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Initial Cycle (initial + cycle)
Selected AbstractsDynamic compressive properties of porcine temporomandibular joint discEUROPEAN JOURNAL OF ORAL SCIENCES, Issue 5 2003Eiji Tanaka This study aimed to evaluate the effect of the strain frequency and amplitude on the compressive properties of the porcine temporomandibular joint disc and to determine the time-dependent changes associated with energy dissipation. Seven discs were used for compressive cycle tests, including various frequencies and magnitudes of compressive strain. Each experiment consisted of 25 cycles of loading and unloading. Hysteresis and the instantaneous and steady moduli were calculated. All specimens showed a clear hysteresis and repeatable stress,strain relationships within 19 cycles. The hysteresis at the initial cycle ranged between 35% and 62%, and gradually decreased in subsequent cycles. The instantaneous modulus became larger when the strain frequency and the strain amplitude increased. The steady modulus was approximately one-third of the instantaneous one. It was concluded that the disc has an energy-dissipating function during dynamic compression. [source] Influence of adjuvant chemotherapy with cyclophosphamide, methotrexate and 5-fluorouracil on plasma melatonin and chosen hormones in breast cancer premenopausal patientsJOURNAL OF CLINICAL PHARMACY & THERAPEUTICS, Issue 4 2001D. Kajdaniuk Objective:,To investigate the effect of chemotherapy on levels of melatonin in patients with breast cancer. Background:,In light of reports on the possible oncostatic role of melatonin in breast cancer patients, it is essential to know the influence of adjuvant chemotherapy with cyclophosphamide, methotrexate and 5-fluorouracil (CMF) on plasma melatonin concentration as well as on its contributing factors, e.g. current hormonal state of the organism. The combination therapy is one of the oldest, safest and most commonly prescribed adjuvant treatments. Method:,Twenty-four breast cancer patients on CMF chemotherapy were studied along with a control group of 16 healthy pre-menopausal women. Results:,Plasma melatonin concentration (determined by RIA method) in breast cancer patients prior to treatment did not differ significantly from that of healthy women, but it was significantly increased after the initial cycle of CMF, and significantly increased as compared to a group of healthy women. We did not notice any significant interactions between plasma melatonin and growth hormone, prolactin, estradiol, progesterone, cortisol and met-enkephalin concentrations in all studied groups. Conclusion:,The possible oncostatic action of melatonin warrants further investigation to elucidate whether the induced increase of blood melatonin concentration is essential to successful CMF chemotherapy. [source] Osteon pullout in the equine third metacarpal bone: Effects of ex vivo fatigueJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 3 2003L. P. Hiller Abstract An important concept in bone mechanics is that osteons influence mechanical properties in several ways, including contributing to toughness and fatigue strength by debonding from the interstitial matrix so as to ,bridge" developing cracks. Observations of ,pulled out, osteons on fracture surfaces are thought to be indicative of such behavior. We tested the hypothesis that osteon pullout varies with mode of loading (fatigue vs. monotonic), cortical region, elastic modulus, and fatigue life. Mid-diaphseal beams from the dorsal, medial, and lateral regions of the equine third metacarpal bone were fractured in four point bending by monotonic loading to failure under deflection control, with or without 105 cycles of previous fatigue loading producing 5000 microstrain (15,20% of the expected failure strain) on the first cycle; or sinusoidal fatigue loading to failure, under load or deflection control, with the initial cycle producing 10,000 microstrain (30,40% of the expected failure strain). Using scanning electron microscopy, percent fracture surface area exhibiting osteon pullout (%OP.Ar) was measured. Monotonically loaded specimens and the compression side of fatigue fracture surfaces exhibited no osteon pullout. In load-controlled fatigue, pullout was present on the tension side of fracture surfaces, was regionally dependent (occurring to a greater amount dorsally), and was correlated negatively with elastic modulus and positively with fatigue life. Regional variation in %OP.Ar was also significant for the pooled (load and deflection controlled) fatigue specimens. %OP.Ar was nearly significantly greater in deflection controlled fatigue specimens than in load-controlled specimens (p < 0.059). The data suggest that tensile fatigue loading of cortical bone eventually introduces damage that results in osteonal debonding and pullout, which is also associated with increased fatigue life via mechanisms that are not yet clear. © 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved. [source] Immunosuppression for liver transplantation in HCV-infected patients: Mechanism-based principlesLIVER TRANSPLANTATION, Issue 11 2005Bijan Eghtesad We retrospectively analyzed 42 hepatitis C virus (HCV)-infected patients who underwent cadaveric liver transplantation under two strategies of immunosuppression: (1) daily tacrolimus (TAC) throughout and an initial cycle of high-dose prednisone (PRED) with subsequent gradual steroid weaning, or (2) intraoperative antithymocyte globulin (ATG) and daily TAC that was later space weaned. After 36 ± 4 months, patient and graft survival in the first group was 18/19 (94.7%) with no examples of clinically serious HCV recurrence. In the second group, the three-year patient survival was 12/23 (52%), and graft survival was 9/23 (39%); accelerated recurrent hepatitis was the principal cause of the poor results. The data were interpreted in the context of a recently proposed immunologic paradigm that is equally applicable to transplantation and viral immunity. In the framework of this paradigm, the disparate hepatitis outcomes reflected different equilibria reached under the two immunosuppression regimens between the relative kinetics of viral distribution (systemically and in the liver) and the slowly recovering HCV-specific T-cell response. As a corollary, the aims of treatment of the HCV-infected liver recipients should be to predict, monitor, and equilibrate beneficial balances between virus distribution and the absence of an immunopathologic antiviral T-cell response. In this view, favorable equilibria were accomplished in the nonweaned group of patients but not in the weaned group. In conclusion, since the anti-HCV response is unleashed when immunosuppression is weaned, treatment protocols that minimize disease recurrence in HCV-infected allograft recipients must balance the desire to reduce immunosuppression or induce allotolerance with the need to prevent antiviral immunopathology. (Liver Transpl 2005;11:1343,1352.) [source] Management of nonresponse to rituximab in rheumatoid arthritis: Predictors and outcome of re-treatmentARTHRITIS & RHEUMATISM, Issue 5 2010E. M. Vital Objective A proportion of patients with rheumatoid arthritis (RA) have disease that fails to respond to an initial cycle of rituximab. Using highly sensitive flow cytometry (HSFC), it has been shown that most patients who do not exhibit a response, as measured using the European League Against Rheumatism (EULAR) criteria, have persistent circulating B cell levels at week 2 after initial treatment with rituximab. This study was undertaken to examine whether an additional cycle of rituximab would improve B cell depletion and clinical response in patients whose disease did not respond to the initial cycle. Methods Patients with RA (n = 158) were treated with a first cycle of rituximab (2 infusions of 1 gm each). Clinical responses were assessed using EULAR criteria, and patients were categorized as either first-cycle responders or first-cycle nonresponders. Baseline characteristics of first-cycle nonresponders (n = 38) and first-cycle responders (n = 65) with complete data were compared. First-cycle nonresponders (n = 25) were treated with a second cycle of rituximab at least 6 months after the first cycle. HSFC was performed at baseline, immediately prior to the second infusion (week 2), 1 month after the second infusion (week 6), and then every 3 months for each cycle of rituximab. Complete B cell depletion was defined as being <0.0001 × 109 cells/liter. Results At baseline, the number of preplasma cells was significantly higher in first-cycle nonresponders than in first-cycle responders (P = 0.003). Following the first infusion of the first cycle of rituximab, only 9% of first-cycle nonresponders (3 of 34) exhibited complete depletion of B-lineage cells, compared with 37% of first-cycle responders (22 of 59) (P = 0.007). Following the first infusion of the second cycle of rituximab, 38% of first-cycle nonresponders exhibited complete depletion. Twenty-six weeks after the second cycle, there was a significant improvement in the Disease Activity Score in 28 joints, with 72% of patients exhibiting a EULAR response. Conclusion RA patients whose disease did not respond to an initial cycle of rituximab have higher circulating preplasma cell numbers at baseline and incomplete depletion. Our findings indicate that an additional cycle of rituximab administered prior to total B cell repopulation enhances B cell depletion and clinical responses. [source] Effects of selection for resistance to Sesamia nonagrioides on maize yield, performance and stability under infestation with Sesamia nonagrioides and Ostrinia nubilalis in SpainANNALS OF APPLIED BIOLOGY, Issue 3 2010G. Sandoya A maize synthetic population was improved for resistance to the Mediterranean corn borer (MCB, Sesamia nonagrioides) while maintaining yield. The objectives of this research were to investigate whether yield and yield stability of the maize synthetic population named EPS12 were affected by selection for MCB resistance; also to determine which genotypic and environmental covariates could explain the genotype (G), environment (E) and genotype × environment (GE) effects for yield under corn borer infestation. Plants from three cycles of selection and their testcrosses to three inbred testers (A639, B93 and EP42) were evaluated at two locations in 2 years, under MCB and European corn borer infestations. After selection EPS12 was a more stable genotype. Hybrids derived from crosses between B93 and inbreds obtained from the initial cycles of selection could be recommended for cultivation in northern Spain. The yield of crosses between cycles of selection and testers increased when there were fewer days with temperatures >25°C and higher mean maximum temperatures. Differences in yield among these genotypes were mostly explained by resistance to corn borer attack. In general, among EPS12-derived materials, genetic characteristics that contribute to increased grain yield were also responsible for increased abiotic stress tolerance. [source] | |||||||||||||