Transsaccadic integration relies on a limited memory resource

Saccadic eye movements cause large-scale transformations of the image falling on the retina. Rather than starting visual processing anew after each saccade, the visual system combines post-saccadic information with visual input from before the saccade. Crucially, the relative contribution of each source of information is weighted according to its precision, consistent with principles of optimal integration. We reasoned that, if pre-saccadic input is maintained in a resource-limited store, such as visual working memory, its precision will depend on the number of items stored, as well as their attentional priority. Observers estimated the color of stimuli that changed imperceptibly during a saccade, and we examined where reports fell on the continuum between pre- and post-saccadic values. Bias toward the post-saccadic color increased with the set size of the pre-saccadic display, consistent with an increased weighting of the post-saccadic input as precision of the pre-saccadic representation declined. In a second experiment, we investigated if transsaccadic memory resources are preferentially allocated to attentionally prioritized items. An arrow cue indicated one pre-saccadic item as more likely to be chosen for report. As predicted, valid cues increased response precision and biased responses toward the pre-saccadic color. We conclude that transsaccadic integration relies on a limited memory resource that is flexibly distributed between pre-saccadic stimuli.     

Liver transplantation in the critically ill: donation after cardiac death compared to donation after brain death grafts

Patients with end stage liver disease may become critically ill prior to LT requiring admission to the intensive care unit (ICU). The high acuity patients may be thought too ill to transplant; however, often LT is the only therapeutic option. Choosing the correct liver allograft for these patients is often difficult and it is imperative that the allograft work immediately. Donation after cardiac death (DCD) donors provide an important source of livers, however, DCD graft allocation remains a controversial topic, in critically ill patients. Between January 2003-December 2008, 1215 LTs were performed: 85 patients at the time of LT were in the ICU. Twelve patients received DCD grafts and 73 received donation after brain dead (DBD) grafts. After retransplant cases and multiorgan transplants were excluded, 8 recipients of DCD grafts and 42 recipients of DBD grafts were included in this study. Post-transplant outcomes of DCD and DBD liver grafts were compared. While there were differences in graft and survival between DCD and DBD groups at 4 month and 1 year time points, the differences did not reach statistical significance. The graft and patient survival rates were similar among the groups at 3-year time point. There is need for other large liver transplant programs to report their outcomes using liver grafts from DCD and DBD donors. We believe that the experience of the surgical, medical and critical care team is important for successfully using DCD grafts for critically ill patients.     

Sequential mTOR inhibitor treatment with temsirolimus in metastatic renal cell carcinoma following failure of VEGF receptor tyrosine kinase inhibitors

Purpose

Agents targeting the mammalian target of rapamycin (mTOR) pathway, e. g. everolimus, can provide clinical benefit in pretreated patients with metastatic renal cell carcinoma (mRCC), but data from randomized trials on the sequential use of temsirolimus are lacking. We retrospectively studied the efficacy and safety of temsirolimus therapy following failure of rTKI therapy.

Methods

Twenty-nine patients treated with temsirolimus (25 mg/week) following progression on rTKI therapy were studied at four institutions. All patients had failed at least one prior rTKI therapy (sunitinib, n = 6; sorafenib, n = 1; both, n = 22). Over 80% had two or more prior therapies. Data on efficacy (response assessment, progression-free survival [PFS], overall survival [OS]) and safety (NCI-CTC) were analyzed.

Results

Adverse events occurred in 90% of patients with the majority being grade 1 (n = 4, 14%) or grade 2 (n = 12, 41%). Most grade 3/4 toxicities (n = 10, 34%) were manageable and included anemia (n = 4, 14%), leukopenia/neutropenia (n = 2, 7%), hyperglycemia (n = 1, 3%), acidosis/alkalosis (n = 2, 7%), and infection (n = 1, 3%). One patient discontinued temsirolimus for grade 3 pneumonitis. Median (range) PFS and OS were 5.1 months (1–10.4) and 18.0 months (12.6–23.3), respectively. Best response included partial response (n = 1) and stable disease (n = 15) for a disease control rate of 55%, and disease progression of 45% (n = 13).

Conclusions

Temsirolimus after rTKI failure appears to provide promising safety and efficacy comparable to other treatment options in pretreated patients with mRCC.     

Surgical safety checklist: implementation in an ambulatory surgical facility

Purpose

In 2007, the World Health Organization created a Surgical Safety Checklist (SSC) that encompassed a simple set of surgical safety standards. The threefold purpose of this study was to add ambulatory-specific items to the SSC, to introduce the items into an ambulatory surgical facility, and to determine if patient outcomes regarding postoperative pain and nausea/vomiting improved following implementation. In addition, safety attitudes, antibiotic timing, regional anesthesia/nerve blocks, preemptive pain medications, prophylactic antiemetics, length of stay, and hospital admission were also assessed.

Methods

After Research Ethics Board approval, staff complete a Safety Attitudes Questionnaire. Seven items were added to the SSC. Data were then collected on 180 surgical cases before SSC implementation and 195 cases following implementation. Compliance with each section of the SSC was assessed.

Results

On postoperative day one, the median (97.5% confidence interval [CI]) difference between pre- and post-implementation pain scores was 0.5 (97.5% CI, 0 to 1; P = 0.13), and the median difference in the rate of post-discharge nausea/vomiting was ?8.4% (97.5% CI, ?17.9 to 1.1; P = 0.06). There was no improvement in safety attitudes or any of the secondary outcomes, with the exception of the use of preemptive pain medications. Compliance with the three sections of the checklist, i.e., BRIEFING, TIME OUT, and DEBRIEFING was 99.49%, 97.95%, and 96.92%, respectively. There was low compliance in verbalization of the added “ambulatory-specific items”.

Conclusion

Potential reasons for lack of uptake and integration include poor “user” buy-in, an overly lengthy checklist, and lack of prioritization of ambulatory-specific items. A shortened SSC was developed based on the results of this study. This trial was registered at ClinicalTrials.gov ID: NCT00934310.     

Meal conditions affect the absorption of supplemental vitamin D3 but not the plasma 25‐hydroxyvitamin D response to supplementation

It is sometimes assumed that dietary fat is required for vitamin D absorption, although the impact of different amounts of dietary fat on vitamin D absorption is not established. This study was conducted to determine whether the presence of a meal and the fat content of the meal influences vitamin D absorption or the 25‐hydroxyvitamin D [25(OH)D] response to supplemental vitamin D₃. Based on earlier studies in rats we postulated that absorption would be greatest in the low‐fat meal group. Sixty‐two healthy older men and women were randomly assigned to one of three meal groups: no meal, high‐fat meal, or low‐fat meal; each was given a monthly 50,000 IU vitamin D₃ supplement with the test breakfast meal (or after a fast for the no‐meal group) and followed for 90 days. Plasma vitamin D₃ was measured by liquid chromatography–mass spectroscopy (LC/MS) before and 12 hours after the first dose; plasma 25(OH)D was measured by radioimmunoassay at baseline and after 30 and 90 days. The mean 12‐hour increments in vitamin D₃, after adjusting for age and sex, were 200.9 nmol/L in the no‐meal group, 207.4 nmol/L in the high‐fat meal group, and 241.1 nmol/L in the low‐fat meal group (p = 0.038), with the increase in the low‐fat group being significantly greater than the increases in the other two groups. However, increments in 25(OH)D levels at 30 and 90 days did not differ significantly in the three groups. We conclude that absorption was increased when a 50,000 IU dose of vitamin D was taken with a low‐fat meal, compared with a high‐fat meal and no meal, but that the greater absorption did not result in higher plasma 25(OH)D levels in the low‐fat meal group.     

Triple-V flap: nipple reconstruction using a modified C-V flap technique for long-lasting improvement of projection

Background

Reconstruction of the nipple–areola complex is the last procedure in breast reconstruction after mastectomy. Various techniques have been described, but the creation of a long-lasting projection represents a challenge in plastic surgery causing frequent nipple projection loss.

Methods

From December 2008 and September 2010, we performed 43 nipple reconstructions using our new technique named “triple-V flap.” This procedure is similar to C-V flap but uses a further V limb area that is de-epithelialized and provides significant support to the new nipple. Clinical assessment was performed with a caliper measuring nipple projection at 1, 6, and 12 months after the surgical procedure.

Results

We evaluated the triple-V nipple reconstruction technique in 43 patients. Reconstructed nipple projection ranged between 3.3 and 6.4 mm (mean 4.8 mm). Mean decrease in nipple projection was 0.2 mm at 1 month, 1.4 mm at 6 months, and 1.6 mm at 1 year. After 1 year, mean nipple projection decrease was 34 %.

Conclusions

Our triple-V technique allows the maintenance of long-lasting projection of the reconstructed nipple at 12 months after surgery. Ease and speed of execution made our technique usable in all patients who need to complete the breast reconstruction process. Level of Evidence: Level IV, therapeutic study.     

Effects of a hospital based Wellness and Exercise program on quality of life of children with severe burns

Objective

To examine the effect of a 12-week Wellness and Exercise (W&E) program on the quality of life of pediatric burn survivors with burns of ≥40% total body surface area. We hypothesized this comprehensive regimen would improve physical and psychosocial outcomes.

Methods

Children were recruited for participation upon their discharge from the ICU. They were not taking anabolic/cardiovascular agents. Seventeen children participated in the W&E group and 14 children in the Standard of Care (SOC) group. Quality of life was assessed with the Child Health Questionnaire (CHQ) at discharge and 3 months. Children completed the CHQ-CF 87 and caregivers completed the CHQ-PF 28.

Results

The mean age of children in the W&E group was 14.07 ± 3.5 years and mean TBSA was 58 ± 11.8%. The mean age of children in the SOC group was 13.9 ± 3.1 years and mean TBSA was 49 ± 7.8%. ANOVA did not reveal statistically significant differences between the groups. Matched paired t-tests revealed that parents with children in the W&E group reported significant improvements with their children's physical functioning, role/social physical functioning, mental health, overall physical and psychosocial functioning after exercise.

Conclusions

These results are clinically relevant in that a comprehensive W&E program may be beneficial in promoting physical and psychosocial outcomes.     

Sports activities after medial unicompartmental knee arthroplasty Oxford III—What can we expect?

Purpose

Excellent long-term results have been reported for implantation of unicompartmental knee arthroplasty (UKA). In many patients the desire for improvement in function often includes an aspiration to return to sports. The purpose of our study was to evaluate physical activities after medial Oxford-III (Biomet) UKA surgery.

Methods

Patients’ physical activity before and after the surgery was assessed using a self reporting questionnaire. We used the Oxford knee scoring system (OKS), the WOMAC-, the Knee society- (KSS) and the UCLA-score to assess postoperative knee function. The mean follow-up was 4.2 years. The female-to-male ratio was 1.3:1. The mean age at surgery was 65.3 years.

Results

Of the 131 patients studied 78 participated in some kind of sports before surgery (mean age 64.4 years), while 53 patients did not perform any sports (mean age 66.5 years) (p > 0.05). At follow-up the patients in the active group were significantly younger than the patients in the inactive group (p < 0.05). The majority of patients (80.1 %) returned to their level of sports activity after UKA surgery. Six patients took up sports after surgery while 15 patients stopped their sports. Among the active patients we found a shift from high- towards low-impact sports. The active patients had significantly higher scores for the OKS, KSS, WOMAC and UCLA score. The complication rate was comparable in both groups.

Conclusion

Our study demonstrates that a high degree of patient satisfaction in terms of sports activity can be achieved using the Oxford-III UKA for medial osteoarthritis.