Modern trends in minimally invasive versus open hepatectomy for colorectal liver metastasis: an analysis of ACS-NSQIP.

BACKGROUND: Surgical resection of colorectal liver metastasis (CRLM) provides the best opportunity for prolonged survival. Eligibility for metastasectomy has expanded with technical advancements including parenchymal-sparing hepatectomy (PSH). Meanwhile, enthusiasm for minimally invasive surgery (MIS) has increased, though this approach may be preferentially utilized for technically straightforward cases. The purpose of this study is to characterize modern trends in open versus MIS approaches to partial hepatectomy and anatomic hepatectomy for CRLM within a nationwide cohort. METHODS: The American College of Surgeons' National Surgical Quality Improvement Program (ACS-NSQIP) was used to investigate trends in MIS versus open hepatectomy for CRLM from 2015 to 2019. We examined baseline clinicopathologic and disease-related characteristics and compared trends in treatments over the study period. RESULTS: A total of 7457 patients undergoing hepatectomy for CRLM were identified (1367 MIS, 6090 open). Patients had similar clinicopathologic features between the two groups. Patients undergoing MIS resection less frequently received neoadjuvant therapy (51.1% vs 64.0%, p < 0.001) or concurrent intraoperative ablation (15.0% vs 21.3%, p < 0.001). Patients with tumors < 2 cm (34.9% vs 26.8%, p < 0.001) or only one to two tumors (82.8% vs 65.0%, p < 0.001) more commonly underwent MIS. MIS and open partial hepatectomies both significantly increased over the study period, but open partial hepatectomy increased at a greater rate than MIS (p < 0.001). Rates of anatomic resections have remained the same, with a greater proportion performed using an open approach (34.9% vs 16.4%, p < 0.001). Rates of operations consisting of > 1 concurrent partial hepatectomy are stable, but significantly more likely to be performed open (p < 0.001). CONCLUSIONS: Hepatectomy for CRLM has increased from a rise in partial hepatectomy, potentially translating to increased use of PSH. Current trends suggest MIS approaches appear to be increasing, but selectively implemented for patients with less technically demanding disease characteristics. Educational efforts should be directed towards increased dissemination of parenchymal-sparing MIS techniques for more complex resections.

Effects of intake-based weaning and forage type on feeding behavior and growth of dairy calves fed by automated feeders.

The objective of this study was to assess the effects of intake-based weaning methods and forage type on feeding behavior and growth of dairy calves. Holstein dairy calves (n = 108), housed in 12 groups of 9, were randomly assigned to 1 of 3 weaning treatments: milk reduction based on age (wean-by-age), individual dry matter intake (DMI; wean-by-intake), or a combination of individual DMI and age (wean-by-combination). Groups of calves were alternately assigned to 1 of 2 forage treatments: grass hay or a silage-based total mix ration (TMR; n = 6 groups per treatment). Until 30 d of age, all calves were offered 12 L/d of whole milk. Starting on d 31, milk was gradually reduced by 25% of the individual's average milk intake. For wean-by-age calves (n = 31), the milk allowance remained stable until d 62 when milk was again reduced gradually until weaning at d 70. For wean-by-intake calves (n = 35), milk allowance was reduced by a further 25% once calves consumed on average 200, 600, and (finally) 1,150 g of dry matter (DM) per day of calf starter and forage. For wean-by-combination calves (n = 35), milk intake remained stable until calves consumed on average 200 g of DM/d, at which point milk was reduced linearly until weaning at d 70. If calves failed to reach DMI targets by d 62 (n = 10), milk was then reduced gradually until weaning at d 70. Of the 35 wean-by-intake calves, 27 met all 3 DMI targets (successful-intake), and 33 of the 35 calves in the wean-by-combination treatment met the 200 g of DM/d target (successful-combination). Successful-intake and successful-combination calves had greater final body weight (BW) at 12 wk of age than wean-by-age calves (123.7 vs. 122.3 vs. 117.7 ± 3.1 kg, respectively). During weaning, successful-intake calves ate more starter and consumed less milk than successful-combination and wean-by-age calves (starter: 1.19 vs. 0.89 vs. 0.49 ± 0.07 kg of DM/d, respectively; milk: 2.7 vs. 4.2 vs. 5.9 ± 0.17 L/d, respectively). After weaning, successful-combination and successful-intake calves consumed similar amounts of starter; however, wean-by-age calves continued to consume less starter (2.85 vs. 2.78 vs. 2.44 ± 0.10 kg of DM/d, respectively). During weaning, hay and TMR calves ate similar amounts of forage, but hay calves consumed more starter (0.96 vs. 0.75 ± 0.07 kg of DM/d, respectively). After weaning, hay calves continued to consume more starter (2.88 vs. 2.50 ± 0.10 kg of DM/d, respectively), whereas TMR calves consumed more forage (0.33 vs. 0.15 ± 0.02 kg of DM/d, respectively). Hay calves had greater final BW at 84 d compared with TMR calves (124.0 vs. 119.0 ± 1.6 kg, respectively). These results show that the inclusion of a DMI target can improve starter intake and BW for calves that successfully wean, and that forage type can influence the transition onto solid feed. We also found that approximately 10% of calves failed to consume even 200 g of DM/d by 9 wk of age; more research is needed to better understand why some calves struggle to transition onto solid feed.

The ASACUSA antihydrogen and hydrogen program: results and prospects.

The goal of the ASACUSA-CUSP collaboration at the Antiproton Decelerator of CERN is to measure the ground-state hyperfine splitting of antihydrogen using an atomic spectroscopy beamline. A milestone was achieved in 2012 through the detection of 80 antihydrogen atoms 2.7 m away from their production region. This was the first observation of 'cold' antihydrogen in a magnetic field free region. In parallel to the progress on the antihydrogen production, the spectroscopy beamline was tested with a source of hydrogen. This led to a measurement at a relative precision of 2.7×10-9 which constitutes the most precise measurement of the hydrogen hyperfine splitting in a beam. Further measurements with an upgraded hydrogen apparatus are motivated by CPT and Lorentz violation tests in the framework of the Standard Model Extension. Unlike for hydrogen, the antihydrogen experiment is complicated by the difficulty of synthesizing enough cold antiatoms in the ground state. The first antihydrogen quantum states scan at the entrance of the spectroscopy apparatus was realized in 2016 and is presented here. The prospects for a ppm measurement are also discussed.This article is part of the Theo Murphy meeting issue 'Antiproton physics in the ELENA era'.

Insulin glulisine: a faster onset of action compared with insulin lispro.

AIM: This randomized, single-centre, double-blind, crossover study compared the pharmacodynamic and pharmacokinetic properties of two different doses of insulin glulisine (glulisine) and insulin lispro (lispro) in lean to obese subjects. METHODS: Eighty subjects without diabetes, stratified into four body mass index (BMI) classes (<25, >or=25 to <30, >or=30 to <35 and >or=35 kg/m(2)), were randomized to receive single injections of glulisine and lispro (0.2 and 0.4 U/kg) on four study days under glucose clamp conditions. Glucose infusion rates (GIR) and insulin (INS) concentrations were assessed for 10 h postdose. RESULTS: Glulisine showed a greater early metabolic action than lispro [GIR-area under the curve (GIR-AUC) between 0 and 1 h (0.2 U/kg: 102.3 +/- 75.1 vs. 83.1 +/- 72.8 mg/kg, p < 0.05; 0.4 U/kg: 158.0 +/- 100.0 vs. 112.3 +/- 70.8 mg/kg, p < 0.001)], with an earlier time to 10% of total GIR-AUC (0.2 U/kg: 1.4 +/- 0.4 vs. 1.5 +/- 0.4 h; 0.4 U/kg: 1.4 +/- 0.3 vs. 1.5 +/- 0.3 h, p < 0.05). The total metabolic effect was not different between the two insulins. In accordance with these findings, the time to 10% of total INS-AUC was faster with glulisine compared with lispro at either dose (0.2 U/kg: 0.7 +/- 0.2 vs. 0.8 +/- 0.2 h; 0.4 U/kg: 0.8 +/- 0.2 vs. 0.9 +/- 0.2 h, p < 0.001). The faster rise in insulin concentrations and the earlier onset of activity of glulisine vs. lispro was consistently observed in each individual BMI class. CONCLUSIONS: Glulisine shows a faster onset of action than lispro, independent of BMI and dose.

Width of the specular peak perpendicular to the principal plane for rough surfaces.

The bidirectional reflectance distribution function (BRDF) model developed by Torrance and Sparrow [J. Opt. Soc. Am. 57, 1105-1114 (1967)] is used to describe the specular reflection of rough surfaces. We compare this model with the BRDF measurements of four manmade surfaces with different roughnesses. The model can be used to describe the basic features of the measured BRDFs. We found that the width of the specular peak perpendicular to the principal plane decreases strongly with an increasing illumination zenith angle in the data as well as in the model. A model analysis shows that the width is approximately proportional to the cosine of the illumination angle theta(i), and the deviations are determined by the roughness of the surface. This relationship is accompanied by an increase in reflectance in the specular direction in the principal plane that is 1/cos theta(i) stronger than the increase for a perfectly smooth surface.

The effects of attentional spread and attentional effort on orientation discrimination.

The spatial properties of visual attention and its relation to attentional effort have been investigated, and it has been found that stimulus detectability changes as a function of attentional beam width and degree of task difficulty. Using a matching-to-sample paradigm, two Gabor patches were presented simultaneously both as a sample stimulus and a test stimulus, the stimuli set at three different distances. Task difficulty was gradated by changing the orientation difference of the two Gabor patches on nonmatching trials. 'Difficult' nonmatching probe trials were embedded within an easy block of trials (easy condition), and vice versa for 'easy' probe trials. The detectability, d', differences of probe trials in the two conditions were calculated as a measure of change in attention. Our results show that the detectability of a pair of stimuli decreases with an increase in the distance between stimuli. Furthermore, the results indicate an increase in attentional effort for various attentional beam widths and that r = d'easy/d'difficult of the probe trials is constant throughout the different stimuli separation.

Role of remote adaptation in perceived subjective color.

Light adaptation to illumination that is presented peripherally changes the subjective color of a central Benham disk stimulus. In our experiments we kept the peripheral illumination achromatic and remote (not even adjacent to the test stimulus). Using a high-frame-rate monitor, we produced the subjective color stimulus, to our knowledge for the first time, on a computer screen in emulation of the Benham disk programs. The resulting changes in the perceived subjective color were as follows: (1) Remote adapting illumination caused a dramatic shift in the perceived subjective color with a span from red to green; (2) there was a trade-off dependence between the area and the intensity of the remote adapting illumination with respect to the perceived color of the test stimulus; (3) the effect of the remote adaptation showed no interocular interaction. This finding suggests that the effect is elicited from a low-level stage in the visual pathway. In addition, we were able to approximate experimentally the spatial profile of the contribution of the remote illumination through the shift in the perceived color. We also found an opposite general trend of color shifts that occurred when either the central stimulus luminance or the remote illumination was increased. A suggested model for the reversed color shifts trend is discussed.

An analysis of the health benefits associated with the use of MTBE reformulated gasoline and oxygenated fuels in reducing atmospheric concentrations of selected volatile organic compounds.

To assess the health benefits gained from the use of cleaner burning gasoline, an analysis was conducted of changes in the atmospheric concentration of eight VOCs: acetaldehyde, benzene, 1,3-butadiene, ethylbenzene, formaldehyde, POM, toluene, and xylenes resulting from the use of reformulated gasoline and oxyfuel containing the additive MTBE. Modeled ambient air concentrations of VOCs were used to assess three seasonally-based scenarios: baseline gasoline compared to (a) summer MTBE:RFG, (b) winter MTBE:RFG, and (c) MTBE oxyfuel. The model predicts that the addition of MTBE to RFG or oxyfuel will decrease acetaldehyde, benzene, 1,3-butadiene and POM, but increase formaldehyde tailpipe emissions. The increased formaldehyde emissions, however, will be offset by the reduction of formaldehyde formation in the atmosphere from other VOCs. Using a range of plausible risk estimates, the analysis predicts a positive health benefit, i.e., a decline in cancer incidence associated with use of MTBE:RFG and MTBE oxyfuel. Using EPA cancer risk estimates, reduction in 1,3-butadiene exposure accounts for the greatest health benefit while reduction of benzene exposure accounts for the greatest health benefits based on alternative risk estimates. An analysis of microenvironment monitoring data indicates that most exposures to VOCs are significantly below levels of concern based on established margin-of-safety standards. The analysis does suggest, however, that health effects associated with short-term exposures to acetaldehyde and benzene may warrant further investigation.

Spatiotemporal adaptation model for retinal ganglion cells.

An adaptation model for the level of the ganglion cell in the retina is presented. The model assumes separate adaptation mechanisms for each of the receptive field (RF) regions, i.e., before edge detection. According to the model, the decay in the response time course of each RF region reflects its adaptation process. A mathematical description of adaptation that includes its temporal properties is developed through the change in the semisaturation constant theta in the Naka-Rushton equation. The model and its simulations show a good agreement with a wide variety of physiological studies.

Attentional effort modulated by task difficulty.

It has been assumed that stimulus discrimination in a visual task is performed with fixed attentive effort. Here we show that attention to the same pair of stimuli can be modulated by varying the task difficulty when a task requires the discrimination of only a small number of different stimuli. We used a matching-to-sample paradigm, where a test stimulus is presented after a sample stimulus. When both stimuli Gabor gratings have identical orientations ("matching" trial) the required response is different from when they have different orientations ("non-matching" trial). The task difficulty was manipulated by changing the orientation difference between sample and test stimuli for non-matching trials. Difficult non-matching probe trials were embedded within an easy block of trials (easy environment), and vice versa for easy probe trials. Detectability (d') differences for the same pairs of stimuli (probe trials) in the two environments were calculated as a measure for change in attentional effort, regardless of changes in likelihood ratios (beta). Our results show an increase in d' during the difficult task, for both types of probe trials, in paradigms that contained a small number of stimulus combinations. Thus a modulation in attentional effort along a single discrimination dimension is revealed. However it is restricted by the number of stimulus combinations, due to the limited capacity of the attention available for each stimulus combination.

Model of local velocity in the primary visual cortical cells.

A motion model for the early stages of motion processing in the visual cortex that focuses on velocity properties is presented. The model presents analytically the correlation between the velocity tuning curve and various cell parameters. The building block for this model is the rebound response, which makes possible the detection of spatial and temporal edges. The model suggests that adjacent subunits in the primary cortical cells display different strengths in their rebound responses, and thus a synergistic response is evoked in the preferred direction. The analysis deals separately with the two cutoff points of the velocity tuning curves. The model predicts a linear relation between the low cutoff point and the receptive-field size and an inverse correlation with the integration time. The high cutoff point is inversely correlated with the cell threshold.

Benchmark Dose Workshop: criteria for use of a benchmark dose to estimate a reference dose.

The purpose of the Benchmark Dose Workshop was to assess the feasibility and implications of replacing the no observed adverse effect level (NOAEL) with a benchmark dose (BMD) when deriving reference doses and concentrations (RfDs and RfCs). The workshop participants supported the use of the BMD method to remove many of the limitations inherent in using the NOAEL approach. Participants endorsed in general the use of a BMD for all quantal noncancer health effects and endorsed in particular the BMD for assessing developmental toxicity based on data presented at the workshop. The discussions of implementation recognized the need to demonstrate that changing from a NOAEL to a BMD gives the risk manager more certain information on which to base decisions. Most participants agreed that the current NOAEL-derived RfDs and RfCs are sufficiently protective and should only be changed as data become available for estimating a BMD. It was recognized that to achieve general acceptance of the BMD approach, it will have to be applied to a variety of endpoints.

Effect of degree of uniformity on predicted visual cortical response tuning curves.

The different cortical visual cells exhibit a large repertoire of responses to sinusoidal gratings, depending on their receptive field structure and the stimulation parameters. It has been shown previously that the tuning curves and histogram shapes of cell responses are affected by subunit distances. One receptive field model (Spitzer and Hochstein 1985b) incorporated subunit distance but assigned it as a constant parameter, for ease of calculation. Here we investigate different tuning curve properties of various primary cortical cell types during testing of 10 deg of nonuniform distances of the receptive fields' subunits. The effect of nonuniformity was compared for average responses, tuning curve shapes, maximum peak responses, and bandwidths across four cell types of different sizes. The shapes and other properties of tuning curves are usually found to be retained also when the degree of uniformity is not very high for most of the cell types. In addition, the effect of uniformity is compared across these different response properties. The maximum peak responses of the tuning curve are found to display a lower coefficient of variation than the bandwidth, for all cell types, for most degrees of uniformity.

Spatio-temporal model for subjective colours based on colour coded ganglion cells.

We propose a mathematical model for the generation of the subjective colour phenomenon through Benham's disk stimuli. The model relates to the spatial and temporal properties of three colour coded retinal ganglion cells: L+/M-, M+/L- and S-/(L+M)+ [or (L+M)-/S+]. It is suggested that the phenomenon is based on both the opponent mechanisms in the cells' receptive fields, and the "rebound response"--a common cell response to turning off of an inhibitory stimulus (nonlinear cell dynamics). A physiological mechanism is suggested for this response. The integrated cell responses to Benham disk-stimuli create imbalances between the colour pathways that are interpreted as actual colours. The model also predicts the shift in the perceived colours when the disk rotation rate is varied.

A model for the early stages of motion processing based on spatial and temporal edge detection by X-cells.

A model for the early stages of motion processing in the visual cortex is presented. The 'building block' for this model is the 'rebound response', which is the neuronal response evoked when a sufficient inhibitory stimulus is turned off. This response enables detection of temporal changes when the stimulus involves spatial changes. The model suggests that adjacent subunits in primary cortical cells have different weight functions for rebound responses, and thus a synergistic type of response is evoked in the preferred direction, which is predicted for both light and dark stimuli. Predictions of the model for different stimuli and receptive field structures are discussed. It appears to be more economical than previous motion models.

A model for detection of spatial and temporal edges by a single X cell.

When an inhibitory visual stimulus is turned off, an increased rate of spike discharge is evoked which we term the "rebound response". This response exists as a part of different cell responses from the retina to the cortex. The rebound response, with its temporal dependence on stimulus parameters, has not been previously considered in models. Here we present such a model, and also show its dependence on stimulus duration and its turning off rate. The rebound response enables detection of temporal changes when a visual stimulus involves spatial changes. The temporal change detection is affected by the actual stimulus duration, which can also be seen as a cell memory operation.

[Mycological surveillance of children with cystic fibrosis]. / Mykologische Uberwachung von Kindern mit Mukoviszidose.

The mycological surveillance included 121 patients aged 1 to 21 years treated from 1981 to 1987 in the Centre of Cystic Fibrosis in Dresden. The control groups comprised 136 resp. 140 healthy children aged 1 to 16 years. The study evaluated the incidence of fungi in the oral cavity, bronchial secreta, sputum, faeces and urine as well as the specific serum antibodies to Candida albicans and Aspergillus fumigatus in correlation to the course of the cystic fibrosis and the applied chemotherapy. The study pointed out a parallel run concerning the progression of the clinical manifestation of the basic disease, the duration of the required chemotherapy and the mycological findings indicating more and more pathological levels. The mycological results of the children with a moderate course of cystic fibrosis were conformable to the findings of the children of the control groups. Systemic candidosis or aspergillosis were not seen. Because patients suffering from cystic fibrosis are predisposed for infections with fungi, especially with Aspergillus fumigatus, the authors recommend a mycological surveillance of these patients depending on the clinical course of cystic fibrosis: once in twelve months for patients with mild symptoms and every third month for patients with severe symptoms.

Task difficulty: ignoring, attending to, and discriminating a visual stimulus yield progressively more activity in inferior temporal neurons.

To study the influence of task difficulty on the stimulus-elicited responses of inferior temporal (IT) neurons, the stimulus-elicited responses of 64 neurons were recorded from IT cortex of three rhesus monkeys while they performed three behavioral tasks-an irrelevant-stimulus task, a stimulus detection task, and a stimulus discrimination task. The monkey could ignore the stimulus entirely in the irrelevant-stimulus task, was required only to detect stimulus dimming in the stimulus detection task, and was required to attend to specific properties of the stimulus in the discrimination task. The excitatory responses in the discrimination and stimulus detection tasks were larger than those in the irrelevant-stimulus task (61% and 33%, respectively, of the individual differences were significant), and excitatory responses in the discrimination task were larger than those in the detection task (49% of the individual differences reached significance). Twenty percent of the stimulus presentations elicited inhibitory responses that were followed by off-responses. The off-responses were modulated by the tasks in the same order as the excitatory on-responses. Assuming that the off-response strengths indicate the depth of the stimulus-induced inhibition, these results suggest that inhibitory responses were influenced across these tasks in a manner similar to the excitatory responses. When the neuronal responses were related to the difficulties of these tasks, both the response strength and errors were seen to be least during the irrelevant-stimulus task and greatest during the discrimination task. This relationship suggests that the visual responsiveness of IT neurons is related to the degree of attention the animal pays to the stimulus.(ABSTRACT TRUNCATED AT 250 WORDS)

Temporal encoding of two-dimensional patterns by single units in primate primary visual cortex. I. Stimulus-response relations.

1. Previously we developed a new approach for investigating visual system neuronal activity in which single neurons are considered to be communication channels transmitting stimulus-dependent codes in their responses. Application of this approach to the stimulus-response relations of inferior temporal (IT) neurons showed that these carry stimulus-dependent information in the temporal modulation as well as in the strength of their responses. IT cortex is a late station in the visual processing stream. Presumably the neuronal properties arise from the properties of the inputs. However, the discovery that IT neuronal spike trains transmit information in stimulus-dependent temporally modulated codes could not be assumed to be true for those earlier stations, so the techniques used in the earlier study were applied to single-striate cortical neurons in the studies reported here. 2. Single-striate cortical neurons were recorded from three awake, fixating rhesus monkeys. The neurons were stimulated by two sets of patterns. The first set was made up of 128 black-and-white patterns based on a complete, orthogonal set of two-dimensional Walsh-Hadamard functions. These stimuli appear as combinations of black-and-white rectangles and squares, and they fully span the range of all possible black-and-white pictures that can be constructed in an 8 x 8 grid. Except for the stimulus that appeared as an all-white or all-black square, each stimulus had equal areas of white and black. The second stimulus set was made up of single bars constructed in the same 8 x 8 grid as the Walsh stimuli. These were presented both as black against a gray background and white against a gray background. The stimuli were centered on the receptive field, and each member of the stimulus set was presented once before any stimulus appeared again. 3. The responses of 21 striate cortical neurons were recorded and analyzed. Two were identified as simple cells and the other 19 as complex cells according to the criteria originally used by Hubel and Wiesel. The stimulus set elicited a wide variety of response strengths and patterns from each neuron. The responses from both the bars and the Walsh set could be used to differentiate and classify simple and complex cells. 4. The responses of both simple and complex cells showed striking stimulus-related strength and temporal modulation. For all of the complex cells there were instances where the responses to a stimulus and its contrast-reversed mate were substantially different in response strength or pattern, or both.(ABSTRACT TRUNCATED AT 400 WORDS)