Effects of Environmental Enrichment on the Fertility and Fecundity of Zebrafish (Danio rerio).

Zebrafish (Danio rerio) are a popular vertebrate model in biomedical research, but information describing the effects of environmental enrichment on fertility and fecundity of zebrafish is sparse. In the current study, 18 breeding pairs were placed in divided 1.5-L breeding tanks containing 1 of 3 enrichment conditions: plastic grass (n = 6), plastic leaves (n = 6), or no enrichment (n = 6, control). The pairs were allowed to spawn for 3 h the next day, after which eggs were counted and breeding pairs were returned to holding tanks for use in subsequent sessions. Spawning sessions were repeated at 7-d intervals until the completion of 9 trials, with pairs rotating to a different condition at each interval. Total egg count (mean ± SEM) after 3 h was greater for zebrafish spawning in the grass environment (48.0 ± 7.7 eggs) than in the leaf or control environments (29.4 ± 5.3 and 20.4 ± 3.7 eggs, respectively). An interaction emerged between enrichment type and the age of the spawning pair on the number of fry at 6 d postfertilization (dpf). Initially, more fry were obtained from 110- and 160-dpf pairs with the grass enrichment, but from 173- and 180-dpf pairs there were more obtained with leaf enrichment than grass. A separate experiment showed that enrichment type did not have an effect on fry survivability. Overall, our data indicates that, under certain conditions, zebrafish fertility and fecundity are greater in a breeding tank containing environmental enrichment than in a bare tank.

Local cryoanalgesia is effective for tail-tip biopsy in mice.

Tail-tip biopsy for genotyping of genetically modified mice older than 21 d typically is performed by using isoflurane anesthesia. Isoflurane-induced changes in behavior and metabolism can result in unexpected complications and death. We investigated whether cryoanalgesia by using ethylene chloride spray would be an effective local anesthetic for tail-tip biopsies in mice. C57BL/6J mice were allocated randomly into 4 groups (n = 10 each) to receive isoflurane anesthesia with tail biopsy, ethylene chloride spray on the tip of the tail before biopsy, ethylene chloride spray without biopsy, or no treatment. Blood glucose was measured periodically in both groups undergoing tail biopsy, and the tail-pinch assay was performed in all mice that received ethylene chloride spray. Body weight, water, and food intake were measured daily for 2 wk. In both groups undergoing tail biopsy, blood glucose levels at 15 min were significantly higher than those after 2 min. This elevation was greater and more prolonged after 30 min in mice that received isoflurane compared with ethylene chloride spray. Tail-pinch latency at 20 min was greater than that after 2 min in all mice that received ethylene chloride spray. All mice gained weight, and there was no difference in food and water intake among groups. We conclude that ethylene chloride spray is an effective local anesthetic and a valuable alternative to isoflurane.

Suprapubic bladder catheterization of male spinal-cord-injured Sprague-Dawley rats.

The rat spinal-cord-injury (SCI) model is widely used to study the pathologic mechanisms that contribute to sensory and motor dysfunction in humans. This model is thought to mimic many of the negative outcomes experienced by humans after spinal contusion injury. We theorized that manual bladder expression contributed to the kidney and bladder lesions reported in previous studies using the rat SCI model. In the present study, rats were surgically implanted with bladder catheters after spinal contusion injury to provide continuous drainage of urine. After 72 h, the rats were euthanized and their kidneys and bladders examined histologically. BUN, serum creatinine, and urine protein were compared at 0 and 72 h after surgery. Kidney and bladder lesions were similar in SCI rats with and without implanted bladder catheters. BUN at 72 h was higher than baseline values in both groups, whereas serum creatinine was higher at 72 h compared with baseline values only in the catheterized rats. These findings indicate that suprapubic bladder catheterization does not reduce hydronephrosis in SCI rats and that the standard of care for bladder evacuation should continue to be manual expression of urine.

Selective nanoparticle-directed ablation of the canine prostate.

BACKGROUND AND OBJECTIVES: Prostate cancer is the most frequent cancer type and the second most common cause of cancer death among US men. This study, adapted a previously reported nanoparticle-directed photothermal treatment of brain tumors to the treatment of prostate disease by using normal canine prostate in vivo, directly injected with a suspension of nanoparticles as a proxy for prostate tumor, and by developing laser dosimetry for prostate which is marginally ablative in native tissue, yet producing photothermal coagulation in prostate tissue containing nanoparticles. METHODS: Canine prostates were exposed by surgical laparotomy and directly injected with suspensions of nanoparticles (nanoshells) and irradiated by a NIR laser source delivered percutaneously by an optical fiber catheter and isotropic diffuser. The photothermal lesions were permitted to resolve for up to 8 days, at which time each animal was euthanized, necropsied, and the prostate taken for histopathological and elemental analysis. RESULTS: Nanoparticles were retained for up to 4 hours in prostate and served as a proxy for prostate tumor. A marginally ablative laser dose of 3.0 W for 3 minutes was developed which would yield 4 mm-radius coagulo-necrotic lesions if nanoparticles were present. CONCLUSION: We have shown that the addition of nanoshells to native tissue, combined with a marginally ablative laser dose can generate ablative thermal lesions, and that the radial extent of the thermal lesions is strictly confined to within ∼4 mm of the optical fiber with sub-millimeter uncertainty. This, in turn, suggests a means of precise tumor ablation with an ability to obviate damage to critical structures limited primarily by the precision with which the optical fiber applicator can be placed. In so doing, it should be possible to realize a precise, nerve bundle and urethra sparing prostate cancer treatment using a minimally invasive, percutaneous approach.

Tropical storm and hurricane recovery and preparedness strategies.

The goal of this article is to present lessons learned from the devastating effects of two specific natural disasters in Texas: Tropical Storm Allison, which flooded Houston in June 2001, and Hurricane Ike, which caused severe damage in Galveston in September 2008. When a disaster is predictable, good predisaster planning can help to save animals lives. However, as disasters are usually not predictable and tend not to follow a script, that plan needs to be easily adaptable and flexible. It should address all aspects of the program and include an evacuation strategy for the animals, data backup, and identification of emergency equipment such as generators and communication systems. Media communication must also be considered as the general public may become emotional about animal-related issues; adverse attention and public scrutiny can be expected if animals die. The psychological impact of the disaster on the lives of those it directly affects may require attention and accommodation in the postdisaster recovery period. Following an overview of each disaster we describe plans for recovery, impacts on research, business continuity programs, and planning and preparation strategies developed against future natural disasters. Long-term planning includes building design as an important factor in protecting both the animals and the research equipment. Lessons learned include successful responses, evaluation for improvements, and preparedness plans and procedures to guard against future disaster-related destruction or loss of facilities, research programs, and animal lives.