A decomposition approach to suboptimal control of discrete-time systems

A suboptimal controller for a class of discrete-time systems is presented. The controller is derived by first solving ‘off-line’ a simplified optimal control problem obtained by neglecting part of the system state and by considering a larger time step, then by solving ‘on-line’ at each time step an optimization problem based on the results of the previously solved ‘off-line’ problem. A simple numerical example is presented to illustrate the control scheme.     

Analysis of the epsilon-sarcoglycan gene in familial and sporadic myoclonus-dystonia: evidence for genetic heterogeneity.

The epsilon-sarcoglycan gene (SGCE) on human chromosome 7q21 has been reported to be a major locus for inherited myoclonus-dystonia. Linkage to the SGCE locus has been detected in the majority of families tested, and mutations in the coding region have been found recently in families with autosomal dominant myoclonus-dystonia. To evaluate the relevance of SGCE in myoclonus-dystonia, we sequenced the entire coding region of the epsilon-sarcoglycan gene in 16 patients with either sporadic or familial myoclonus-dystonia. No mutations were found. This study suggests that epsilon-sarcoglycan does not play an important role in sporadic myoclonus-dystonia and supports genetic heterogeneity in familial cases.     

Immunoglobulin Gene Rearrangement in Plasma Cell Dyscrasias: Detection of Small Clonal Cell Populations in Peripheral Blood and Bone Marrow

The bone marrow (BM) and peripheral blood (PB) samples of 71 patients with plasma cell dyscrasias were analysed by the Southern blot technique for the presence of clonal immunoglobulin (Ig) gene rearrangements. 53% of BM samples examined were archival material such as air dried BM slides or frozen trephine biopsies. The results were related to bone marrow plasmacytosis as determined by cytology and flow cytometry, and other clinical parameters. Clonal Ig gene rearrangements were found in BM samples of 45 (83%) of 54 MM patients and in 3 of 6 patients with monoclonal gammopathy of unknown significance (MGUS). Clonal cell populations in the PB were detected in 11 (30%) of 37 examined MM patients, but in none of the patients with MGUS or solitary plasmacytoma of bone. PB involvement was associated with progressive disease. Circulating monoclonal cells were significantly associated with higher M-protein levels (p 0.05). Thus, circulating clonal precursor cells are encountered more frequently in active MM.     

Comparison of the efficacy and safety of ciclesonide 160 μg once daily vs. budesonide 400 μg once daily in children with asthma

Ciclesonide is an onsite-activated inhaled corticosteroid (ICS) for the treatment of asthma. This study compared the efficacy, safety and effect on quality of life (QOL) of ciclesonide 160 microg (ex-actuator; nominal dose 200 microg) vs. budesonide 400 microg (nominal dose) in children with asthma. Six hundred and twenty-one children (aged 6-11 yr) with asthma were randomized to receive ciclesonide 160 microg (ex-actuator) once daily (via hydrofluoroalkane metered-dose inhaler and AeroChamber Plus spacer) or budesonide 400 microg once daily (via Turbohaler) both given in the evening for 12 wk. The primary efficacy end-point was change in forced expiratory volume in 1 s (FEV1). Additional measurements included change in daily peak expiratory flow (PEF), change in asthma symptom score sum, change in use of rescue medication, paediatric and caregiver asthma QOL questionnaire [PAQLQ(S) and PACQLQ, respectively] scores, change in body height assessed by stadiometry, change in 24-h urinary cortisol adjusted for creatinine and adverse events. Both ciclesonide and budesonide increased FEV1, morning PEF and PAQLQ(S) and PACQLQ scores, and improved asthma symptom score sums and the need for rescue medication after 12 wk vs. baseline. The non-inferiority of ciclesonide vs. budesonide was demonstrated for the change in FEV1 (95% confidence interval: -75, 10 ml, p = 0.0009, one-sided non-inferiority, per-protocol). In addition, ciclesonide and budesonide showed similar efficacy in improving asthma symptoms, morning PEF, use of rescue medication and QOL. Ciclesonide was superior to budesonide with regard to increases in body height (p = 0.003, two-sided). The effect on the hypothalamic-pituitary-adrenal axis was significantly different in favor of ciclesonide treatment (p < 0.001, one-sided). Both ciclesonide and budesonide were well tolerated. Ciclesonide 160 microg once daily and budesonide 400 microg once daily were effective in children with asthma. In addition, in children treated with ciclesonide there was significantly less reduction in body height and suppression of 24-h urinary cortisol excretion compared with children treated with budesonide after 12 wk.     

Perioperative complications following sagittal split osteotomy of the mandible.

INTRODUCTION: The aim of this study was to review complications in a series of 1264 consecutive patients who were operated in a single centre during a 20-year-period. MATERIAL AND METHODS: Complications were documented, their incidences calculated and compared with data from the literature. RESULTS: In 35 patients (2.8%) infection developed requiring extraoral incision and drainage; in 27 patients (2.1%) the inferior alveolar nerve was inadvertently cut; 18 patients (1.4%) had to undergo re-operation due to bending or fracture of osteosynthesis material; 15 patients (1.2%) suffered from bleeding complications; in 12 patients (0.9%) an unfavourable split occurred. In 8 patients (0.6%) foreign bodies were left in situ; in 7 patients a partial weakness of the facial nerve occurred, which was permanent in 1 patient. Six patients (0.5%) with a significantly higher age than average (mean: 33.6 years in comparison with 23.1 years) developed non-union at the site of osteotomy, and the mandible had to be bone grafted. Two patients (0.2%) developed osteomyelitis, and in one patient airway problems led to a need for tracheostomy (0.1%). CONCLUSION: Although some of these complications of bilateral sagittal split with osteotomy carry severe limitations in health related quality of life, it remains an overall safe procedure, demanding, however, comprehensive informed consent. Good knowledge of technical reasons for these complications should help to reduce their incidence.     

Treatment of hepatitis B and C after liver transplantation. Part 2, hepatitis C

Abstract End-stage liver disease caused by the hepatitis C virus is a major indication for liver transplantation. However, recurrence of hepatitis in the graft is a major issue. HCV re-infection after transplantation is almost constant, and recent data confirm that it significantly impairs patient and graft survival. Factors that may influence disease severity and consequent progression of HCV graft injury remain unclear. Chronic HCV infection develops in 60%–80% of patients, and 6%–28% ultimately progress to cirrhosis within 5 years. Pre-transplantation antiviral treatment is not easily related to poor tolerance. Attempts to administer prophylactic post-transplantation antiviral treatment are under evaluation but are limited by antiviral drug side effects. Treatment of established graft lesions with interferon or ribavirin as single agents has been disappointing. Combination therapy gave promising results, with sustained virological response in 25% of patients, but indications, modality and duration of treatment should be assessed.     

Nefopam, a Nonsedative Benzoxazocine Analgesic, Selectively Reduces the Shivering Threshold in Unanesthetized Subjects

Background: The analgesic nefopam does not compromise ventilation, is minimally sedating, and is effective as a treatment for postoperative shivering. The authors evaluated the effects of nefopam on the major thermoregulatory responses in humans: sweating, vasoconstriction, and shivering.

Methods: Nine volunteers were studied on three randomly assigned days: (1) control (saline), (2) nefopam at a target plasma concentration of 35 ng/ml (low dose), and (3) nefopam at a target concentration of 70 ng/ml (high dose, approximately 20 mg total). Each day, skin and core temperatures were increased to provoke sweating and then reduced to elicit peripheral vasoconstriction and shivering. The authors determined the thresholds (triggering core temperature at a designated skin temperature of 34[degrees]C) by mathematically compensating for changes in skin temperature using the established linear cutaneous contributions to control of each response.

Results: Nefopam did not significantly modify the slopes for sweating (0.0 +/- 4.9[degrees]C [middle dot] [mu]g-1 [middle dot] ml; r2 = 0.73 +/- 0.32) or vasoconstriction (-3.6 +/- 5.0[degrees]C [middle dot] [mu]g-1 [middle dot] ml; r2 = -0.47 +/- 0.41). In contrast, nefopam significantly reduced the slope of shivering (-16.8 +/- 9.3[degrees]C [middle dot] [mu]g-1 [middle dot] ml; r2 = 0.92 +/- 0.06). Therefore, high-dose nefopam reduced the shivering threshold by 0.9 +/- 0.4[degrees]C (P < 0.001) without any discernible effect on the sweating or vasoconstriction thresholds.     

Esthesioneuroblastoma: endonasal endoscopic treatment.

Objectives: To illustrate endoscopic techniques used in the treatment of esthesioneuroblastoma and to advocate this method of management followed by radiation therapy in selected cases. Methods: A retrospective case series of 10 patients with esthesioneuroblastomas treated between 1999 and 2004 at a tertiary referral center using endonasal techniques. Results: Mean age of patients at presentation was 56.2 years (median 57 years). Seven patients were female and 3 patients were male. Kadish staging at presentation was: A - 3 patients, B - 5 patients, C - 2 patients. Dulguerov stage at presentation was: T1 - 4 patients, T2 - 4 patients, T3 - 2 patients. The period of follow-up ranged from 11 months to 74 months (mean 38.1 months, median 39 months). To date no recurrence has developed in any patient. Conclusions: Our experience suggests that endoscopic surgery can be an effective method of management. Strict attention to selection criteria, careful surgical techniques, and regular follow-up are key elements for success.