Ameloblastoma of the Jaw in Three Species of Rodent: a Domestic Brown Rat (Rattus norvegicus), Syrian Hamster (Mesocricetus auratus) and Amargosa Vole (Microtus californicus scirpensis).

Ameloblastoma is a locally aggressive tumour derived from the odontogenic epithelium of the developing tooth germ. This uncommon odontogenic tumour is generally considered benign, but rarely, both distant metastasis and cytological atypia occur and this malignant version is referred to as malignant ameloblastic carcinoma. Here we document a spontaneous malignant ameloblastic carcinoma in a rat (Rattus norvegicus) with metastasis to the submandibular lymph node. We also describe ameloblastomas in two other muroid rodents, an Amaragosa vole (Microtus californicus scirpensis) and a Syrian hamster (Mesocricetus auratus). To our knowledge, this is the first report of a malignant ameloblastic carcinoma in any animal and the first report of ameloblastoma in a vole and hamster.

Advanced Statistical Analyses to Reduce Inconsistency of Bond Strength Data.

This study was designed to clarify the interrelationship of factors that affect the value of microtensile bond strength (µTBS), focusing on nondestructive testing by which information of the specimens can be stored and quantified. µTBS test specimens were prepared from 10 noncarious human molars. Six factors of µTBS test specimens were evaluated: presence of voids at the interface, X-ray absorption coefficient of resin, X-ray absorption coefficient of dentin, length of dentin part, size of adhesion area, and individual differences of teeth. All specimens were observed nondestructively by optical coherence tomography and micro-computed tomography before µTBS testing. After µTBS testing, the effect of these factors on µTBS data was analyzed by the general linear model, linear mixed effects regression model, and nonlinear regression model with 95% confidence intervals. By the general linear model, a significant difference in individual differences of teeth was observed ( P < 0.001). A significantly positive correlation was shown between µTBS and length of dentin part ( P < 0.001); however, there was no significant nonlinearity ( P = 0.157). Moreover, a significantly negative correlation was observed between µTBS and size of adhesion area ( P = 0.001), with significant nonlinearity ( P = 0.014). No correlation was observed between µTBS and X-ray absorption coefficient of resin ( P = 0.147), and there was no significant nonlinearity ( P = 0.089). Additionally, a significantly positive correlation was observed between µTBS and X-ray absorption coefficient of dentin ( P = 0.022), with significant nonlinearity ( P = 0.036). A significant difference was also observed between the presence and absence of voids by linear mixed effects regression analysis. Our results showed correlations between various parameters of tooth specimens and µTBS data. To evaluate the performance of the adhesive more precisely, the effect of tooth variability and a method to reduce variation in bond strength values should also be considered.

Cutaneous Ossifying Fibroma in a Neon Tetra (Paracheirodon innesi).

A cutaneous proliferative mass was identified arising from the caudal peduncle of a captive neon tetra fish (Paracheirodon innesi). The lesion was histologically consistent with an ossifying fibroma (OF), a fibro-osseous proliferative lesion typically identified in the jaws or tooth-associated supportive tissues of mammals. Although it has been previously reported, there is no recent report of this lesion occurring in a fish. This is the first report of a cutaneous ossifying fibroma in a characin fish. The authors speculate on the pathogenesis of this lesion, which may have arisen from the scale-associated mesenchymal tissues.

Systemic Amyloid A Amyloidosis in Island Foxes (Urocyon littoralis): Severity and Risk Factors.

Systemic amyloid A (AA) amyloidosis is highly prevalent (34%) in endangered island foxes (Urocyon littoralis) and poses a risk to species recovery. Although elevated serum AA (SAA) from prolonged or recurrent inflammation predisposes to AA amyloidosis, additional risk factors are poorly understood. Here we define the severity of glomerular and medullary renal amyloid and identify risk factors for AA amyloidosis in 321 island foxes necropsied from 1987 through 2010. In affected kidneys, amyloid more commonly accumulated in the medullary interstitium than in the glomeruli (98% [n= 78 of 80] vs 56% [n= 45], respectively;P< .0001), and medullary deposition was more commonly severe (19% [n= 20 of 105]) as compared with glomeruli (7% [n= 7];P= .01). Univariate odds ratios (ORs) of severe renal AA amyloidosis were greater for short- and long-term captive foxes as compared with free-ranging foxes (ORs = 3.2, 3.7, respectively; overall P= .05) and for females as compared with males (OR = 2.9;P= .05). Multivariable logistic regression revealed that independent risk factors for amyloid development were increasing age class (OR = 3.8;P< .0001), San Clemente Island subspecies versus San Nicolas Island subspecies (OR = 5.3;P= .0003), captivity (OR = 5.1;P= .0001), and nephritis (OR = 2.3;P= .01). The increased risk associated with the San Clemente subspecies or captivity suggests roles for genetic as well as exogenous risk factors in the development of AA amyloidosis.

Impact of platelets and serotonin on liver regeneration after living donor hepatectomy.

BACKGROUND: Several animal models have revealed that platelet-derived serotonin initiates liver regeneration after hepatectomy. However, there are few reports regarding the effects of serotonin in the clinical setting. The aim of this study was to explore the impact of serotonin and platelets in the early phase after healthy living donor hepatectomy. STUDY DESIGN: Stored samples from 34 living donors who received left lobectomy with caudate lobectomy (LL+C) or right lobectomy (RL) were available in the study. Serum serotonin levels and platelet counts associated with liver regeneration such as whole liver volume and hepatic graft weight (GW) were retrospectively collected from the database and analyzed. RESULTS: The remnant liver volume rate of RL grafts was smaller than that of LL+C grafts (45.4% vs 64.7%; P < .001). The regeneration rate at 7 days after surgery did not differ between the 2 groups (123% vs 122%). The serotonin levels and platelet counts decreased after surgery until postoperative day 3, then increased thereafter. The platelet counts and serotonin levels of LL+C donors were significantly higher than those of RL donors. CONCLUSIONS: Our findings suggest that platelets and serotonin play a pivotal role in initiating liver regeneration in the remnant liver.

Visceral smooth muscle α-actin deficiency associated with chronic intestinal pseudo-obstruction in a Bengal cat (Felis catus x Prionailurus bengalensis).

An adult Bengal cat (Felis catus × Prionailurus bengalensis) with a prolonged history of partial anorexia, regurgitation, and weight loss and a clinical, radiographic, and ultrasonographic diagnosis of persistent megaesophagus and gastrointestinal ileus was submitted for necropsy. The intestinal tract was diffusely distended by gas and fluid with appreciable loss of muscle tone and an absence of luminal obstruction, consistent with the clinical history of chronic intestinal pseudo-obstruction. Histologically, the autonomic nervous system was intact, but the smooth muscle within the gastrointestinal wall exhibited a marked basophilia that was most pronounced in the jejunum. Immunohistochemistry for neurofilament, synaptophysin, CD117, and desmin demonstrated that the number of myenteric ganglia, number of interstitial cells, and leiomyocyte desmin content were similar when compared with the unaffected age- and species-matched control. Immunohistochemistry for smooth muscle α-actin demonstrated a striking loss of immunoreactivity, predominantly in the circular layer of the jejunum, that corresponded with the tinctorial change in leiomyocytes. Transmission electron microscopy revealed loss of myofibrils, loss of organelle polarity, and significantly larger central mitochondria (megamitochondria) in affected leiomyocytes, as well as nonspecific degenerative changes. Although the presence of a primary leiomyopathy and a causal relationship could not be confirmed in this case, leiomyopathies are considered a cause of chronic intestinal pseudo-obstruction in human medicine, and loss of smooth muscle α-actin immunoreactivity is one recognized marker for intestinal dysmotility.

Lyme neuroborreliosis in 2 horses.

Lyme neuroborreliosis--characterized as chronic, necrosuppurative to nonsuppurative, perivascular to diffuse meningoradiculoneuritis--was diagnosed in 2 horses with progressive neurologic disease. In 1 horse, Borrelia burgdorferi sensu stricto was identified by polymerase chain reaction amplification of B burgdorferi sensu stricto-specific gene targets (ospA, ospC, flaB, dbpA, arp). Highest spirochetal burdens were in tissues with inflammation, including spinal cord, muscle, and joint capsule. Sequence analysis of ospA, ospC, and flaB revealed 99.9% sequence identity to the respective genes in B burgdorferi strain 297, an isolate from a human case of neuroborreliosis. In both horses, spirochetes were visualized in affected tissues with Steiner silver impregnation and by immunohistochemistry, predominantly within the dense collagenous tissue of the dura mater and leptomeninges.

Study on the propagation of ultra-short pulse light in cylindrical optical phantoms.

A detailed study about ultra-short pulse light propagation inside cylindrical scattering and absorbing phantoms is presented. Some comparisons between a Monte Carlo code and the analytical solution of diffusion equation for a delta(t) source and point-like detectors placed at different angles of detection are shown. To better quantify the agreement between the temporal profiles obtained from the two different methods of calculation, a fitting procedure based on the Levenberg-Marquardt algorithm has been implemented. Some examples on the retrieval of the optical properties for both the Monte Carlo and experimental data are presented. In the case of inhomogeneous cylindrical phantoms, some comparisons between the results of the time-domain 3D model of finite element method and 3D Monte Carlo are also shown.

Estimation of internal absorbed dose of L-[methyl-11C]methionine using whole-body positron emission tomography.

L-[Methyl-11C]-methionine (11C-methionine) is proposed as a useful radiotracer for tumour diagnosis. Human biodistribution data of cumulated activities and absorbed doses estimated by the MIRD (medical internal radiation dosimetry) method for 11C-methionine are not available in the literature. In this study we measured the organ activity for 11C-methionine by using whole-body positron emission tomography (PET) and estimated the absorbed doses to 25 organs by the MIRD method. Whole-body dynamic PET scans were performed on five normal volunteers to measure the time course of the organ activity concentration (activity/volume) after intravenous administration of 11C-methionine. Cumulated activities of the ten source organs were calculated from the time-activity curves, obtained from the dynamic PET data. Absorbed dose estimates were performed by the MIRD method for the Caucasian reference man and for the Japanese reference man. The organs which received the highest absorbed doses for the Caucasian reference man were found to be the bladder wall (2.7x10(-2) mGy/MBq), the pancreas (1.9x10(-2) mGy/ MBq), the liver (1.8x10(-2) mGy/MBq) and the kidney (1.1x10(-2) mGy/MBq). The effective doses for the Caucasian reference man and the Japanese reference man were calculated as 5.2x10(-3) and 5.0x10(-3) mSv/MBq, respectively.

Evaluation of fluorimetrically estimated serum bile acid in liver disease.

Fasting serum bile acid (SBA) was measured by the enzymic fluorimetric method coupled with the NAD-resazurin system in 23 controls, 35 asymptomatic carriers of HIs antigen including 4 e antigen carriers and 91 patients with various liver diseases. All GHBs and e antigen carriers showed SBA within the normal range. SBA was most significantly correlated with serum bilirubin (gamma=0.74) and was a more sensitive index for impaired liver function than bilirubin or alkaline phosphatase in 164 radomly chosen samples from the liver disease group. In serial determinations of SBA with reference to GOT, GPT, changing patterns of these two parameters were classified into the parallel type and the discrepant type. Thirty two out of 40 cases with chronic liver disease belonged to the parallel type. SBA remained abnormal even after the normalization of transaminase in 12 out of 20 resolving episodes in cases of the parallel type, regardless of diagnosis. Since SBA changes according to the stage of the disease activity, serial and simultaneous estimation of SBA and GOT, GPT was found to be helpful in the observation of liver diseases. Maximum values of SBA elevation in an endogenous bile acid tolerance test after eating two egg yolks were higher than controls in 4 out of 7 cases with liver disease, who were associated with normal fasting SBA.