bluuebunny/crossref_metadata_2025 huggingface dataset:
Human capital and financial development in economic growth: new evidence using the translog production function
Authors: Dwyfor Evans Alun , Green Christopher J. , Murinde Victor
Published: August 2002

In this paper we evaluate the contributions of human capital and financial development to economic growth in a panel of 82 countries covering 21 years. The main innovations in the paper stem from the fact that we use a translog production function as a framework for estimating the relationships among economic growth and factor inputs. The factor inputs considered are: labour, physical capital, human capital (deriving from endogenous growth theory), and a monetary factor (money or credit, deriving from the theory of money in the production function). The translog production function enables a richer specification of the relationships among growth and factor inputs, than the more commonly used Cobb–Douglas approach, as it allows for interactions among factor inputs. We find significant evidence of such interactions, suggesting that studies which ignore such interactions are likely to be misleading. Overall, our results suggest that financial development is at least as important as human capital in the growth process. Copyright © 2002 John Wiley & Sons, Ltd.
Exposure of Rana ridibunda to lead II. Impact of lead on various parameters of liver metabolism of the frog Rana ridibunda
Authors: Vogiatzis Angelos K. , Loumbourdis Nikolaos S.
Published: August 2002

There are no data at present on the impact of lead (Pb) on amphibian metabolism, although declines of amphibian populations due to man‐made changes in the environment have been recorded in recent years. We studied the impact of Pb on the liver metabolism of the frog Rana ridibunda by measuring the hepatic levels of glycogen, lactate, total fat, protein and glucose. Liver is one of the primary target organs of Pb bioaccumulation. Frogs were exposed for 4, 10 and 30 days to 14 mg l−1 of Pb (in the form of Pb(NO3)2 dissolved in water) and compared with matched controls. The level of glycogen in the liver increased until day 30. The increase of the metabolite was time‐dependent because there was a positive correlation (r = 0.994, P = 0.006) between glycogen concentration and the days of Pb exposure. Lactate concentration declined continuously up to day 30. Liver fat content decreased from day 10 to day 30. Protein concentration declined continuously until day 30. Glucose concentration increased up to day 30. Glycogen concentration was correlated negatively with liver fat content (r = −0.474, P = 0.005), liver protein content (r = −0.562, P = 0.0004) and lactate concentration (r = −0.472, P = 0.005), whereas it was correlated positively with the Pb burden of the liver (r = 0.578, P = 0.0005). The frog appeared to face a metabolic stress over the 30 days of Pb exposure, without being able to control it. We concluded that the increase of liver glycogen concentration was due to gluconeogenesis via lactate and lipolysis. Further experimentation on key gluconeogenic and lipolytic enzymes over the 30 days of Pb exposure would elucidate the mechanisms that may lead to such phenomena. Copyright © 2001 John Wiley & Sons, Ltd.
Poisoning in Zimbabwe: a survey of eight major referral hospitals
Authors: Tagwireyi D. , Ball D. E. , Nhachi C. F. B.
Published: August 2002

A retrospective study of the pattern of poisoning cases admitted to eight major urban referral hospitals in Zimbabwe over a 2‐year period (1998–1999 inclusive) was conducted to describe the pattern of poisoning at these centres. There were a total of 2764 hospital admissions due to poisoning, involving a total of 2846 toxic agents. Accidental poisoning (AP) and deliberate self‐poisoning (DSP) accounted for 48.9% (1352 cases) and 41.3% (1142 cases), respectively. With AP, the highest number of cases (45.9%) occurred in children below the age of 5 years, with half of these due to chemicals, mainly paraffin. In the DSP group, however, more than 60% of all cases occurred in the 16–25‐year age group. In addition, twice as many females as males were admitted for DSP compared with an overall male/female ratio of 1 : 1.2. Pesticides (31.4%) and pharmaceuticals (30.4%) were the most common groups of toxic agents responsible for the hospital admissions. Unknown toxins, natural toxins and pesticides showed the highest mortality rates (15.4%, 8.3% and 6.7%, respectively). Compared with the last major survey of poisoning in Zimbabwe, the pattern of poisoning at referral hospitals has changed over the last decade, with an increase in pesticide and pharmaceutical cases and a marked fall in cases of traditional medicine poisoning. Educational and legislative interventions may be required to address these changes. There is the need also to investigate further the high mortality rates associated with traditional medicine poisoning. Copyright © 2002 John Wiley & Sons, Ltd.
In vivo investigations on composites made of resorbable ceramics and poly(lactide) used as bone graft substitutes
Authors: Ignatius Anita A. , Betz Oliver , Augat Peter , Claes Lutz E.
Published: August 2002

Porous composites made of poly(L, DL‐lactide) (PLA) and α‐tricalcium phosphate (α‐TCP) or the glass ceramic, GB14N, respectively, were investigated in a loaded implant model in sheep. Six, 12 and 24 months after implantation histological and biomechanical evaluation were performed and compared to autogenous bone transplants. No significant differences were observed between the composites. After 6 months, the interconnecting pores of the α‐TCP‐composite and the GB14N‐composite were filled with newly formed bone (14 ± 5% or 29 ±15% of the implant, respectively) and soft tissue (30 ±9% or 21 ±12% of the implant, respectively). Only a mild inflammatory response was observed. The reaction was similar after 12 months. However, after 24 months a strong inflammatory reaction was seen. The newly formed bone was partly osteolytic. The adverse reaction occurred simultaneously to a significant reduction of the PLA component. The histological results were reflected by the biomechanical outcomes. Both composites showed compression strengths in the range of the autologous bone graft until 12 months of implantation. After 2 years, however, the strengths were significantly decreased. It is concluded that the new composites cannot yet be used for clinical application. An improvement in biocompatibility might be reached by a better coordination of the degradation times of the polymer and the ceramic component. © 2001 John Wiley & Sons, Inc. J Biomed Mater Res (Appl Biomater) 58: 701–709, 2001
In vitro behavior of sintered powder injection molded Ti‐6Al‐4V/HA
Authors: Thian E. S. , Loh N. H. , Khor K. A. , Tor S. B.
Published: August 2002

This article reports the morphology and mechanical properties of sintered powder injection molded Ti‐6Al‐4V/HA parts in a simulated physiological environment. Sintered Ti‐6Al‐4V/HA parts were immersed in a simulated body fluid (SBF) with ion concentrations that were comparable to those of human blood plasma for a total period of 12 weeks. At intervals of 2 weeks, the immersed Ti‐6Al‐4V/HA parts were analyzed with the use of scanning electron microscopy (SEM), X‐ray diffractometry (XRD), and inductively coupled plasma–atomic emission spectroscopy (ICP‐AES). Mechanical properties such as flexural strength, flexural modulus, compressive strength, and compressive modulus were also evaluated. Results showed that complete dissolution of the more soluble phases such as tricalcium phosphate (TCP), tetracalcium phosphate (TTCP), and calcium oxide (CaO) were found after 2 weeks of immersion in SBF. ICP analysis showed that high calcium concentration release of around 200 ppm was observed in the SBF solution after 2–4 weeks of immersion, indicating that dissolution has taken place. Next, a gradual decrease in calcium concentration release in the SBF solution was observed after immersion for 4–6 weeks, with increasing amounts of calcium phosphate precipitates being observed on the Ti‐6Al‐4V/HA surface. Mechanical properties such as strength and modulus were found to deteriorate during 2–4 weeks of immersion, followed by gradual increment as the immersion period increased. This study also showed that parts sintered at 1150 °C exhibited faster dissolution and precipitation rates than parts sintered at 1050 °C in a physiological environment. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res (Appl Biomater) 63: 79–87, 2002; DOI 10.1002/jbm.10082
Fibrin as an alternative biopolymer to type‐I collagen for the fabrication of a media equivalent
Authors: Grassl E. D. , Oegema T. R. , Tranquillo R. T.
Published: August 2002

We report here on studies examining the use of fibrin as an alternative to collagen for the entrapment of neonatal aortic rat smooth muscle cells (SMCs) in the fabrication of media equivalents. The studies show increased collagen production by fibroblasts entrapped in fibrin, which suggests that fibrin may be used in the fabrication of tissue equivalents to promote increased protein synthesis and remodeling. However, one of the challenges of working with fibrin is the rapid degradation by SMCs. This degradation was effectively inhibited with the addition of ϵ‐aminocaproic acid (EACA) to the culture medium in concentrations ranging from 0.25 to 1 mg/mL. We also present results showing that fibrin stimulates collagen production by SMCs. SMCs in fibrin produced 3.2 and 4.9 times the amount of collagen produced by SMCs in collagen when supplemented with 1 and 0.25 mg/mL EACA, respectively. More than half of the collagen produced appeared in the medium rather than the matrix. The collagen in the medium appeared to be processed beyond the proform and may be in an aggregate form. In addition, the presence of type‐III collagen or a type‐I trimer was indicated by the results of an analysis of the medium by autoradiography. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 60: 607–612, 2002
The effect of alendronate (Fosamax™) and implant surface on bone integration and remodeling in a canine model
Authors: Frenkel Sally R. , Jaffe William L. , Valle Craig Della , Jazrawi Laith , Maurer Stephen , Baitner Avi , Wright Kevin , Sala Debra , Hawkins Monica , Di Cesare Paul E.
Published: August 2002

Patients at high risk for osteoporosis and its associated morbidity, including postmenopausal women, are being pharmacologically managed to stabilize and improve bone mass. Alendronate sodium (Fosamax™) is a commonly used antiresorptive agent effective in osteopenic women for reducing bone resorption, increasing bone density, and decreasing fracture incidence. With the increased incidence of alendronate‐treated women who are undergoing hip replacement or fracture repair by prosthesis placement, data are needed to predict how alendronate affects host bone integration with uncemented surfaces. The aim of this study was to determine the effect of alendronate on new bone formation and attachment to implant surfaces in a normal and simulated estrogen‐deficient, calcium‐deficient canine model, using an implantable bone growth chamber. Alendronate did not affect host bone integration to surfaces commonly used in uncemented total joint arthroplasty, but there were significant differences dependent solely on the type of surface. © 2001 John Wiley & Sons, Inc. J Biomed Mater Res (Appl Biomater) 58: 645–650, 2001
Preparation of TiO2 layers on cp‐Ti and Ti6Al4V by thermal and anodic oxidation and by sol‐gel coating techniques and their characterization
Authors: Velten D. , Biehl V. , Aubertin F. , Valeske B. , Possart W. , Breme J.
Published: August 2002

The excellent biocompatibility of titanium and its alloys used, for example, for medical devices, is associated with the properties of their surface oxide. For a better understanding of the tissue reaction in contact with the oxide layer, knowledge of the chemical and physical properties of this layer is of increasing interest. In this study, titania films were produced on cp‐Ti and Ti6Al4V substrates by thermal oxidation, anodic oxidation, and by the sol‐gel process. The thickness and structure of the films produced under different conditions were determined by ellipsometry, infrared spectroscopy, and X‐ray diffraction measurements. The corrosion properties of these layers were investigated by current density–potential curves under physiological conditions. The oxide layers produced on cp‐Ti and Ti6Al4V by thermal oxidation consist of TiO2 in the rutile structure. For the anodized samples the structure of TiO2 is a mixture of amorphous phase and anatase. The structure of the coatings produced by the sol‐gel process for a constant annealing time depends on the annealing temperature, and with increasing temperature successively amorphous, anatase, and rutile structure is observed. Compared to the uncoated, polished substrate with a natural oxide layer, the corrosion resistance of cp‐Ti and Ti6Al4V is increased for the samples with an oxide layer thickness of about 100 nm, independent of the oxidation procedure. © 2001 Wiley Periodicals, Inc. J Biomed Mater Res 59: 18–28, 2002
Quantifying adhesive penetration in adhesive/dentin interface using confocal Raman microspectroscopy
Authors: Wang Yong , Spencer Paulette
Published: August 2002

Confocal Raman microspectroscopy (CRM) provides an important and novel means of analyzing the chemical composition of the adhesive/dentin (a/d) interface. The purpose of this study was to develop a method for quantitative determination of the degree of adhesive penetration at the a/d interface using CRM. Three commercial dentin adhesive systems [Scotchbond Multipurpose Plus (SBMP+), Single Bond (SB), and Primer Bond NT (PBNT)] based on the total etch and “wet” bonding technique were examined in this study. Human dentin specimens treated with these adhesives were analyzed with CRM mapping across the a/d interface. Also, Raman spectra were collected on model mixtures of adhesive and type I collagen, and the ratios of the relative intensities of the Raman bands corresponding to adhesive and collagen were used for the construction of calibration curves. By comparing the Raman band ratios of interface specimens to the calibration curves, the percent of adhesive as a function of spatial position across the a/d interface was determined. The results show that there is a gradual decrease in penetration as a function of position for all three adhesive systems while the adhesive concentration gradient decreases in the order of SBMP+ > SB > PBNT. These differences in penetration of the three adhesives at the a/d interface also are discussed relative to the composition and phase segregation in adhesives. Additionally, our results indicate that confocal Raman microspectroscopy is a reliable in situ analytical technique for simple and rapid quantitative determination of adhesive penetration at its interface with prepared dentin. © 2001 Wiley Periodicals, Inc. J Biomed Mater Res 59: 46–55, 2002
Hydrogel properties influence ECM production by chondrocytes photoencapsulated in poly(ethylene glycol) hydrogels
Authors: Bryant Stephanie J. , Anseth Kristi S.
Published: August 2002

When using hydrogel scaffolds for cartilage tissue engineering, two gel properties are particularly important: the equilibrium water content (q, equilibrium swelling ratio) and the compressive modulus, K. In this work, chondrocytes were photoencapsulated in degrading and nondegrading poly(ethylene glycol)‐based hydrogels to assess extracellular matrix (ECM) formation as a function of these gel properties. In nondegrading gels, the glycosaminoglycan (GAG) content was not significantly different in gels when q was varied from 4.2 to 9.3 after 2 and 4 weeks in vitro. However, gels with a q of 9.3 allowed GAGs to diffuse throughout the gels homogenously, but a q ≤ 5.2 resulted in localization of GAGs pericellularly. Interestingly, in the moderately crosslinked gels with a K of 360 kPa, an increase in type II collagen synthesis was observed compared with gels with a higher (960 kPa) and lower (30 kPa) K after 4 weeks. With the incorporation of degradable linkages into the network, gel properties with an initially high K (350 kPa) and final high q (7.9) were obtained, which allowed for increased type II collagen synthesis coupled with a homogenous distribution of GAGs. Thus, a critical balance exists between gel swelling, mechanics, and degradation in forming a functional ECM. © 2001 Wiley Periodicals, Inc. J Biomed Mater Res 59: 63–72, 2002
PMMA‐based bioactive cement: Effect of glass bead filler content and histological change with time
Authors: Shinzato Shuichi , Nakamura Takashi , Kokubo Tadashi , Kitamura Yoshiro
Published: August 2002

A new bioactive bone cement (designated GBC), which is a polymethyl methacrylate (PMMA)‐based composite consisting of bioactive glass beads as an inorganic filler and high molecular‐weight PMMA as an organic matrix, has been developed. The purpose of the present study was to evaluate the effect of the filler content on the mechanical properties and osteoconductivity of GBC, to decide the most suitable filler proportion, and to evaluate the degree of cement degradation with time. The bioactive beads, consisting of MgO‐CaO‐SiO2‐P2O5‐CaF2 glass, were added to the cement in various proportions (40–70 wt %). The bending strength of GBC did not differ among the proportions (approximately 136 MPa), but the elastic modulus of bending of GBC increased as the glass bead filler content increased (approximately 4.1–7.2 GPa). The all types of GBC were packed into the intramedullary canals of rat tibiae to evaluate osteoconductivity, as determined by an affinity index calculated as the length of bone in direct contact with the cement surface expressed as a percentage of the total length of the cement surface. Rats were sacrificed at 4, 8, 25, and 39 weeks after implantation, and the affinity index was calculated for each type of GBC at each time point. Histologically, new bone had formed along the surface of all types of GBC within 4 weeks, even in GBC containing only 40 wt % of glass beads. The affinity indices of GBC tended to increase as the proportion of glass bead filler increased and as the implantation period increased. In GBC containing 60 or 70 wt % of glass beads, significant rapid increases in the affinity indices were found from 4 to 8 weeks, and the high values (approximately 70%) were maintained up to 39 weeks. A sign of glass bead degradation was observed at the bone–cement interface in the rat tibiae at 39 weeks. We conclude that, when mechanical properties and osteoconductivity are both taken into consideration, GBC containing 60 or 70 wt % of glass beads is the most suitable formulation, but that further studies are needed to investigate and overcome the degradation. © 2001 Wiley Periodicals, Inc. J Biomed Mater Res 59: 225–232, 2002
TGF‐β, BMPS, and their signal transducing mediators, Smads, in rat fracture healing
Authors: Yu Yan , Yang Jia‐Lin , Chapman‐Sheath Philip J. , Walsh Williams R.
Published: August 2002

Smads are cytoplasmic signal transducers of transforming growth factor‐β (TGF‐β) and bone morphogenetic proteins (BMPs). Their relation to fracture healing is unknown. This study examined the temporal protein expression of Smads, together with TGF‐β and BMPs, using immunohistochemistry in a rodent fracture model. Over‐expression of TGF‐β, BMPs‐2, 4, and 7, common‐mediator Smad (Smad4), and receptor‐regulated Smads (Smads1, 2, 3, and 5) versus lower levels of inhibitory Smad (Smad6), were detected at day 3 in osteogenic cells in the thickened periosteum and bone marrow at the fracture sites. At day 10, Smad6 increased dramatically, Smad2, Smad3, and Smad4 remained elevated while Smad1 and Smad5 decreased in the fracture callus. Smad7 was expressed only in vascular endothelial cells. By day 28, when new bone had replaced the fracture callus, all the protein regulators decreased, approaching control levels. During fracture healing, the expression patterns of Smads1 and 5 were similar to that of BMPs‐2 and 7 whereas the expression of Smads2 and 3 was parallel with that of TGF‐β. The Smad family, associated with BMPs and TGF‐β, may play an important role in the early stage of rat fracture healing. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 60: 392–397, 2002; DOI 10.1002/jbm.1289
Evaluation of women with clinically suspected thrombotic thrombocytopenic purpura‐hemolytic uremic syndrome during pregnancy
Authors: McMinn Johnny R. , George James N.
Published: August 2002

Thrombotic thrombocytopenic purpura‐hemolytic uremic syndrome (TTP‐HUS) is more common in women, and commonly occurs during pregnancy and the immediate postpartum period. An important clinical issue is the distinction of TTP‐HUS from the more common obstetric complications, preeclampsia and HELLP syndrome (hemolysis, elevated liver function tests, low platelets). Clinical suspicion of TTP‐HUS requires urgent intervention with plasma exchange treatment, a procedure with substantial risk, while preeclampsia and HELLP syndrome typically resolve spontaneously following delivery. Since clinical features of these syndromes can be similar, especially if preeclampsia becomes severe or if seizures (defining eclampsia) occur, the differential diagnosis may be arbitrary. This review addresses the evaluation and management of these syndromes and describes a clinical approach for determining when plasma exchange is appropriate. J. Clin. Apheresis 16:202–209, 2001. © 2001 Wiley‐Liss, Inc.
The effects of three different LDL‐apheresis methods on the plasma concentrations of E‐selectin, VCAM‐1, and ICAM‐1
Authors: Empen Klaus , Otto Carsten , Brödl Uli C. , Parhofer Klaus G.
Published: August 2002

Plasma concentrations of cellular adhesion molecules are associated with atherosclerotic diseases and major cardiovascular risk factors. It was shown that LDL‐apheresis with dextran sulfate lowers the levels of E‐selectin and ICAM‐1 in patients with familial hypercholesterolemia. The effects of different LDL‐apheresis methods have not been studied yet. Cholesterol, triglycerides, LDL cholesterol, HDL cholesterol, fibrinogen, and the adhesion molecules E‐selectin, VCAM‐1, and ICAM‐1 were measured in 20 patients with coronary heart disease and severe hyperlipoproteinemia immediately before and after regular LDL‐apheresis. Treatment was performed by different apheresis methods (direct absorption, DA, n = 6; dextran sulfate adsorption, DS, n = 7; heparin precipitation, HP, n = 7). Rebound data of adhesion molecule levels were obtained from 2 patients of each group. Lipids were reduced similarly in all groups. The concentrations of all adhesion molecules were lowered during apheresis. The reduction of E‐selectin (−31 ± 7 vs. −6 ± 5 and −6 ± 5%, respectively, P < 0.001) was most prominent in the patients treated by heparin precipitation. Depending on the method of LDL‐apheresis, the concentrations of VCAM‐1 and E‐selectin in the outlets of the LDL‐apheresis columns were significantly lower compared to the concentration in the inlets. Plasma concentrations of adhesion molecules increased to their pre‐apheresis values within 2 to 4 days following LDL‐apheresis. The reductions of adhesion molecule levels observed during LDL‐apheresis are at least partly due to adsorption to the LDL‐apheresis column. The extent of absorption depends on the principle of extracorporeal LDL elimination. J. Clin. Apheresis 17:38–43, 2002. © 2002 Wiley‐Liss, Inc.
Incidence of allergic reactions with fresh frozen plasma or cryo‐supernatant plasma in the treatment of thrombotic thrombocytopenic purpura
Authors: Reutter Jason C. , Sanders Kendace F. , Brecher Mark E. , Jones Helen G. , Bandarenko Nicholas
Published: August 2002

Plasma replacement for thrombotic thrombocytopenic purpura (TTP) is accomplished with various plasma products. This study sought to determine the incidence of allergic reactions with FFP or CPP as replacement in therapeutic plasma exchange (TPE). Forty‐one TTP patients were identified retrospectively who received TPE replacement with either FFP (n=21) or CPP (n=20). Anti‐histamine was administered prophylactically following the initial occurrence of an allergic reaction (urticaria, respiratory distress, or anaphylaxis with hypotension). Fifty‐one allergic reactions occurred in 65.8% of patients. Urticaria comprised 49 of 51 (96%) of reactions and respiratory distress the remaining 4%. No anaphylaxis occurred. Nineteen urticarial reactions occurred in 50% of CPP recipients compared to 71% of FFP recipients (P=0.28). Anti‐histamine breakthrough occurred in 36.3% of patients who experienced a previous allergic reaction with CPP and 37.5% with FFP (P=1.0). The overall risk of allergy per unit of plasma was 1.37% (1.23 % CPP, 1.48% FFP), comparable to estimates in non‐TTP recipients. The median number of donor exposures preceding the first allergic reaction was 35 and 32, CPP and FFP, respectively (P=0.63). The mean volume of plasma transfused prior to reaction was 9,883 mL for CPP and 9,348 mL for FFP (P=0.85). Neither product was advantageous in preventing allergic complications. Because of the large volume, the number of donor exposures, and prolonged duration of therapy, allergic reactions to plasma are common (65.8%) in the treatment of TTP. J. Clin. Apheresis. 16:134–138, 2001. © 2001 Wiley‐Liss, Inc.
Neuroprotective MK801 is associated with nitric oxide synthase during hypoxia/reoxygenation in rat cortical cell cultures
Authors: Huang Hsueh‐Meei , Shen Chiung‐Chyi , Ou Hsiu‐Chung , Yu Jean‐Yuan , Chen Huan‐Lian , Kuo Jon‐Son , Hsieh Shon‐Jean
Published: August 2002

The neuroprotective effect of MK801 against hypoxia and/or reoxygenation‐induced neuronal cell injury and its relationship to neuronal nitric oxide synthetase (nNOS) expression were examined in cultured rat cortical cells. Treatment of cortical neuronal cells with hypoxia (95% N2/5% CO2) for 2 h followed by reoxygenation for 24 h induced a release of lactate dehydrogenase (LDH) into the medium, and reduced the protein level of MAP‐2 as well. MK801 attenuated the release of LDH and the reduction of the MAP‐2 protein by hypoxia, suggesting a neuroprotective role of MK801. MK801 also diminished the number of nuclear condensation by hypoxia/reoxygenation. The NOS inhibitors 7‐nitroindazole (7‐NI) and N (G)‐nitro‐l‐arginine methyl ester (l‐NAME), as well as the Ca2+ channel blocker nimodipine, reduced hypoxia‐induced LDH, suggesting that nitric oxide (NO) and calcium homeostasis contribute to hypoxia and/or the reoxygenation‐induced cell injury. The levels of nNOS immunoactivities and mRNA by RT‐PCR were enhanced by hypoxia with time and, down regulated following 24 h reoxygenation after hypoxia, and were attenuated by MK801. In addition, the reduction of nNOS mRNA levels by hypoxia/reoxygenation was also diminished by MK801. Further delineation of the mechanisms of NO production and nNOS regulation are needed and may lead to additional strategies to protect neuronal cells against hypoxic/reoxygenation insults. J. Cell. Biochem. 84: 367–376, 2002. © 2001 Wiley‐Liss, Inc.
Substrate specificity of protein tyrosine phosphatase: Differential behavior of SHP‐1 and SHP‐2 towards signal regulation protein SIRPα1
Authors: Mishra Ashwini K. , Zhang Aihua , Niu Tianqi , Yang Jian , Liang Xiaoshan , Zhao Zhizhuang Joe , Zhou G. Wayne
Published: August 2002

The substrate specificity of catalytic domains and the activation of full length protein tyrosine phosphatases, SHP‐1 and SHP‐2 have been investigated using synthetic phosphotyrosyl peptides derived from SIPRα1. We found that the catalytic domains of SHP‐1 and SHP‐2 exhibit different substrate specificity towards a longer trideca‐peptide pY469+3 (−7RPEDTLTpYADLDM+5) and not to the shorter decapeptide pY469 (−5EDTLTpYADLD+4), the former being the substrate of SHP‐2 only. Furthermore, the activation of full‐length SHP‐1 and not the SHP‐2 by the deca/trideca‐peptides suggested SIRPα 1 to be possibly acting as both an upstream activator and a substrate for SHP‐1, and merely as the downstream substrate for SHP‐2 in signaling events. J. Cell. Biochem. 84: 840–846, 2002. © 2002 Wiley‐Liss, Inc.
Leptin stimulates human osteoblastic cell proliferation, de novo collagen synthesis, and mineralization: Impact on differentiation markers, apoptosis, and osteoclastic signaling
Authors: Gordeladze Jan O. , Drevon Christian A. , Syversen Unni , Reseland Janne E.
Published: August 2002

Anabolic hormones, mechanical loading, and the obese protein leptin play separate roles in maintaining bone mass. We have previously shown that leptin, as well as its receptor, are expressed by normal human osteoblasts. Consequently, we have investigated how leptin affects proliferation, differentiation, and apoptosis of human osteoblasts. Iliac crest osteoblasts, incubated with either leptin (100 ng/ml), calcitriol (1,25(OH)2D3; 10−9 M) or 1–84 human parathyroid hormone (PTH; 10−8 M), were cultured for 35 consecutive days and assayed for expression of various differentiation‐related marker genes (as estimated by RT‐PCR), de novo collagen synthesis, proliferation, in vitro mineralization, and osteoclast signaling. The effects of leptin on protection against retinoic acid (RA; 10−7 M) induced apoptosis, as well as transition into preosteocytes, were also tested. Leptin exposure enhanced cell proliferation and collagen synthesis over both control condition and PTH exposure. Leptin inhibited in vitro calcified nodule production after 1–2 weeks in culture, however, subsequent to 4–5 weeks, leptin significantly stimulated mineralization. The mineralization profile throughout the entire incubation period was almost undistinguishable from the one induced by PTH. In comparison, 1,25(OH)2D3 generally reduced proliferation and collagen production rates, whereas mineralization was markedly enhanced. Leptin exposure (at 2 and 5 weeks) significantly enhanced the expression of TGFβ, IGF‐I, collagen‐Iα, ALP, and osteocalcin mRNA. Leptin also protected against RA‐induced apoptosis, as estimated by soluble DNA fractions and DNA laddering patterns subsequent to 10 days of culture. The expression profiles of Bax‐α and Bcl‐2 mRNAs indicated that leptin per se significantly protected against apoptosis throughout the entire incubation period. Furthermore, the osteoblast marker OSF‐2 was diminished, whereas the CD44 osteocyte marker gene expression was stimulated, indicating a transition into preosteocytes. In terms of osteoclastic signaling, leptin significantly augmented the mRNA levels of both interleukin‐6 (IL‐6) and osteoprotegerin (OPG). In summary, continuous leptin exposure of iliac crest osteoblasts, promotes collagen synthesis, cell differentiation and in vitro mineralization, as well as cell survival and transition into preosteocytes. Leptin may also facilitate osteoblastic signaling to the osteoclast. © 2002 Wiley‐Liss, Inc.
Evidence that protein disulfide isomerase (PDI) is involved in DNA–nuclear matrix anchoring
Authors: VanderWaal Robert P. , Spitz Douglas R. , Griffith Cara L. , Higashikubo Ryuji , Roti Roti Joseph L.
Published: August 2002

DNA–nuclear matrix (NM) anchoring plays a critical role in the organization of DNA within the nucleus and in functional access to DNA for transcription, replication, and DNA repair. The cellular response to oxidative stress involves both gene expression and DNA repair. We, therefore, determined if changes in the oxidative–reductive environment can affect DNA–NM anchoring. The present study used two approaches to study the effect of the reducing agent DTT on DNA–NM anchoring. First, the relative stringency of the DNA–NM attachment was determined by measuring the ability of NM attached DNA loops to undergo supercoiling changes. Second, the effects of DTT on the association of nuclear proteins with DNA were determined by cisplatin crosslinking. When nucleoids (nuclear matrices with attached DNA loops) were prepared from HeLa cells with 1 mM dithiothreitol (DTT), supercoiled DNA loops unwound more efficiently compared with control in the presence of increasing propidium iodide (PI) concentrations. In addition, the rewinding of DNA supercoils in nucleoids treated with DTT was inhibited. Both effects on DNA supercoiling ability were reversed by diamide suggesting that they are dependent on the oxidation state of the protein thiols. When DTT treated nucleoids were isolated from γ‐irradiated cells, the inhibition of DNA supercoil rewinding was equal to the sum of the inhibition due to DTT and γ‐rays alone. Nucleoids isolated from heat‐shocked cells with DTT, showed no inhibition of DNA rewinding, except a small inhibition at high PI concentrations. Nuclear DNA in DTT‐treated nuclei was digested faster by DNase I than in untreated nuclei. These results suggest that DTT is altering DNA–NM anchoring by affecting the protein component(s) of the anchoring complex. Extracting NM with increasing concentrations of DTT did not solubilize any protein to a significant extent until measurable NM disintegration occurred. Therefore, we determined if 1 mM DTT affected the ability of 1 mM cisplatin to crosslink proteins to DNA. Isolated nuclei were treated with 1 mM DTT for 30 min or left untreated prior to crosslinking with 1 mM cisplatin for 2 h at 4°C. The ability of capsulation to crosslink DNA to proteins per se, did not appear to be affected by 1 mM DTT because relative amounts of at least four proteins, 69, 60, 40, and 35 kDa, were crosslinked to DNA to the same extent in DTT‐treated and untreated nuclei. However, protein disulfide isomerase (PDI) crosslinked to DNA in untreated nuclei, but did not crosslink DNA in nuclei that were treated with 1 mM DTT; 1 mM DTT did not affect the intranuclear localization of PDI. Thus, DTT appears to alter the conformation of PDI, as suggested by the DTT‐induced change in DNA association, but not its NM association. These results also imply that DNA–NM anchoring involves the redox state of protein sulfhydryl groups. J. Cell. Biochem. 85: 689–702, 2002. © 2002 Wiley‐Liss, Inc.
Comparative efficiencies of C‐terminal signals of native glycophosphatidylinositol (GPI)‐anchored proproteins in conferring GPI‐anchoring
Authors: Chen Rui , Knez Jansen J. , Merrick William C. , Medof M. Edward
Published: August 2002

Every protein fated to receive the glycophosphatidylinositol (GPI) anchor post‐translational modification has a C‐terminal GPI‐anchor attachment signal sequence. This signal peptide varies with respect to length, content, and hydrophobicity. With the exception of predictions based on an upstream amino acid triplet termed ω→ω + 2 which designates the site of GPI uptake, there is no information on how the efficiencies of different native signal sequences compare in the transamidation reaction that catalyzes the substitution of the GPI anchor for the C‐terminal peptide. In this study we utilized the placental alkaline phosphatase (PLAP) minigene, miniPLAP, and replaced its native 3′ end‐sequence encoding ω‐2 to the C‐terminus with the corresponding C‐terminal sequences of nine other human GPI‐anchored proteins. The resulting chimeras then were fed into an in vitro processing microsomal system where the cleavages leading to mature product from the nascent preproprotein could be followed by resolution on an SDS–PAGE system after immunoprecipitation. The results showed that the native signal of each protein differed markedly with respect to transamidation efficiency, with the signals of three proteins out‐performing the others in GPI‐anchor addition and those of two proteins being poorer substrates for the GPI transamidase. The data additionally indicated that the hierarchical order of efficiency of transamidation did not depend solely on the combination of permissible residues at ω→ω + 2. J. Cell. Biochem. 84: 68–83, 2002. © 2001 Wiley‐Liss, Inc.
The Dirac equation in quantum chemistry: Strategies to overcome the current computational problems
Authors: Visscher Lucas
Published: August 2002

A perspective on the use of the relativistic Dirac equation in quantum chemistry is given. It is demonstrated that many of the computational problems that plague the current implementations of the different electronic structure methods can be overcome by utilizing the locality of the small component wave function and density. Possible applications of such new and more efficient formulations are discussed. © 2002 Wiley Periodicals, Inc. J Comput Chem 23: 759–766, 2002
Influence of the presence of small gas molecules in the structure of comblike polyacrylates: A Monte Carlo study
Authors: León Salvador , Zanuy David , Alemán Carlos
Published: August 2002

A theoretical strategy has been developed to study the motion of small molecules through ordered polymeric systems. The strategy, which has been incorporated into a computer program denoted MCDP/2, is especially useful to study comblike polymers organized in biphasic arrangements. This is because it is based on a configurational bias Monte Carlo algorithm, which is more efficient than conventional methods to study dense systems. The MCDP/2 program has been used to investigate the influence of CH4 and CO2 gas molecules in the structure of isotactic poly(octadecyl acrylate), a typical comblike polymer. For this purpose, the pure polymer and different molecular systems constituted by several gas molecules dissolved in the polymer matrix have been simulated. Results indicated that the structural relaxation of the polymer is not coupled to the motion of gas molecules. The importance of these results in the field of molecular modeling of transport properties in comblike polymers is discussed. © 2002 Wiley Periodicals, Inc. J Comput Chem 23: 685–696, 2002
Theoretical study of endohedral metallofullerenes: Sc3−nLanN@C80 (n=0–3)
Authors: Kobayashi Kaoru , Sano Yuko , Nagase Shigeru
Published: August 2002

To provide theoretical insight into the structures and properties of Sc3N@C80, which has been isolated in high yield and purity as a new stable endohedral metallofullerene, density functional calculations are carried out for the Sc3−nLanN@C80 (n=0–3) series. Because of electron transfer from Sc3N to C80, the electronic structure of Sc3N@C80 is formally described as (Sc3N)6+C\documentclass{article}\pagestyle{empty}\begin{document}$_{80}^{6-}$\end{document}. The encapsulated Sc3N cluster takes a planar structure with long Sc–Sc distances and is highly stabilized inside the Ih cage of C80, which rotates rapidly. As the number of La atoms increases, the Sc3−nLanN cluster is forced to maintain a pyramidal structure in Sc3−nLanN@C80. In addition, the C80 cage takes an open‐shell electronic structure due to an increase in the number of electrons transferring from Sc3−nLanN. These make the endohedral structure less stable and more reactive. © 2001 John Wiley & Sons, Inc. J Comput Chem 22: 1353–1358, 2001
The dependent patient in a psychiatric inpatient setting: Relationship of interpersonal dependency to consultation and medication frequencies
Authors: O'Neill Richard M. , Bornstein Robert F.
Published: August 2002

To examine the relationship between interpersonal dependency and medical service use in a hospital setting, the number of medical consultations and psychotropic medication prescriptions were compared in matched, mixed‐sex samples of 40 dependent and 40 nondependent psychiatric inpatients. Results indicated that dependent patients received more medical consultations and a greater number of medications than did nondependent patients with similar demographic and diagnostic profiles. Implications of these results for theoretical models of interpersonal dependency and for previous research on the dependency–help‐seeking relationship are discussed. Practical implications of these findings for work with dependent patients are summarized. © 2001 John Wiley & Sons, Inc. J Clin Psychol 57: 289–298, 2001.
Sakai et al. is not an adequate demonstration of TFT effectiveness
Authors: Lohr Jeffrey M.
Published: August 2002

Sakai et al. (2001) report an uncontrolled case series of TFT treatments applied to a wide range of psychological complaints in a large health maintenance facility. They analyze verbal report measures of symptom severity and conclude that the specific treatment is effective for a wide range of psychological problems. A review of the theory and research on TFT efficacy indicates that the theoretical basis for the specific treatment is unfounded and that adequately controlled efficacy research has yet to be conducted. The authors' conclusions about effectiveness and applicability are not supported by either theory, prior research, or the findings of their clincial application. © 2001 John Wiley & Sons, Inc. J Clin Psychol 57: 1229–1235, 2001.
Comparison of two treatments for traumatic stress: A community‐based study of EMDR and prolonged exposure
Authors: Ironson G. , Freund B. , Strauss J.L. , Williams J.
Published: August 2002

This pilot study compared the efficacy of two treatments for postraumatic stress disorder (PTSD): Eye Movement Desensitization and Reprocessing (EMDR) and Prolonged Exposure (PE). Data were analyzed for 22 patients from a university‐based clinic serving the outside community (predominantly rape and crime victims) who completed at least one active session of treatment after three preparatory sessions. Results showed both approaches produced a significant reduction in PTSD and depression symptoms, which were maintained at three‐month follow‐up. Successful treatment was faster with EMDR as a larger number of people (7 of 10) had a 70% reduction in PTSD symptoms after three active sessions compared to 2 of 12 with PE. EMDR appeared to be better tolerated as the dropout rate was significantly lower in those randomized to EMDR versus PE (0 of 10 vs. 3 of 10). However all patients who remained in treatment with PE had a reduction in PTSD scores. Finally, Subjective Units of Distress (SUDS) ratings decreased significantly during the initial session of EMDR, but changed little during PE. Postsession SUDS were significantly lower for EMDR than for PE. Suggestions for future research are discussed. © 2002 John Wiley & Sons, Inc. J Clin Psychol 58: 113–128, 2002.
Considering a multisite study? How to take the leap and have a soft landing
Authors: Dewa Carolyn S. , Durbin Janet , Wasylenki Donald , Ochocka Joanna , Eastabrook Shirley , Boydell Katherine M. , Goering Paula
Published: August 2002

Although most policymakers agree that a fundamental goal of the mental health system is to provide integrated community‐based services, there is little empirical evidence with which to plan such a system. Studies in the community mental health literature have not used a standard set of evaluation methods. One way of addressing this gap is through a multisite program evaluation in which multiple sites and programs evaluate the same outcomes using the same instruments and time frame. The proposition of introducing the same study design in different settings and programs is deceptively straightforward. The difficulty is not in the conceptualization but in the implementation. This article examines the factors that act as implementation barriers, how are they magnified in a multisite study design, and how they can be successfully addressed. In discussing the issue of study design, this article considers processes used to address six major types of barriers to conducting collaborative studies identified by Lancaster or Lancaster's six Cs—contribution, communication, compatibility, consensus, credit, and commitment. A case study approach is used to examine implementation of a multisite community mental health evaluation of services and supports (case management, self‐help initiatives, crisis interventions) represented by six independent evaluations of 15 community health programs. A principal finding was that one of the main vehicles to a successful multisite project is participation. It is only through participation that Lancaster's six Cs can be addressed. Key factors in large, geographically dispersed, and diverse groups include the use of advisory committees, explicit criteria and opportunities for participation, reliance on all modes of communication, and valuing informal interactions. The article concludes that whereas modern technology has assisted in making complicated research designs feasible, the operationalization of timeless virtues such as mutual respect and trust, flexibility, and commitment make them successful. © 2002 John Wiley & Sons, Inc.
Homeobox genes in normal and malignant cells
Authors: Cillo Clemente , Cantile Monica , Faiella Antonio , Boncinelli Edoardo
Published: August 2002

Homeobox genes are transcription factors primarily involved in embryonic development. Several homeobox gene families have so far been identified: Hox, EMX, PAX, MSX as well as many isolated divergent homeobox genes. Among these, Hox genes are most intriguing for having a regulatory network structure organization. Recent indications suggest the involvement of homeobox genes in (i) crucial adult eukariotic cell functions and (ii) human diseases, spanning from diabetes to cancer. In this review we will discuss the mechanisms through which homeobox genes act, and will propose a model for the function of the Hox gene network as decoding system for achieving specific genetic programs. New technologies for whole‐genome RNA expression will be crucial to evaluate the clinical relevance of homeobox genes in structural and metabolic diseases. © 2001 Wiley‐Liss, Inc.
Influence of nitrogen on the degradation of toluene in a compost‐based biofilter
Authors: Delhoménie Marie‐Caroline , Bibeau Louise , Roy Sébastien , Brzezinski Ryszard , Heitz Michèle
Published: August 2002

Two identical laboratory‐scale bioreactors were operated simultaneously, each treating an input air flow rate of 1 m3 h−1. The biofilters consisted of multi‐stage columns, each stage packed with a compost‐based filtering material, which was not previously inoculated. The toluene inlet concentration was fixed at 1.5 g m−3 of air. Apart from the necessary carbon, the elements nitrogen, phosphorus, sulfur, potassium and other micro‐elements are also essential for microbial metabolism. These were distributed throughout the filter bed material by periodic ‘irrigations’ with various test nutrient solutions. The performance of each biofilter was quantified by determining its toluene removal efficiency, and elimination capacity. Nutrient solution nitrogen levels were varied from 0 to 6.0 g dm−3, which led to elimination capacities of up to 50 g m−3 h−1 being obtained for a toluene inlet load of 80 g m−3 h−1. A theoretical analysis also confirmed that the optimum nitrogen solution concentration lays in the range 4.0–6.0 g dm−3. Validation of the irrigation mode was achieved by watering each biofilter stage individually. Vertical stage‐by‐stage stratification of the biofilter performance was not detected, ie each filter bed section removed the same amount of pollutant, the elimination capacity per stage being about 16 g m−3 h−1 per section of column.

© 2001 Society of Chemical Industry