNA for transforming growth factor‐β1 than normal cells (116 ± 6 vs. 97 ± 7, p = 0.017, n = 5). These results were supported by Northern analysis for transforming growth factor‐β1 mRNA in the cells and enzyme‐linked immunosorbent assay for TGF‐β1 protein in fibroblast‐conditioned medium. In conclusion, hypertrophic scar tissue and fibroblasts produce more mRNA and protein for transforming growth factor‐β1, which may be important in hypertrophic scar formation. The construction of the gene specific internal standard for reverse transcription‐polymerase chain reaction is a simple and reliable procedure useful to quantitate gene expression in a small amount of tissue or number of cells.
Healing of defects in canine articular cartilage: Distribution of nonvascular α‐smooth muscle actin‐containing cells
Authors: Wang Qi , Breinan Howie A , Hsu Hu‐Ping , Spector Myron
Published: March 2003

The objective of this study was to evaluate the types of tissue resulting from spontaneous healing of surgically created defects in adult canine articular cartilage up to 29 weeks postoperatively, with specific attention directed toward the presence and distribution of cells containing the contractile actin isoform, α‐smooth muscle actin. Two 4‐mm diameter defects were made in the trochlear groove to the depth of the tidemark in 20 adult mongrel dogs. The areal percentage of specific tissue types in the reparative material was determined histomorphometrically. Immunohistochemistry was employed to evaluate the percentage of α‐smooth muscle actin‐containing cells. The results showed that approximately 50% of the chondrocytes in the superficial zone of the uninvolved articular cartilage expressed α‐smooth muscle actin. A significantly lower percentage of α‐smooth muscle actin‐positive chondrocytes appeared in the uninvolved deep zone. Notably, the deep zone adjacent to the defect contained a greater percentage of such cells than in the uninvolved deep zone. Also of interest was that a greater percentage of nonvascular cells in the hyaline cartilage and fibrocartilage of the reparative tissue contained α‐smooth muscle actin‐positive cells, compared to the fibrous tissue in the defects. The findings of this study revealed that canine articular cartilage has some potential for spontaneous regeneration, including integration with the calcified cartilage zone. By 29 weeks, up to 40% of an areal cross section of an untreated full‐thickness chondral defect was found to fill with hyaline cartilage, with up to 19% judged histologically similar to articular cartilage. The results warrant further consideration of the role of α‐smooth muscle actin in chondrocytes in normal articular cartilage and in reparative tissue.
Influence of deformation partitioning and metamorphic re‐equilibration onP–Tpath reconstruction in the pre‐Alpine basement of central Southern Alps (Northern Italy)
Authors: SPALLA  , CARMINATI  , CERIANI  , OLIVA  , BATTAGLIA
Published: March 2003

The dominant foliation (S2) in the metapelites of the Southalpine basement, near the western side of the Tertiary Adamello intrusive stock, is a Variscan greenschist facies planar fabric, slightly reworked during thick‐skin Alpine tectonics. S2 is defined by muscovite and chlorite and was formed by decrenulation of pre‐existing foliations, which are confined to metre‐size, less‐deformed domains and defined by biotite and white mica. The pre‐S2 fabric is composite (D1a & D1b) and defined by contrasting amphibolite facies metamorphic assemblages in different residual sites. Cld+BtI+Grt+MsI+Pl+Qtz and St+BtII+Grt+MsII+Pl+Qtz assemblages mark D1a and D1b fabrics respectively; these developed during successive steps of a single, temperature‐prograde polyphase event, rather than during separate tectonometamorphic imprints affecting different tectonic units, later coupled during a D2 greenschist facies stage. Thermobarometric estimates of assemblages formed during D1a, D1b and D2 show a transition fromT =480–540 °C (during D1a) toT =570–660 °C (during D1b), corresponding to a slight pressure‐increase from 0.75–0.95 GPa to 0.85–1.15 GPa. D2 greenschist retrogression corresponds to a pressure and temperature decrease (T <400–550 °C andP<0.3–0.4 GPa). ThisP–T–deformation–time path is inferred to be the result of uplift from a depth ofc.35 km, after Palaeozoic subduction and continental collision; it is consistent with models postulated for other metamorphic units of the Variscan Belt in Europe. This is the first documented example in the Southern Alps of temperature‐prograde metamorphism before Palaeozoic collision.
Experimental investigation of melt topology in partially molten quartzo‐feldspathic aggregates under hydrostatic and non‐hydrostatic stress
Authors: Gleason  , Bruce  , Green
Published: March 2003

Continental collision results in deep burial of crustal rocks and their subsequent partial melting. Field relations of melt along zones of intense deformation suggest that partially molten rocks may play an important role in regional tectonics. However, subsequent deformation may erase the microstructures produced by the earlier deformation mechanisms, inhibiting our understanding of the rheology of partially molten crustal rocks. Thus, in this paper, we report the results of an experimental study of the distribution of 2–5 vol% melt in quartzo‐feldspathic aggregates of various grain sizes: 2–5, 5–10, 10–16 and 26–31 μm. Three types of samples were examined, all with the composition of 60 wt% albite, 25 wt% potassium feldspar, 10 wt% quartz and 5 wt% biotite. The first group included mineral powders annealed at 1000 °C, 1.0 GPa, for c. 100 h. The second group included commercially hot‐pressed mineral powders which yielded c. 25 vol% glass; cores of this material were also annealed at 1000 °C, 1.0 GPa, for c. 100 h. The third group included cores of hot‐pressed material that were annealed at 1000 °C, 1.0 GPa, for c. 45 h, then deformed. All samples were quenched rapidly in order to examine the melt distribution. Wetting angles are very similar in both the hydrostatically annealed and the deformed samples. Analysis of melt pool orientations reveal that melt migrates away from grain boundaries normal to the maximum compressive stress direction in response to the applied non‐hydrostatic stress. This response is easily seen in the coarser‐grained samples in which melt pools elongated parallel to the maximum compressive stress direction formed during deformation. If these results extrapolate to naturally deformed rocks, it will be important to consider the orientation of the state of stress in a region during syn‐magmatic deformation because of its effect on the melt distribution.
Numerical simulations of spiral‐shaped inclusion trails: can 3D geometry distinguish between end‐member models of spiral formation?
Authors: Stallard A. , Ikei H. , Masuda T.
Published: March 2003

Numerical 3D simulations of the development of spiral inclusion trails in porphyroblasts were conducted in order to test the proposals that (a) 3D spiral geometry differs between the rotation and nonrotation end‐member models of spiral formation proposed in the literature, and (b) 3D spiral geometry can be used as a criterion to distinguish between the two end‐member models in rocks. Four principal differences are identified between the two sets of simulations: smoothness of spiral curvature; spacing of foliation planes; alignment of individual foliation planes either side of the sphere representing the porphyroblast; and spiral asymmetry with respect to matrix shear sense. Of these differences, only spiral asymmetry and possibly the alignment of individual foliation planes are diagnostic criteria for distinguishing between the end‐member models. In the absence of a readily applied test to distinguish the end‐member models, interpretation of spiral inclusion trails is problematic. It is necessary to determine complementary evidence to distinguish porphyroblast rotation or nonrotation during spiral formation.
Carboniferous and Triassic eclogites in the western Dabie Mountains, east‐central China: evidence for protracted convergence of the North and South China Blocks
Authors: Sun Weidong , Williams I. S. , Li Shuguang
Published: March 2003

SHRIMP U–Pb dating and laser ablation ICP‐MS trace element analyses of zircon from four eclogite samples from the north‐western Dabie Mountains, central China, provide evidence for two eclogite facies metamorphic events. Three samples from the Huwan shear zone yield indistinguishable late Carboniferous metamorphic ages of 312 ± 5, 307 ± 4 and 311 ± 17 Ma, with a mean age of 309 ± 3 Ma. One sample from the Hong'an Group, 1 km south of the shear zone yields a late Triassic age of 232 ± 10 Ma, similar to the age of ultra‐high pressure (UHP) metamorphism in the east Qinling–Dabie orogenic belt. REE and other trace element compositions of the zircon from two of the Huwan samples indicate metamorphic zircon growth in the presence of garnet but not plagioclase, namely in the eclogite facies, an interpretation supported by the presence of garnet, omphacite and phengite inclusions. Zircon also grew during later retrogression. Zircon cores from the Huwan shear zone have Ordovician to Devonian (440–350 Ma) ages, flat to steep heavy‐REE patterns, negative Eu anomalies, and in some cases plagioclase inclusions, indicative of derivation from North China Block igneous and low pressure metamorphic source rocks. Cores from Hong'an Group zircon are Neoproterozoic (780–610 Ma), consistent with derivation from the South China Block. In the western Dabie Mountains, the first stage of the collision between the North and South China Blocks took place in the Carboniferous along a suture north of the Huwan shear zone. The major Triassic continent–continent collision occurred along a suture at the southern boundary of the shear zone. The first collision produced local eclogite facies metamorphism in the Huwan shear zone. The second produced widespread eclogite facies metamorphism throughout the Dabie Mountains–Sulu terrane and a lower grade overprint in the shear zone.
ACID‐BASE IN RENAL FAILURE: New Perspectives on Acid‐Base Balance
Authors: Oh Man S.
Published: March 2003

This review will cover two main areas of acid‐base balance, both of which are attended with much misconception and misunderstanding. One is the external balance of acids and alkali; the other is the contribution of bone buffering in acute and chronic metabolic acidosis.
Regulation of Bone Remodeling: Impact of Novel Therapies
Authors: Hercz Gavril
Published: March 2003

The kidneys serve as both an endocrine organ and as a target of endocrine action, with the aim of controlling mineral and water balance. Hormones and other key metabolites regulate mineral homeostasis by altering gene function directly or by initiating a sequence of events, leading ultimately to a change in enzyme function. Two of these hormones, parathyroid hormone (PTH) and calcitriol (the active form of vitamin D), interact in multiple tissues in the body to regulate the flux of calcium and phosphorus between extra‐ and intracellular compartments. Changes in the concentration of PTH and vitamin D, or the interaction of these with other factors, lead to the aberrant regulation of calcium and phosphorus. Among other effects, this aberrant regulation leads to pathologic changes in bone metabolism. The pathology of renal bone disease varies along a spectrum from disorders of low turnover to those of high turnover. This spectrum reflects the results of therapeutic intervention, hormone balances, and other causes. Effective management of renal bone disease therefore requires thorough evaluation of relevant risk factors, measurement of biochemical markers of bone remodeling, and determination of the physical status of bone tissue either by bone mineral density or bone biopsy. Subsequent therapeutic intervention with newer vitamin D compounds, novel phosphate binders, calcimimetics, and the use of alternative dialysis modalities offer hope in normalizing bone remodeling and mineral balance.  The human skeleton functions in two capacities: the storage of minerals and structural support of the body. It is the only tissue that behaves as both a major source and a sink of calcium (Ca) and phosphorus (P). Healthy bone is a composite of a collagenous matrix embedded with crystals of hydroxyapatite. On the surface of bone and within the calcified matrix are specialized cells that build and maintain the tissue, and facilitate the movement of Ca and P into and out of serum. Bone undergoes remodeling in response to either damage from mechanical strain or as part of the normal cycle of bone renewal. The process involves distinct steps of cellular activation, bone resorption, and subsequent bone formation. It is a relatively slow process that takes several months, and at any one time occurs at many different sites along the bone surface. Systemic factors, such as PTH and vitamin D, regulate the resorption and formation of bone, and thus the systemic movement of Ca and P. However, during conditions of stress and disease, other factors may also play a role. In patients with chronic renal disease, the balance of Ca and P is profoundly disturbed. This disruption and the compensatory changes that occur in response alter the normal processes of bone metabolism.
The Role of the Synovium and Cartilage in the Pathogenesis of β2‐Microglobulin Amyloidosis
Authors: Moe Sharon M. , Chen Neal X.
Published: March 2003

The predilection for β2‐microglobulin (β2M) amyloid deposition in articular structures is unique compared to other forms of amyloid; this article focuses on possible pathogenic mechanisms. The synovium and/or cartilage appear to be important in the pathogenesis of β2M amyloidosis (Aβ2M), as amyloid is not found in the shafts of long bones. The concentration of β2M in the joint fluid parallels that in serum. Once in the joint space, evidence suggests that the β2M binds to collagen in cartilage as the initial site of deposition. This binding may serve as the first step in subsequent amyloid formation, although this remains to be proven. β2M has been shown to have many direct effects on synovial fibroblasts, including induction of the release of cytokines, metalloproteinases, cyclooxygenase‐2, and vascular cell adhesion molecule‐1 (VCAM‐1). The release of these inflammatory mediators that lead to tissue degradation is also observed in other forms of arthritis. Thus β2M itself may elicit the release of inflammatory mediators from synovial fibroblasts even in the absence of cellular infiltrates.
The Clinical Utility of Doppler Ultrasound Prior to Arteriovenous Fistula Creation
Authors: Brimble K. Scott , Rabbat Christian G. , Schiff David , Ingram Alistair J.
Published: March 2003

Arteriovenous fistula (AVF) is the preferred access for long‐term hemodialysis, with superior long‐term patency rates; however, early failure rates are significant. Recent evidence has brought into question the preferred site of AVF creation in many patient groups. A preoperative test that could reliably predict the outcome of a proposed AVF would be of great benefit. Doppler ultrasound has been the most extensively studied and widely used test to guide access creation. Accurate and validated measurements of internal vessel diameter, both arterial and venous, and blood flow in the upper extremity are obtainable by Doppler ultrasound. Studies evaluating the utility of Doppler ultrasound prior to AVF creation suggest that vessel size and blood flow are predictive of AVF outcome. An AVF created using a cephalic vein and/or radial artery smaller than 1.5–2.0 mm is likely to fail; such preoperative data may indicate that an upper arm AVF should be the primary access attempted. Further prospective studies are needed to evaluate the utility of Doppler ultrasound.
Acute Dialysis Catheters
Authors: Oliver Matthew J.
Published: March 2003

Acute dialysis catheters are non‐cuffed, non‐tunnelled catheters used for immediate vascular access. They are primarily used for acute renal failure in bed‐bound patients and for short‐term use in patients with malfunction of permanent access. Long‐term use of acute catheters is not recommended, but does occur with acceptable infection rates in dialysis centers where tunnelled, cuffed catheters are not available. Most acute catheters are made of polyurethane, but silicone catheters are now available with larger lumen sizes capable of delivering blood flow rates over 300 ml/min. Acute catheters should be inserted in the internal jugular or femoral vein under ultrasound guidance to minimize complications. Subclavian catheters cause stenosis, thrombosis, and perforation of vessels. Intermittent catheter malfunction still occurs, particularly for left‐sdied internal jugular catheters and catheters placed in women. Blood flow may improve with lumen reversal, intraluminal t‐PA, or guidewire exchange. Limiting duration of use and dressing catheter exit sites with dry gauze and antiseptic ointments can prevent catheter‐related infections.
Subcutaneous Vascular Access Devices
Authors: Moran John E.
Published: March 2003

Tunneled dialysis catheters have played an important role in providing vascular access for hemodialysis for over 20 years, yet limitations associated with poor flow, thrombosis, and infections due to the transcutaneous nature of catheters have led to the development of alternative vascular access devices. This article reviews two historical devices—the Hemasite and the Bentley DiaTAP button—and provides an overview of two new fully subcutaneous vascular access devices—the LifeSite Hemodialysis Access System (Vasca, Inc., Tewksbury, MA) and the Dialock Hemodialysis System (Biolink Corp., Norwell, MA). These new subcutaneous devices differ significantly from currently available tunneled dialysis catheters in their design and method of use and may result in improved outcomes in hemodialysis patients. Indeed, initial clinical experiences with this new class of fully implanted access devices validate a subcutaneous approach to hemodialysis access and suggest that their high flow rates and low complication rates may make subcutaneous devices an attractive alternative to dialysis catheters for hemodialysis patients.
Water Treatment for Hemodialysis: Ensuring Patient Safety
Authors: Ouseph Rosemary , Ward Richard A.
Published: March 2003

Patient safety has become an important focus of the Institute of Medicine and the medical community. Although hemodialysis is a routine therapy, it is nonetheless a complex procedure where errors can occur. In particular, errors related to water quality can lead to patient injury and to increased medical costs. Using the Institute of Medicine report on errors in medicine as a basis, this article discusses previously published incidents of patient injury related to water quality in terms of the types of errors that occurred. Epidemiologic techniques provide a framework to identify, correct, and possibly avert these types of errors in the future. While the ultimate responsibility for ensuring water quality rests with the medical director of the hemodialysis unit, patient safety should be a concern of all members of the nephrology community.
A Phase II Trial of Humanized Anti‐Vascular Endothelial Growth Factor Antibody for the Treatment of Androgen‐Independent Prostate Cancer
Authors: Reese David M. , Fratesi Paige , Corry Michelle , Novotny William , Holmgren Eric , Small Eric J.
Published: March 2003

Objective: Vascular endothelial growth factor (VEGF) is a glycoprotein that is important in promoting tumor angiogenesis. Recombinant humanized anti (rhuMAb)‐VEGF is a humanized murine monoclonal antibody that neutralizes VEGF activity and has shown promise in animal tumor models. Methods: To evaluate the efficacy and safety of single‐agent rhuMAb VEGF in metastatic androgen‐independent prostate cancer (AIPC), we treated 15 patients with 10 mg/kg rhuMAb VEGF every 14 days for six infusions (one cycle), followed by additional treatment for selected patients who had a response or were stable. Results: After one cycle, none of the 15 patients who were evaluable for tumor response had an objective complete or partial response. Three possible mixed responses were observed. No patient achieved a >50% decrease in serum prostate specific antigen (PSA) level after one cycle. Four patients (27%) had a PSA decline of <50%, three patients (20%) had a PSA level increase of <50%, and eight patients (53%) had a PSA increase of >50%. The median time to objective progression was 118 days, and the median time to PSA progression was 57 days. Toxicity was generally mild, with asthenia present in 6 (40%) of 15 patients. Severe hyponatremia developed in two patients, although the association with rhuMAb VEGF was unclear. Conclusions: We concluded that single‐agent rhuMAb VEGF in this dose and with this schedule did not produce significant objective responses in patients with AIPC. Further development of this agent in patients with prostate cancer should focus on earlier stage disease or should evaluate it in combination with other therapies.
Treatment of Metastatic Hormone Refractory Prostate Cancer with Ketoconazole, Hydrocortisone, and Cyclophosphamide
Authors: Pecora Andrew , Richter Frank , Pavlick Anna , Lanteri Vincent , Scheuch John , Levy Stuart , Rosenberg Gene , Vitenson Jack
Published: March 2003

Objective: Patients with metastatic hormone‐refractory prostate cancer have a poor overall survival rate. Newer agents have shown promise in slowing disease progression but are mostly ineffective in improving the overall survival rate, are toxic, and require intravenous administration. In an attempt to maintain treatment efficacy, but to minimize toxicity and improve ease of use, we conducted a pilot trial of an oral regimen consisting of ketoconazole, hydrocortisone, and cyclophosphamide combination therapy.

Materials and Methods: Twenty‐seven patients with metastatic hormone‐refractory prostate cancer were treated with an oral regimen of ketoconazole, 400 mg tid, and hydrocortisone, 20 mg qam and 10 mg qpm, on Days 1–28. Cyclophosphamide, 100 mg/m2, was added on Days 1–14. Treatment was recycled every 28 days. Progression of disease was defined by a progressively rising prostate specific antigen (PSA) level, new lesions as seen on bone scans, or progression of soft‐tissue disease. Patient age ranged from 57 to 87 years. Performance status (PS; Eastern Cooperative Oncology Group scale) was 0–2. Pretreatment PSA values ranged from 5.8 ng/mL to 3400 ng/mL (median 68).

Results: Twenty‐one (78%) of 27 patients with elevated PSA levels demonstrated a ≥50% decline in PSA level for 3 consecutive months. Of the remaining six patients (22%), two progressed within 3 months, two withdrew from the study due to toxicity, and two responded with <50% decline in PSA level. Nadir PSA values ranged from <0.2 to 155, with a median nadir of 5.1. Mean and median declines in PSA levels were 79% and 93%, respectively. The duration of response ranged from 3 to >96 months, with a median response duration of 9 months. Twenty‐two (81%) of 27 patients experienced no significant toxicity, 4 of 27 patients experienced Grade I–III gastrointestinal toxicity, and 1 of 27 patients experienced Grade III hematologic toxicity.

Conclusions: The combination of ketoconazole, hydrocortisone, and cyclophosphamide is a well‐tolerated oral regimen for the treatment of patients with metastatic hormone‐refractory prostate cancer with significant disease activity, and it warrants further investigation.
Perceived Ownership in a Community Coalition
Authors: Armbruster Charlotte , Gale Betty , Brady Jane , Thompson Nancy ,   Charlotte Armbruster is a Faculty Associate and Betty Gale is an Associate Professor at the Arizona State University College of Nursing, Tempe, Arizona. Jane Brady is a Research Coordinator, Department of Obstetrics & Gynecology, Maricopa Integrated Health System, Phoenix, Arizona. Nancy Thompson is the Oncology Program Coordinator, W. O. Boswell Memorial Hospital, Sun City, Arizona.
Published: March 2003

Coalitions are emerging as a force for change in many communities and offer the opportunity for broad community involvement in the planning and implementation of needed health promotion and health education services. Perceived ownership promotes greater participation by the community but efforts to systematically evaluate ownership are lacking. The aim of this study was to determine ownership of a local ElderCARE Coalition's activities and its health promotion program, Healthy WAY, as perceived by coalition members. Fifteen of the coalition members returned the questionnaire that included the Community Ownership Scale. As shown by mean scores, the agencies perceived as having the most influence or greatest perceived ownership were the university college of nursing and the community action programs. Coalition members represented a wide variety of roles and responsibilities as well as length of time in the coalition (1 month to 6 years). Responses to open‐ended questions, analyzed by content analysis, supported the work of the coalition and identified the senior participants in the Healthy WAY program as being “enthusiastic” but also needing to be more “involved.” Process measures are important indicators of how close coalitions are staying to their grassroots constituency. Implications for public health nurses include participating as partners in community coalitions and assisting coalitions in determining their sense of ownership and the need for change.
Promoting Positive Affect and Diminishing Loneliness of Widowed Seniors Through a Support Intervention
Authors: Stewart Miriam , Craig Dorothy , MacPherson Kathleen , Alexander Sharon
Published: March 2003

Seniors are most vulnerable to conjugal bereavement. Although social support buffers the effects of bereavement, widows and widowers have lower levels of social support than married individuals. Self‐help/support groups can supplement support from their depleted natural networks. Accordingly, the aim of this demonstration project was to examine the impact of support groups on widowed seniors' loneliness, affect, and perceived support. Four face‐to‐face support groups for widowed seniors were conducted weekly for a maximum of 20 weeks.

Participants completed pretest, posttest, and delayed posttest measures of support need and support satisfaction, positive and negative affect, and loneliness/isolation. The statistically significant impacts of the intervention were enhanced support satisfaction, diminished support needs, and increased positive affect. There was a trend toward decreased social isolation and emotional loneliness. In postintervention semistructured interviews, bereaved seniors reported increased hope, improved skills in developing social relationships, enhanced coping, new role identities, and less loneliness. Community health nurse researchers could conduct randomized controlled trials of face‐to‐face and telephone support groups for bereaved people of all ages. Community health nurse practitioners could benefit from lessons learned about timing, duration, and selection of sensitive outcomes.
Client Perceptions of Parish Nursing
Authors: Wallace Debra C. , Tuck Inez , Boland Clara S. , Witucki Janet M.
Published: March 2003

The purpose of this study was to examine parish nursing from a client's perspective.Parish nursing is a relatively new health delivery model that has rarely been investigated. In order to describe the client perception, an ethnographic approach was used. The convenience sample included clients from two congregations in a southeastern Appalachian area served by parish nurses. Face‐to‐face client interviews were conducted, and the Spradley's ethnographic approach to data analysis of transcripts was used. Each interview was analyzed separately by the research group for patterns and meanings reflecting the emic perspective. Five themes of client perception of parish nursing emerged from the data: (1) being available, (2) integrating spirituality and health, (3) helping us help ourselves, (4) exploring parish nursing, and (5) evaluating parish nursing.Clients perceived having a parish nurse as positive and beneficial for individuals, the congregation, the church, and community. Parish nursing was viewed as a useful, meaningful, and effective health intervention and setting, and parish nurses were viewed as effective and meaningful health providers. Further exploration of the effectiveness of this nursing delivery model is warranted.
Interdisciplinary Collaboration: A Study in Progress
Authors: Boswell Carol , Cannon Sharon , Aung KoKo , Hammack Becky , Ienatsch G. Peter , Prado Melvin
Published: March 2003

A multidisciplinary, multi‐institutional collaborative effort was initiated to address the perspectives of health care literacy in an urban/rural area of west Texas. This article presents the mechanisms utilized in the development and implementation of this collaborative process. Individuals within multiple institutions realized the importance of working together to address health care issues. As a result of this consortium development, an initial endeavor addressing health care literacy and functional health status was initiated. The development of the consortium and the project is presented in this article to provide a model for consortium development applicable to other professions.