bluuebunny/crossref_metadata_2025_split huggingface dataset:
Poisoning in Zimbabwe: a survey of eight major referral hospitals
Authors: Tagwireyi D. , Ball D. E. , Nhachi C. F. B. 
Published: August 2002

AbstractA 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

AbstractPorous 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

AbstractThis 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

AbstractWe 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

AbstractPatients 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

AbstractThe 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

AbstractConfocal 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

AbstractWhen 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

AbstractA 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

AbstractSmads 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

AbstractThrombotic 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

AbstractPlasma 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

AbstractPlasma 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

AbstractThe 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.