bluuebunny/crossref_metadata_2025 huggingface dataset:
Directed differentiation of embryonic stem cells: Genetic and epigenetic methods
Authors: O'SHEA K. SUE
Published: March 2003

Embryonic stem cells are derived from the inner cell mass of the pre‐implantation blastocyst, and can both self‐renew and differentiate into all the cells and tissues of the body. The embryonic stem cell is an unsurpassed starting material to begin to understand a critical, largely inaccessible, period of development, as well as an important source of cells for transplantation and gene therapy. Despite their potential, attempts to obtain specific cell types from embryonic stem cells have been only partially successful because many of the growth factor combinations and developmental control genes involved in cell type restricted differentiation are unknown. This article summarizes some of the recent advances in promoting lineage restricted differentiation of embryonic stem cells, focusing on growth factor manipulation, or genetically altering embryonic stem cells to produce a desired phenotype. The two approaches epitomize current scientific concerns regarding the therapeutic use of these cells; genetic alterations will produce more pure cells with the risk of increasing the likelihood of malignant transformation; epigenetic methods for the manipulation of stem cell phenotype are often incomplete and remaining pluripotent cells are likely to form teratomas. As more is known about lineage specification during development, it will be possible to more precisely control cell type specification.
The role of progenitor cells in repair of liver injury and in liver transplantation
Authors: SELL STEWART
Published: March 2003

There are three levels of cells in the hepatic lineage that respond to injury or carcinogenesis: the mature hepatocyte, the ductular “bipolar” progenitor cell, and a putative periductular stem cell. Hepatocytes are numerous, and respond rapidly to liver cell loss by one or two cell cycles but can only produce other hepatocytes. The ductular progenitor cells are less numerous, may proliferate for more cycles than hepatocytes, and are generally considered “bipolar,” i.e., they can give rise to biliary cells or hepatocytes. Periductular stem cells are rare in the liver, have a very long proliferation potential, and may be multipotent. Extrahepatic (bone marrow) origin of the periductular stem cells is supported by recent data showing that hepatocytes may express genetic markers of donor hematopoietic cells after bone marrow transplantation. These different regenerative cells with variations in potential for proliferation and differentiation may provide different sources of cells for liver transplantation: hepatocytes for treatment of acute liver damage, liver progenitor cell lines for liver‐directed gene therapy, and bone marrow‐derived cells for chronic long‐term liver replacement. A limiting factor in the success of liver cell transplantation is the condition of the hepatic microenvrionment in which the cells must proliferate and set up housekeeping.
Transforming growth factor‐β levels during second‐ intention healing are related to the different course of wound contraction in horses and ponies
Authors: Van Den Boom Robin , Wilmink Jacintha M. , O'Kane Sharon , Wood Jason , Ferguson Mark W. J.
Published: March 2003

Wound healing in horses is often complicated by wound infection, exuberant granulation tissue, and hypertrophic scars, especially when wounds are located on the limbs. Wound healing in ponies is less problematic, characterized by a greater degree of wound contraction and a more intense initial inflammatory response. Because both processes are influenced by transforming growth factor‐β (TGF‐β), it was hypothesized that the better wound healing in ponies was associated with different TGF‐β profiles. A series of small wounds was created on the distal limbs and hindquarters of ponies and horses. Tissue samples were harvested on alternate days until day 13 postwounding, and levels of total and active TGF‐β were determined. Levels of TGF‐β were significantly higher in pony wounds than in those of horses. The TGF‐β profile differed between limb and body wounds, with levels in body wounds decreasing at the end of the experiment and persisting in limb wounds. In ponies, the higher TGF‐β levels can, to a large extent, explain the more intense inflammatory response and may explain the greater degree of wound contraction. Apparently adequate levels in the limbs fail to result in greater wound contraction, probably because of a stronger fixation of the skin. The persistence of elevated levels of TGF‐β may result in the production of exuberant granulation tissue. Further research on the temporal patterns of the different TGF‐β isoforms seems indicated, because manipulation of TGF‐β levels appears to be a promising option for intervention in problematic wound healing in horses.(WOUND REP REG 2002;10:)
Mast cells modulate the inflammatory but not the proliferative response in healing wounds
Authors: Egozi Eric I. , Ferreira Ahalia M. , Burns Aime L. , Gamelli Richard L. , Dipietro Luisa A.
Published: March 2003

Upon stimulation, mast cells release a heterogeneous group of factors that promote inflammation and influence cell proliferation. Mast cells accumulate at sites of injury, further suggesting a critical role in wound healing. To assess the importance of mast cells in tissue repair, we compared wound healing in mast cell–deficient WBB6F1/J‐KitW/KitW–v (KitW/KitW–v) and wild type WBB6F1/++ (WT) mice. During the inflammatory phase, neutrophil infiltration into wounds of the KitW/KitW–v mice was significantly less than that of WT mice (84.6 ± 10.3 vs. 218 ± 26.0 cells/10 high‐power fields at day 3, p < 0.001), while wound macrophage and T cell infiltration were similar in both strains. The decrease in neutrophils could not be explained by changes in tumor necrosis factor‐α or macrophage inflammatory protein‐2 levels, because the amounts of these two neutrophil chemoattractants were similar in both KitW/KitW–v and WT mice. Surprisingly, the absence of mast cells had no effect on the proliferative aspects of wound healing, including reepithelialization, collagen synthesis, and angiogenesis. Although mast cells are known to release proangiogenic mediators, vascular endothelial growth factor levels were similar in WT and KitW/KitW–v mice. Moreover, levels of fibroblast growth factor‐2 were increased in KitW/KitW–v mice (4206 ± 107 vs. 1865 ± 249 pg/ml, p < 0.01). These results suggest that mast cells modulate the recruitment of neutrophils into sites of injury, yet indicate that mast cells are unlikely to exert a major influence on the proliferative response within healing wounds. (WOUND REP REG 2003;11:46–54)
Melanocytes do not migrate directionally in physiological DC electric fields
Authors: Grahn Jennifer C. , Reilly Debra A. , Nuccitelli Richard L. , Isseroff R. Rivkah
Published: March 2003

Wounding skin generates an endogenous electric field of 100–200 mV/mm in the immediate vicinity of the wound. When keratinocytes are exposed to direct current electric fields of this magnitude, they exhibit galvanotaxis, or directional migration toward the cathode, suggesting that wound‐generated electric fields provide migrational cues that contribute to wound healing. Because melanocytes must also migrate into the healing wound to repigment it, their motility in response to electric fields of physiologic magnitude was examined. Human skin–derived melanocytes, either exposed to 100 mV/mm direct current electric fields or nonexposed controls, both exhibited motility rates of 9 µm/hour, significantly (three‐ to five‐fold) lower than the motility rates of keratinocytes under identical conditions. However, in sharp contrast to keratinocytes, melanocytes exhibited no directional migration in the electric field. Additionally, neither the number of primary dendrites per cell, nor the orientation of the dendrites with respect to the field vector, nor the average length of the dendrites was significantly different in melanocytes exposed to the electric field as compared to nonexposed controls. Thus, in marked contrast to keratinocytes, human skin–derived melanocytes do not respond to direct current electric fields of physiologic magnitude with either directional migration or reorientation of dendrites. This may account for the delay in repigmentation that often accompanies wound reepithelialization. (WOUND REP REG 2003;11:64–70)
Contrasting responses of Rb–Sr systematics to regional and contact metamorphism, Laramie Mountains, Wyoming, USA
Authors: PATEL*  , FROST  , FROST
Published: March 2003

Archean supracrustal sequences of pelitic, quartzitic, calcareous and mafic compositions in the central Laramie Mountains, Wyoming, have been affected by two metamorphic events: a 1.78 Ga amphibolite‐grade regional metamorphism, and a 1.43 Ga contact metamorphism resulting from the intrusion of the Laramie Anorthosite Complex (LAC). Rb–Sr whole‐rock isotopic data from both outside and within the LAC contact aureole define a linear array that lies along a 1.78 Ga isochron. This date has been independently established as the time of amphibolite facies regional metamorphism associated with collision of the Archean Wyoming province and the Proterozoic Colorado province along the Cheyenne belt. The Rb–Sr isotopic data require that Sr was redistributed during regional metamorphism on a scale of at least tens of metres. Although within the 2 km‐wide aureole of LAC the pelitic rocks were thermally metamorphosed at temperatures greater than 800 °C, none of the whole‐rock Rb–Sr data from samples within the LAC aureole show evidence of resetting at 1.43 Ga. It is interpreted that the regional metamorphism involved fluid transport which facilitated Sr isotopic resetting, whereas the contact metamorphism occurred in a relatively dry environment in which isotopic mobility was restricted to centimetre‐scale or less. Rb–Sr data for biotite, feldspar and whole rock from a regional metamorphosed pelitic schist give an isochron age of 1450±40 Ma, which is interpreted as a cooling age resulting from crustal uplift. Rb–Sr data for biotite, quartz+feldspar and whole rock from a pelitic schist affected by contact metamorphism give an isochron age of 1420±43 Ma, the time of isotopic re‐equilibration in response either to crustal uplift or to both contact metamorphism and crustal uplift. This study demonstrates that although the response of isotopic systems to metamorphism is complex, isotopic data provide insight into metamorphic processes that is difficult to obtain by other means.
Petrology and P–T path of the Fuping mafic granulites: implications for tectonic evolution of the central zone of the North China craton
Authors: Zhao G. C. , Wilde S. A. , Cawood P. A. , Lu L. Z.
Published: March 2003

The Fuping Complex and the adjoining Wutai and Hengshan Complexes are located in the central zone of the North China craton. The dominant rock types in the Fuping Complex are high‐grade tonalitic–trondhjemitic–granodioritic (TTG) gneisses, with minor amounts of mafic granulites, syntectonic granitic rocks and supracrustal rocks. The petrological evidence from the mafic granulites indicates three stages of metamorphic evolution. The M1 stage is represented by garnet porphyroblasts and matrix plagioclase, quartz, orthopyroxene, clinopyroxene and hornblende. Orthopyroxene+plagioclase symplectites and clinopyroxene+plagioclase±orthopyroxene coronas formed in response to decompression during M2 following the peak metamorphism at M1. Hornblende+plagioclase symplectites formed as a result of further isobaric cooling and retrograde metamorphism during M3. The P–T  estimates using TWQ thermobarometry are: 900–950 °C and 8.0–8.5 kbar for the peak assemblage (M1), based on the core compositions of garnet, matrix pyroxene and plagioclase; 700–800 °C and 6.0–7.0 kbar for the pyroxene+plagioclase symplectites or coronas (M2); and 550–650 °C and 5.3–6.3 kbar for the hornblende+plagioclase symplectites (M3), based on garnet rim and corresponding symplectic mineral compositions. These P–T  estimates define a clockwise P–T  path involving near‐isothermal decompression for the Fuping Complex, similar to the P–T  path estimated for the metapelitic gneisses. The inferred P–T  path suggests that the Fuping Complex underwent initial crustal thickening, subsequent exhumation, and finally cooling and retrogression. This tectonothermal path is similar to P–T  paths inferred for the Wutai and Hengshan Complexes and other tectonic units in the central zone of the North China craton, but different from anti‐clockwise P–T paths estimated for the basement rocks in the eastern and western zones of the craton. Based on lithological, structural, metamorphic and geochronological data, the eastern and western zones of the craton are considered to represent two different Archean to Paleoproterozoic continental blocks that amalgamated along the central zone at the end of Paleoproterozoic. The P–T paths of the Fuping Complex and other tectonic units in the central zone record the collision between the eastern and western zones that led to the final assembly of the North China craton at c. 1800 Ma.
Geochemical constraints of the eclogite and granulite facies metamorphism as recognized in the Raobazhai complex from North Dabie Shan, China
Authors: Xiao Y. L. , Hoefs J. , Van Den Kerkhof A. M. , Li S. G
Published: March 2003

A combined study of major and trace elements, fluid inclusions and oxygen isotopes has been carried out on garnet pyroxenite from the Raobazhai complex in the North Dabie Terrane (NDT). Well‐preserved compositional zoning with Na decreasing and Ca and Mg increasing from the core to rim of pyroxene in the garnet pyroxenite indicates eclogite facies metamorphism at the peak metamorphic stage and subsequent granulite facies metamorphism during uplift. A P–T path with substantial heating (from c. 750 to 900 °C) after the maximum pressure reveals a different uplift history compared with most other eclogites in the South Dabie Terrane (SDT). Fluid inclusion data can be correlated with the metamorphic grade: the fluid regime during the peak metamorphism (eclogite facies) was dominated by N2‐bearing NaCl‐rich solutions, whereas it changed into CO2‐dominated fluids during the granulite facies retrograde metamorphism. At a late retrograde metamorphic stage, probably after amphibolite facies metamorphism, some external low‐salinity fluids were involved. In situ UV‐laser oxygen isotope analysis was undertaken on a 7 mm garnet, and impure pyroxene, amphibole and plagioclase. The nearly homogeneous oxygen isotopic composition (δ18OVSMOW = c. 6.7‰) in the garnet porphyroblast indicates closed fluid system conditions during garnet growth. However, isotopic fractionations between retrograde phases (amphibole and plagioclase) and garnet show an oxygen isotopic disequilibrium, indicating retrograde fluid–rock interactions. Unusual MORB‐like rare earth element (REE) patterns for whole rock of the garnet pyroxenite contrast with most ultra‐high‐pressure (UHP) eclogites in the Dabie‐Sulu area. However, the age‐corrected initial εNd(t) is − 2.9, which indicates that the protolith of the garnet pyroxenite was derived from an enriched mantle rather than from a MORB source. Combined with the present data of oxygen isotopic compositions and the characteristic N2 content in the fluid inclusions, we suggest that the protolith of the garnet pyroxenite from Raobazhai formed in an enriched mantle fragment, which has been exposed to the surface prior to the Triassic metamorphism.
Crack‐fill porphyroblastesis
Authors: Barker Andrew J.
Published: March 2003

Garnet‐mica schists from the Scottish Highlands provide new insight into an important mechanism of phyllosilicate growth, termed ‘crack‐fill porphyroblastesis’. It is shown that grain boundary dilatancy, microcracking and porphyroblast‐matrix decoupling all play a significant role in facilitating growth in regimes of noncoaxial shear.

 With respect to chlorite porphyroblasts, there are three growth stages. Following nucleation, the initial phase of growth is by progressive matrix replacement, to preserve inclusion trails of fine carbonaceous material. The second growth stage produced new optically continuous inclusion‐free chlorite on the {001} margins of those crystals at a high angle to the schistosity. This growth results from decoupling at the porphyroblast–matrix contact on those margins at a high angle to the principal axis of extension. The development of dilatant cracks at porphyroblast margins provides a sink for material migrating down Pf and chemical potential gradients. This causes precipitation of new optically continuous ‘clear’ chlorite on the pre‐existing, heavily included core. The porphyroblast–matrix boundary continues to dilate after porphyroblast growth had terminated, producing plano‐convex quartz‐rich strain shadows.

 Similar growth behaviour is recognised in biotite porphyroblasts, indicating that ‘crack‐fill porphyroblastesis’ is an important growth mechanism for phyllosilicates in actively deforming metamorphic rocks. It also indicates that decoupling and crack‐fill development at porphyroblast margins could be important in controlling the pattern of material transfer, and may have significant implications for matrix permeability and fluid‐flow characteristics.
The development of spiral‐shaped inclusion trails during multiple metamorphism and folding
Authors: Bell T. H. , Chen A.
Published: March 2003

Three periods of mineral growth and three generations of spiral‐shaped inclusion trails have been distinguished within folded rocks of the Qinling‐Dabie Orogen, China, using the development of three successive and differently trending sets of foliation intersection axes preserved in porphyroblasts (FIAs). This progression is revealed by the consistent relative sequence of changes in FIA trends from the core to rim of garnet porphyroblasts in samples with multiple FIAs. The first and second formed sets of FIAs trend oblique to the axial planes of macroscopic folds that dominate the outcrop pattern in this region. The porphyroblasts containing these FIAs grew prior to the development of the macroscopic folds, yet the FIAs do not change orientation across the fold hinges. The youngest formed FIAs (set 3) lie subparallel to the axial planes of these folds and the porphyroblasts containing these FIAs formed in part as the folds developed. The deformation associated with all three generations of spiral‐shaped inclusion trails in garnet porphyroblasts involved the formation of subhorizontal and subvertical foliations against porphyroblast rims accompanied by periods of garnet growth; pervasive structures have not necessarily formed in the matrix away from the porphyroblasts. The macroscopic folds are heterogeneously strained from limb to limb, doubly plunging and have moderately dipping axial planes. The consistent orientation of Set 1 FIAs indicates that the development of spiral‐shaped inclusion trails in porphyroblasts with FIAs belonging to Set 2 did not involve rotation of the previously formed porphyroblasts. The consistent orientation of Sets 1 and 2 FIAs indicate that the development of spiral‐shaped inclusion trails in porphyroblasts with FIAs belonging to Set 3 did not involve rotation of the previously formed porphyroblasts during folding. This requires a fold mechanism of progressive bulk inhomogeneous shortening and demonstrates that spiral‐shaped inclusion trails can form outside of shear zones.
ACID‐BASE IN RENAL FAILURE: Acidosis in Chronic Renal Insufficiency
Authors: Uribarri Jaime
Published: March 2003

In this article we deal with three aspects of acidosis in patients with chronic renal insufficiency: clinical characteristics, pathophysiology, and therapeutic approach.
ACID‐BASE IN RENAL FAILURE: Use of Different Buffers in Peritoneal Dialysis
Authors: Feriani Mariano
Published: March 2003

A buffer is included in the peritoneal dialysis solution in order to offset the hydrogen ions normally produced during the metabolic processes. Nowadays, the buffer used is lactate, and its concentration in conventional peritoneal dialysis fluids is 35 or 40 mmol/L. Despite the general thought that peritoneal dialysis adequately corrects uremic acidosis, several studies have demonstrated that more than 50% of patients present mild to moderate acidosis with the solution containing 35 mmol/L of lactate, although with a 40 mmol/L solution this percentage decreases, a substantial number of patients still remain acidotic. This acid‐base derangement is characterized by a normal pH and a below‐normal plasma bicarbonate concentration, although the external body base balance is in equilibrium. There is evidence that this condition contributes to uremic osteodystrophy and has a detrimental effect on protein metabolism. Conventional solutions also affect mesothelial cell viability and local leukocyte function and have potential systemic effects such as the impairment of cellular redox state. New solutions containing pure bicarbonate or a mixture of bicarbonate and lactate have recently been investigated. A bicarbonate solution containing 34 mmol/L significantly increased plasma bicarbonate levels as compared with the lactate 35 mmol/L solution. It has been demonstrated that bicarbonate solutions have better biocompatibility than the lactate buffered solution and substantially reduce abdominal discomfort experienced by a certain percentage of patients during the solution infusion. These studies demonstrated that the bicarbonate‐buffered CAPD solution is safe, well‐tolerated, and does not present any, even potential, side effects. Thus, it seems reasonable to consider the bicarbonate buffered solution the standard instead of the alternative, and it might entirely replace lactate as buffer in peritoneal dialysis fluid.
Racial Inequity in America's ESRD Program
Authors: Reddan Donal N. , Szczech Lynda Anne , Klassen Preston S. , Owen William F.
Published: March 2003

The end‐stage renal disease (ESRD) program has a significant overrepresentation of racial and ethnic minority groups. The increased susceptibility of nonwhite populations to ESRD has not been fully explained and probably represents a complex interplay of genetic, cultural, and environmental influences. Because the program delivers care under a uniform health care payment system, it represents a unique environment in which to explore variation in health care delivery. A number of disparities in outcomes and delivery of ESRD care have been noted for racial minority participants. These include possible overdiagnosis of hypertensive nephrosclerosis, decreased provision of renal replacement therapy, limited referral for home dialysis modalities, underprescription of dialysis, increased use of synthetic grafts rather than fistulas as permanent angioaccess, and delayed wait‐listing for renal transplantation. Transplantation inequities mean that black patients are likely to remain on dialysis relatively longer, so that their susceptibility to less than optimal processes of care increases disproportionately. Improved survival and quality of life (QOL) for blacks with ESRD may have encouraged provider complacency about racial disparities in the ESRD program and in particular about referral for transplantation. It is also apparent that minority ESRD patients may, similar to their non‐ESRD counterparts, be referred less frequently for invasive cardiovascular (CV) procedures. Despite these observations of inequality in ESRD care, the adjusted mortality for minority participants in the ESRD program are better than for the majority population. This seeming paradox may define an opportunity to improve outcomes for minorities with ESRD even more.
Dialysis‐Related Amyloidosis After Renal Transplantation
Authors: Campistol Josep M.
Published: March 2003

There is no effective therapy for dialysis‐related amyloidosis (DRA). The restoration of renal function with a functional graft seems the most reasonable therapy for this disturbing disease. Although there are not many prospective series on the efficacy of renal transplantation for DRA, all the studies agree that most of the patients experienced a significantly clinical improvement of the articular symptoms after a successful renal transplantation. Nevertheless, radiologic (bone cysts) and histologic lesions did not disappear after long‐term follow‐up.
Blood Flow Surveillance of Hemodialysis Grafts and the Dysfunction Hypothesis
Authors: Paulson William D.
Published: March 2003

It is widely recommended that hemodialysis graft surveillance programs should be implemented and that significant stenosis should be corrected when it is accompanied by graft dysfunction. The rationale for surveillance depends on the dysfunction hypothesis, which states that stenosis causes graft dysfunction [such as a decrease in graft blood flow (Qa)], and this dysfunction reliably precedes and accurately predicts thrombosis. The usefulness of Qa surveillance depends on accurate prediction of thrombosis so that stenosis can be corrected prior to thrombosis. An analysis of the dysfunction hypothesis indicates that some or all of its underlying assumptions are invalid. Most importantly, the presence of wide hemodynamic variation during Qa measurements makes Qa a relatively inaccurate predictor of thrombosis. A number of studies have evaluated the value of surveillance with intervention in reducing thrombosis rates and prolonging graft life. Review of these studies show that few have been prospective and randomized, and many have included historical control groups. It is debatable whether these studies have established that Qa surveillance with intervention should be applied to all grafts. Data from several studies suggest that severity of stenosis may be at least as accurate as Qa in predicting thrombosis. Consequently, inclusion of stenosis measurements (e.g., by duplex ultrasound) may improve the results of surveillance. These unresolved issues indicate it is premature to recommend routine Qa surveillance with intervention of all hemodialysis patients with grafts.
Factors Affecting Hemodialysis and Peritoneal Dialysis Efficiency
Authors: Ronco Claudio , Clark William
Published: March 2003

Hemodialysis and peritoneal dialysis are two blood purification techniques that use similar operating systems. The hemodialysis system is based on three components (blood, membrane, and dialysate). The peritoneal dialysis system is based on the same components that can, however, be less manipulated and adjusted. In hemodialysis the blood flow is the main determinant of small solute removal thanks to a prevalently diffusive mechanism. Convection is also used to transport larger solutes across the membrane, but this mechanism relies on the high permeability coefficient of the membrane and high transmembrane pressure leading to high ultrafiltration rates. The membrane can therefore influence the performance of the techniques as far as solute removal and ultrafiltration are concerned. Finally, diffusion is facilitated by an improved distribution of dialysate flow in the dialysate compartment. This can be achieved with a special dialysate pathway configuration based on space yarns or micronodulation of the fibers. In peritoneal dialysis, blood flow and membrane characteristics can be less manipulated or almost not at all. The only variables are dialysate volume, flow, dwell time, and composition. Thanks to modification in these aspects of the dialysate, peritoneal dialysis techniques with different clearances and ultrafiltration rates can be accomplished.
Quantification of Middle Molecular Weight Solute Removal in Dialysis
Authors: Henderson Lee W. , Clark William R. , Cheung Alfred K.
Published: March 2003

The pioneering work of Gotch emphasized the critical need to be quantitative with respect to treatment prescription. Through his meticulous derivations and analyses regarding Kt/Vurea, he has provided powerful insight into the standard therapy prescriptions that we now employ clinically. However, time has seen the proliferation of treatment techniques, most of which are too “young” to have been characterized with respect to clinical outcomes. Further, the relationship between removal of urea and removal of middle molecular size solutes associated with these newer techniques deviates from that associated with conventional, clinically qualified techniques. In this article we examine the solute clearance profile of some of these new methodologies and their relationship to current criteria for treatment adequacy. Our approach is to discuss components of the overall transport process and then utilize modeling of surrogate molecules over the size range of interest whose transport characteristics are known. Alteration in the solute clearance profile of these surrogate markers in response to changes in prescription variables will thus offer insight into the spectrum of toxic middle molecules that are removed when size, space of distribution, and generation rate are known.
Past, Present, and Future of Quantified Peritoneal Dialysis
Authors: Haq Naveed U. , Nolph Karl D.
Published: March 2003

The role of peritoneal dialysis (PD) as a modality in renal replacement therapy has been well established. In this article we review various aspects in the evolution of PD, with special emphasis on adequacy. Until the late 1950s PD was still considered as a last resort in the treatment of terminal uremia. The introduction of a chronic indwelling catheter made chronic PD possible. The concept of continuous ambulatory peritoneal dialysis (CAPD), proposed in 1975, had a major impact on the way PD was performed later. The value of determining the adequacy, using urea clearance normalized to total body water (Kt/V) or creatinine clearance normalized to body surface area, was clearly highlighted by the Canada‐USA (CANUSA) study. Introduction of standardized peritoneal equilibration tests has been very helpful in enhancing the efficiency of PD. In 1995 the National Kidney Foundation‐Dialysis Outcomes Quality Initiatives (NKF‐DOQI) established guidelines to improve patient survival and outcome on dialysis. These guidelines established minimum criteria for PD adequacy. Compliance and malnutrition remain important factors determining the efficacy of PD. The “healthy start” concept emphasizes an early start of dialysis in patients with end‐stage renal disease (ESRD). The quest for an ideal PD modality has recently led to renewed interest in the idea of continuous flow peritoneal dialysis (CFPD). PD continues to grow and at the same time faces many challenges. Its role as a renal replacement therapy is likely to evolve further in the years to come.
Continuous Flow Peritoneal Dialysis: Solution Formulation and Biocompatibility
Authors: Passlick‐Deetjen Jutta , Lage Cristina , Jörres Achim
Published: March 2003

When peritoneal dialysis was introduced several years ago an important alternative dialysis therapy to hemodialysis was made available for the treatment of end‐stage chronic disease. However, a continuous search for new developments and technologies is necessary to find the optimal peritoneal dialysis fluid (PDF) to preserve peritoneal membrane function as long as possible. Conventional PDFs are known to compromise the functional integrity of the peritoneal membrane as a consequence of their acidic pH in combination with their high lactate content, as well as the high concentrations of glucose and glucose degradation products (GDPs) present in currently used conventional solutions. Novel solutions such as bicarbonate‐buffered PDF (at neutral pH) display improved in vitro biocompatibility as compared to conventional, acidic lactate‐buffered PDF. Since these novel solutions are manufactured in dual‐chambered bags they also contain fewer GDPs, thus further reducing their potential toxicity and protein glycation. Clinically the novel solutions reduce inflow pain and improve peritoneal membrane transport characteristics, ultrafiltration capacity, and effluent markers of peritoneal membrane integrity. The concept of continuous flow peritoneal dialysis (CFPD) is another approach to optimize PDF. The technique of CFPD not only enables the individualization of acid‐base correction by variable concentrations of HCO3− but may also help to restore peritoneal cell functions by neutral pH, reduced glucose load, diminished GDP content, and reduced advanced glycation end product (AGE) formation, thereby potentially contributing to the improved preservation of peritoneal membrane function.
Where Are All the AV Fistulas?
Authors: Sands Jeffrey , Perry Mike
Published: March 2003

Increasing the prevalence of arteriovenous (AV) fistulas is crucial to decreasing the incidence and costs of dialysis access failure. Despite almost uniform agreement in the dialysis community of the need to increase AV fistulas, U.S. fistula prevalence has only increased modestly since the publication of the Dialysis Outcomes Quality Initiative (DOQI) clinical practice guidelines in 1997. Fistula rates of 28% in incident patients and 27% in prevalent patients [Health Care Finance Administration (HCFA) clinical performance measures project data for 1999] do not approach the fistula rates achieved by various focused U.S. programs, nor those routinely observed in Europe. Systemic barriers that limit the availability and funding of both pre‐end‐stage renal disease (ESRD) care and preoperative imaging, coupled with financial disincentives, lack of accountability, and educational deficiencies, impede progress toward increased fistula placement. Improvements in AV fistula prevalence require a realistic appraisal and correction of the system problems hindering achievement of this goal. The DOQI and Kidney Disease Outcomes and quality Initiative (K/DOQI) were excellent first steps; however, implementation will require modification of other structures that impact on patient care delivery.
Imaging in the Dialysis Patient: Renal Imaging in Patients Requiring Renal Replacement Therapy
Authors: Cowie Alistair
Published: March 2003

Recent advances in imaging technology and interventional radiologic procedures have resulted in an increased variety of radiological techniques that can be used to assess patients who present with renal failure and require renal replacement therapy. This chapter provides an overview of the relative strengths and weaknesses of the available imaging methods. In particular, it covers the expanding role of the cross‐sectional, noninvasive, multiplanar imaging techniques such as gray‐scale and Doppler ultrasound, magnetic resonance imaging (MRI) and angiography (MRA), and nonenhanced helical or multislice computed tomography (CT). These imaging methods are increasingly replacing those used in the past, such as the conventional radiographic urogram, which requires a high dose of intravenous contrast media, and digital subtraction arteriography. The chapter also covers the radiologic investigation of complications of acquired renal cystic disease, including renal cell carcinoma, hemorrhage, cyst infection and rupture, and nephrolithiasis.
Automated Peritoneal Dialysis Symposium: Determinants in APD Selection
Authors: Wilson Jimmy , Nissenson Allen R.
Published: March 2003

Automated peritoneal dialysis (APD) is the most prevalent form of peritoneal dialysis in the United States. Optimizing the success of this treatment requires appropriate patient selection; however, there are few data available on which patients are most likely to benefit the most from this form of therapy. The key factors to evaluate when APD is being considered include patient preferences and lifestyle, patient age, solute transport characteristics, residual renal function (RRF), cost, dialysis adequacy targets, and the potential for complications of therapy. Patients who prefer home dialysis at night, children, those with high average or high peritoneal transport characteristics, and those with significant RRF are ideal candidates for APD. Because of the flexibility that is possible in prescribing this form of dialysis, APD can be successfully performed in individuals who do not meet this ideal profile, and it can be an excellent form of dialysis, particularly as part of an integrated care program for patients with end‐stage renal disease (ESRD).
Incidental Carcinoma of the Prostate in the PSA Era
Authors: Galejs Laris E. , Hollander Jay B.
Published: March 2003

Background: Prostate cancer has classically been discovered in 10% of prostatectomy specimens from presumed benign disease. Our objective was to review incidental cancer in transurethral prostatectomy (TURP) specimens and to establish whether or not the incidence, presentation, and pathology have changed since the advent of prostate specific antigen (PSA).

Methods: Five hundred and thirty patients underwent TURP for presumed benign disease at our institution in 1985 (before PSA), and 481 underwent TURP between 1994 and 1995. The charts of all patients with cancer were reviewed. Patients with known cancer preoperatively were excluded. Charts were reviewed with regard to indication for TURP, presentation, age, size of prostate, digital rectal exam, PSA, and pathology report. The most recent preoperative PSA value was utilized. Pathologic factors included the weight (grams resected), grade, and extent of tumors. Stage T1a tumors were defined as having Gleason scores of <6 and volumes of <5%. If the percentage of volume was not given, the specimen was considered to be Stage T1a if cancer was present in three chips or less. All other tumors were considered Stage T1b disease.

Results: In 1985, Stage T1a cancer comprised 4% of specimens, and Stage T1b comprised 6%. In 1994 and 1995, Stage T1a cancer comprised 4%, but Stage T1b comprised 3%. This change in the incidence of T1b disease was statistically significant with a p value of 0.04. There was no difference with regard to patient age, specimen weight, or Gleason score. Urinary retention was a more common indication for TURP in 1994 and 1995.

Conclusions: Our findings suggest that PSA screening has decreased the incidence of Stage T1b prostate cancer.
A Critical Evaluation of Prostate Specific Antigen Parameter Responses to Manipulation According to Prostatic Histology
Authors: Alexandrou Kyriacos , Collins Gerald N. , Wynn‐Davies Alison , O'Reilly Patrick H.
Published: March 2003

Introduction: The degree of increase in prostate specific antigen (PSA) forms after prostatic manipulation may differ depending on histology. We sought to critically evaluate this hypothesis and to examine possible clinical implications.

Methods: A series of 198 men referred for transrectal ultrasound‐guided biopsy on clinical grounds had free (fPSA) and total PSA (tPSA) levels determined before undergoing biopsy and 30 min after biopsy. A subset of 100 men had the same analysis immediately before and 30 min after digital rectal examination (DRE). Geometric mean ratios and two‐sample t tests compared the change in levels of fPSA, PSA, the ratio of fPSA to tPSA (f/t PSA), fPSA density, and PSA density after manipulation to prostatic histology.

Results: After undergoing biopsies, 57 men (29%) received a diagnosis of prostate cancer. The biopsy significantly altered all parameters. The degree of change was less in the malignant group for all parameters, although this only approached statistical significance for PSA and PSA density levles (p = 0.159 and p = 0.170, respectively). In the DRE group, the PSA changes were similar, although the cancer patients tended to release slightly less PSA forms (PSA, p = 0.376; fPSA, p = 0.657; f/t PSA, p = 0.396).

Conclusion: PSA release and PSA parameter alteration after manipulation differ in the neoplastic prostate. The subtlety of change after DRE currently limits clinical application.
Expression of Prostate Specific Molecules in Bacille Calmette‐Guerin: An Immunotherapeutic Approach to Prostate Cancer
Authors: Zeoli Christina D. , Maitland Michael , Rose Herbert , Bloom Barry , Mittelman Abraham , Geliebter Jan
Published: March 2003

Objective: The objective is to develop an immunotherapeutic vaccine for the treatment of metastatic prostate cancer.

Results: Bacille Calmette Guerin (BCG) were engineered to express prostate specific antigen (PSA) or prostate specific membrane antigen (PSMA). Western blotting techniques indicate that recombinant BCG (rBCG) express approximately 25 ng PSA or 112 pg PSMA per 1 μg microgram of protein in rBCG bacterial lysates.

Discussion: BCG, the vaccine for tuberculosis, is a potent immunologic adjuvant stimulating both the humoral and cell‐mediated immune systems. Prostate cancer patients can generate cytotoxic lymphocytes against specific peptides from normal, self‐molecules such as PSA and PSMA. Therefore, a rBCG vaccine that expresses prostate specific proteins may stimulate an immune response to recognize and destroy prostate cancer cells.

Conclusion: BCG can be engineered to express prostate specific molecules and may be useful as an immunotherapeutic vaccine against prostate cancer.
The Effectiveness of Health Promotion Counseling to Family Caregivers
Authors: Chen Mei‐Yen
Published: March 2003

This study examined the effectiveness of health promotion counseling of the family caregivers from Taipei Metropolitan Area. An established Chinese version of the health‐promoting scale was developed by the author of this study (which was modified and authorized by Walker, Sechrist, & Pender, 1987). A two‐group quasi‐experimental research design was employed. From October 1996 to July 1997, 84 family caregivers were selected and assigned to one of the two groups. Members of the treatment group received health promotion counseling from four trained professional home care nurses during home visiting. The members of the control group were given no counseling but instead received traditional care. Pre‐assessment was carried out after subjects were selected and post evaluation was done 6 months later. The findings showed that the counseling enabled members of the treatment group to adopt healthier lifestyles. The research outcome supports the value of home‐care nurse counseling of family caregivers.
The Adolescent Parenting Program: Improving Outcomes Through Mentorship
Authors: Flynn Linda
Published: March 2003

Adolescent parents and their infants are a population at risk. Infant mortality, low‐birthweight, and child maltreatment are inordinately higher within this population than within slightly older cohorts. The purpose of this one group pretest‐posttest intervention study was to analyze the efficacy of a program designed to improve infant outcomes through the enhancement of health practices and parenting skills in a sample of 137 low‐income, pregnant and parenting adolescents who reside in an urban area and who screened positive for risk of child maltreatment. Based on theories of mentorship and social support, the program provided intensive home visitation by nursing paraprofessionals, indigenous to the community, for the 2 year study period. Program outcomes were compared to local and national data. Findings revealed only 4.6% of program infants were low‐birthweight compared to local and national percentages of 13.5% and 9.42%. The mean length of gestation was 39.27 weeks (SD= 1.55). The incidence of infant mortality was zero, comparing favorably with national data as well as the local infant mortality rate (almost twice the state average). There were only four cases of child neglect, representing only 2.91% of the sample. This finding also compares favorably with national data.
Interprofessional Education for Undergraduate Students
Authors: Russell Kathleen M. , Hymans Dwight
Published: March 2003

Collaborative practice is an essential component of public health nursing. Using an interprofessional collaboration process, community health nursing and social work faculty developed joint classroom instruction and clinical experiences for their students. In partnership with a neighborhood organization, the undergraduate nursing and social work students conducted a community assessment and recommended a plan of action. Analysis of the student collaborative practice revealed both similarities and differences in role perceptions, group process, problem solving, and discipline‐specific values and attitudes. Logistical concerns revolved around student scheduling and communications. Based on the analysis, specific recommendations are provided for faculty in developing student collaborative experiences across disciplines.
Public Health Nursing in Children's Protective Services
Authors: Smart Jeanne D.
Published: March 2003

This article describes the development and integration of a Los Angeles County, Department of Health Services, Public Health Nursing (PHN) program within the local Children's Protective Services (CPS) agency to assist the Children's Social Workers (CSWs) with their legally mandated health case management services. It summarizes the unique health needs of children who enter protective services, and explains why CPS agencies, often overwhelmed by an increasing number of cases and diminishing resources, have had difficulty providing necessary health care monitoring and oversight. Program evaluation data detailing PHN services during the first 2 years of program implementation gives valuable insight into their evolving role function within this new practice arena. Issues regarding the integration of disciplines, and the contribution of the PHNs to the CPS agency are discussed.
Home Care Nursing in Japan: A Challenge for Providing Good Care at Home
Authors: Murashima Sachiyo , Nagata Satoko , Magilvy Joan K. , Fukui Sakiko , Kayama Mami
Published: March 2003

Home care in Japan has developed over the past 30 years. Nurses have taken leadership in promoting home care and at the same time have expanded their roles. The roles of Japanese nurses in the field of home care are presented in the context of the historical perspective and view for the future. Home care nurses have performed care management for their community as well as for individual older clients living in their community. Currently, nurses work as high‐tech and personal care providers and are developing a new role in health care enterprises. The number of nurses working as clinical nurse specialists will increase consistently with the rapid increase of master's programs. In the future, nurses should take a lead in developing health policy. The purpose of the article is to describe the current situation of home care clients and home care nursing in Japan. In addition, four issues of home care in Japan are described related to home care for older persons, high‐tech home care, terminal care, and home care for psychiatric patients.
How Often Are Dermatophytes Present in Apparently Normal Versus Scaly Feet of Children?
Authors: Becerril‐Chihu Georgina , Bazán‐Mora Elva , López‐Martínez Rubén , Sosa‐de‐Martínez Cristina , Ruiz‐Maldonado Ramón
Published: March 2003

The purpose of this investigation was to find out how often pathogenic dermatophytes are found in apparently normal versus scaly feet of children. In this prospective protocol, we studied 100 patients, 2 to 12 years of age, consulting for plantar and/or interdigital scaling with or without erythema, maceration, and pruritus, and 100 controls with apparently healthy feet. Direct microscopic examination (KOH) and mycologic culture (Mycosel) of skin scrapings were performed from the lesions of patients and from the soles and interdigital folds of controls. Mean age of patients and controls was 7 years 7 months (SD = 3 years 2 months). Scaling was present in 100% of patients with a mean time of evolution of 8.9 months (SD = 16.3 months). Shoes fashioned from man‐made material were significantly more frequently used by patients than by controls (ξ2(df = 1) = 9.4; p = 0.002). Pathogenic dermatophytes were present in the soles and/or interdigital webs of 21 patients and 7 controls. Not all foot scaling in children, pruritic or not, is associated with dermatophytes. Dermatophytes may be present on the apparently healthy feet of children.
Alopecia Areata with Features of Loose Anagen Hair
Authors: Nunez Janna , Grande Kimberly , Hsu Sylvia
Published: March 2003

Abstract: A child with alopecia areata (AA) presented initially with clinical features of loose anagen hair (LAH) and had features consistent with LAH on microscopic hair analysis. However, a scalp biopsy specimen demonstrated peribulbar inflammatory infiltrates characteristic of AA. We suggest that AA may mimic LAH clinically and a scalp biopsy may help in making the correct diagnosis.