Minimally Invasive Approach to the Lingual and Hypoglossal Nerves in the Adult Rat.

Surgical manipulation of the sensory and motor nerves of the rat tongue is often employed in studies evaluating the oral cavity functions of mastication and deglutition. A noninvasive, atraumatic approach that will then facilitate sufficient manipulation of these structures is required. In this study, we detail an approach that consistently allows identification of the hypoglossal (motor) and lingual (sensory) nerves of the rat. Six Wistar rats (250-500 g) were anesthetized and dissected either as fresh tissue (N = 3) or following transcardial perfusion with 4% paraformaldehyde (N = 3). Both fixed and non-fixed specimens of the rat head and neck were incised in the right submandibular region. The first animal in each group was used to gain a basic understanding of the regional muscular anatomy with reference to the hypoglossal and lingual nerves. Subsequent animals were used for the development of an efficient and minimally invasive approach to these nerves. The resultant approach begins as an incision through skin and platysma, followed by medial reflection of the digastric muscle. This allows visualization of the hypoglossal nerve in the region of the bifurcation of the common trunk into medial and lateral subdivisions. Next, the lingual nerve dissection is approached by reflection rostrally of the transversus mandibularis muscle and a caudal reflection of the mylohyoid muscle. This dissection reveals the geniohyoid muscle which when separated bluntly using forceps, exposes the lingual nerve. The anatomical approach described and illustrated herein will aid investigators in consistent identification of these two nerves as fundamental methods of their projects.

Oleanolic Acid Improves Gut Atrophy Induced by Parenteral Nutrition.

BACKGROUND: Nutrition support with parenteral nutrition (PN) is associated with gut atrophy. Prior studies have shown improvement with enteral chenodeoxycholic acid, a dual agonist for the farnesoid X receptor (FXR) and bile acid receptor TGR5. We hypothesized that gut growth is induced by TGR5 activation, and gut atrophy during PN administration could be prevented with the TGR5-specific agonist oleanolic acid (OA). METHODS: Neonatal pigs were implanted with duodenal and jugular vein catheters. Animals were provided equi-nutritious PN or enteral swine milk. A PN subgroup received enteral OA at 50 mg/kg/d. RESULTS: PN caused marked gut atrophy compared with enterally fed (EN) control animals. OA treatment led to preservation of gut mass demonstrated grossly and histologically. The mean ± SD gut weight as a percentage of body weight was 4.30 ± 0.26 for EN, 1.92 ± 0.06 for PN (P < .05, EN vs PN), and 3.39 ± 0.79 for PN+OA (P < .05, PN+OA vs PN). Mean ± SD gut density (g/cm) was 0.31 ± 0.03 for EN, 0.18 ± 0.03 for PN (P < .05 EN vs PN), and 0.27 ± 0.01 for PN+OA (P < .05 PN+OA vs PN). Histologically, a markedly decreased villous to crypt ratio was noted with PN, and OA significantly prevented this decrease. The mean ± SD v/c ratio was 3.51 ± 0.59 for EN, 1.69 ± 0.10 for PN (P < .05, EN vs PN), and 2.90 ± 0.23 for PN+OA (P < .05, PN+OA vs PN). Gut TGR5 messenger RNA expression was significantly elevated with OA treatment compared with both PN and EN. CONCLUSION: The bile acid-activated G protein-coupled receptor TGR5 agonist OA prevented gut atrophy associated with PN.

Validating hyperbilirubinemia and gut mucosal atrophy with a novel ultramobile ambulatory total parenteral nutrition piglet model.

Total parenteral nutrition (TPN) provides all nutrition intravenously. Although TPN therapy has grown enormously, it causes significant complications, including gut and hepatic dysfunction. Current models use animal tethering which is unlike ambulatory human TPN delivery and is cost prohibitive. We hypothesize that using ultramobile infusion pumps, TPN can be delivered cost-effectively, resulting in classical gut and hepatic injury, and we thus aim to establish a new model system. Neonatal pigs (n=8) were implanted with jugular vein and duodenal catheters. Animals were fitted in dual-pocket jackets. An ultramobile ambulatory pump was placed in one pocket and connected to the jugular vein or duodenal catheter. Isocaloric TPN or swine formula was placed in the other pocket. Rigorous Wifi-based video and scheduled monitoring was performed. After 14days, the animals were euthanized. The mean (±SD) daily weight gain (in grams) for enteral-fed control (EN) vs TPN animals was 102.4±10.8 and 91.03±12.1 respectively (P<.05). Total parenteral nutrition resulted in significant conjugated bilirubin elevation and hepatomegaly. Mean (±SD) serum conjugated bilirubin (in µmol/L) was 1.5±0.7 for EN and 6.3±2.8 for TPN (P<.05). Marked gut atrophy was noted with TPN. The mean (±SD) gut weight as a percent of body weight was 4.30±0.26 for EN and 2.62±0.48 for TPN (P<.05). Surgical sites healed well. All animals remained completely mobile. We thus established that TPN can be successfully delivered using ultramobile pumps and believe that this remains the first such description of an ambulatory piglet TPN model system. In addition to cholestasis and gut atrophy, classical TPN-induced injury was documented.

Cryosurgical ablation of the prostate: current technique and clinical outcomes.

In addition to established therapies such as radiotherapy and radical prostatectomy, a number of newer therapies have been suggested to be effective in treating patients with clinically localized prostate carcinoma (PCA). One of these is cryoablation, a procedure that infarcts the prostate by the in situ application of percutaneous cryoprobes. Although results with this approach were mixed when introduced initially in 1993, recent improvements in technique and understanding of the mechanisms of cryo-injury in the prostate have led to renewed interest in this treatment option for patients with PCA.

Hemostatic agent microporous polysaccharide hemospheres (MPH) does not affect healing or intact sinus mucosa.

OBJECTIVES/HYPOTHESIS: Absorbable hemostatic agents are used routinely following sinus surgery. Recent studies suggest that current biomaterials, such as FloSeal Matrix Hemostatic Sealant (Fusion Medical Technologies, Mountain View, CA) may interfere with mucosal regeneration. This study was designed to evaluate the effects of Microporous Polysaccharide Hemospheres (MPH, Medafor, Inc., Minneapolis, MN), a novel rapidly-absorbing hemostatic powder, on healing and intact sinus mucosa. STUDY DESIGN: Prospective, controlled study using the rabbit model. METHODS: Both maxillary sinuses of 14 New Zealand white rabbits were surgically opened. The mucosa of 10 rabbits were stripped bilaterally, and the left sinus of each was then treated with either MPH or FloSeal. The mucosa of four additional rabbits were incised but otherwise remained undisturbed. Again, the left sinus of each of the four additional rabbits was treated with either MPH or FloSeal. The right sinus served as an untreated control (stripped or intact) in both arms of the study. Animals were recovered and euthanized 2 weeks later. Specimens were examined by a blinded pathologist using light microscopy. RESULTS: Untreated regenerated mucosa showed expected areas of sparse cilia, mild serous gland reduction, and fibrosis. MPH-treated sinuses showed no significant changes compared to respective controls, and no MPH substance was identified. In contrast, regenerating mucosa treated with FloSeal showed extensive loss of cilia, inflammation, and fibrosis. Residual FloSeal particles were present within the sinus cavity and grossly incorporated within healing mucosa. Unexpectedly, intact mucosa exposed to FloSeal showed similar findings. CONCLUSIONS: Absorbable hemostatic materials have starkly different effects on mucosal healing. Unlike other agents, MPH is rapidly cleared and has no negative effects on healing or intact sinus mucosa.

Intensity-modulated radiotherapy of the prostate after cryotherapy: initial experience.

OBJECTIVES: To analyze results of intensity-modulated radiotherapy after cryotherapy ablation for adenocarcinoma of the prostate. METHODS: Patients were either treated adjuvantly after targeted cryotherapy or treated for salvage after local failure of standard whole-prostate cryotherapy. Patients were treated with intensity-modulated radiotherapy to a minimum dose of 73 Gy (mean dose, >75Gy). Prostate-specific antigen (PSA) failure was defined according to the Radiation Therapy Oncology Group-American Society for Therapeutic Radiology and Oncology 2006 consensus definition. Late gastrointestinal and genitourinary toxicity were graded according to the Radiation Therapy Oncology Group late toxicity scale and the Late Effects of Normal Tissue-Subjective, Objective, Management, and Analytic scale. RESULTS: A total of 16 patients were treated from 1997 to 2007. Three patients were treated adjuvantly, and 13 patients were treated for local failure. The mean pre-cryotherapy PSA value was 8.7 ng/mL. The mean PSA value before irradiation was 6.0 ng/mL. Most patients were intermediate to high risk (8 intermediate risk, 7 high risk). Median follow-up was 33 months. No grade 3 or greater toxicity was seen. Biochemical (PSA) control was achieved in 12 of the 16 patients at last follow-up. CONCLUSIONS: Full-dose intensity-modulated radiotherapy after cryotherapy is well tolerated, without excess late morbidity. This study supports the use of radiation for cryotherapy failure salvage. Furthermore, the combination of cryotherapy and irradiation may be considered in a phase II trial.