This Letter presents a novel modeless predictive current control (PCC) based on two vectors for a synchronous reluctance motor (SynRM) drive system fed by a four-switch three-phase (FSTP) inverter. ...In each sampling period, two voltage vectors generated by the FSTP inverter are applied to emulate the operation of a six-switch three-phase inverter. Unlike model-based approaches, the proposed method is modeless, meaning that it does not require a system model or its parameters nor the capacitor voltage. For comparison purpose, both model-based and modeless PCCs are realised on a FSTP inverter-fed SynRM drive system via a 32-bit digital signal controller to contrast their current-tracking performances.
Whether and how pulmonary hypertension (PH) impacts perioperative outcome in non-cardiac surgery is incompletely understood.
From November 1999, all patients undergoing non-cardiac, non-local ...anaesthetic surgery and ever examined by echocardiography within 30 days before surgery were screened. Those having echocardiographic pulmonary artery systolic pressure >70 mm Hg were enrolled provided they were not already intubated. Case-matched peers with normal pulmonary pressures served as controls. Perioperative outcomes were compared between the two groups, and predictors of adverse perioperative outcomes were investigated by multivariate logistic regression analysis.
From November 1999 to August 2004, a total of 62 patients (male 38, mean age 67 yr) with PH were found. Compared with the case-matched controls, patients with PH experienced equivalently smooth operative courses, but significantly more frequent postoperative heart failure (9.7 vs 0%, P = 0.028), delayed tracheal extubation (21 vs 3%, P = 0.004), and in-hospital deaths (9.7 vs 0%, P = 0.028). Multivariate regression analysis identified emergency surgery odds ratio (OR), 44.738; P = 0.028, coronary artery disease (CAD; OR, 9.933; P = 0.042), and systolic pulmonary artery pressure (OR, 1.101; P = 0.026) as independent predictors of postoperative mortality and surgery-specific cardiac risk level (OR, 6.791; P = 0.033) and CAD (OR 6.546, P = 0.017) as predictors of morbidity.
PH is an important predictor of adverse cardiopulmonary outcome in non-cardiac surgery as reflected by markedly increased postoperative complications, especially in patients with coexistent high-risk clinical and surgical characteristics.
The effects of treatment of obstructive sleep apnoea (OSA) on glucose metabolism have been investigated previously with conflicting results. This study evaluated the impact of nasal continuous ...positive airway pressure (nCPAP) treatment of OSA on insulin sensitivity. Males with moderate/severe OSA and no significant comorbidity were randomised to a therapeutic or sham nCPAP treatment group for 1 week and then reassessed. Those who received therapeutic nCPAP were further evaluated at 12 weeks. Insulin sensitivity (K(itt)) was estimated by the short insulin tolerance test. Other evaluations included blood pressure, metabolic profile, urinary catecholamines and intra-abdominal fat. In total, 61 Chinese subjects were randomised. 31 subjects receiving therapeutic nCPAP showed an increase in K(itt) (6.6+/-2.9 to 7.6+/-3.2 % x min(-1); p = 0.017), while the 30 patients on sham CPAP had no significant change, and the changes in K(itt) were different between the two groups (p = 0.022). At 12 weeks, improvement in K(itt) was seen in 20 subjects with BMI >or=25 kg x m(-2) (median (interquartile range) 28.3 (26.6-31.5); p = 0.044), but not in the nine subjects with BMI<25 kg x m(-2), or the entire group. The findings indicate that therapeutic nCPAP treatment of OSA for 1 week improved insulin sensitivity in nondiabetic males, and the improvement appeared to be maintained after 12 weeks of treatment in those with moderate obesity.
Electrocochleography (ECochG) is emerging as a tool for monitoring cochlear function during cochlear implant (CI) surgery. ECochG may be recorded directly from electrodes on the implant array ...intraoperatively. For low-frequency stimulation, its amplitude tends to rise or may plateau as the electrode is inserted. The aim of this study was to explore whether compromise of the ECochG signal, defined as a fall in its amplitude of 30% or more during insertion, whether transient or permanent, is associated with poorer postoperative acoustic hearing, and to examine how preoperative hearing levels may influence the ability to record ECochG. The specific hypotheses tested were threefold: (a) deterioration in the pure-tone average of low-frequency hearing at the first postoperative follow-up interval (follow-up visit 1 FUV1, 4 to 6 weeks) will be associated with compromise of the cochlear microphonic (CM) amplitude during electrode insertion (primary hypothesis); (b) an association is observed at the second postoperative follow-up interval (FUV2, 3 months) (secondary hypothesis 1); and (c) the CM response will be recorded earlier during electrode array insertion when the preoperative high-frequency hearing is better (secondary hypothesis 2).
International, multi-site prospective, observational, between groups design, targeting 41 adult participants in each of two groups, (compromised CM versus preserved CM). Adult CI candidates who were scheduled to receive a Cochlear Nucleus CI with a Slim Straight or a Slim Modiolar electrode array and had a preoperative audiometric low-frequency average thresholds of ≤80 dB HL at 500, 750, and 1000 Hz in the ear to be implanted, were recruited from eight international implant sites. Pure tone audiometry was measured preoperatively and at postoperative visits (FUV1 and follow-up visit 2 FUV2). ECochG was measured during and immediately after the implantation of the array.
From a total of 78 enrolled individuals (80 ears), 77 participants (79 ears) underwent surgery. Due to protocol deviations, 18 ears (23%) were excluded. Of the 61 ears with ECochG responses, amplitudes were < 1 µV throughout implantation for 18 ears (23%) and deemed "unclear" for classification. EcochG responses >1 µV in 43 ears (55%) were stable throughout implantation for 8 ears and compromised in 35 ears. For the primary endpoint at FUV1, 7/41 ears (17%) with preserved CM had a median hearing loss of 12.6 dB versus 34/41 ears (83%) with compromised CM and a median hearing loss of 26.9 dB ( p < 0.014). In assessing the practicalities of measuring intraoperative ECochG, the presence of a measurable CM (>1 µV) during implantation was dependent on preoperative, low-frequency thresholds, particularly at the stimulus frequency (0.5 kHz). High-frequency, preoperative thresholds were also associated with a measurable CM > 1 µV during surgery.
Our data shows that CM drops occurring during electrode insertion were correlated with significantly poorer hearing preservation postoperatively compared to CMs that remained stable throughout the electrode insertion. The practicality of measuring ECochG in a large cohort is discussed, regarding the suggested optimal preoperative low-frequency hearing levels ( < 80 dB HL) considered necessary to obtain a CM signal >1 µV.
This study aimed to determine the impact of blood stream infections (BSIs) on outcome of allogeneic hematopoietic SCT (HSCT), and to examine the influence of old (non-levofloxacin-containing) and new ...(levofloxacin-based) prophylactic antibiotic protocols on the pattern of BSIs. We retrospectively enrolled 246 allogeneic HSCT recipients between January 1999 and June 2006, dividing patients into BSI (within 6 months post-HSCT, n=61) and non-BSI groups (n=185). We found that Gram-negative bacteria (GNB) predominated BSI pathogens (54%). Multivariate analyses showed that patients with a BSI, compared with those without, had a significantly greater 6-month mortality (hazard ratio, 1.75; 95% confidence interval, 1.09-2.82; P=0.021) and a significantly increased length of hospital (LOH) stay (70.8 vs 55.2 days, P=0.014). Moreover, recipients of old and new protocols did not have a significantly different 6-month mortality and time-to-occurrence of BSIs. However, there were significantly more resistant GNB to third-generation cephalosporins and carbapenem in recipients of levofloxacin-based prophylaxis. Our data suggest that BSIs occur substantially and impact negatively on the outcome and LOH stay after allogeneic HSCT despite antibiotic prophylaxis. Levofloxacin-based prophylaxis, albeit providing similar efficacy to non-levofloxacin-containing regimens, may be associated with increased antimicrobial resistance.
Background: Whether and how chronic advanced aortic regurgitation (AR) impacts the perioperative outcome of noncardiac surgery remains unclear.
Methods: From November 1999 to December 2006, all ...patients undergoing noncardiac operations and ever examined by echocardiography within the last 6 months were screened. Those with chronic moderate–severe or severe AR were enrolled, provided they were not already trachea‐intubated or aortic valve operated, and the surgery was not performed under local anesthesia. Case‐matched subjects without significant AR served as controls. The perioperative outcomes of these patients were analyzed, and independent prognostic correlates were investigated by multivariate logistic regression analysis.
Results: A total of 167 patients (male 131, mean age of 75 years) complying with the enrollment criteria were studied. Compared with the other 167 case‐matched control peers, patients with advanced AR risked potential hazards of serious hemodynamic instability (0.6%) and circulatory collapse (1.2%) during surgery despite the similar incidence of overall cardiac adverse events, and were further distressed with more cardiopulmonary complications (16.2% vs. 5.4%, P=0.003) and in‐hospital deaths (9% vs. 1.8%, P=0.008) post‐operatively. Multivariate regression analysis confirmed the correlation of advanced AR with perioperative mortality, and identified depressed left ventricular function, renal dysfunction, high surgical risk, and lack of cardiac medication as predictors of in‐hospital death.
Conclusion: Chronic advanced AR complicates the perioperative outcome of noncardiac surgery as reflected by frequent cardiopulmonary morbidities and in‐hospital deaths, especially when coexisting with specified high‐risk clinical and surgical characteristics.
Background and purpose: Doxorubicin evokes oxidative stress and precipitates cell apoptosis in testicular tissues. The aim of this study was to investigate whether the Ginkgo biloba extract 761 ...(EGb), a widely used herbal medicine with potent anti‐oxidant and anti‐apoptotic properties, could protect testes from such doxorubicin injury.
Experimental approach: Sprague‐Dawley male rats (8 weeks old) were given vehicle, doxorubicin alone (3 mg kg−1 every 2 days for three doses), EGb alone (5 mg kg−1 every 2 days for three doses), or EGb followed by doxorubicin (each dose administered 1 day after EGb). At 7 days after the first drug treatment oxidative and apoptotic testicular toxicity was evaluated by biochemical, histological and flow cytometric analyses.
Key results: Compared with controls, testes from doxorubicin‐treated rats displayed impaired spermatogenesis, depleted haploid germ cell subpopulations, increased lipid peroxidation products (malondialdehyde), depressed antioxidant enzyme activities (superoxide dismutase, glutathione peroxidase and glutathione), reduced antioxidant enzyme expression (superoxide dismutase) and elevated apoptotic indexes (pro‐apoptotic modulation of Bcl‐2 family proteins, intensification of p53 and Apaf‐1, release of mitochondrial cytochrome c, activation of caspase‐3 and increase of terminal deoxynucleotidyl transferase nick‐end labelling/sub‐haploid cells), while EGb pretreatment effectively alleviated all of these doxorubicin‐induced abnormalities in testes.
Conclusions and implications: These results demonstrate that EGb protected against the oxidative and apoptotic actions of doxorubicin on testes. EGb may be a promising adjuvant therapy medicine, potentially ameliorating testicular toxicity of this anti‐neoplastic agent in clinical practice.
Summary
Background
The temporal relationship between nucleoside analogue therapy for chronic hepatitis B (CHB) and liver cancer development has not been evaluated at a population level.
Aim
To ...investigate the impact of nucleoside analogue prescription on liver cancer incidence in a CHB‐prevalent region.
Methods
We obtained territory‐wide nucleoside analogue prescription data from 1999, when nucleoside analogue was first available in Hong Kong, to 2012 and the population‐based liver cancer incidence data from 1990 to 2012. We compared the liver cancer incidences from 1990 to 1998 and 1999 to 2012 with adjustment for local hepatitis B surface antigen seroprevalence.
Results
Nucleoside analogue prescription patient headcount increased from 2006 per year in 1999 to 26 411 in 2012. Prescription volume in 2012 was highest among 55–64 years (30.3%), higher than 65–74 years (13.0%) and ≥75 years (5.8%). Age‐standardised liver cancer incidence 1999–2012 decreased by 1.88%/year (95% CI 3.34% to 0.42%/year). NA therapy was associated with decline in age‐adjusted liver cancer incidence (2.7 per 100 000 persons, P < 0.001, 95% CI 1.4–4.0 per 100 000 persons). Fifty‐five to sixty‐four years age group had the most significant decline (men: 24.0 per 100 000 persons, P = 0.001, 95% CI 11.4–36.6 per 100 000 persons; women: 8.5 per 100 000 persons, P = 0.009, 95% CI 2.3–14.6 per 100 000 persons). No significant association was noted in age groups 65–74 years and ≥75 years (both P > 0.05).
Conclusions
Nucleoside analogue prescription was associated with a reduction of overall liver cancer incidence in a CHB‐prevalent region. The lack of association among individuals of ≥65 years was consistent with the low nucleoside analogue prescription volume in elderly patients, mitigating the impact of CHB treatment on liver cancer.
Linked ContentThis article is linked to Xuan et al paper. To view this article visit https://doi.org/10.1111/apt.14025.
Osteonecrosis of the femoral head is the most common diagnosis leading to total hip arthroplasty in young adults. Joint-preserving treatment options have been mainly surgical, with inconsistent ...results. Alendronate (a bisphosphonate agent) has been shown to lower the prevalence of vertebral compression fractures and could potentially retard the collapse of an osteonecrotic femoral head. The purpose of this study was to test the effect of alendronate in preventing early collapse of the femoral head in patients with nontraumatic osteonecrosis.
Forty patients with Steinberg stage-II or III nontraumatic osteonecrosis of the femoral head and a necrotic area of >30% (class C) were randomly divided into alendronate and control groups of twenty patients each. Patients in the alendronate group took 70 mg of alendronate orally per week for twenty-five weeks, while the patients in the control group did not receive this medication or a placebo. The patients were observed for a minimum of twenty-four months. Harris hip scores, plain radiographs, and magnetic resonance imaging scans were obtained.
During the study period, only two of twenty-nine femoral heads in the alendronate group collapsed, whereas nineteen of twenty-five femoral heads in the control group collapsed (p < 0.001). One hip in the alendronate group underwent total hip arthroplasty, whereas sixteen hips in the control group underwent total hip arthroplasty (p < 0.001).
Alendronate appeared to prevent early collapse of the femoral head in the hips with Steinberg stage-II or IIIC nontraumatic osteonecrosis. A longer duration of follow-up is needed to confirm whether alendronate prevents or only retards collapse.
Therapeutic Level I.
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