Biomaterial effects in articular cartilage tissue engineering using polyglycolic acid, a novel marine origin biomaterial, IGF-I, and TGF-beta 1

Bovine articular chondrocytes were seeded on either polyglycolic acid (PGA) non-woven mesh scaffolds or a biomatrix from the species Porites lutea (POR). These constructs were cultured for 6 weeks in the presence of insulin-like growth factor (IGF)-I (10 ng/ml or 100 ng/ml) or transforming growth factor (TGF)-beta 1 (5 ng/ml or 30 ng/ml) to determine the in-vitro articular cartilage regeneration capacity of each. Histology, deoxyribonucleic acid content, collagen I and II (immunohistochemistry and enzyme-linked immunosorbent assay), and glycosaminoglycan (GAG) contents were measured at 0 weeks, 2 weeks, and 6 weeks to assess the characteristics of chondrogenesis. Both scaffolds supported the maintenance of the chondrocytic phenotype, as evidenced by the predominance of collagen II and the presence of rounded chondrocytes embedded in lacunae. Regardless of growth factor treatment, cells cultured on PGA scaffolds produced more collagen type II than those cultured on POR. Conversely, by 6 weeks, cells cultured on POR scaffolds produced more GAG than those cultured on PGA scaffolds, again regardless of the growth factor used. Across the two groups, 100 ng/ml of IGF-I had the greatest overall effect in GAG content. This work indicates that PGA and the POR scaffolds are both effective growth matrices for articular cartilage, with each scaffold exhibiting different yet desirable profiles of articular cartilage growth.

Stabilization due to predator interference: comparison of different analysis approaches

We study the influence of the particular form of the functional response in two-dimensional predator-prey models with respect to the stability of the nontrivial equilibrium. This equilibrium is stable between its appearance at a transcritical bifurcation and its destabilization at a Hopf bifurcation, giving rise to periodic behavior. Based on local bifurcation analysis, we introduce a classification of stabilizing effects. The classical Rosenzweig-MacArthur model can be classified as weakly stabilizing, undergoing the paradox of enrichment, while the well known Beddington-DeAngelis model can be classified as strongly stabilizing. Under certain conditions we obtain a complete stabilization, resulting in an avoidance of limit cycles. Both models, in their conventional formulation, are compared to a generalized, steady-state independent two-dimensional version of these models, based on a previously developed normalization method. We show explicitly how conventional and generalized models are related and how to interpret the results from the rather abstract stability analysis of generalized models.

[Quality management of interdisciplinary treatment of polytrauma. Possibilities and limits of retrospective routine data collection]

BACKGROUND

The purpose of this study was to evaluate the quality of interdisciplinary multiple trauma management using routinely taken data.

METHODS

A retrospective analysis of all multiple traumatized patients [Injury Severity Score (ISS)>15] in a university hospital (n=172; time period 01.01.1997-31.12.1999) was carried out concerning epidemiological and clinical variables and hospital outcome (p<0.05).

RESULTS

The overall mortality was 22% [n=38; expected Trauma Injury Severity Score (TRISS) mortality 29%]. Significant parameters for worse outcome in univariate analysis were age>74 years, hypotension, decreasing hemoglobin level and prothrombin time, decreased Glasgow Coma Scale and the number of erythrocyte or plasma concentrates received in the initial period of treatment. The comparison of our results with the data of the German Association for Trauma Surgery registry demonstrated comparable results with respect to management sequence and outcome.

CONCLUSIONS

In the quality management of multiple trauma patients retrospective analysis of routinely registered parameters can be a reliable and practical alternative to time-consuming prospective studies when based on prognostic relevant data. Such a procedure allows a preliminary critical comparison with other centers.

Lung-surfactant-meconium interaction: in vitro study in bulk and at the air-solution interface

Lung surfactants (LSs) form a monolayer at the lung's alveoli air-solution interface and play a crucial role in making normal breathing possible by reducing the surface tension. LS are affected by various agents that hamper their normal functioning. Tobacco smoke [Bringezu, F.; Pinkerton, K. E.; Zasadzinski, J. A. Langmuir 2003, 19, 2900-2907] and meconium, the first excrement of the newborn, are examples for such LS poison. In neonates, intrauterine aspiration of meconium is a known cause for morbidity and mortality. We studied in vitro the interactions between modified porcine LSs (Curosurf), used as LS replacement, and meconium, as well as between their artificial analogues, phospholipids mixture, and taurocholic acid (TA), respectively. The interactions were examined both in the bulk solution and at the air-water interface, representing the pre- and postnatal situations. It was found that the artificial analogues represent the natural system reliably and exhibit similar effects. TA, a principle component of bile, is an amphiphilic sterol compound in which the hydrophilic and hydrophobic moieties are presented at different faces of the sterol plane. Here we found that TA affects the structure of both monolayers at the interface and surfactant aggregates in solution. A likely poisoning mechanism is by stereoselective penetration of TA into the lamellar or monolayer structures, thus disrupting the contiguous structure of the intact monolayer or the bilayer vesicle structure.

Optical broadband monitoring of conventional and ion processes

This contribution is focused on applications of spectroscopic methods for the precise control of deposition processes. Besides a monochromator system with a moving grating for the deep ultraviolet/vacuum ultraviolet (DUV/VUV) spectral range, two approaches are presented for online spectrophotometers with CCD arrays. The conventional spectrophotometer is considered for the operator-assisted deposition of fluoride coatings applied in the DUV/VUV range. The concepts with CCD arrays are combined with an advanced software tool for an automatic production of optical coatings. An ion-assisted deposition process and ion-beam sputtering are considered for rapid manufacturing of complex layer systems in the visible and near-infrared spectral ranges. The present contribution summarizes and discusses the major aspects of the described combinations.

[Interdisciplinary emergency room management of trauma patients from the standpoint of coworkers]

INTRODUCTION

The purpose of this study was to examine whether staff questionnaire evaluation is useful for quality control in the emergency room (ER) setting.

METHODS

Consecutive anonymous questionnaires (Likert scale 1-5) were filled out by the involved medical staff in all ER trauma cases in a university hospital from July 2002 to December 2003 (analysis of variance, P<0.05).

RESULTS

In 171 ER cases, 844 staff members responded. Main criticisms concerned time management or satisfaction with personal ER training (Likert <4). Consultants rated the quality of their training significantly higher than younger doctors, two thirds of consultants vs one third of residents having passed an Advanced Trauma and Life Support course (P<0.001). Depending on responders' professional specialties and whether the situation concerned multiple trauma (Injury Severity Score >15), a significant systematic difference resulted.

CONCLUSION

Our standardized staff questionnaire evaluation was revealed to be a discriminative instrument for quality management of trauma cases in the ER. To confirm these findings, correlation with clinical outcome data and further validation of the method are needed.

Multiple-trauma management

BACKGROUND AND OBJECTIVE

Staff attitude plays a pivotal role in quality management. The objective of the present study was to further define how interdisciplinary emergency hospital staff experience their daily work and the extent to which the professional speciality and training of an individual influences his/her assessment of multiple-trauma team performance.

METHODS

The clinical staff involved in multiple-trauma emergency management of a university hospital was asked to answer a confidential questionnaire. Factorial analysis was used to identify 8 major dimensions from a total of 53 items.

RESULTS

The questionnaire was returned by 128 team members. All professional groups were most dissatisfied with the dimensions 'education and training', 'work sequence between specialities' and 'communication between specialities'. Assessment of the quality of in-hospital emergency-trauma management differed significantly between professional specialities (ANOVA, F=5.2; P=0.028); surgeons gave the highest ratings for all but one dimension. Having taken an Advanced Trauma Life Support (ATLS) course influenced significantly the total rating of multiple-trauma treatments of anaesthetists and surgeons (F=5.5; P=0.024).

CONCLUSIONS

The perceptions of interdisciplinary trauma team members without the completion of an ATLS training course were that they did not communicate enough with each other and that there were differences between their expectations and reality. The differences and the communication deficits were overcome in team members who had passed an ATLS course.

Central Nervous System Tumors in Donors: Misdiagnosis Carries a High Morbidity and Mortality

INTRODUCTION

The cost of misdiagnosis of central nervous system (CNS) tumors in donors has not been previously described. The purpose of this study was to examine the Israel Penn International Transplant Tumor Registry experience with these donors.

METHODS

All cases where an error in diagnosis was made due to intracranial hemorrhage from undiagnosed CNS tumors and where CNS metastases were misdiagnosed as primary brain tumor were examined.

RESULTS

Forty-two organ recipients with misdiagnosed primary brain deaths from 29 donors were examined. After transplantation these donors were identified with: melanoma (23%), renal cell carcinoma (19%), choriocarcinoma (12%), sarcoma (10%), Kaposi's sarcoma (7%), and variable tumors (22%). The majority of patients were renal allograft recipients (84%) followed by liver (n = 4) and lung recipients (n = 1). The most commonly diagnostic error was with intracranial hemorrhage (ICH) (62%). A donor-related transmission rate of 74% (31/42) was identified among those patients with a misdiagnosed brain death. The majority of donor-transmitted cancers were identified in the recipient allograft (71%). Sixty-four percent of recipients suffered diffuse metastatic disease. Overall survival was poor, with a 5-year survival rate of 32% (10/31). Explantation was performed in 17 patients with confirmed donor-transmitted cancer, and in these patients a survival benefit was noted (10/17, 59%, vs 0/14, 0%; P < .01).

CONCLUSIONS

Error in the diagnosis of donor brain death due to CNS tumors has significant and often fatal consequences. Allograft explantation for kidney recipients or retransplantation for extrarenal recipients may provide a survival benefit. Potential donors with unclear etiologies for brain death, particularly ICH, should be considered for a limited brain autopsy after donation.

Displaced anterior column acetabular fracture: closed reduction and percutaneous CT-navigated fixation

The purpose of this study is to demonstrate the feasibility of computer-tomography-navigated closed reduction and percutaneous fixation (CRPF) in a patient with an externally rotated left acetabular fracture. After a follow-up of 18 months the patient was pain-free and had a normal range of motion in both hip joints. Radiologically, the fracture was fully consolidated, remodelled, and there were no signs of osteoarthritis. To our knowledge, CT-navigated CRPF of a rotated acetabular fracture has not been reported before. Further studies regarding the feasibility of the method are warranted.

Neue Stabilisierungsverfahren an der proximalen Tibia (LISS/LCP)

Bei instabilen proximalen Tibiafrakturen kommt es infolge ungenügender Abstützung nicht selten zu Sekundärdislokationen mit konsekutiver Gelenksinkongruenz und Achsenfehlstellung. Doppelplattenosteosynthesen erhöhen zwar die Stabilität, sind aber wenig biologisch und führen leicht zu Wundheilungsproblemen. Neue Stabilisierungsverfahren wie das LISS (Less Invasive Stabilization System) und die LCP (Locked Compression Plate) ermöglichen eine winkelstabile und minimal invasive Osteosynthese. Dadurch können die Stabilität verbessert und Wundheilungsprobleme vermindert werden. Somit werden einfache Frakturen weiterhin mit den herkömmlichen Implantaten versorgt, bicondyläre Frakturen mit metaphysärer Trümmerzone und/oder ausgedehntem Weichteilschaden werden aber zunehmend mit minimal invasiven winkelstabilen Osteosyntheseverfahren stabilisiert.

Delayed Union of a Sacral Fracture: Percutaneous Navigated Autologous Cancellous Bone Grafting and Screw Fixation

Delayed or non-union of a sacral fracture is a serious clinical condition that may include chronic pain, sitting discomfort, gait disturbances, neurological problems, and inability to work. It is also a difficult reconstruction problem. Late correction of the deformity is technically more demanding than the primary treatment of acute pelvic injuries. Open reduction, internal fixation (ORIF), excision of scar tissue, and bone grafting often in a multi-step approach are considered to be the treatment of choice in delayed unions of the pelvic ring. This procedure implies the risk of neurological and vascular injuries, infection, repeated failure of union, incomplete correction of the deformity, and incomplete pain relief as the most important complications. We report a new approach for minimally invasive treatment of a delayed union of the sacrum without vertical displacement. A patient who suffered a Malgaigne fracture (Tile C1.3) was initially treated with closed reduction and percutaneous screw fixation (CRPF) of the posterior pelvic ring under CT navigation and plating of the anterior pelvic ring. Three months after surgery he presented with increasing hip pain caused by a delayed union of the sacral fracture. The lesion was successfully treated percutaneously in a single step procedure using CT navigation for drilling of the delayed union, autologous bone grafting, and screw fixation.

Internal olefins to linear amines

The selective synthesis of linear amines from internal olefins or olefin mixtures was achieved through a catalytic one-pot reaction consisting of an initial olefin isomerization followed by hydroformylation and reductive amination. Key to the success is the use of specially designed phosphine ligands in the presence of rhodium catalysts. This reaction constitutes an economically attractive and environmentally favorable synthesis of linear aliphatic amines.

[Pain management in surgical wards. Quality and solutions for improvement in the early postoperative period]

INTRODUCTION

Following guidelines pain levels should not exceed a score of 3 on the visual analog scale (VAS 1-10). We were interested in the actual surgical pain management of the postoperative period and the potential influences of a nurse-controlled intravenous morphine administration (NCA) on its quality.

METHODS

Interventional study: interview of patients and nursing staff and examination of records concerning pain treatment following surgery.

RESULTS

The interviews were conducted with 110 patients before and 125 patients after the intervention program. Before the intervention, one-half of the patients noted that they were never asked about their pain intensity within the first 24 h after surgery. Only 42% of the records showed at least one VAS documentation. Every fourth individual experienced a pain intensity > 3 without having received a supplementary pain medication. Following the morphine intervention program, documentation of pain scores increased significantly (72%; p < 0.0001) and more patients were familiar with the VAS (64% vs 46%; p < 0.0004). Median maximum as well as actual pain at the time of the interview decreased by one point (VAS). The percentage of patients whose supplementary pain prescription was totally used showed a significant increase (p = 0.035). Following morphine administration, no single individual complained about an undue waiting time in comparison to 15% of patients previously. Even though the morphine intervention project caused more work for the nursing staff, 75% of the personnel were convinced that the procedure was worth this investment.

CONCLUSION

This data revealed a relevant deficiency of surgical pain management. Already basic instructions on pain management can significantly improve this treatment. Assigning additional authority to the nursing staff, such as a nurse-based intravenous opioid administration, can significantly raise the motivation of the personnel as well as the satisfaction of the patients involved.

The deubiquitinating enzyme Ubp21p of fission yeast stabilizes a mutant form of protein kinase Prp4p

The protein kinase Prp4p of Schizosaccharomyces pombe is involved in control of the formation of active spliceosomes, phosphorylating the spliceosomal component Prp1p. The kinase domain of Prp4p is closely related to cyclin-dependent kinases (CDKs) and mitogen-activated kinases (MAPKs). A mutational analysis of the highly conserved amino acid sequence ALKHP in subdomain XI of this kinase showed that structural features of this sequence are important for the function of the kinase. We identified ubp21 as a high-copy-number suppressor of a mutation in the ALKHP motif. Characterization of this gene revealed that it encodes a deubiquitinating enzyme belonging to the family of ubiquitin-specific processing proteases (Ubps). The results presented in this report are consistent with the notion that the deubiquitinating activity of Ubp21p may be involved in regulating the steady-state levels of proteins including Prp4p.

[Technology integration and process management. Concept and implementation of a new platform for simultaneous diagnosis and therapy of acutely ill and injured patients and for elective computer assisted surgery (CAS)]

Modern imaging and computer technology gain more and more importance in surgery. This is true for elective and emergency diagnosis and treatment. However integration of technology and optimization of process management is severely behind. A new diagnostic-therapeutic platform should balance this deficit. The platform is composed of a fully equipped operation room environment with integrated high end computer-tomography with navigation, a digital subtraction angiography and an OR- and imaging-table particularly developed for this set-up. The platform may be used for elective diagnosis, for diagnosis and therapy in polytraumatized patients in one and the same location (one stop shop) and for computer assisted surgery (CAS). Bringing the technology to the patient and not the patient to the technology can save time consuming and potentially dangerous transports and expensive personnel can be reduced. Navigation-technology and high quality intra-operative imaging expand the spectrum of minimally invasive surgery.

Investigation of rational syntheses of heteroleptic porphyrinic lanthanide (europium, cerium) triple-decker sandwich complexes

The use of lanthanide triple-decker sandwich molecules containing porphyrins and phthalocyanines in molecular information storage applications requires the ability to attach monomeric triple deckers or arrays of triple deckers to electroactive surfaces. Such applications are limited by existing methods for preparing triple deckers. The reaction of a lanthanide porphyrin half-sandwich complex ((Por)M(acac)) with a dilithium phthalocyanine (PcLi2) in refluxing 1,2,4-trichlorobenzene (bp 214 degrees C) affords a mixture of triple deckers of composition (Pc)M(Pc)M(Por), (Por)M(Pc)M(Por), and (Pc)M(Por)M(Pc). We have investigated more directed methods for preparing triple deckers of a given type with distinct metals in each layer. Application of the method of Weiss, which employs reaction of a (Por)M(acac) species with a lanthanide double decker in refluxing 1,2,4-trichlorobenzene, afforded the desired triple decker in some cases but a mixture of triple deckers in others. The approach we developed employs in situ formation of the lanthanide reagent EuCl[N(SiMe3)2]2 or CeI[N(SiMe3)2]2, which upon reaction with a porphyrin affords the half-sandwich complex (Por)EuX or (Por)CeX' (X = Cl, N(SiMe3)2; X' = I, N(SiMe3)2). Subsequent reaction with PcLi2 gives the double decker (Por)M(Pc). The (Por(1))EuX half-sandwich complex gave the desired triple decker upon reaction with (Pc)Eu(Pc) but little of the desired product upon reaction with (Por(2))Eu(Pc). The (Por(1))CeX' half-sandwich complex reacted with europium double deckers (e.g., (tBPc)Eu(Por(2)), (tBPc)2Eu) to give the triple deckers (Por(1))Ce(tBPc)Eu(Por(2)) and (Por(1))Ce(tBPc)Eu(tBPc) in a rational manner (tB = tetra-tert-butyl). The reactions yielding the half-sandwich, double-decker, and triple-decker complexes were performed in refluxing bis(2-methoxyethyl) ether (bp 162 degrees C). The porphyrins incorporated in the various triple deckers include meso-tetrapentylporphyrin, meso-tetra-p-tolylporphyrin, octaethylporphyrin, and meso-tetraarylporphyrins bearing iodo, ethynyl, or iodo and ethynyl substituents. The triple deckers bearing iodo and/or ethynyl substituents constitute useful building blocks for information storage applications.