Number of Donor Renal Arteries and Early Outcomes after Deceased Donor Kidney Transplantation.

Background: Anatomic abnormalities increase the risk of deceased donor kidney discard, but their effect on transplant outcomes is understudied. We sought to determine the effect of multiple donor renal arteries on early outcomes after deceased donor kidney transplantation. Methods: For this retrospective cohort study, we identified 1443 kidneys from 832 deceased donors with ≥1 kidney transplanted at our center (2006-2016). We compared the odds of delayed graft function and 90-day graft failure using logistic regression. To reduce potential selection bias, we then repeated the analysis using a paired-kidney cohort, including kidney pairs from 162 donors with one single-artery kidney and one multiartery kidney. Results: Of 1443 kidneys included, 319 (22%) had multiple arteries. Multiartery kidneys experienced longer cold ischemia time, but other characteristics were similar between groups. Delayed graft function (50% multiartery versus 45% one artery, P=0.07) and 90-day graft failure (3% versus 3%, P=0.83) were similar between groups before and after adjusting for donor and recipient characteristics. In the paired kidney analysis, cold ischemia time was significantly longer for multiartery kidneys compared with single-artery kidneys from the same donor (33.5 versus 26.1 hours, P<0.001), but delayed graft function and 90-day graft failure were again similar between groups. Conclusions: Compared with single-artery deceased donor kidneys, those with multiple renal arteries are harder to place, but experience similar delayed graft function and early graft failure.

COVID-19 in pancreas transplant recipients.

Coronavirus disease 2019 (COVID-19) has become a pandemic since first being described in January 2020. Clinical manifestations in non-transplant patients range from asymptomatic infection to severe pneumonia with acute respiratory distress syndrome, multiorgan system failure, and death. Limited reports in kidney transplant recipients suggest similar characteristics in that population. We report here the first case series of COVID-19 infection occurring in pancreas transplant recipients.

Cytochrome c-poly(acrylic acid) conjugates with improved peroxidase turnover number.

Cytochrome c-poly(acrylic acid) (cyt c-PAA) conjugates with 34-fold enchancement in peroxidase turnover number (kcat) are reported. Cyt c-PAA conjugates were prepared by carbodiimide coupling. PAA with molecular weight (Mw) ranging from 1.8k to 250k g mol-1 were employed, and the effect of PAA Mw on peroxiodase kinetics was assessed. The kcat value increased with increased Mw of PAA, ranging from 0.077(±0.002) s-1 in the absence of PAA to 2.66(±0.08) s-1 for the conjugate of cyt c with 250k PAA. Enzymatic activity studies over pH 6-8 indicated improved activity for cyt c-PAA conjugates at neutral or slightly alkaline pH. Examination of the cyt c heme spectroscopy in the presence of H2O2 revealed that formation of compound III, a reactive intermediate that leads to enzyme inactivation, was supressed in cyt c-PAA conjugates. Thus, we suggest the kcat enhancement can be attributed to acidification of the pH microenvironment and inhibition of the formation of a reactive intermediate that deactivates cyt c during the catalytic cycle.

Covalent interlocking of glucose oxidase and peroxidase in the voids of paper: enzyme-polymer "spider webs".

A modular, general method for trapping enzymes within the voids of paper, without chemical activation of cellulose, is reported. Glucose oxidase and peroxidase were crosslinked with poly(acrylic acid) via carbodiimide chemistry, producing 3-dimensional networks interlocked in cellulose fibers. Interlocking prevented enzyme activity loss and enhanced the washability and stability.

Nature, timing, and severity of complications from ultrasound-guided percutaneous renal transplant biopsy.

We sought to review our kidney transplant biopsy experience to assess the incidence, type, presenting symptoms, and timing of renal transplant biopsy complications, as well as determine any modifiable risk factors for postbiopsy complications. This is an observational analysis of patients at the University of Wisconsin between January 1, 2000, and December 31, 2009. Patients with an INR ≥1.5 or platelet counts less than 50 000 were not biopsied. An 18-gauge needle was used for biopsy. Over the study period, 3738 biopsies were performed with 66 complications (1.8%). No deaths occurred. A total of 0.7% were mild complications, 0.7% were moderate complications, 0.21% were severe complications, and 0.19% were life-threatening. Most complications occurred within the 4-h postbiopsy period, although serious complications were often delayed: 67% of complications requiring surgical intervention presented greater than 4 h after biopsy. Biopsy within 1 week of transplant had a 311% increased risk of a complication. Postbiopsy reduction in hematocrit and hemoglobin at 4 h was associated with a complication. In conclusion, life-threatening complications after renal allograft biopsy occurred in 0.19% of patients. Most complications occurred within 4 h postprocedure; however, many serious complications occurred with a time delay after initially uneventful monitoring. The only clinically significant laboratory predictor of a complication was a fall in the hematocrit or hemoglobin within 4 h. Patients biopsied within a week of transplant were at the highest risk for a complication and should therefore be most closely monitored.

Increased fusiform area activation in schizophrenia during processing of spatial frequency-degraded faces, as revealed by fMRI.

BACKGROUND: People with schizophrenia demonstrate perceptual organization impairments, and these are thought to contribute to their face processing difficulties. METHOD: We examined the neural substrates of emotionally neutral face processing in schizophrenia by investigating neural activity under three stimulus conditions: faces characterized by the full spectrum of spatial frequencies, faces with low spatial frequency information removed [high spatial frequency (HSF) condition], and faces with high spatial frequency information removed [low spatial frequency (LSF) condition]. Face perception in the HSF condition is more reliant on local feature processing whereas perception in the LSF condition requires greater reliance on global form processing. Past studies of perceptual organization in schizophrenia indicate that patients perform relatively more poorly with degraded stimuli but also that, when global information is absent, patients may perform better than controls because of their relatively increased ability to initially process individual features. Therefore, we hypothesized that people with schizophrenia (n=14) would demonstrate greater face processing difficulties than controls (n=13) in the LSF condition, whereas they would demonstrate a smaller difference or superior performance in the HSF condition. RESULTS: In a gender-discrimination task, behavioral data indicated high levels of accuracy for both groups, with a trend toward an interaction involving higher patient performance in the HSF condition and poorer patient performance in the LSF condition. Patients demonstrated greater activity in the fusiform gyrus compared to controls in both degraded conditions. CONCLUSIONS: These data suggest that impairments in basic integration abilities may be compensated for by relatively increased activity in this region.