Neocapsular reconstruction for challenging partial nephrectomy: A feasibility study in a porcine model and recent clinical experience.

OBJECTIVES: Multifocal renal masses and large central-endophytic tumors can be challenging for partial nephrectomy (PN) due to the paucity of capsule remaining after tumor removal. Our objective was to develop a neocapsule to provide tamponade and test its feasibility/safety in a porcine model. METHODS: Eight live pigs (50-70 kg) underwent unclamped open right flank PN. Renal defects were 1 cm deep and had moderate ongoing venous bleeding. A 6 × 9 inch sheet of Nu-knit® was used for neocapsular reconstruction with Fibrillar™ packing to provide modest tamponade and preclude ongoing bleeding. Blood chemistry and hemoglobin (Hb) levels were drawn preoperatively and postoperative Days 3/5/8. On postoperative Day 8, euthanasia was performed, and both kidneys were inspected and analyzed for histologic changes. RESULTS: PN defects ranged from 1 × 1 × 1 cm to 4 × 2 × 1 cm; four pigs had PN performed in both poles and four in one pole. Neocapsular reconstruction was successful (n = 8), with no perioperative complications. Median baseline Hb was 10.4 g/dL, and median Hb postoperative Days 3/5/8 were 10.0/10.8/10.6 g/dL, respectively. Median baseline serum creatinine (SCr) was 1.9 mg/dL, and median SCr postoperative Days 3/5/8 were 1.5/1.4/1.5 mg/dL, respectively. At sacrifice, no significant hematomas were observed. Other than adjacent to the PN site, there were no significant histologic changes in the parenchyma for operative kidneys versus controls. Based on our experience, we recently performed neocapsular reconstruction safely/effectively after extensive PN for multifocal tumors and for an allograft with difficult-to-manage subcapsular hematoma. CONCLUSIONS: Neocapsular reconstruction after PN or capsular trauma appears feasible and safe and may be considered to reduce the risk of perioperative bleeding. However, further study will be needed to confirm the utility/efficacy of this approach.

Influence of Light Phase Exposure to LED Lighting on Circadian Levels of Neuroendocrine Hormones in Sprague-Dawley Rats.

Light and lighting protocols of animal research facilities are critically important to the outcomes of biomedical research that uses animals. Previous studies from our laboratory showed that the wavelength (color) of light in animal housing areas affects the nocturnal melatonin signal that temporally coordinates circadian rhythms in rodents. Here, we tested the hypothesis that exposure to LED light enriched in the blue-appearing portion (460-480 nm) of the visible spectrum during the light phase (bLAD) influences circadian concentrations of select neuroendocrine hormones in adolescent Sprague-Dawley rats. Male and female rats (4 to 5 wk old) were housed on a novel IVC system under a 12L:12D in either cool-white fluorescent (control, n = 72) or bLAD (experimental, n = 72) lighting. Every third day, body weight and food and water consumption were measured. On Day 30, rats were anesthetized with ketamine/xylazine and terminal collection of arterial blood was performed to quantify serum concentrations of melatonin, corticosterone, insulin, and glucose at 6 circadian time points (0400, 0800, 1200, 1600, 2000, 2400). As compared with male and female rats housed under cool white fluorescent (CWF) lighting, rats in bLAD lighting showed a 6-fold higher peak in dark phase serum melatonin (P < 0.05). Effects on serum corticosterone were sex dependent, as CWF and bLAD females had significantly higher corticosterone levels than did CWF and bLAD males, respectively. CWF and bLAD females had significantly higher serum glucose overall as compared with males. However, serum insulin was not affected by sex (M or F) or lighting conditions (CWF or bLAD). These data show that housing Sprague-Dawley rats under bLAD lighting conditions increases circadian peaks of melatonin without increasing serum levels of corticosterone, glucose or insulin, indicating less variation of circadian cycling of key neuroendocrine hormones in bLAD-exposed rats.

Pulsatility hemodynamics during speed modulation of continuous-flow total artificial heart in a chronic in vivo model.

BACKGROUND: The evaluation of pulsatile flow created by the new Cleveland Clinic continuous-flow total artificial heart (CFTAH100), which has a re-designed right impeller and motor, had not been tested in vivo. The purpose of this study was to evaluate the feasibility of pulsatility with the CFTAH100 during the application of pump speed modulation protocols in a chronic animal model. METHODS: A 30-day chronic animal experiment was conducted with a calf. Five pulsatile studies were performed on the alert animal. The mean pump speed was set at 2800 rpm, and modulated sinusoidally within a range of 0 to ± 35% of mean speed, in increments of 5% at 80 beats per minute (bpm). The pressures and pump flow were collected and a pulsatility index (PI) was calculated. RESULTS: The calf was supported with the CFTAH100 without any major complications. The maximum and minimum pump flows changed significantly from baseline in all conditions, while the mean pump flow did not change. All flow pulsatility (FP) readings in all conditions significantly increased from baseline, and the percent modulation (%S) and FP had a strong positive correlation (r = 0.99, p < 0.01). The PI also increased significantly in all conditions (maximum at %S of 35%, 2.2 ± 0.05, p < 0.01), and a positive correlation between %S and PI (r = 0.99, p < 0.01) was observed. CONCLUSION: The CFTAH100 showed the feasibility of creating pulsatile circulation with sinusoidal pump speed modulation.

Effects of Daytime Blue-Enriched LED Light on Physiologic Parameters of Three Common Mouse Strains Maintained on an IVC System.

Light has been a crucial part of everyday life since the beginning of time. Most recently, light-emitting diode (LED) light enriched in the blue-appearing portion of the visible spectrum (465 to 485 nm), which is more efficient in energy use, is becoming the normal lighting technology in facilities around the world. Previous reports revealed that blue-enriched LED light at day (bLAD) enhances animal health and wellbeing as compared with cool white fluorescent (CWF) lighting. We hypothesized that bLAD, compared with CWF light, has a positive influence on basic physiologic indices such as food consumption, water consumption, weight gain, nesting behavior, complete blood count, and blood chemistry profile. To test this, we allocated 360 mice into equal-sized groups by sex, strain (C3H/HeNCrl, C57BL/6NCrl, BALB/cAnNCrl), lighting conditions, and 6 blood collection time points (n = 5 mice/sex/strain/lighting condition/time point). Food consumption, water consumption, body weight, nest location, and nest type were recorded every 3 d. At the end of the study, all mice were anesthetized over a period of 1 wk and blood was collected via cardiocentesis at 6 different time points. Overall, male C3H/HeNCrl consumed more food under bLAD conditions as compared with CWF conditions; male C3H/HeNCrl had lower cholesterol levels under bLAD conditions than under CWF conditions; female BALB/cAnNCrl mice had higher serum total protein under bLAD conditions than under CWF conditions; female C57BL/6NCrl mice had higher phosphorus levels under bLAD conditions than under CWF conditions, and female C3H/HeNCrl mice had a higher neutrophil count under bLAD conditions as compared with CWF conditions. Although sex and strain differences were found in various physiologic parameters under bLAD as compared with CWF lighting conditions, the differences were minimal. Thus, this study suggests that for these strains of mice, bLAD and CWF are largely equivalent with regard to indices of health and wellbeing, although some differences could affect research outcomes.

Evaluation of Therapeutic Approaches for the Treatment of Spironucleus muris in Mice.

Spironucleus muris is an intestinal protozoal pathogen that can infect various species of rodents. The infection can have a wide range of clinical presentations, from no signs of disease to death. In addition, this pathogen can adversely affect research results, especially immunologic and gastrointestinal studies. For these reasons, institutions may exclude Spironucleus muris. However, despite rigorous efforts to keep this pathogen out, it can be common in rodent colonies. The current recommended approach to eradicating this pathogen is by testing and culling positive animals. A similar organism, Giardia muris, has been effectively eliminated by using chemotherapeutics. Therefore, the objective of this study was to determine whether S. muris is also susceptible to chemotherapeutics. Naturally infected mice were randomized to treatment groups after confirmation of positive infection via PCR. Mice received either metronidazole, fenbendazole, a combination of metronidazole-fenbendazole, or acidified water (control) treatments for a period of 4 wk. Each week fecal testing of S. muris was performed via PCR to evaluate the effectiveness of the treatments. At the end of the 4 wk period, mice were euthanized via CO2 inhalation and segments of the proximal gastrointestinal tract were submitted for histopathologic analysis. Treatment with metronidazole or fenbendazole alone or in combination, failed to clear S. muris infected mice. After 4 wk of treatment, none of the mice given fenbendazole via sucralose medicated gel were positive by either PCR or histopathology; however, this finding is most likely due to intermittent shedding rather than chemotherapeutic success. Therefore, the recommendation remains to test-and-cull or rederive mice as necessary to eliminate S. muris from laboratory animal facilities.