bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effects of wearing corrective lenses for presbyopia on distance vision
Authors: McGarry Mona B. , Manning Terri M. 
Published: March 2003

AbstractThe possibility of patient behaviour concerning the wearing of reading spectacles influencing the magnitude and rate of change in distance vision has been hypothesised but not fully examined. This study examined the changes in distance vision over time of 674 presbyopic patients between the ages of 44 and 69 who came to their eye professional needing reading spectacles. Prior to this study, these patients had never worn spectacles. The majority of patients opted for full‐eye (complete) reading spectacles and 150 patients selected bifocals. It was found that patients wearing complete reading spectacles eventually adapted to wearing their reading spectacles for intermediate or distance work. Through X2, it was found that there were significant differences in the reduction of distance visual acuity between groups based on the amount of time spent wearing reading spectacles for intermediate or distance work. The greater the number of hours spent wearing reading spectacles and viewing beyond their focal point, the greater the change in distance visual acuity. It also appeared to affect the degree of change in their prescription. Age was not significantly related.
Benefits of Exercise for Patients with Rheumatoid Arthritis
Authors: Rall Laura C. , Roubenoff Ronenn 
Published: March 2003

AbstractRheumatoid arthritis (RA) is a chronic, systemic, autoimmune, inflammatory disorder of unknown etiology and is the most common type of inflammatory arthritis. The disease is most often characterized by morning stiffness, tenderness, and swelling. Other systemic symptoms, such as anemia, increased free radical production, muscle atrophy, and weakness, also occur. Most likely, a combination of these factors contributes to physical inactivity as well, which, in turn, reinforces the muscle wasting. Despite these barriers, it is now becoming recognized that patients with well‐controlled RA can tolerate increased physical activity under carefully supervised conditions and that there are many benefits to exercise. This article reviews the effects of various types of physical activity on RA, with particular emphasis on studies that have examined the use of strength training in clinical practice for the management of RA. Without exception, the studies have shown that increased physical activity in patients with RA improves physical capacity without exacerbating disease activity. Important criteria to consider when recommending an exercise program for patients with RA are outlined.
Plant Stanol/Sterol Ester‐Containing Foods and Cardiovascular Disease Risk
Authors: Lichtenstein Alice H. 
Published: March 2003

AbstractCardiovascular disease (CVD) is the leading cause of death and disability in the United States, and an elevated low‐density‐lipoprotein (LDL) cholesterol level is one risk factor. The primary nonpharmacological approach to reducing LDL‐cholesterol levels is to restrict dietary saturated fat and cholesterol. Adjunct strategies are frequently superimposed as well. One newer approach is to substitute foods containing plant sterol/stanol esters for conventional foods such as margarines and salad dressings. Daily consumption of 2–3 g of plant sterol/stanol esters has been reported to reduce LDL‐cholesterol levels by 9% to 20%, with considerable individual variability. This cholesterol lowering appears additive to that achieved with saturated fat and cholesterol restriction or use of hydroxymethylgluteryl‐CoA‐reductase inhibitors. The hypocholesterolemic effect of plant sterol/stanol esters is thought to be mediated primarily by decreasing intestinal cholesterol absorption. Few adverse effects have been reported for short‐ and long‐term use of sterol/stanol ester‐containing foods. However, declines in plasma carotenoids and tocopherol levels have been reported. The clinical significance of this observation is unknown but needs further evaluation. Plant sterol/stanol ester‐containing foods can be used to augment a low‐saturated‐fat and low‐cholesterol diet; however, patients should be cautioned that use beyond the manufacturer‐recommended levels will not result in greater LDL‐cholesterol lowering. If a patient decides to use plant sterol/stanol ester‐containing foods, they should be substituted, not added, to the diet to avoid increasing caloric intake. Additionally, there is no evidence that use of sterol/stanol ester‐containing foods in normocholesterolemic individuals will prevent the onset of elevated cholesterol levels.
Including Nutrition in an Ambulatory Care Path for Patients with Type 2 Diabetes
Authors: Peery Annette , Darrow Mark , Hardee Sandra , Kolasa Kathryn M. 
Published: March 2003

AbstractCare paths are known to improve the performance of health care providers in delivering diabetes education. This paper describes the efforts of a rural family practice to implement a provider‐and patient‐focused care path for the improved management of Type 2 diabetes. Dietary and lifestyle advice were included elements in the care path. Family physicians with limited access to dietetic services need to provide more diet and lifestyle advice than other physicians. Patient‐focused care paths are expected to enhance provider‐patient communication and improve patient adherence.
Preventive Nutrition and Physical Activity: An Exercise in Interviewing for Medical Students
Authors: Ross Elizabeth M. 
Published: March 2003

AbstractPreventive care guidelines for physicians recommend patient counseling to promote a healthy diet and regular physical activity. Unfortunately, there is a paucity of materials to support training in these skills for medical students. This assignment is intended to help medical students learn to integrate questions about preventive nutrition and physical activity into the standard medical history, and then to synthesize the information they gather into a coherent assessment and plan using evidence‐based national guidelines.
Nutrition and Oral Precancerous Lesions
Authors: Mayne Susan Taylor , Morse Douglas E. 
Published: March 2003

AbstractOral precancerous lesions include oral leukoplakia, erythroplakia, and erythroleukoplakia. These lesions are of interest clinically because they can progress into oral carcinomas and therefore denote individuals who are at increased risk for oral carcinomas. Oral precancerous lesions are also of interest as intermediate endpoints for intervention trials, in order to screen agents that might have efficacy in oral cancer chemoprevention. While tobacco and alcohol reduction and/or cessation are clearly the most important strategies for reducing the risk of oral precancerous lesions and oral cancers, evidence also supports a possible role for nutrition in the etiology and management of both conditions. Observational epidemiologic studies indicate that lower consumption of fruits and vegetables is associated with an increased risk of oral precancerous lesions, a finding consistent with associations seen for oral cancers. Chemoprevention studies have evaluated the effects of supplemental nutrients (eg, β‐carotene; vitamins A, C, and E; selenium) on oral leukoplakia and oral dysplasia. Supplemental β‐carotene, in particular, has documented efficacy in the regression of oral precancerous lesions. However, supplemental β‐carotene may not be advisable in this patient population due to concerns about a possible increase in lung cancer risk. Retinoids also have documented efficacy in the regression of oral precancerous lesions, but retinoids can have considerable side effects, and long‐term efficacy in the prevention of oral cancer is unknown. Given these findings, encouraging increased fruit and vegetable intake for the prevention and management of oral precancerous lesions is prudent; all other nutritional approaches for these conditions remain investigational.
Stress and Distress in Clinical Practice: A Mind‐Body Approach
Authors: Selhub Eva M. 
Published: March 2003

AbstractPrimary care physicians are often taxed by patient complaints that do not seem to have a clear etiology, nor do the patients improve despite good medications and expensive procedures. Current studies show that stress or distress may have a significant effect on the onset, the course, and the management of many, if not all, diseases. Understanding patient's underlying stress physiology and coping mechanisms may enable physicians to better understand various clinical disorders and treat their manifested symptoms. Evidence is reviewed by which stress may exacerbate or cause illness and by which behavioral medicine interventions can improve clinical outcomes.
Approaches to equilibrium in the distribution of trace elements among the principal minerals in a high‐grade metamorphic terrane
Authors: Kretz  , Campbell  , Hoffman  , Hartree  , Teesdale  
Published: March 2003

X‐ray fluorescence, instrumental neutron activation, and particle‐induced X‐ray emission methods were used to determine the distribution of numerous trace elements among garnet (Grt), Ca‐pyroxene (Cpx), hornblende (Hbl), biotite (Bt), plagioclase (Pl) and K‐feldspar (Kf) in a high‐grade metamorphic terrane within the Grenville Province of the Canadian Shield. Results are presented as distribution formulae, e.g.Sr: Kf 1.1 Pl 16 Hbl 2.2 Cpx 1.0 Bt 1.2 GrtSc: Hbl 1.1 Cpx 1.0 Grt 7.8 Bt 22 Pl 2.6 KfV: Hbl 1.15 Bt 2.07 Cpx 6.0 Grt (1.4% CaO)>1 (Pl, Kf)Zn: Bt 1.6 Hbl 1.62 Cpx 2.9 Grt 10 PlGa: Bt 1.2 Hbl 1.2 Pl 2.5 Cpx 1.3 Grtwhere numbers are distribution ratios, e.g. ppm Sr in Hbl/ppm Sr in Cpx=2.2. Examples of inter‐element similarities and differences are (a) both Rb and Cs are concentrated in biotite relative to K‐feldspar, but for Rb the ratio is 2.3 and for Cs it is 16, (b) the distribution formulae for seven lanthanides are similar except for the position of garnet, e.g.Ce: Hbl 2.7 Cpx 2.8 Pl 1.1 Bt 11 Kf 16 GrtYb: Grt 2.8 Hbl 2.7 Cpx 9 Pl 1.0 Bt 7 Kfand (c) all of Sr, eight lanthanides, Zr, V and Cr are concentrated in hornblende relative to Ca‐pyroxene by a factor that lies in the narrow range of 2.2–3.1. There is a larger variation (departure from the mean) in some distribution ratios than in others. Thus the mean ratios (Hbl/Cpx) for each of six elements and in parentheses the percentage relative standard deviation are Zn 1.62 (8.6), V 2.38 (12), Cr 2.42 (18), Sr 2.7 (28), Ba 2.9 (36) and Ni 1.66 (38). We suggest that variation of this kind is the result of differences from place to place in the magnitude of deformation and recrystallization (which facilitated the rearrangement of atoms), combined with rates of lattice and crystal‐boundary diffusion that are unique for the various elements, thus permitting some trace elements to approach equilibrium more closely than others.
Eclogites in the Makuti gneisses of Zimbabwe: implications for the tectonic evolution of the Zambezi Belt in southern Africa
Authors: Dirks  , Sithole  
Published: March 2003

The gneisses of the Makuti Group in north‐west Zimbabwe are characterized by complex geometries that resulted from intense non‐coaxial deformation in a crustal scale high‐strain zone that accommodated extensional deformation along the axis of the Zambezi Belt at c. 800 Ma. Within low‐strain domains in the Makuti gneisses, undeformed metagabbroic lenses preserve eclogite and granulite facies assemblages, which record a part of the metamorphic history that predates Pan‐African events. Eclogitic rocks can be subdivided into: (1) corona‐textured metagabbros that preserve igneous textures, and (2) garnet–omphacite rocks in which primary textures are destroyed. The lenses of eclogitic rocks are enveloped in a mantle of garnet–clinopyroxene–hornblende gneiss, which is a common rock type in the Makuti gneisses. The eclogites preserve multi‐staged, domainal, symplectic reaction textures that developed progressively as the rocks experienced loading followed by decompression–heating. In the metagabbros, the original clinopyroxene, plagioclase and olivine domains acted separately during the peak of metamorphism, with plagioclase being replaced by garnet and kyanite, and olivine being replaced by orthopyroxene and possibly omphacite. The peak assemblage was overprinted by: (1) the multi‐mineralic corona assemblage pargasite–orthopyroxene–spinel–plagioclase replacing garnet–kyanite–clinopyroxene (possibly at c. 19 kbar, 760±25 °C); (2) orthopyroxene–pargasite–plagioclase–scapolite coronas replacing orthopyroxene (15±1.5 kbar, 750±50 °C); and (3) moats of orthopyroxene–plagioclase replacing garnet (10±1 kbar, 760±50 °C). The garnet–omphacite rocks record similar peak conditions (15±1.1 kbar, 760±60 °C). Garnet–clinopyroxene–hornblende–plagioclase gneisses envelop the eclogites and record matrix conditions of 11±1.5 kbar at 730±50 °C using assemblages that are oriented in the regional fabric. These rocks are characterized by decompression‐heating textures, reflecting temperature increases during exhumation of the Makuti gneisses.The eclogite facies rocks formed during a collisional event prior to 850 Ma. Their formation could be related to a suture zone that developed along the axis of the Zambezi Belt during the formation of Rodinia (between 1400 and 850 Ma). The main deformation‐metamorphism in the Makuti gneisses occurred around 800 Ma and involved extension and exhumation of the high‐P rocks (break‐up of Rodinia), which experienced a high‐T metamorphic overprint. Around 550–500 Ma, a collisional event associated with the formation of Gondwana resulted in renewed burial and metamorphic recrystallization of the Makuti gneisses.
P–T evolution of glaucophane–omphacite bearing HP–LT rocks in the western Tianshan Orogen, NW China:new evidence for ‘Alpine‐type’ tectonics
Authors: Klemd R. , Schröter F. C. , Will T. M. , Gao J. 
Published: March 2003

AbstractThe late Palaeozoic western Tianshan high‐pressure /low‐temperature belt extends for about 200 km along the south‐central Tianshan suture zone and is composed mainly of blueschist, eclogite and epidote amphibolite/greenschist facies rocks. P–T conditions of mafic garnet omphacite and garnet–omphacite blueschist, which are interlayered with eclogite, were investigated in order to establish an exhumation path for these high‐pressure rocks. Maximum pressure conditions are represented by the assemblage garnet–omphacite–paragonite–phengite–glaucophane–quartz–rutile. Estimated maximum pressures range between 18 and 21 kbar at temperatures between 490 and 570 °C. Decompression caused the destabilization of omphacite, garnet and glaucophane to albite, Ca‐amphibole and chlorite. The post‐eclogite facies metamorphic conditions between 9 and 14 kbar at 480–570 °C suggest an almost isothermal decompression from eclogite to epidote–amphibolite facies conditions. Prograde growth zoning and mineral inclusions in garnet as well as post‐eclogite facies conditions are evidence for a clockwise P–T path. Analysis of phase diagrams constrains the P–T path to more or less isothermal cooling which is well corroborated by the results of geothermobarometry and mineral textures. This implies that the high‐pressure rocks from the western Tianshan Orogen formed in a tectonic regime similar to ‘Alpine‐type’ tectonics. This contradicts previous models which favour ‘Franciscan‐type’ tectonics for the southern Tianshan high‐pressure rocks.
Blueschist facies metamorphism of peralkaline rhyolites from the Tenda crystalline massif (northern Corsica): evidence for involvement in the Alpine subduction event?
Authors: Tribuzio R. , Giacomini F. 
Published: March 2003

AbstractThe Tenda crystalline massif (northern Corsica) is a fragment of the western Corsica basement involved in the Alpine orogeny. Rhyolite dykes crosscutting the gabbroic complex of Bocca di Tenda (southern sector of the Tenda crystalline massif) show an unusual metamorphic mineral assemblage, defined by jadeite‐bearing (up to 46 mol percentage) aegirine, riebeckite, celadonite‐rich phengite (Si=3.50–3.65 apfu), quartz, albite and K‐feldspar. Jadeite‐bearing aegirine and riebeckite mostly occur as coronas around jadeite‐free aegirine and arfvedsonite, respectively, which both are relics of igneous origin. This metamorphic assemblage reflects the peralkaline compositions, which are characterised by anomalously high contents of SiO2 and Na2O, and negligible CaO and MgO. The evolved rocks of the gabbroic sequence (quartz‐diorites to tonalites) and the surrounding granitoids are characterised by the development of riebeckite/ferroglaucophane, epidote, celadonite‐rich phengite and albite, thus pointing to a metamorphic crystallization in the epidote‐blueschist facies. In all the studied rocks, metamorphic reactions were controlled by fluid‐assisted mass‐transfer through grain boundaries and microfractures. The different mineral assemblages allow the peak P–T metamorphic conditions to be constrained to between 0.8 GPa/300 °C and 1.1 GPa/500 °C. These estimates attest to a geothermal gradient (dT/dP) of 10–13 °C km−1 and indicate that the Tenda crystalline massif was buried to a minimum depth of 27 km during the Alpine orogeny. The blueschist facies recrystallization in the Tenda crystalline massif has been related to the cessation of an eastward‐dipping subduction event.
ACID‐BASE IN RENAL FAILURE: Disturbances of Acid‐Base Balance and Bone Disease in End‐Stage Renal Disease
Authors: Kraut Jeffrey A. 
Published: March 2003

ABSTRACTBone disease in patients with chronic renal failure (CRF) is thought to be the consequence primarily of the interplay of several factors, including the serum levels of parathyroid hormone (PTH), vitamin D, calcium, and phosphorus, and exposure to bone toxins such as aluminum or amyloid. Recently the metabolic acidosis noted with CRF has been implicated as an additional factor contributing to the genesis of bone disease. Although metabolic acidosis might be the dominant factor in the cause of bone disease in some instances, more commonly this acid‐base disturbance interacts with other factors contributing to the development of bone disease. The following article summarizes the data in support of an important role for metabolic acidosis in the genesis of bone disease in patients with CRF and presents our recommendations for treatment of uremic acidosis to prevent or treat the bone disease.
Ultrapure Dialysate: A Desirable and Achievable Goal for Routine Hemodialysis
Authors: Ward Richard A. 
Published: March 2003

ABSTRACTUnited States standards for the microbiologic quality of dialysate are not very stringent and have remained unchanged for more than 20 years, despite significant changes in the patient population and in the technology of hemodialysis. Numerous studies have demonstrated that bacterial products can cross dialysis membranes and stimulate an inflammatory response in the patient. Inflammation has been implicated in several complications associated with long‐term hemodialysis therapy, and the use of ultrapure dialysate has been shown to reduce the incidence of one of these complications, β2‐microglobulin amyloidosis. Since technological innovations in water treatment and improvements in dialysis machine design allow the routine production of ultrapure dialysate, its use should now become standard.
Serum Albumin: Its Significance in Patients with ESRD
Authors: Steinman Theodore I. 
Published: March 2003

ABSTRACTHypoalbuminemia is a major risk factor for morbidity and mortality in the ESRD population. The Core Indicators Project notes that the serum albumin value is a measure of the patient's nutritional status. Since 1994 every outcome parameter of the Core Indicators Project has shown improvement except for the serum albumin measurement. While the serum albumin level is a measure of the visceral protein pool size, a decrease in albumin synthesis is due to more than poor nutritional intake (in part related to inadequate dialysis). Acute‐phase reactants and the plasma volume status are other major factors that impact on serum albumin determination. Plasma volume expansion, albumin redistribution, exogenous loss (in peritoneal dialysis patients), and decreased albumin synthesis all contribute to hypoalbuminemia. Understanding the cause (s) of hypoalbuminemia will allow us to target treatment modalities directed at correcting the hypoalbuminemia. It is still unknown if the serum albumin can be effectively raised in the chronic dialysis patient. Also unknown is whether an increase in the serum albumin level can alter long‐term morbidity and mortality. We should not be using serum albumin as an indicator of adequate dialysis or nutritional status since the causes of hypoalbuminemia are multifactorial. It is recommended that the serum albumin level be eliminated as an indicator of nutritional status in the ESRD patient.
Reconciling Differences in Effective Solute Removal Between Intermittent and Continuous Therapies
Authors: Clark William R. , Ronco Claudio 
Published: March 2003

ABSTRACTSolute removal by various forms of renal replacement therapy (RRT) differs from that occurring in the native kidney in several ways. Among the dialytic therapies, the relationship between clearance and mass removal rate may differ substantially. The purpose of this article is to review the various approaches that have been proposed to account for this differing relationship among the various types of RRT. Specific quantitative approaches along with clinical applications are provided.
Uremic Toxicity: Urea and Beyond
Authors: Depner Thomas A. 
Published: March 2003

ABSTRACTSuccessful replacement of renal function with dialysis supports the concept that uremia is a toxic state resulting from accumulated solutes and that toxicity results from high concentrations of these solutes in body fluids. Dialyzer clearance of urea, a surrogate toxin, is the currently accepted best measure of dialysis and dialysis adequacy, but it is admittedly a compromise due to current lack of knowledge about and inability to measure more toxic solutes. This failure could be explained if uremic toxicity is actually a summation effect of multiple toxins, each at individual subtoxic levels in the patient. Other solutes could be used as surrogates to measure clearance, but urea happens to be available in high concentrations, is easily measured by all clinical laboratories, and is easily dialyzed, so changes in concentration are sensitive indicators of clearance. Measurements of creatinine clearance are confounded by the disequilibrium that occurs across red cells within the dialyzer and in the patient. Other solutes probably behave more like creatinine than urea, so urea stands out as uniquely diffusible, a property that actually spoils its effectiveness as a surrogate toxin, especially when applied to more frequent and continuous dialysis. Accumulation of other solutes may correlate better with toxic uremic symptoms and the residual syndrome. More studies are needed to examine the kinetics of other solutes, their generation rates, and their distribution volumes to provide clinicians with more knowledge and tools to optimize dialysis treatments. Examination of the effectiveness of solute removal in patients dialyzed more frequently may provide significant insight into the pathogenesis of uremia.