bluuebunny/crossref_metadata_2025 huggingface dataset:
Patient Age and Cancer Treatment Decisions
Authors: Kutner Jean S. , Vu Kieu O. , Prindiville Sheila A. , Byers Tim E.
Published: March 2003

Purpose: The purpose of this study was to examine patient and physician factors influencing the decision to use adjuvant chemotherapy for stage III colon cancer in elderly persons.

Description of study: A cross‐sectional mailed population‐based survey of patients 65 years of age and older who had undergone surgical resection of stage III colon cancer in Colorado between August 1995 and December 1997 were identified by the statewide cancer registry (n = 276) and their treating physicians (n = 232). A questionnaire about the determinants of colon cancer treatment decisions was mailed to all patients for whom physician permission was granted (n = 119). A similar questionnaire was sent to treating physicians.

Results: Ninety‐two physicians (internal medicine 23%; family medicine 12%; surgery 37%; and oncology 24%) and 67 patients (mean age 75.8 years; 55% women) completed surveys. Fifty‐four (80.6%) of the patients had received adjuvant chemotherapy. The major determinants of receiving adjuvant chemotherapy were having seen an oncologist (P = .003), being younger (P = .003), and being married (P = .021). After controlling for other potential influences, only having seen an oncologist (odds ratio 8.0; confidence interval 1.5–43.1) remained significantly associated with the receipt of chemotherapy. Physicians were more likely than patients to rank comorbid conditions (39.1% versus 3.0%, respectively; P < .001) and the medical literature (20.7% versus 4.5%, respectively; P = .004) as important factors in making treatment decisions, while patients were more likely than physicians to rank physician opinion (73.1% versus 26.1%, respectively; P = .001), family preference (31.3% versus 9.8%, respectively; P = .001), and family burden (10.4% versus 2.2%, respectively; P = .038).

Clinical implications: In this elderly population, patient age is not recognized by patients or physicians as affecting the decision to use adjuvant chemotherapy. Other biologic and social factors are important, however, and the perspectives of physicians and patients differ regarding their relative importance.
Cancer Screening Among Korean Americans
Authors: Sarna Linda , Tae Young Sook , Kim Young Hae , Brecht Mary Lynn , Maxwell Annette E.
Published: March 2003

Purpose: Cancer is a leading cause of death among Korean Americans (KAs), one of the most rapidly growing ethnic minority communities in the United States. An understanding about cancer screening practices among Koreans (Ks) living in Korea can be useful in designing culturally sensitive health promotion programs in the United States. The purpose of this study was to describe the cancer screening knowledge and behaviors of a sample of KAs in Los Angeles, California, compared with a similar sample of Ks in Korea.

Description of study: This descriptive survey used a convenience sample of 140 KAs age 40 and older, living in Los Angeles, California, in 1998. A random sample of 149 Ks from Pusan, Korea, in 1995 to 1996 was used as a comparison group. KAs had lived in the United States for an average of 15 years. A Korean and English language 58‐item self‐administered questionnaire assessed knowledge of cancer screening tests and personal cancer screening practices.

Results: The findings demonstrate that both KAs and Ks had low participation in cancer screening. Breast cancer screening was significantly more likely among KA women than among Ks; screening rates for cervical cancer and gastrointestinal malignancies were not significantly different between the two groups.

Clinical implications: These data can be used to assist healthcare professionals in the development of educational tools and strategies for promoting cancer screening programs for KAs. The unique contribution of this study was the opportunity to compare findings from an immigrant Korean population with a similar population in the country of origin.
Patient and Caregiver Interest in Internet‐Based Cancer Services
Authors: Monnier Jeannine , Laken Marilyn , Carter Cindy L.
Published: March 2003

purpose: The primary goal of this study was to identify the needs for, the interest in, and the feasibility of the implementation of an Internet‐based cancer services web site. Additionally, group differences (racial, patient vs caregiver, or rural vs urban) were identified that might influence the implementation of such a project.

description of study: Patients with cancer and caregivers (N = 319) in the waiting rooms of a cancer center located within a southeastern medical university completed questionnaires regarding their interest in Internet‐based services. Topics included the likelihood of using Internet‐based services, interest in home healthcare services delivered via a personal computer, and knowledge about and use of the Internet.

results: Results indicated that most patient and caregiver respondents were interested in Internet‐based cancer‐related services such as information related to treatment (80%), conversations with physicians via the Internet (70%), and online support groups (65%). In addition, respondents reported that they would be likely to use such services (70%) and were interested in home healthcare services delivered via personal computers (60%). No group differences were found across ethnic groups, geographic settings, and patient status (patient vs caregivers) on these variables. Minorities, older individuals, and less educated individuals were less likely to have knowledge of and to have used the Internet.

clinical implications: Patients with cancer and their caregivers are interested in supplementing in‐person services with Internet‐based services relating to their cancer treatment. Special efforts need to be made to reach ethnic minorities, the elderly, and those with less education with Internet‐based programs.
Tapestry
Authors: Angen Maureen J. , MacRae J. Helen , Simpson J. Steven A. , Hundleby Marilyn
Published: March 2003

purpose: In an effort to mitigate the negative psychological sequelae of a cancer diagnosis and cancer treatment, efforts have been made to explore a variety of psychosocial issues and interventions. This article describes the provision and preliminary evaluation of a novel psychosocial service delivery, a residential “retreat” program called Tapestry, which is run under the aegis of the established cancer care community in Alberta, Canada.

overview: Retreat programs offer a novel way to provide psychosocial support for those persons who are living with cancer. The retreats are unique in the provision of a respite and the opportunity to address the isolation and other existential issues arising from a cancer diagnosis. The program described in this article has provided such a service six times per year since 1998. The intervention is described, and preliminary evaluation data are presented.

clinical implications: Cancer care has begun to move beyond a solely biomedical paradigm toward a more holistic ethos in service delivery and research orientation. While the face value of and demand for such programming continues to grow, few residential psychosocial programs are offered under the auspices of conventional cancer care centers, and little work has been done to examine the nature and possible efficacy of retreat programs as a valid forum for psychosocial service delivery.
Modularity and dissociation in the evolution of gene expression territories in development
Authors: Raff Rudolf A. , Sly Belinda J.
Published: March 2003

SUMMARY Modularity is a salient feature of development and crucial to its evolution. This paper extends modularity to include the concept of gene expression territory, as established for sea urchin embryos. Territories provide a mechanism for partitioning of the cells of a rapidly developing embryo into functional units of a feeding larva. Territories exhibit the characteristics of modules. The paper asks if the embryo and the nonfeeding larva of the direct‐developing sea urchin Heliocidaris erythrogramma are organized into gene expression territories, and if its territories correspond to the canonical territories of the pluteus. An analysis of cell lineage and gene expression data for H. erythrogramma shows that skeletogenic cell, coelomic, and vegetal plate gene expression territories are conserved, although they arise from cell lineages distinct from those of the pluteus, and the overall morphology of the larva differs from that of a pluteus. The ectoderm, as in indirect developers, is divided into territories. However, the oral ectodermal territory characteristic of the pluteus is absent in H. erythrogramma. Oral ectoderm is restored in hybrids of H. erythrogramma eggs fertilized by Heliocidaris tuberculata sperm. This indicates that embryonic modules evolve by changes in expression of dominant regulatory genes within territories and that entire modules can be eliminated in evolution of embryos.
Characterization of amphioxusAmphiWnt8 : insights into the evolution of patterning of the embryonic dorsoventral axis
Authors: Schubert Michael , Holland Linda Z. , Panopoulou Georgia D. , Lehrach Hans , Holland Nicholas D.
Published: March 2003

SUMMARYThe full‐length sequence and developmental expression of an amphioxusWntgene (AmphiWnt8 ) are described. In amphioxus embryos, the expression patterns ofAmphiWnt8suggest patterning roles in the forebrain, in the hindgut, and in the paraxial mesoderm that gives rise to the muscular somites. Phylogenetic analysis indicates that a singleWnt8subfamily gene in an ancestral chordate duplicated early in vertebrate evolution into aWnt8clade and aWnt8bclade. Coincident with this gene duplication, the functions of the ancestralAmphiWnt8‐like gene appear to have been divided between vertebrateWnt8b(exclusively neurogenic, especially in the forebrain) and vertebrateWnt8(miscellaneous, especially in early somitogenesis). AmphioxusAmphiWnt8and its vertebrateWnt8homologs probably play comparable roles in the early dorsoventral patterning of the embryonic body axis.
Interpreting the homeobox: metaphors of gene action and activation in development and evolution
Authors: Robert Jason Scott
Published: March 2003

SUMMARYDespite countless research efforts to demonstrate the precise developmental and evolutionary nature of homeobox genes, we are far from consensus on the role of this class of genes in development and evolution. This essay attempts to clarify the debate and to nip some problematic interpretations in the bud, by exploring metaphors of homeobox gene function in development and evolution.
Glucose‐Insulin Kinetics of a Bioartificial Pancreas Made of an AN69 Hydrogel Hollow Fiber Containing Porcine Islets and Implanted in Diabetic Mice
Authors: Delaunay  , Darquy  , Honiger  , Capron  , Rouault  , Reac
Published: March 2003

The goal of this study was to determine whether porcine islets encapsulated in hollow fibers made of AN69 copolymer can correct hyperglycemia in diabetic mice and provide normal tolerance to a glucose challenge. In vitro perifusion of hollow fibers demonstrated the rapid kinetics of insulin release in response to glucose. Two fibers containing islets were transplanted into the peritoneal cavity of each of 17 streptozotocin induced diabetic mice. In 11 mice, diabetes was reversed within 3 days with plasma glucose levels decreasing from 19.7 ± 0.9 (mean ± SEM) before implantation to 10.9 ± 0.8 mmol/L. Intraperitoneal glucose tolerance tests were performed in transplanted (n = 7), nondiabetic (n = 15), and diabetic mice (n = 6). A normal glucose pattern was observed in the transplanted diabetic mice. This was achieved in the presence of plasma insulin levels lower than those observed in control nondiabetic mice, suggesting the presence of a state of hypersensitivity to insulin, which was demonstrated in this model by exogenous insulin tolerance tests. In conclusion, encapsulation of islets suspended in ultraculture medium in biocompatible membranes of AN69 can provide xenograft survival, and complete normalization of glucose tolerance can be achieved.
Enhanced, Simplified Glucose Sensors: Long‐Term Clinical Application of Wearable Artificial Endocrine Pancreas
Authors: Shichiri Motoaki , Sakakida Michiharu , Nishida Kenro , Shimoda Seiya
Published: March 2003

At present, 2 major problems should be solved before long‐term application of the wearable artificial endocrine pancreas, the development of a reliable and stable glucose monitoring system and the development of a subcutaneous insulin infusion algorithm. With either a miniaturized extracorporeal glucose monitoring system based on microdialysis sampling method or a ferrocene‐mediated needle‐type glucose sensor covered with highly biocompatible membrane, poly(2‐methacryloyloxyethyl phosphorylcholine‐co‐n‐butyl methacrylate) (poly[MPC‐co‐BMA]) membrane, subcutaneous glucose concentrations could be monitored for 7 days without any in vivo calibrations, followed by 14 days with one point calibration. Considering the management and safety of the insulin delivery route, subcutaneous insulin infusion is obligatory. With the subcutaneous insulin infusion algorithm using a short acting insulin analogue (Insulin Lispro), near physiological glycemic control could be established in diabetic patients without showing any delayed hyperinsulinemia or hypoglycemia. The wearable artificial endocrine pancreas is now recognized as an excellent therapeutic tool for regulating blood glucose excursions physiologically in ambulatory diabetic patients on a long‐term basis.
Arteriovenous Difference of Blood Ammonia in Uremic Patients Under Hemodialysis
Authors: Agroyannis Basil , Tzanatos Helen , Fourtounas Costas , Kopelias Ioannis , Katsoudas Spyros , Chondros Kostas
Published: March 2003

It is the goal of this section to publish material that provides information regarding specific issues, aspects of artificial organ application, approach, philosophy, suggestions, and/or thoughts for the future.

In this study the ammonia concentration was determined in arterial and venous blood samples pre‐ and posthemodialysis (HD) in 18 uremic patients and in 18 health subjects (controls). The mean values (±SD) of ammonia in the arterial blood of uremic patients pre‐HD were 98.32 ± 26.55; post‐HD, 63.18 ± 17.09; and in control group patients, 72.37 ± 10.09 μg/dl. In venous blood they were pre‐HD, 71.70 ± 20.68; post‐HD, 58.05 ± 16.73; and in control patients, 74.46 ± 12.0 μg/dl. Accord than that post‐HD and that of control patients. The ammonia contents of venous blood pre‐ and post‐HD ranges were within normal values, but the post‐HD range was significantly lower than the pre‐HD range (p < 0.05) and the control range (p < 0.01). Comparison between ammonia levels from arterial and venous blood showed significant and positive arteriovenous differences pre‐HD (p < 0.001), which disappeared post‐HD and were not observed in the control patients. In conclusion, uremic patients under HD present pre‐HD high levels of ammonia in arterial blood with a significantly positive arteriovenous difference. In contrast, the post‐HD ammonia levels in arterial and venous blood are decreased, and the arteriovenous difference is not significant.
Induced Cell Trauma During in Vitro Perfusion: A Comparison Between Two Different Perfusion Systems
Authors: Skogby  , Mellgren  , Adrian  , Friberg  , Chevalier  , Mellgren
Published: March 2003

The purpose of this study was to compare blood cell activation during in vitro long‐term perfusion using 2 parallel in vitro extracorporeal membrane oxygenation (ECMO) systems. We compared two substantially different perfusion systems, an assistance respiratoire extra corporelle (AREC) system on one hand, containing an AREC pump, silicon tubing, and a hollow‐fiber oxygenator, and a centrifugal pump system, on the other hand, containing a Biomedicus centrifugal pump, PVC tubing, and a membrane oxygenator. We measured the platelet count using an automated blood cell counter. Platelet activation was evaluated using a flow cytometric technique for the platelet membrane expression of glycoproteins and ELISA for the plasma concentration of β‐thromboglobulin (β‐TG), a platelet specific protein released into the blood upon platelet activation. The neutrophil count was assayed using an automated blood cell counter and the plasma concentration of cytokines using an ELISA kit. A significant difference between the two systems was observed in terms of the platelet membrane expression of glycoprotein (GP)Ib (p = 0. 0001) and GPIIb/IIIa (p = 0.0037), indicating a lower degree of platelet activation in the AREC system. The concentration of neutrophils was significantly lower in the centrifugal system (p = 0.002) compared to the AREC system. The neutrophil membrane expression of CD11b was significantly lower (p = 0.0067) in the AREC system, indicating a lower degree of neutrophil activation compared to the centrifugal pump system. A significantly lower degree of hemolysis, as expressed by plasma hemoglobin, was observed in the AREC pump system (p = 0.0491). In conclusion, lower degrees of the platelet membrane expression of GPIb and GPIIb/IIIa and of the neutrophil membrane expression of CD11b were observed in the AREC system, indicating a lower degree of platelet and neutrophil activation in this system. No significant difference between the two systems as to the plasma concentration of interleukin (IL)‐1β, IL‐6, or IL‐8 could be recorded. Further studies are warranted to specify the role of each individual component of the two systems.
Minimally Invasive Cardiac Surgery: Current Status and Perspective
Authors: Matsuda Hikaru , Sawa Yoshiki , Takahashi Toshiki , Hirata Nobuaki , Ohtake Shigeaki
Published: March 2003

Recently, the minimally invasive approach has become a growing aspect in the field of cardiac surgery with the goal of eliminating cardiopulmonary bypass (CPB) and/or median sternotomy. In coronary bypass surgery, the application of this approach is direct anastomosis, primarily of the left internal thoracic artery to the left descending coronary artery under a beating condition without the use of CPB through a small left thoracotomy minimally invasive direct coronary artery bypass (MIDCAB). In the repair of intracardiac lesions, CPB cannot be excluded, but a small right parasternal incision or small partial sternotomy (ministernotomy) has been applied for congenital defects and mitral and aortic valve lesions. With technological advances in CPB, these approaches may become more popular in the near future.
Washout Hole Flow Measurement for the Development of a Centrifugal Blood Pump
Authors: Nishida Masahiro , Yamane Takashi , Asztalos Balázs
Published: March 2003

Abstract Washout holes in the impeller of a centrifugal blood pump reduce thrombus formation in areas where blood is apt to stagnate, especially in the back gap of the impeller. In this study, flow through the washout holes is quantified by pressure measurement and flow visualization with a 300% scaled‐up model to understand the force driving flow through the washout holes and the flow itself. When external circuit resistance is constant, pressure distribution normalized by the square of the tip speed is constant and independent of the impeller rotational speed. The ratio of the flow rate through the washout holes to the flow rate of the external circuit is also constant. When the external circuit resistance increases, the pressure difference at the washout holes between the front and back gap of the impeller increases and generates a greater flow rate through the washout holes.
Artificial Cells with Emphasis on Cell Encapsulation of Genetically Engineered Cells
Authors: Chang Thomas Ming Swi
Published: March 2003

Artificial cells are prepared in the laboratory for medical and biotechnological applications. Encapsulated cells are being studied for the treatment of diabetes, liver failure, and other conditions. More recently, there have been extensive studies into the use of encapsulated genetically engineered cells for gene therapy. We recently found that daily orally administered artificial cells, each containing a genetically engineered microorganism, can lower the elevated urea level in uremic rats to normal levels. This may solve the final obstacle of the lack of an effective oral urea removal system for the simple and inexpensive oral treatment of uremia. This is important because 85% of the world's uremic population cannot afford standard dialysis. Other areas of artificial cell application include use in hemoperfusion. Red blood cell substitutes based on modified hemoglobin are already in Phase 3 clinical trials in patients. Artificial cells containing enzymes are being developed for clinical trial in hereditary enzyme deficiency disease and other diseases. They are also being investigated for drug delivery and for use in other applications in biotechnology, chemical engineering, and medicine.
Partially Degradable Film/Fabric Composites: Textile Scaffolds for Liver Cell Culture
Authors: Karamuk Erdal , Mayer Jörg , Wintermantel Erich , Akaike Toshihiro
Published: March 2003

Abstract: In this study, a composite scaffold combining textile superstructures and biomimetic glycopolymers is introduced, which may allow engineering of organotypic liver tissue in vitro. Woven poly(ethylene therephtalat) (PET) fabrics were coated on one side with a thin biodegradable polymer film (poly[d‐l‐lactic‐co‐glycolic acid] PLGA), in order to obtain a polar structure. The composite structure ensured the stability of the membrane during in vitro degradation, independently of mesh size. Matrix porosity increased when a polymer blend matrix was used. For hepatocyte culturing studies, the scaffolds were additionally coated with an artificial glycopolymer (poly[N‐p‐vinylbenzyl‐d‐lactoamide], PVLA) in order to improve cell attachment. It was observed that formation of aggregates depends on the scaffold geometry as well as on the pretreatment and medium conditions. After 4 days in culture, the pores of the fabric were filled with aggregates illustrating the possibility of immobilizing hepatocyte aggregates in well‐defined spatial configurations on textile structures.
Three‐Dimensional Thoracic Modeling for an Anatomical Compatibility Study of the Implantable Total Artificial Heart
Authors: Zhang Bin , Masuzawa Toru , Tatsumi Eisuke , Taenaka Yoshiyuki , Uyama Chikao , Takano Hisateru , Takamiya Makoto
Published: March 2003

Anatomical compatibility with the thoracic cavity is important in developing a completely implantable total artificial heart (TAH). The purpose of this study was to examine the optimal morphology of our TAH and to develop a computer implantation simulation environment for preoperational discussion. As the first stage, we constructed a prototype simulation system by creating a 3‐D surface model of a thoracic cavity and one of a TAH. In this system, the thoracic surface model, composed of the aorta, pulmonary artery, ventricle resected heart, diaphragm, and thoracic wall, was created based on the organ contours extracted from electrocardiogram (ECG)‐synchronized ultrafast computer tomographic images. The accuracy of the thoracic model was discussed using a phantom. The fitting study can be performed on the computer with the model of the thorax and that of the TAH. In the future, construction of a database for the thoracic cavities of heart failure patients is planned to improve the morphology of the TAH.
Ex Vivo Evaluation of a Roller Screw Linear Muscle Actuator for an Implantable Ventricular Assist Device Using Trained and Untrained Latissimus Dorsi Muscles
Authors: Sasaki Yasushi , Chikazawa Genta , Nogawa Masamichi , Nishida Hiroshi , Koyanagi Hitoshi , Takatani Setsuo
Published: March 2003

In this study, the power output and contraction length of trained and untrained canine latissimus dorsi (LD) muscles were measured using a roller screw linear muscle actuator (RSLMA). The RSLMA consisted of a roller screw‐nut assembly and translation unit to convert the linear pull force of the muscle into an axial displacement of the roller screw. When a cable wound around a spool attached at each end of the roller screw nut was pulled in either direction, the nut was rotated which in turn advanced the roller screw in the axial direction. Under anesthesia, a Telectronics myostimulator (Model 7220) was implanted in the subcutaneous area of the canine left thoracic region with its bipolar intramuscular leads implanted around the thoracodorsal nerve and the distal muscle. A total of 6 dogs went through the myostimulator implantation, followed with 8 weeks of continuous stimulation. After completion of the training, the contraction lengths of the trained and untrained LD muscles were measured, and they were 4.25 and 5.5 cm, respectively, while the instantaneous power outputs were 4.24 and 8 W, respectively. Although untrained muscles could provide much higher instantaneous power immediately following the start of the stimulation, it diminished rapidly. On the other hand, the trained muscle showed prolonged fatigue resistance. The thoracolumbar and humeral approaches in attaching the actuator cable did not show a difference with respect to muscle power output. The trained LD muscle can provide sufficient power in the range of 3–4 W to drive a left heart assist device, but its long‐term evaluation awaits development of an appropriate muscle‐device interface for chronic in vivo application.
Standing Up with Denervated Muscles in Humans Using Functional Electrical Stimulation
Authors: Kern  , Hofer  , Strohhofer  , Mayr  , Richter  , Stöhr
Published: March 2003

The use of electrical stimulation for denervated muscles is still considered to be a controversial issue by many rehabilitation facilities and medical professionals because prior clinical experience has shown that treating denervated muscle tissue using exponential current over a long time period constitutes an impossible task. Despite this fact, we managed to evoke tetanic contractions in denervated muscle using a long duration stimulation with anatomically shaped electrodes and sufficiently high amplitudes. The pulse amplitudes, which were being used for this purpose, exceeded by far the MED‐GV and EC regulations (300 mJ/impulse). For this reason, an application has recently been submitted to have the EC regulations changed accordingly. It takes a tetanic contraction to achieve the desired muscle fiber tension, constituting a hypertrophic stimulus. It is also an appropriate means of exercise, which is capable of creating the metabolic and structural conditions needed (e.g, increased mitochondrial volume and capillary density) to obtain satisfactory muscle performance. With patients suffering from a complete spinal cord injury at level D12/L1, having motor and sensory loss in both lower extremities, we were able to train denervated muscle using long‐duration stimulation, evoking single muscle contractions at first, soon followed by tetanic contractions against gravity. To increase the efficacy of this functional electrical stimulation (FES) strengthening program, we used ankle weights. With daily FES training over a period of 1–2 years, denervated muscle was exercised until it produced torques between 16 and 38 Nm in the m. quadriceps. With that muscle force, it is possible to stand up from a sitting position in parallel bars. Our results show that denervated muscle in humans is indeed trainable and can perform functional activities with FES. Furthermore, this method of stimulation can assist in decubitus prevention and significantly improve the mobility of paraplegics.
Blood Flow in a Continuous Flow Ventricular Assist Device
Authors: Allaire Paul E. , Wood Houston G. , Awad Ramy S. , Olsen Don B.
Published: March 2003

A numerical analysis was performed to predict the shear stresses, flow rates, and the velocity profiles in a continuous flow ventricular assist device, the CFVAD3. The problem was modeled as a rotating disk over a stationary disk. A variety of clearances was tested for the CFVAD3 coupled with a range of rotational speeds and pressure gradients. Velocity fields were generated using solutions obtained with FLOW3D software (AEA Technology, Pittsburgh, PA, U.S.A.) Analysis of these solutions shows that the pressure differential effect has a stronger influence on the flow than the rotational effect of the impeller Ekman layer. The predicted shear stresses reflect these changes in the volume flow rates and the speeds shown in the velocity profiles. Based on the predictions of the software, the optimum clearance and rotational speed were chosen. The conclusion is that a speed in the range of 2,200–2,400 rpm should be chosen depending on the efficiency of the pump.
Perfusate Lactate Dehydrogenase Level and Intrarenal Resistance Could Not Be Adequate Markers of Perfusion Quality During Isolated Kidney Perfusion
Authors: Herrera Berta , Eisenberg Gustavo , Desco M. Mar , Holberndt Oliver , Rábano Alberto , Castilla Manuela , García‐Barreno Pedro , Del Cañizo Juan F.
Published: March 2003

Abstract: The main goal of this work was to study the influence of perfusion pressure and flow waveform during kidney perfusion, and the relationship between renal vascular resistance (RVR) and lactate dehydrogenase (LDH) concentration in the perfusate. Simultaneous constant pressure kidney perfusions were performed with either pulsatile or continuous flow at either 30 or 80 mm Hg of constant perfusion pressure. Mean flow, pressure, and RVR were displayed online during perfusion. Perfusate samples for LDH, creatine phosphatase kinase (CPK), and alkaline phosphatase (AP) determinations were taken. At the end of the perfusion, 2 ml of Evans blue was injected into the circuit to obtain images of perfusate distribution, and the kidneys were weighed. Also, hematoxylin/eosine studies were performed, showing more Bowman's space and tubular dilation in kidneys perfused with high pressure. We did not find differences in RVR between kidneys perfused at 30 and 80 mm Hg; nevertheless, perfusate distribution was better in the 80 mm Hg perfusions. We did not find any correlation between enzyme release and RVR in kidneys perfused with different mean pressures. These findings suggest that vascular resistance and LDH concentration cannot be independently considered as adequate markers of perfusate distribution.
Effect of Electrolyzed Water on Wound Healing
Authors: Yahagi Naoki , Kono Masashi , Kitahara Masaki , Ohmura Akito , Sumita Osao , Hashimoto Toshimasa , Hori Katsuaki , Ning‐Juan Chen , Woodson Paul , Kubota Shoji , Murakami Arata , Takamoto Shinichi
Published: March 2003

Abstract: Electrolyzed water accelerated the healing of full‐thickness cutaneous wounds in rats, but only anode chamber water (acid pH or neutralized) was effective. Hypochlorous acid (HOCl), also produced by electrolysis, was ineffective, suggesting that these types of electrolyzed water enhance wound healing by a mechanism unrelated to the well‐known antibacterial action of HOCl. One possibility is that reactive oxygen species, shown to be electron spin resonance spectra present in anode chamber water, might trigger early wound healing through fibroblast migration and proliferation.
Resuscitation and Circulatory Support Using Extracorporeal Membrane Oxygenation for Fulminant Pulmonary Embolism
Authors: Kawahito Koji , Murata Sei‐ichiro , Adachi Hideo , Ino Takashi , Fuse Katsuo
Published: March 2003

Abstract: Fulminant pulmonary embolism (PE) with circulatory collapse is associated with a high mortality rate due to acute right ventricular failure and hypoxia. Immediate and appropriate resuscitation and circulatory support in the perioperative period is mandatory to prevent sudden death. Extracorporeal membrane oxygenation (ECMO) was recently introduced for extracorporeal life support in patients with circulatory collapse and has provided an excellent outcome. We report on the effectiveness of ECMO support for fulminant PE. Seven patients were placed on veno‐arterial ECMO for circulatory collapse caused by fulminant PE refractory to conventional treatment. After resuscitation, all patients underwent pulmonary angiography, and thrombolytic therapy was administered in all 7 patients under ECMO support. Three patients who did not improve by thrombolysis underwent embolectomy with standard cardiopulmonary bypass. Two thrombolysis and 2 surgery patients were weaned from bypass and survived. The duration of support ranged from 18–168 h (mean = 67.8 ± 67.1 h), with maximum bypass flow rates of 2.0–4.5 (mean = 3.5 ± 0.9). There were no device‐related complications during support. In total, 4 patients (57%) were successfully weaned from support and discharged from the hospital in good condition. All patients who survived required prolonged support (27, 82, 151, and 168 h). We conclude that resuscitation and circulatory support using ECMO can be effective, life‐saving measures in cases of circulatory collapse caused by fulminant PE.
Transient Rise in Serum Soluble Fas (APO‐1/CD95) in Patients Undergoing Cardiac Surgery
Authors: Kawahito Koji , Misawa Yoshio , Fuse Katsuo
Published: March 2003

Abstract: The Fas molecule, also designated APO‐1/CD95, belongs to the tumor necrosis factor (TNF) receptor family. It is a widely expressed membrane‐anchored protein that induces apoptosis by Fas/Fas ligand (Fas‐L) mediation. It was reported that Fas‐mediated apoptosis plays an important role in regulation of the immune system, systemic inflammatory response, and ischemia/reperfusion injury. A soluble form of Fas (sFas) is produced either through the proteolytic cleavage of membrane‐bound receptors or by alternative splicing, and sFas is thought to be implicated in apoptosis. In addition, sFas released damaged cells, and elevated serum levels of sFas reflect systemic tissue damage. To examine the specificity of sFas production during cardiac surgery with cardiopulmonary bypass, we serially measured the serum sFas levels in 13 patients during and after surgery. Blood samples were obtained before surgery, at the end of cardiopulmonary bypass, at the end of surgery, and at 12 h after surgery. Levels of serum sFas were determined by sandwich ELISA. Seven patients undergoing other types of surgeries served as controls. Although increased sFas was not observed in the control group, a significantly higher sFas level was detected in cardiac surgical patients at the end of surgery than before surgery (p = 0.028), and the level decreased at 12 h after surgery. A significant correlation was observed between the maximum sFas values and the length of surgery (r = 0.659, p = 0.012) and cardioplegic arrest (r = 0.559, p = 0.046). Elevated serum sFas levels were observed in patients undergoing cardiac surgery, and these serum sFas levels reflect the severity of a surgery. sFas may play an important role in the pathophysiology of surgical damage caused by cardiac surgery with cardiopulmonary bypass.
Jostra Rota Flow RF‐30 Pump System: A New Centrifugal Blood Pump for Cardiopulmonary Bypass
Authors: Orime Yukihiko , Shiono Motomi , Yagi Shinya , Yamamoto Tomonori , Okumura Haruhiko , Nakata Kin‐ichi , Kimura Shun‐ichi , Hata Mitsumasa , Sezai Akira , Kashiwazaki Satoshi , Choh Shinsuke , Negishi Nanao , Sezai Yukiyasu , Matsui Takahiro , Suzuki Mitsunori
Published: March 2003

Abstract:The Rota Flow pump is a fully integrated centrifugal pump system in the Jostra heart‐lung machine HL‐20 with features such as a less friction mono‐pivot bearing system, sealless pump housing, and spiral housing. To evaluate its biocompatibility, antithrombogenesity, and hemolysis, we used it as a main pump of cardiopulmonary bypass (CPB) in coronary artery bypass grafting (CABG) cases and compared it with the BioMedicus pump. From February 1999 to May 1999, 30 consecutive patients underwent CABG under conventional CPB. Fifteen cases were supported by the Rota Flow RF‐32 (Group R), and the remaining 15 were pumped by the BioMedicus BP‐80 (Group B). In both groups, the flow rate was controlled in an equivalent value. Blood sampling was as follows: preoperative, 60 min after, postoperative Days (POD) 0, 1, and 2. We evaluated the plasma free hemoglobin (fHb) as the hemolysis parameter, β‐thromboglobulin (β‐TG) and platelet factor IV (PF‐4) as the platelet deterioration index, C3, C4, and CH50as complement activation, coagulation function, fibrinolytic factor and thrombomodulin, nitric oxide (NO), and endothelin as endothelial deterioration. This system was very easily and simply controlled and had excellent response. Perioperative laboratory data were not markedly changed in either group. The Rota Flow demonstrated equivalent value of biocompatibility and hemolysis as compared with the BioMedicus BP‐80, which is a standard centrifugal pump. After pumping, no thrombus formation or pivot wear was observed inside the pump. This atraumatic, small centrifugal pump is suitable not only for CPB but also for long‐term circulatory support.
Hemolipodialysis Attenuates Oxidative Stress and Removes Hydrophobic Toxins
Authors: Wratten Mary Lou , Sereni Luisa , Tetta Ciro
Published: March 2003

Abstract: Uremic patients undergoing hemodialysis often have increased oxidant stress and accumulation of uremic toxins. Hemodialysis, per se, often can exacerbate oxidant stress and may be inefficient at removing hydrophobic or protein bound toxins. We describe a new hemodialytic method that incorporates liposomes and antioxidants to remove hydrophobic/uremic toxins and minimize free radical mediated damage. In vitro experiments measured advanced oxidation protein products (AOPP), malonaldehyde, reactive carbonyls, and the removal of platelet activating factor (PAF) and bilirubin during extracorporeal circulation with or without liposomes. We observed a significant reduction of oxidation products as well as a significant removal of PAF and bilirubin compared to normal hemodialysis.
Particles Released From the Gyro C1E3 During Simulated Extracorporeal Circulation
Authors: Takano Tamaki , Nakata Kin‐ichi , Schulte‐Eistrup Sebastian , Kawahito Shinji , Glueck Julie , Clarke Ian C. , Williams Paul Allen , Maeda Tomohiro , Nonaka Kenji , Linneweber Joerg , Yoshikawa Masaharu , Fujisawa Akira , Makinouchi Kenzo , Yokokawa Michihiro , Nosé Yukihiko
Published: March 2003

Abstract: Evaluation of released particles from the blood pump during extracorporeal circulation is an important aspect because the particles may cause microembolism. The Gyro C1E3 is a centrifugal blood pump that has an impeller suspended by double pivot bearings inside the housing; therefore, it is important to evaluate the released particles. The C1E3 was driven for 14 days to simulate clinical left ventricular assist device (LVAD) and percutaneouns cardiopulmonary support (PCPS). Also, a roller pump was driven for 2 days as a comparison. Released particles were weighed and examined by SEM. After 14 days of pumping, the particles from the C1E3 were 238.6 μg in an LVAD condition. The particles with the roller pump were 270.2 μg after only 2 days. Average particle sizes with the roller pump and C1E3 were 3.7 and 0.6 μm, respectively. These results suggest that the Gyro C1E3 substantially reduces the risk of microembolism from released particles.
Stimulated IFNγ and IL‐10 Secretion of Blood Mononuclear Cells in Patients on Renal Replacement Therapies Show Different Secretion Patterns
Authors: Alscher Dominik Mark , Pauli‐Magnus Christiane , Kuhlmann Ulrich , Mettang Thomas
Published: March 2003

Abstract: Infection is still a leading cause of morbidity and mortality in patients on renal replacement therapy (RRT). Although the role of the immune system is of great importance, little is known about the influence of the mode of RRT to the preferential excretions of regulator cytokines of mononuclear cells. Therefore, we investigated the stimulated IFNγ (Th1) and IL‐10 (Th2) secretions of mononuclear cells from patients on RRT. Blood was drawn from 10 controls, 15 patients on hemodialysis (HD), 15 on peritoneal dialysis (PD), and 10 after kidney transplantation (Tx). The cells were separated, and phytohemagglutinine (PHA) was added for stimulation. After 0, 6, and 24 h, IFNγ and IL‐10 (pg/ml) were measured by enzyme‐linked immunosorbent assay. IFNγ secretion was significantly enhanced 6 (p < 0.001) and 24 h (p = 0.002) after stimulation in all groups (in mean ± SEM). The analysis of the subgroups 6 h after adding PHA showed significant differences (p = 0.0239) with the lowest IFNγ in Tx (16 ± 5) and the highest in PD (79 ± 30). For IL‐10, secretion was enhanced in all groups 6 h after stimulation (p < 0.0116). The lowest secretions were seen in HD (18 ± 8) and controls (27 ± 9); the highest secretions were in Tx (98 ± 20) and PD (57 ± 12). The differences between HD and Tx (p < 0.01) and HD versus PD (p = 0.05) were significant. The stimulated cytokine secretion of blood mononuclear cells is preserved with RRT. The modes of RRT could influence the pattern of cytokine secretion. Surprisingly, the cells from patients on PD showed enhanced IL‐10 secretion compared to HD. Presumably, this is due to the chronic contact of peritoneal dialysis fluids with monocytes and the lymphatic system in PD.
Better Correction of Metabolic Acidosis, Blood Pressure Control, and Phagocytosis with Bicarbonate Compared to Lactate Solution in Acute Peritoneal Dialysis
Authors: Thongboonkerd Visith , Lumlertgul Dusit , Supajatura Volaluck
Published: March 2003

Abstract: Lactate solution has been the standard dialysate fluid for a long time. However, it tends to convert back into lactic acid in poor tissue‐perfusion states. The aim of this study was to evaluate the efficacy of magnesium (Mg)‐ and calcium (Ca)‐free bicarbonate solution compared with lactate solution in acute peritoneal dialysis (PD). Renal failure patients who were indicated for dialysis and needed acute PD were classified as shock and nonshock groups, and then were randomized to receive either bicarbonate or lactate solution. Twenty patients were enrolled in this study (5 in each subgroup). In the shock group, there were more rapid improvements and significantly higher levels of blood pH (7.40 ± 0.04 versus 7.28 ± 0.05, p < 0.05), serum bicarbonate (23.30 ± 1.46 versus 18.37 ± 1.25 mmol/L, p < 0.05), systolic pressure (106.80 ± 3.68 versus 97.44 ± 3.94 mm Hg, p < 0.05), mean arterial pressure (80.72 ± 2.01 versus 73.28 ± 2.41 mm Hg, p < 0.05), percentages of phagocytosis of circulating leukocytes (65.85%± 2.22 versus 52.12%± 2.71, p < 0.05), and percentages of positive nitroblue tetrazolium (NBT) reduction test without and with stimulation (14.43 ± 1.93 versus 9.43 ± 2.12, p < 0.05 and 65.08 ± 6.80 versus 50.23 ± 4.21, p < 0.05, respectively) in the bicarbonate subgroup compared with the lactate subgroup. In the nonshock group, blood pH, serum bicarbonate, and phagocytosis assays in both subgroups were comparable. Lactic acidosis was more rapidly recovered and was significantly lower with bicarbonate solution for both shock and nonshock groups (3.63 ± 0.37 versus 5.21 ± 0.30 mmol/L, p < 0.05 and 2.92 ± 0.40 versus 3.44 ± 0.34 mmol/L, p < 0.05, respectively). Peritoneal urea and creatinine clearances in both subgroups were comparable for both shock and nonshock groups. There was no peritonitis observed during the study. Serum Mg and Ca levels in the bicarbonate subgroup were significantly lower, but no clinical and electrocardiographic abnormality were observed. We concluded that Mg‐ and Ca‐free bicarbonate solution could be safely used and had better outcomes in correction of metabolic acidosis, blood pressure control, and nonspecific systemic host defense with comparable efficacy when compared to lactate solution. It should be the dialysate of choice for acute PD especially in the poor tissue‐perfusion states such as shock, lactic acidosis, and multiple organ failure.
Computational Fluid Dynamics as a Development Tool for Rotary Blood Pumps
Authors: Burgreen Greg W. , Antaki James F. , Wu Z.J. , Holmes Andrew J.
Published: March 2003

Abstract: Computational fluid dynamics (CFD) is beginning to significantly impact the development of biomedical devices, in particular rotary cardiac assist devices. The University of Pittsburgh's McGowan Center for Artificial Organ Development has extensively used CFD as the primary tool to analyze and design a novel axial flow blood pump having a magnetically suspended rotor. The blood‐contacting surfaces of the pump were developed using a design strategy based on CFD that involved closely coupling a Navier‐Stokes solver to a parameterized geometry modeler and advanced mesh movement techniques. CFD‐based blood damage models for shear‐induced hemolysis as well as surrogate functions describing thrombosis potential were employed to help guide design improvements. This CFD‐based design approach resulted in the timely development of a pump subjected to multiple geometric refinements without building expensive physical prototypes for each design iteration. A physical prototype of the final improved pump was fabricated and experimentally analyzed using particle imaging flow visualization. The CFD predicted results correlated well with the experimental data including pressure‐flow (H‐Q) performance and specific flow field features. It is estimated that the present CFD‐based design approach shortened the overall design time frame from an order of years to months.
The Effect of Methanol Washing of Plasticized Polyvinyl Chloride on Biomaterial‐Contact‐Mediated CD11b (mac‐1) Expression in a Rat Recirculation Model
Authors: Gourlay Terence , Stefanou Demetrios , Taylor Kenneth M.
Published: March 2003

Abstract: Our objective was to assess whether using a methanol wash to reduce the level of plasticizer present on the surface of medical‐grade polyvinyl chloride (PVC) has a moderating effect on the expression of CD11b (mac‐1) on neutrophils in rats undergoing recirculation. The study was carried out on 3 groups of 10 adult male Sprague‐Dawley rats weighing between 350 and 450 g. In the 2 test groups, the animals were exposed to 48 cm2 of di‐(2‐ethyl‐hexyl)‐phthalate (DEHP)‐plasticized PVC in a parallel plate recirculating test cell through which blood was recirculated at 1.5 ml/min. In the first test group, the PVC was untreated; in the second test group, the PVC was washed in methanol to reduce the level of plasticizer on the surface. The test cell was connected to the right femoral circulation, and recirculation was established for a period of 60 min. Blood samples were taken at 0, 30, and 60 min for assessment of CD11b expression on neutrophils using flow cytometric analysis. In a third group of 10 control experiments, rats underwent the entire surgical procedure, but without recirculation through the test cell. There was statistically significant (p < 0.001) lower Cd11b expression on neutrophils in the blood of rats perfused through the cell containing methanol‐washed PVC after 30 min and at 60 min. CD11b expression was significantly (p < 0.001) lower in the control group than in both test groups at both the 30 and 60 min time points and at the 60 min time point on comparison with the group where blood was perfused through methanol‐washed PVC. These results demonstrate that the biomaterial‐contact‐mediated upregulation of CD11b may be significantly reduced by employing a methanol‐washing technique on the plasticized PVC. Although this technique does not entirely eliminate the expression of CD11b on neutrophils, the difference is significant and suggests the role of the plasticizer in the development of this inappropriate inflammatory response.
Improving the Clinical Patency of Prosthetic Vascular and Coronary Bypass Grafts: The Role of Seeding and Tissue Engineering
Authors: Seifalian Alexander M. , Tiwari Alok , Hamilton George , Salacinski Henryk J.
Published: March 2003

Abstract: In patients requiring coronary or peripheral vascular bypass procedures, autogenous vein is currently the conduit of choice. If this is unavailable, then a prosthetic material is used. Prosthetic graft is liable to fail due to occlusion of the graft. To prevent graft occlusion, seeding of the graft lumen with endothelial cells is undertaken. Recent advances have also looked at developing a completely artificial biological graft engineered from the patient's cells with properties similar to autogenous vessels. This review encompasses the developments in the two principal technologies used in developing hybrid coronary and peripheral vascular bypass grafts, that is, seeding and tissue engineering.