Preoperative physical performance as predictor of postoperative outcomes in patients aged 65 and older scheduled for major abdominal cancer surgery: A systematic review.

BACKGROUND: Abdominal cancer surgery is associated with considerable morbidity in older patients. Assessment of preoperative physical status is therefore essential. The aim of this review was to describe and compare the objective physical tests that are currently used in abdominal cancer surgery in the older patient population with regard to postoperative outcomes. METHODS: Medline, Embase, CINAHL and Web of Science were searched until 31 December 2020. Non-interventional cohort studies were eligible if they included patients ≥65 years undergoing abdominal cancer surgery, reported results on objective preoperative physical assessment such as Cardiopulmonary Exercise Testing (CPET), field walk tests or muscle strength, and on postoperative outcomes. RESULTS: 23 publications were included (10 CPET, 13 non-CPET including Timed Up & Go, grip strength, 6-minute walking test (6MWT) and incremental shuttle walk test (ISWT)). Meta-analysis was precluded due to heterogeneity between study cohorts, different cut-off points, and inconsistent reporting of outcomes. In CPET studies, ventilatory anaerobic threshold and minute ventilation/carbon dioxide production gradient were associated with adverse outcomes. ISWT and 6MWT predicted outcomes in two studies. Tests addressing muscle strength and function were of limited value. No study compared different physical tests. DISCUSSION: CPET has the ability to predict adverse postoperative outcomes, but it is time-consuming and requires expert assessment. ISWT or 6MWT might be a feasible alternative to estimate aerobic capacity. Muscle strength and function tests currently have limited value in risk prediction. Future research should compare the predictive value of different physical instruments with regard to postoperative outcomes in older surgical patients.

Anti-BP180 autoantibody levels at diagnosis correlate with 1-year mortality rates in patients with bullous pemphigoid.

BACKGROUND: Bullous pemphigoid (BP) is the most frequent autoimmune blistering disease mainly affecting elderly patients. Among several published risk factors, a recent post hoc analysis linked anti-BP180 autoantibodies (AABs) to fatal outcomes in BP. To date, this finding has not been confirmed independently. OBJECTIVE: To investigate the potential of anti-BP180-AAB levels as a marker of prognosis and to identify a cut-off level indicative of an increased risk for early death. Secondly, to characterize parameters associated with mortality. METHODS: Retrospective, single-centre study of BP patients diagnosed between 2001 and 2012. Analyses included epidemiological and patient- and disease-specific characteristics as well as immunological parameters at diagnosis and during follow-up. Standardized mortality ratios as well as uni- and multivariate regression analyses were calculated. RESULTS: One hundred patients (56 women, 44 men) with a median age of 81 years (interquartile range 74-86) were followed up for a median of 775 days (interquartile range 162-1617). One-year mortality rates were 25.0% implying a 2.4-fold increased risk of death compared with the general population. High anti-BP180 autoantibody levels at diagnosis (CI95 1.30-2.89; P = 0.001), dementia (CI95 1.13-6.72; P =0.03), length of hospitalization (CI95 1.16-2.41; P = 0.01) and age (CI95 1.23-4.19; P = 0.009) correlated significantly with 1-year mortality. BP180-AAB concentrations of ≥61 U/mL characterized a subgroup of patients with a particular higher risk for early death compared with the general population (CI95 1.81-3.81; P < 0.0001). CONCLUSION: In bullous pemphigoid, serum concentrations of BP180 autoantibodies at diagnosis could help to identify patients at risk for death within the first year after diagnosis (cut-off value 61 U/mL).

Tailored optical vector fields for ultrashort-pulse laser induced complex surface plasmon structuring.

Precise tailoring of optical vector beams is demonstrated, shaping their focal electric fields and used to create complex laser micro-patterning on a metal surface. A Spatial Light Modulator (SLM) and a micro-structured S-waveplate were integrated with a picosecond laser system and employed to structure the vector fields into radial and azimuthal polarizations with and without a vortex phase wavefront as well as superposition states. Imprinting Laser Induced Periodic Surface Structures (LIPSS) elucidates the detailed vector fields around the focal region. In addition to clear azimuthal and radial plasmon surface structures, unique, variable logarithmic spiral micro-structures with a pitch Λ âˆ¼1µm, not observed previously, were imprinted on the surface, confirming unambiguously the complex 2D focal electric fields. We show clearly also how the Orbital Angular Momentum(OAM) associated with a helical wavefront induces rotation of vector fields along the optic axis of a focusing lens and confirmed by the observed surface micro-structures.

Tailoring precursors for deposition: synthesis, structure, and thermal studies of cyclopentadienylcopper(i) isocyanide complexes.

We report here the synthesis and characterization of a family of copper(I) metal precursors based around cyclopentadienyl and isocyanide ligands. The molecular structures of several cyclopentadienylcopper(I) isocyanide complexes have been unambiguously determined by single-crystal X-ray diffraction analysis. Thermogravimetric analysis of the complexes highlighted the isopropyl isocyanide complex [(η(5)-C5H5)Cu(CN(i)Pr)] (2a) and the tert-butyl isocyanide complex [(η(5)-C5H5)Cu(CN(t)Bu)] (2b) as possible copper metal chemical vapor deposition (CVD) precursors. Further modification of the precursors with variation of the substituents on the cyclopentadienyl ligand system (varying between H, Me, Et, and (i)Pr) has allowed the affect that these changes would have on features such as stability, volatility, and decomposition to be investigated. As part of this study, the vapor pressures of the complexes 2b, [(η(5)-MeC5H4)Cu(CN(t)Bu)] (3b), [(η(5)-EtC5H4)Cu(CN(t)Bu)] (4b), and [(η(5)-(i)PrC5H4)Cu(CN(t)Bu)] (5b) over a 40-65 °C temperature range have been determined. Low-pressure chemical vapor deposition (LP-CVD) was employed using precursors 2a and 2b to synthesize thin films of metallic copper on silicon, gold, and platinum substrates under a H2 atmosphere. Analysis of the thin films deposited onto both silicon and gold substrates at substrate temperatures of 180 and 300 °C by scanning electron microscopy and atomic force microscopy reveals temperature-dependent growth features: Films grown at 300 °C are continuous and pinhole-free, whereas films grown at 180 °C consist of highly crystalline nanoparticles. In contrast, deposition onto platinum substrates at 180 °C shows a high degree of surface coverage with the formation of high-density, continuous, and pinhole-free thin films. Powder X-ray diffraction and X-ray photoelectron spectroscopy (XPS) both show the films to be high-purity metallic copper.

Delay dynamics of semiconductor lasers with short external cavities: bifurcation scenarios and mechanisms.

We present a comprehensive study of the emission dynamics of semiconductor lasers induced by delayed optical feedback from a short external cavity. Our analysis includes experiments, numerical modeling, and bifurcation analysis by means of computing unstable manifolds. This provides a unique overview and a detailed insight into the dynamics of this technologically important system and into the mechanisms leading to delayed feedback instabilities. By varying the external cavity phase, we find a cyclic scenario leading from stable intensity emission via periodic behavior to regular and irregular pulse packages, and finally back to stable emission. We reveal the underlying interplay of localized dynamics and global bifurcations.

Human peripheral blood monocytes versus THP-1 monocytes for in vitro biocompatibility testing of dental material components.

Monocytes play a central role in the response of tissues to biomaterials. Monocytic cell lines such as the THP-1 cell line have been used extensively as models for primary monocytes (directly from blood) in biocompatibility research. However, little information exists about the appropriateness of these cell lines as models. Thus, the current study compared the biological response of both primary peripheral blood monocytes (PBMs) and the THP-1 cell line to four common components of dental materials known to be released into the oral environment: nickel ions, 2-hydroxyethyl methacrylate (HEMA), triethylene glycol dimethacrylate (TEGDMA), and 2,2-bis[4(2-hydroxy-3-methacryloloxy)-phenyl]propane (Bis-GMA). Comparisons were made by constructing dose-response curves for each type of monocyte and the four components. The 50% cytotoxicity values (TC50 values) were then statistically compared. In addition, the response of the monocytes to the materials with and without lipopolysaccharide (LPS) stimulation were assessed by measuring TNF-alpha secretion from the monocytes. The results showed that the PBMs were 5-10 times less sensitive than the THP-1 monocytes to these dental components, but that both cell lines ranked the components identically. TNF-alpha secretion from both types of monocytes often showed similar trends, although some inconsistent results were noted. The current study supports the use of THP-1s as a model for ranking the cytotoxicity of components of dental biomaterials. Furthermore, the secretory activity of PBMs appears to be generally well represented by the THP-1s. However, sufficient differences between these cell types exist to recommend confirmation of any critical results obtained with THP-1s using PBMs.

Dynamics of semiconductor lasers subject to delayed optical feedback: the short cavity regime.

We give experimental and numerical evidence for a new dynamical regime in the operation of semiconductor lasers subject to delayed optical feedback occurring for short delay times. This short cavity regime is dominated by a striking dynamical phenomenon: regular pulse packages forming a robust low-frequency state with underlying fast, regular intensity pulsations. We demonstrate that these regular pulse packages correspond to trajectories moving on global orbits comprising several destabilized fixed points within the complicated phase space structure of this delay system.

Chaos synchronization and spontaneous symmetry-breaking in symmetrically delay-coupled semiconductor lasers.

We present experimental and numerical investigations of the dynamics of two device-identical, optically coupled semiconductor lasers exhibiting a delay in the coupling. Our results give evidence for subnanosecond coupling-induced synchronized chaotic dynamics in conjunction with a spontaneous symmetry-breaking: we find a well-defined time lag between the dynamics of the two lasers, and an asymmetric physical role of the subsystems. We demonstrate that the leading laser synchronizes its lagging counterpart, whereas the synchronized lagging laser drives the coupling-induced instabilities.

Statistical properties of low-frequency fluctuations during single-mode operation in distributed-feedback lasers: experiments and modeling.

Extensive experimental and numerical investigations of feedback-induced instabilities in single-mode distributed-feedback lasers are presented that confirm the basic assumptions of the Lang-Kobayashi model. We give experimental evidence of the occurrence of low-frequency fluctuation (LFF), alternation between LFF and stable emission, and coherence collapse during single-mode operation of the laser. We have obtained quantitative agreement between modeling and experiment in long-time statistical investigations of the time intervals between subsequent LFF dropouts. In particular, we show that even the dependence of the dynamics on the injection current, which results in a scaling law, is quantitatively identical in modeling and experiment.

Life-cycle analysis of depot versus rehabilitation manual wheelchairs.

The proper selection of a wheelchair requires making several critical decisions, not the least of which is what type of wheelchair is appropriate. The International Organization for Standards (ISO) continues to develop and refine wheelchair standards. Standards allow the objective comparison of products from various sources, permitting consumers or clinicians to assess wheelchairs with which they are not familiar by comparing test results. This study consisted of three components: 1) the comparison of fatigue test results with a planar ANSI/RESNA test dummy to a HERL contoured test dummy; 2) the comparison of fatigue test results for common depot versus common rehabilitation manual wheelchairs; and 3) the comparison of fatigue test results for manual rehabilitation wheelchairs with solid 8-inch casters versus those with pneumatic 8-inch casters. Rehabilitation wheelchairs lasted on average 13.2 times longer than the depot wheelchairs. Both types, tested with the standard ISO-ANSI/RESNA dummy, lasted on average 2.1 times longer than those wheelchairs tested using the contoured dummy. The three rehabilitation wheelchairs equipped with 8-inch pneumatic casters lasted on average 3.2 times longer than the 6 rehabilitation wheelchairs equipped with solid 8-inch casters. The depot wheelchairs cost about 3.4 times as much to operate per cycle or per meter than the rehabilitation wheelchairs. The rehabilitation wheelchairs tended to experience component failures, while the depot wheelchairs tended to experience frame failures. Our testing indicates that the tests in the ISO-ANSI/RESNA standards can relate design features to fatigue test results and durability. Rehabilitation wheelchairs tend to use higher quality materials and better manufacturing practices, and they provide greater mobility for wheelchair users. Purchasers and prescribers of wheelchairs should consider the life-cycle cost and not just the purchase price for wheelchairs.

[The relevance of CDT (carbohydrate-deficient transferrin). Preoperative diagnosis of chronic alcohol abuse in intensive care patients following elective tumor resection]. / Der Stellenwert des kohlenhydratdefizienten Transferrin (CDT). Präoperative Diagnostik des chronischen Alkoholabusus bei intensivmedizinischen Patienten nach elektiver Tumorresektion.

The increase of alcoholism-related problems is associated with vital postoperative clinical complications in chronic alcohol abusers. In particular, the alcohol withdrawal syndrome (AWS) may provoke potentially life-threatening complications in alcohol-dependent patients. Hence, a precise diagnosis of alcohol dependence is mandatory preoperatively, requiring an extensive case history using alcoholism-associated questionnaires. Additional new biological markers for detecting alcoholism could improve the accuracy of preoperative diagnosis. Carbohydrate-deficient transferrin (CDT) reflects increased alcohol consumption. The aim of our interdisciplinary study was to investigate whether the validity of the preoperative diagnosis of chronic alcohol abuse might be improved by measuring CDT. METHODS. A total of 45 patients from the departments of Otorhinolaryngology, Maxillofacial Surgery, and Abdominal and Thoracic Surgery were included in our prospective clinical study. Patients underwent resection of malignant oral, pharyngeal, laryngeal, or oesophageal tumours and were transferred to the intensive care unit for postoperative management. Routine preoperative history, examinations, and laboratory tests including GGT, MCV, ASAT, and ALAT, were supplemented by a specific alcohol-related questionnaire and CDT measurement. The patients were categorised in four groups based on history and the questionnaire: continuously abstinent subjects; sober subjects for at least 7 days; chronic abusers; and dependent subjects. CDT was separated by isocratic anion exchange chromatography and quantified by turbidimetric determination. Statistical analysis was performed by the Kruskal-Wallis test. RESULTS. Preoperatively, 21 patients were at major risk for alcoholism-related complications: 12 were chronic abusers and 9 were diagnosed as dependent. CDT was significantly increased in both groups, and was pathologically elevated in 16 of the 21 patients. Sampling occurred significantly long after the last alcohol intake in the 5 patients with normal CDT values (median: 6.0 days; range: 2-12 days) compared with the 16 with pathologically elevated CDT levels (median: 1.0 day; range: 0-4 days; P = 0.002). The sensitivity of CDT elevation was 16 out of 24 (76%), the specificity 16 out of 16 (100%). Sixteen patients had no previous history of alcohol consumption (sober for at least 7 days) and 8 were definitely abstinent. Both of these groups had normal CDT values. CONCLUSIONS. CDT was a sensitive and specific marker for chronic alcohol consumption in our patient population. Since CDT is a state marker, repeated determinations might be useful to estimate a patient's drinking habits. The combination of CDT and an alcohol-related questionnaire was reliable for detecting alcohol-dependent patients preoperatively.

[The role of clonidine in anesthesia]. / Clonidin-Stellenwert in der Anästhesie.

For decades the adrenergic alpha2 agonist clonidine has been considered to be one of the classical, centrally acting antihypertensive agents. In addition to its antihypertensive and sympathicolytic effects, in recent studies clonidine has been demonstrated to be an effective sedative and analgesic and to reduce the amount of anaesthetic agents required. Therefore, a reconsideration of possible new indications for clonidine in clinical anaesthesiology seems to be justified. This paper presents the pharmacological basis for treatment with clonidine and reviews the extensive literature on its clinical indications in anaesthesia. Clonidine apparently produces its sedative and anaesthetic-sparing effects by stimulation of centrally located alpha2 adrenoceptors. Analgesia seems to be mediated mainly by activation of alpha2 adrenoceptors in the dorsal horn of the spinal cord. Considering its clinical indications, clonidine is often used as a supplement in the treatment of alcohol withdrawal syndromes. Future indications for clonidine may be the treatment of postoperative shivering and chronic pain management. Administration of clonidine in combination with a local anaesthetic prolongs analgesia and motor blockade. Its use in premedication and postoperative pain management may be limited by its principal effects of hypotension and bradycardia. In future, cardiovascular side effects may be minimized if all the subtypes of alpha2 adrenoceptors, their distribution within the central nervous system, and their specific action are clearly defined. This could result in a detailed therapeutic index of more selective and potent alpha2 agonists.

[Prophylaxis of alcohol withdrawal syndrome in prolonged oral and maxillofacial surgery procedures]. / Zur Prophylaxe des Alkoholentzungs-syndroms bei Langzeiteingriffen in der Zahn-Mund-Kieferchirurgie.

Alcohol-addicted patients have a high risk of intercurrent complications during the postoperative period. In addition to the predisposition for infection, alcohol withdrawal syndrome is potentially life-threatening in these patients. However, this concerns only addicts, and definite preoperative diagnosis of addiction therefore is a crucial parameter in assessing the postoperative risks. In our department, 40% of maxillofacial tumor patients with a history of alcohol abuse were assessed as alcohol-addicted according to a complex diagnosis scheme. In these patients, postoperative withdrawal syndrome prophylaxis with continuous, low-dose alcohol infusion is indicated after exclusion of contraindications. If prophylaxis is impossible and differential diagnosis has confirmed a withdrawal syndrome, therapy must take into account the patient's symptoms and the latest neurobiochemical findings on withdrawal-related imbalances in neuronal transmitter systems.

Environmental and industrial factors relating to flavor tainting of fish in the upper Wisconsin river.

Extracts from Large Toothed Aspen (Populous grandidenta Michx.) and Jack Pine (Pinus banksiana Lamb.) contained many odor compounds found in flavor-tainted walleye from the Wisconsin River, including alkylphenols. Aspen wood contained 8 ppb of 2-isopropylphenol, and river sediments also contained low ppb levels of many alkylphenols, including 2-isopropylphenol. Thiophenol and thiocresol which sporadically cause offensive sulfury taints in Wisconsin River fish were also found in river sediment. Quantitative analysis of fish for alkylphenols supported a hypothesis involving a food chain-mediated seasonal fluctuation of alkylphenol levels in fish. Thiophenols are postulated to be derived from pulp mill activities on the river.

[Alcohol withdrawal syndrome in the postoperative phase--therapy or prevention?]. / Das Alkoholentzugssyndrom in der postoperativen Phase--Therapie oder Prophylaxe?

In a prospective study 50 patients who reported regular ethanol consumption and who underwent neck dissection were evaluated by clinical examination and the Munich alcohol test (MALT). 31 patients were not classified as alcohol abusers and none of them developed withdrawal symptoms (WS) postoperatively. 19 patients were diagnosed as alcohol abusers; 9 of them (group 1) received symptomatic therapy with clomethiazol and haloperidol, 10 patients (group 2) received continuous ethanol infusions (2-4 g/h) postoperatively as prophylaxis for WS. 6 patients in group 1 developed WS; none of group 2 developed WS. Thus the period of intensive care therapy of group 2 was significantly shorter (3.0 versus 11.5 days). It was concluded that postoperative continuous ethanol infusions prevent the occurrence of WS and should be administered to severely alcoholic patients.

Freezing-induced changes in the heart rate of wood frogs (Rana sylvatica).

During the first few hours of freezing the cardiovascular system must distribute cryoprotectant throughout the body of freeze-tolerant frogs. This study presents initial documentation of the changes in heart rate of wood frogs (Rana sylvatica) during nonlethal freezing. Heart rate was determined by measuring the electrocardiogram of frogs. Within 1 min of the onset of freezing the heart rate nearly doubled to approximately 8.0 beats/min. The heart rate began to slow after the first hour of the freeze, and the heart completely stopped beating near the completion of ice formation approximately 20 h later. Recordings from a single frog revealed that the heart beat resumes within 1 h after thawing and near-normal function is achieved after only a few hours. The release of the latent heat of fusion caused a rise in body temperature (1.7 degrees C) for a few hours and was closely correlated with an increase in the heart rate. However, other factors such as reduction in blood volume, increase in blood viscosity, and progressive hypoxia may prominently influence cardiac function indirectly. Regardless, the heart functions long enough to distribute glucose throughout the body during the first few hours of the freeze.

Toxicological properties of thio- and alkylphenols causing flavor tainting in fish from the upper Wisconsin River.

EC50 Microtox (5 min, 25 degrees C) assay values for 2-isopropylphenol, 3-isopropylphenol, 4-isopropylphenol, 2,4-diisopropylphenol, 2,5-diisopropylphenol 2,6-diisopropylphenol, 3,5-diisopropylphenol, carvacrol, thymol, thiophenol, and thiocresol ranged from 2 x 10(-2) mM for thymol (least toxic) to 2 x 10(-4) mM for 2,4-diisopropylphenol and 4-isopropylphenol (most toxic).

P-hydroxy-norephedrine as a possible mediator causing the reduction of oral intake of D-amphetamine in rats.

In rats D-amphetamine is predominantly metabolized by hydroxylation to p-hydroxy-norephedrine (p-HNE); in guinea pigs, however, by deamination to benzoic acid. After 2-3 days on dosages of 1 mg/kg per day and more rats begin to reduce their oral intake of the stimulant whereas guinea pigs do not. In the present study we examined the hypothesis that the formation of p-HNE in the CNS is partially responsible for this aversion. To determine the elimination of D-amphetamine and the increase in p-HNE, groups of male Wistar rats were given various doses (0.5-5 mg/kg per day) of D-amphetamine in their drinking water intragastrically and intravenously. D-Amphetamine in the brain was determined by radioimmunoassay, p-HNE by high performance liquid chromatography followed by electrochemical detection. In contrast to the concentration of D-amphetamine, the p-HNE-content is independent of the route of administration; after oral treatment it showed a linear increase. The results reveal that p-HNE induces the aversion to the stimulant and that the ratio of D-amphetamine to its metabolite determines the onset of this aversion. No p-HNE was found in the brain of guinea pigs. Guinea pigs do not show any aversion to drinking D-amphetamine solutions, even in high dosages.

A method for quantitative analysis of flavor-tainting alkylphenols and aromatic thiols in fish.

Simultaneous steam distillation-extraction (SDE) of fortified rainbow trout tissue resulted in greater than 95% recovery of 2-isopropylphenol, 3-isopropylphenol, 4-isopropylphenol, 2,4-diisopropylphenol, 2,5-diisopropylphenol, 3,5-diisopropylphenol, carvacrol and thymol. Lower recoveries were obtained for 2,6-diisopropylphenol (81%), thiophenol (55%), and thiocresol (85%). Analysis of concentrated extracts by gas chromatography/mass spectrometry operated in the selected ion monitoring mode allowed quantitative detection of these compounds down to 0.5 ppb based on 20 g of initial sample.

Volatile compounds in flavor-tainted fish from the Upper Wisconsin River.

Fillets from Walleye pike (Stizostedion vitreum) and Northern pike (Esox lucius) captured from the Upper Wisconsin River were analyzed for volatile components using simultaneous steam distillation-extraction and GC-MS techniques. Based on comparative odor assessments of eluting GC fractions and GC-MS analysis between control and tainted fish, trace amounts (ppb) of alkylphenols (2-isopropyl-, 4-isopropyl-, 2,4-diisopropyl-, 2,5-diisopropyl-, 2,6-diisopropyl-, 3,5-diisopropyl-, 5-methyl-2-isopropyl-, and 2-methyl-5-isopropyl-) and thiophenol were identified as the principal contributors to flavor-tainting found in fish during the spring of the year. Geosmin and 2-methylisoborneol were major contributors to mustiness flavor-tainting occurring in fish captured in the late summer and were more abundant in downstream fish than in upstream control fish.