The surgical risk of pancreas transplantation in the cyclosporine era: an overview

BACKGROUND: Pancreas transplants are still associated with the highest surgical complication rate of all routinely performed solid organ transplants. To date, the impact of serious surgical complications in the cyclosporine era on perioperative patient morbidity, graft and patient survival, and hospital costs has not been analyzed in detail. STUDY DESIGN: We retrospectively studied surgical complications after 445 consecutive pancreas transplants (45% simultaneous pancreas-kidney [SPK], 24% pancreas after kidney [PAK], and 31% pancreas transplant alone [PTA]). Of these, 80% were primary transplants, 20% were retransplants. Cadaver donors were used in 92%, living related donors in 8%. To develop guidelines for their prevention and management, we studied the impact of significant surgical complications (intra-abdominal infections, vascular graft thrombosis, and anastomotic leak) requiring relaparotomy on graft and patient survival. RESULTS: Relaparotomy was required after 32% of all pancreas transplants (SPK: 36%, PAK: 25%, PTA: 16% [p = 0.04]). Perioperative mortality was 9%. Graft and patient survival rates were significantly lower for recipients with (versus without) relaparotomy. The most common procedures were drainage of intra-abdominal abscess with graft necrosectomy (50% of all relaparotomies) and transplant pancreatectomy (34%). The most common causes of relaparotomy were intra-abdominal infection, vascular graft thrombosis, and anastomotic leak. Intra-abdominal infection occurred in 20% (SPK: 18%, PAK: 24%, PTA: 20% [p = NS]). The rate was significantly higher for living related donor (42%) versus cadaver donor (18%) recipients and for those with enteric-drained (39%) versus bladder-drained (18%) transplants. Graft and patient survival rates were significantly lower for recipients with (versus without) intra-abdominal infection. Outcome was better after bacterial (versus fungal) infections. For SPK recipients, those not on dialysis before the transplant had significantly higher graft survival than those on dialysis. Vascular graft thrombosis occurred in 12% of all recipients. The rate was significantly higher for PAK (21%) than for PTA (10%) and SPK (9%) recipients. It was significantly lower for recipients of grafts with donor iliac Y-graft reconstruction (versus all other types of arterial reconstruction) and with right-sided (versus left-sided) graft placement. Of note, patient survival was not different for recipients with versus without vascular graft thrombosis. The incidence of anastomotic or duodenal stump leaks was 10%; of these recipients, 70% required relaparotomy. Patient and graft survival rates were no different for recipients with versus without leaks. CONCLUSIONS: Serious surgical complications occurred in 35% of pancreas recipients and had a significant impact on patient and graft survival. Based on multivariate risk factor analyses, we recommend the following: donors over 45 years and those dying of cerebrocardiovascular disease should not be used; recipients over 45 years and those with a history of cardiac disease should be considered for a kidney transplant alone (KTA); surgical technique for graft procurement, preparation, and implantation should be meticulous; right-sided implantation and arterial Y-graft reconstruction should be performed when possible, since they had the highest success rates; when complications require relaparotomy, the focus must switch from graft salvage to life preservation; and the threshold for pancreatectomy should be low. Diagnosis should be timely, and treatment and relaparotomy expeditious. These cornerstones of success should help decrease the risk of surgical complications and mortality after pancreas transplants.     

Fatigue Assessment of Defect-Free and Defect-Containing Brazed Steel Joints

This work aims at the development of lifetime estimation procedures for defect-free and defect-containing brazed joints. Preliminary investigations were performed to measure the influence of specimen geometry on the joint strength. To estimate the influence of defects on the fatigue lifetime, defect-free specimens were compared with specimens containing defects. The experiments show that defect-containing specimens provide considerably lower joint strengths than defect-free specimens. The decrease of the fatigue strength with increasing defect size can be shown, but the direct comparison of different defects is not possible with S-N-curves. Based on the experimental results and on theoretical investigations, a procedure was developed to estimate the lifetime of defect-free and defect-containing brazed joints based on the stress intensity caused by a defect.     

Structure–Property Relation of SrTiO3/LaAlO3 Interfaces

A large variety of transport properties have been observed at the interface between the insulating oxides SrTiO₃ and LaAlO₃ such as insulation, 2D interface metallicity, 3D bulk metallicity, magnetic scattering, and superconductivity. The relation between the structure and the properties of the SrTiO₃/LaAlO₃ interface can be explained in a meaningful way by taking into account the relative contribution of three structural aspects: oxygen vacancies, structural deformations (including cation disorder), and electronic interface reconstruction. The emerging phase diagram is much richer than for related bulk oxides due to the occurrence of interface electronic reconstruction. The observation of this interface phenomenon is a display of recent advances in thin film deposition and characterization techniques, and provides an extension to the range of exceptional electronic properties of complex oxides.     

Identification of cross-linked peptides for protein interaction studies using mass spectrometry and 18O labeling

A new method is presented to screen proteolytic mass maps of cross-linked protein complexes for the presence of cross-linked peptides and for the verification of proposed structures. On the basis of the incorporation of 18O from isotopically enriched water into the C-termini of proteolytic peptides, cross-linked peptides are readily distinguished in mass spectra by a characteristic 8 amu shift. This is due to the incorporation of two 18O atoms in each C-terminus, so that normal and surface-labeled peptides shift 4 amu and cross-linked peptides containing two C-termini will shift 8 amu compared with their unlabeled counterparts. The method is fast, sensitive, and reliable and can be combined with any available cross-linking reagent and a wide range of proteolytic agents. As proof of principle, we successfully applied the method to a complex of two DNA repair proteins (Rad18-Rad6) and identified the interaction domain.     

High-Efficiency Light Coupling in a Submicrometric Silicon-on-Insulator Waveguide

Light coupling into a sub-micrometer-thick waveguide is usually done through a grating coupler. Coupling efficiency is strongly enhanced by addition of a mirror above the grating. This new kind of coupler can be designed to achieve efficiencies as great as 80%. Numerical calculations for a high-angular-spread Gaussian incident beam are compared with experimental results obtained for a standard silicon-on-insulator waveguide.     

Cartilage degeneration in relation to repetitive pressure: case study of a unilateral hip hemiarthroplasty patient

The mitochondrial, inner-membrane-associated, reversible NADPH-->NAD transhydrogenase of adult Hymenolepis diminuta physiologically couples matrix-localized, NADP-specific "malic" enzyme with NADH-dependent anaerobic electron transport. Employing submitochondrial particles (SMP) as the source of enzyme activity and both spectrophotometric and fluorometric assessments, the present study made evident that in its catalysis of transhydrogenation between NADPH and NAD, the cestode enzyme engages in the concomitant transmembrane translocation of protons. As assessed spectrophotometrically, the catalysis of NADPH-dependent NAD reduction by H. diminuta SMP was stimulated significantly by carbonyl cyanide 3-chlorophenylhydrazone (CCCP), carbonyl cyanide 4-(trifluoromethoxy) phenylhydrazone (FCCP), as well as by the protonophoric anthelmintic, niclosamide. In addition, N,N'-dicyclohexylcarbodiimide (DCCD) markedly diminished SMP-catalyzed hydride ion transfer between NADPH and NAD. The catalysis by SMP of concomitant, transhydrogenase-mediated proton translocation was evaluated more directly via fluorometric assays using 8-anilino-1-napthalenesulfonic acid (ANS) as the probe. These latter evaluations revealed a transhydrogenase-dependent enhancement of ANS fluorescence in accord with an intravesicular accumulation of protons. ANS fluorescence was quenched rapidly when the assay system was supplemented with CCCP, FCCP, or niclosamide. Consistent with the helminth transhydrogenase acting as a proton pump, transhydrogenase-mediated enhanced fluorescence also was inhibited by DCCD. Considered collectively, these data indicated, apparently for the first time for any invertebrate system, that the transhydrogenase, in catalyzing the NADPH-->NAD reaction, acts in the translocation of protons from the matrix to the intermembrane space mitochondrial compartment.     

Analysis of grocery chain pharmacists' work-related behaviors

OBJECTIVE: To measure grocery chain pharmacists' work-related behaviors to assess the impact of a Pharmaceutical Care Certificate Program (PCCP) and other future interventions intended to alter pharmacists' practice behaviors. DESIGN: This study used multidimensional work sampling (MWS), a work measurement methodology that breaks "work" into three components: activity (what was done), contact (with whom the activity was performed), and function (the purpose or objective of the activity). Pharmacists were signaled at random intervals during the workday by a random signal generator. A selection was made from a list of items in each of the three dimensions of work to form an activity-contact-function combination code that described the work-related behavior at that point in time. SETTING AND PARTICIPANTS: Pharmacists in 15 grocery chain stores in the Indianapolis area; 20 pharmacists were enrolled in Purdue University's PCCP and 10 served as controls. Data were collected for a period of six weeks during April through June 1997 before the beginning of the PCCP program. MAIN OUTCOME MEASURES: Pharmacists' work-related behaviors. RESULTS: Writing/keyboarding was the most frequently recorded activity (22%), followed by one-to-one meetings (21.6%), and drug preparation (18%). Pharmacists spent most of their time working alone (62.9%), while a smaller but still substantial proportion of time was spent interacting with patients (17.9%). The most frequently recorded purpose (i.e., function) of pharmacists' activities was drug distribution (23.9%), followed by personal time (12.4%), receiving or transferring a medication order (10.2%), and patient counseling (6.6%). Out of a possible, 1,760 activity-contact-function combinations, 10 accounted for 46.3% of all reported observations, with "Prepare drug-Self-Drug distribution" representing the most frequently recorded activity-contact-function combination (15.7%). CONCLUSION: MWS is useful in helping grocery chain management better understand how pharmacy personnel are currently being utilized. This study provides a baseline for evaluating the impact of training programs or other alterations in the practice environment on pharmacists' work-related behaviors.     

Schizophrenia research: a biennium of progress. Proceedings from the Sixth International Congress on Schizophrenia Research. Colorado Springs, CO, April 12-16, 1997

The Sixth International Congress on Schizophrenia Research (ICOSR) took place in Colorado Springs, Colorado, April 12-16, 1997, where over 1,000 scientists presented and listened to the latest developments in the search for the cause and treatment of schizophrenia. The ICOSR is sponsored by Maryland Psychiatric Research Center, Case Western Reserve University, and the William K. Warren Foundation. The National Institute of Mental Health and several pharmaceutical companies contributed generously to the meeting. The ICOSR is co-organized by Dr. Carol A. Tamminga, Maryland Psychiatric Research Center, University of Maryland at Baltimore, and Dr. S. Charles Schulz, Case Western Reserve University, Cleveland, Ohio. The William K. Warren Research Award is given to a senior investigator, who has made outstanding contributions to our understanding of schizophrenia. The fifth William K. Warren Research Award was presented to Dr. Philip S. Holzman in recognition of his contributions to the identification of eye-tracking abnormalities as a potential phenotypic marker of the illness and also in recognition of his work as a lifelong mentor for schizophrenia researchers. The ICOSR Young Investigator Awards are presented to junior investigators who have demonstrated the potential to make significant contributions to research on schizophrenia. These awards promote scientific development by enabling these young researchers to attend the meeting. There were 30 Young Investigator Award winners. The ICOSR meeting is organized into four sessions: (1) a morning plenary session; (2) a plenary lecture; (3) a poster session; and (4) concurrent afternoon oral sessions. The morning plenary sessions are comprised of a set of 30-minute lectures, which provide an overview of a particular topic area relevant to schizophrenia research. The plenary lecture is an invited lecture on a basic topic related to current research efforts in schizophrenia. The poster sessions provide a forum for the presentation of prepublication reports of basic and clinical science projects. The afternoon sessions are a collection of approximately 10 focused presentations on current research projects related to a specific topic area. The purpose of this report is to provide an account of the proceedings from the plenary and afternoon oral sessions.