Heavily T2-weighted imaging findings of spinal cord swelling in dogs with intervertebral disc extrusion

This study investigated causes of attenuation of cerebrospinal fluid (CSF) signal on heavily T2-weighted (T2W) images in dogs with thoracolumbar disc extrusion. Medical records and magnetic resonance images were retrospectively reviewed. Dogs were classified into the following grades; grade 1, non-ambulatory paraparesis; grade 2, paraplegia with deep pain perception and grade 3, paraplegia without deep pain perception. The length of intramedullary T2W hyperintensity of the spinal cord, cranial/ caudal expansion of extradural compressive materials (ECM), and the CSF signal attenuation were measured. Ratios to the second lumbar vertebra (L2) were calculated for the length of intramedullary T2W hyperintensity (T2W:L2), cranial/caudal expansion of ECM (ECML:L2), and CSF signal attenuation (CSF:L2). The dogs were classified into focal or extended T2W hyperintensity groups according to the length [focal, shorter than length of L2; extended, longer than L2]. The area of EMC and the spinal canal were measured on transverse images at the lesion deriving occupancy ratio. The correlation between CSF:L2 and other data were analysed, and CSF:L2 was compared between the grades. In dogs with intramedullary T2W hyperintensity, the locations of CSF attenuation and the hyperintensity were compared if those locations were matched. Fifty-five dogs were included, 36 of which showed intramedullary T2W hyperintensity. Twenty-two of 36 dogs were considered as match of the location of the CSF attenuation and hyperintensity. CSF:L2 was significantly correlated with T2W:L2 in dogs with extended T2W hyperintensity (p = 0.0002), while CSF:L2 was significantly correlated with ECML:L2 in dogs with focal or no T2W hyperintensity (p = 0.0103 and p = 0.0364, respectively). CSF:L2 in grade 3 was significantly greater than those in patients who were grade 1 or 2 (both p < 0.001). In conclusion, higher CSF:L2, which was frequently seen in grade 3, would be most consistent with a higher T2W:L2 which might indicate spinal cord swelling.

Effect of different contrast medium injection protocols for analysis of hepatic computed tomography perfusion in healthy dogs

OBJECTIVE

To evaluate the hepatic CT perfusion (CTP) for determining the appropriate protocol for the dual-input maximum-slope model in dogs.

ANIMALS

5 healthy dogs.

PROCEDURES

Each dog underwent CTP with different contrast medium administration protocols. Combinations of three different injected doses of iohexol (450, 600, and 750 mg/kg) and injection durations (5, 10, and 15 seconds) were used. The CT values at the aorta, portal vein, and hepatic parenchyma were measured to create a time-density curve, and CTP parameters were measured simultaneously on each hepatic lobe using a 320-row multidetector CT scanner.

RESULTS

The maximum peak enhancement at the aorta, portal vein, and hepatic parenchyma was greater with the 750-mg/kg dose than with the 450-mg/kg dose. With an injection duration of 15 seconds, the aortic enhancement peak was less, and the arrival time at the aortic enhancement peak was longer compared to that with a 5-second injection duration. The CTP parameters in the caudate process of the caudate lobe and left lateral lobe differed with different injection durations. The CTP parameters in the caudate process of the caudate lobe, left lateral lobe, and right lateral lobe differed with varying injected doses.

CLINICAL RELEVANCE

Our study demonstrated that rapid administration of the contrast medium was required for quantitative analysis of hepatic CTP in healthy dogs. The CTP parameters differed with respect to the contrast medium administration protocol, and it was necessary to administer the contrast medium within a fixed duration and at a fixed dose to evaluate CTP correctly.

Computed tomographic features of portal vein thrombosis in two cats with splenosystemic shunts

Two spayed female cats presented with hepatic encephalopathy due to hyperammonaemia. On abdominal ultrasound, concurrent portal vein thrombosis and splenosystemic shunts were suspected in both cats. Computed tomographic angiography clearly detected thrombi as non-contrast enhancing intraluminal structures in the main portal vein of both cats. Additionally, splenorenal shunts were revealed in both cats. Follow-up computed tomographic angiography for portal vein thrombosis was performed in both cats, only one of whom received anticoagulant therapy. In the untreated cat, portal vein thrombosis had progressed with the development of an aberrant tortuous vessel. In the cat treated with low-molecular-weight heparin, the thrombus progressively decreased in size and disappeared on follow-up diagnostic imaging. Computed tomographic angiography might be useful for the diagnosis and follow-up of portal vein thrombosis in cats.

Long-term follow-up of portal vein thrombosis in an American Cocker Spaniel with lobular dissecting hepatitis: a case report

BACKGROUND

Lobular dissecting hepatitis (LDH) is a rare form of canine liver cirrhosis that may be accompanied by portal hypertension in American Cocker Spaniels. In human patients with liver cirrhosis, portal vein thrombosis (PVT) is a common complication. However, PVT has not been reported in dogs with LDH. Herein, we describe the long-term follow-up of PVT in an American Cocker Spaniel with LDH.

CASE PRESENTATION

An 8-year-old neutered male American Cocker Spaniel presented with a 1-month history of severe abdominal effusion. The dog was histopathologically diagnosed with LDH and treated with low-dose prednisolone on day 14. On day 115, computed tomography angiography (CTA) confirmed the presence of a thrombus in the portal vein. Therefore, the dog was subcutaneously administered with the anticoagulant dalteparin, and low-dose prednisolone was continued. As a follow-up for PVT, CTA examinations were performed on days 207, 515, 886, and 1168, and the dog's antithrombin and D-dimer levels were measured. Following anticoagulant therapy, the dog was confirmed to have gradually increased antithrombin activity and decreased D-dimer concentrations. In addition, although the thrombus was confirmed to be in the same area of the portal vein system by CTA, atrophy and increased CT values due to organization were observed during the follow-up period. The dog's condition remained stable without clinical signs until day 1112 when it developed hepatic encephalopathy. The dog died on day 1208. On postmortem examination, histopathologically, the liver showed marked bile duct hyperplasia and fibrosis with chronic thrombus in the portal vein.

CONCLUSIONS

This case demonstrated that low-dose glucocorticoid combined with dalteparin allowed long-term follow-up of PVT in an American Cocker Spaniel with LDH.

Cerebrospinal fluid flow on time-spatial labeling inversion pulse images before and after treatment of congenital hydrocephalus in a dog

A 3-month-old male cross-breed dog presented with signs of progressive diffuse brain disease. Noncommunicating congenital hydrocephalus concurrent with cervical syringomyelia was diagnosed on magnetic resonance images. On time-spatial labeling inversion pulse (Time-SLIP) images CSF flow through the mesencephalic aqueduct was poorly defined and there was flow into the syrinx across the craniocervical junction. After percutaneous ventricular drainage and ventriculoperitoneal shunting, CSF flow through the aqueduct was clearly detected and flow into the syrinx disappeared. In addition, CSF flow in the subarachnoid space at the pons and ventral aspect of the cervical subarachnoid space was restored. Signs of neurological dysfunction improved after ventriculoperitoneal shunting and the cerebral parenchyma was increased in thickness on 2-year follow-up computed tomography images. Patterns of CSF flow on Time-SLIP images before and after CSF drainage or ventriculoperitoneal shunting aid in clarifying disease pathogenesis and confirm effects of CSF drainage.

Successful management of portal vein thrombosis in a Yorkshire Terrier with protein-losing enteropathy

Background

Portal vein thrombosis (PVT) is a rare presentation in dogs with protein-losing enteropathy (PLE). Rivaroxaban, an oral, selective, direct factor Xa inhibitor, has not been reported to be administrated for canine PVT and the effect is unclear in dogs with PLE.

Case presentation

An 11-year-old Yorkshire Terrier presented with moderate ascites. The dog had severe hypoalbuminemia (1.2 g/dL), and a portal vein thrombus was confirmed on computed tomographic angiography (CTA). On endoscopic examination, it became apparent that the hypoalbuminemia was caused by PLE, which was consequent of lymphatic dilation and lymphoplasmacytic enteritis. Therefore, the dog was initially treated with oral administrations of spironolactone and clopidogrel, with dietary fat restriction. However, a follow-up CTA showed no changes in the ascites, thrombus, and portal vein to aorta (PV/Ao) ratio. Therefore, the dog was additionally prescribed rivaroxaban and low-dose prednisolone for the portal vein thrombus and hypoalbuminemia due to lymphoplasmacytic enteritis, respectively. Following the treatment, the PV/Ao ratio decreased because of a decrease in the thrombus and the ascites disappeared completely with an elevation of albumin concentration (1.9 g/dL).

Conclusions

This case report demonstrated that oral administration of rivaroxaban combined with low-dose glucocorticoid was effective management for PVT in a dog with PLE.

Diagnostic utility of computed tomographic angiography in dogs with portal vein thrombosis

Computed tomographic (CT) angiography, the gold standard for diagnosing portal vein thrombosis (PVT) in humans, is poorly documented in dogs. Therefore, we retrospectively reviewed dogs with PVT diagnosed by CT angiography. Medical records of 13 client-owned dogs diagnosed with PVT by CT angiography were reviewed. All dogs had chronic PVT, and the most frequent clinical sign was vomiting (5/13), with pancreatitis the most frequent concurrent disease (6/13). All dogs tested for plasma D-dimer concentration (12/12) revealed elevated levels. On CT angiography, a thrombus was detected as a non-contrast enhancement structure in the portal vessel of 13 dogs. There was no evidence of complete obstruction of the portal vein in any of the dogs. The median luminal filling of the portal vein was 60.4%. The thrombus extension was variable among dogs, with a median of 34.9 mm. CT angiography identified the thrombus in the main portal vein of 12/13 dogs and multiple thrombus formation other than the main portal vein in 9/13 dogs. CT angiography provided specific information such as detecting the presence, location, and number of PVT in dogs. Therefore, CT angiography might be useful for the diagnosis and follow-up evaluation of PVT in dogs.

Computed tomographic-derived measurements of shunt fraction and hepatic perfusion in dogs with a single extrahepatic portosystemic shunt in a clinical setting

OBJECTIVE

To evaluate the clinical feasibility and usefulness of measuring shunt fraction (SF) and hepatic perfusion with CT in dogs with a single extrahepatic portosystemic shunt (EPSS).

ANIMALS

36 client-owned dogs with EPSS.

PROCEDURES

Dogs with EPSS referred for treatment between February 2016 and May 2017 were eligible for the clinical trial. Shunt type, SF, and hepatic perfusion were determined in each dog with a 320-row multidetector CT scanner, and surgical treatment was performed by a single veterinary surgeon. Differences in results between dogs grouped according to age (< 3 years vs ≥ 3 years), shunt type, and subgroups (eg, clinical signs and surgical procedure) were analyzed, and correlations between the SF and hepatic perfusion variables were evaluated.

RESULTS

The median SF was higher in dogs < 3 years old (74.6%; n = 18) versus dogs ≥ 3 years old (35.1%; 18). Correlations were identified between SF and hepatic perfusion variables, and differences in results for SF and hepatic perfusion variables were detected between dogs grouped according to shunt type.

CONCLUSIONS AND CLINICAL RELEVANCE

Results indicated that CT-derived measurements of SF and hepatic perfusion variables in dogs with EPSS were feasible and could be useful (eg, estimating EPSS condition status and planning treatment) in clinical settings. In addition, our findings suggested that perfusion CT could be useful for distinguishing hemodynamic characteristics among different types of portosystemic shunts in dogs.

Repeated surgical treatment and long-term outcome of a cat with vertebral vascular hamartoma

A 30-month-old Maine Coon presented with progressive proprioceptive ataxia, paraparesis, thoracolumbar pain, and decreased appetite. An extradural mass was detected within the left side of the 13th thoracic vertebral canal that compressed the spinal cord on magnetic resonance (MR) and was considered to be mineralized on computed tomography (CT) images. The resected mass was diagnosed as a vertebral vascular hamartoma. Clinical signs improved, but recurrence was diagnosed by MR and CT imaging at 7 months after surgery. Repeated excisional surgery yielded the same diagnosis and the clinical signs abated. Fifteen months after the second surgery, there was apparent vertebral deformation, but there was no further change on CT images by 29 months.

Use of three-dimensional time-of-flight magnetic resonance angiography at 1.5 Tesla to evaluate the intracranial arteries of 39 dogs with idiopathic epilepsy

OBJECTIVE

To assess visualization of the intracranial arteries and internal carotid artery (ICA) on 3-D time-of-flight (TOF) magnetic resonance angiography (MRA) images obtained at 1.5 T and to investigate factors that affect the image quality of those arteries in dogs.

ANIMALS

39 dogs with idiopathic epilepsy.

PROCEDURES

Each dog underwent 3-D TOF MRA, and 5 pairs of intracranial arteries, the basilar artery, and both ICAs were evaluated. Each artery was assigned an image-quality score on a scale of 0 to 3, where 0 = poor and 3 = excellent. Multivariable regression analysis was used to assess whether age, body weight (BW), serum total cholesterol concentration, intracranial volume (ICV), and mean arterial pressure were significantly associated with the image quality of each vessel.

RESULTS

In all dogs, the image-quality score was 2 or 3 for the proximal middle cerebral arteries, basilar artery, and caudal aspect of the caudal communicating arteries. In some dogs, the rostral cerebellar arteries, rostral aspect of the caudal communicating arteries, and middle and rostral aspects of the ICA were poorly visualized. For various arteries, image quality was negatively associated with age and positively associated with BW and ICV.

CONCLUSIONS AND CLINICAL RELEVANCE

Results indicated that 3-D TOF MRA images obtained at 1.5 T did not consistently and clearly delineate the ICA and narrow or peripheral intracranial arteries of dogs; therefore, careful attention is required when such images are assessed. Patient age, BW, and ICV can also affect the image quality of some intracranial arteries on 3-D TOF MRA images. (Am J Vet Res 2019;80:480-489).

Two-Year Follow-Up Magnetic Resonance Imaging and Spectroscopy Findings and Cerebrospinal Fluid Analysis of a Dog with Sandhoff's Disease

A 13‐month‐old female Toy Poodle was presented for progressive ataxia and intention tremors of head movement. The diagnosis of Sandhoff's disease (GM2 gangliosidosis) was confirmed by deficient β‐N‐acetylhexosaminidase A and B activity in circulating leukocytes and identification of the homozygous mutation (HEXB: c.283delG). White matter in the cerebrum and cerebellum was hyperintense on T2‐weighted and fluid‐attenuated inversion recovery magnetic resonance images. Over the next 2 years, the white matter lesions expanded, and bilateral lesions appeared in the cerebellum and thalamus, associated with clinical deterioration. Magnetic resonance spectroscopy showed progressive decrease in brain N‐acetylaspartate, and glycine‐myo‐inositol and lactate‐alanine were increased in the terminal clinical stage. The concentrations of myelin basic protein and neuron specific enolase in cerebrospinal fluid were persistently increased. Imaging and spectroscopic appearance correlated with histopathological findings of severe myelin loss in cerebral and cerebellar white matter and destruction of the majority of cerebral and cerebellar neurons.

Triple-phase helical computed tomography in dogs with solid splenic masses

We investigated the utility of triple-phase helical computed tomography (CT) in differentiating between benign and malignant splenic masses in dogs. Forty-two dogs with primary splenic masses underwent triple-phase helical CT scanning (before administration of contrast, and in the arterial phase, portal venous phase, and delayed phase) prior to splenectomy. Tissue specimens were sent for pathological diagnosis; these included hematomas (n=14), nodular hyperplasias (n=12), hemangiosarcomas (n=11), and undifferentiated sarcomas (n=5). The CT findings were compared with the histological findings. Nodular hyperplasia significantly displayed a homogeneous normal enhancement pattern in all phases. Hemangiosarcoma displayed 2 significant contrast-enhancement patterns, including a homogeneous pattern of poor enhancement in all phases, and a heterogeneous remarkable enhancement pattern in the arterial and portal venous phases. Hematoma and undifferentiated sarcoma displayed a heterogeneous normal enhancement pattern in all phases. The contrast-enhanced volumetric ratios of hematoma tended to be greater than those of undifferentiated sarcoma. Our study demonstrated that the characteristic findings on triple-phase helical CT could be useful for the preoperative differentiation of hematoma, nodular hyperplasia, hemangiosarcoma, and undifferentiated sarcoma in dogs. Triple-phase helical CT may be a useful diagnostic tool in dogs with splenic masses.

Comparison of conventional magnetic resonance imaging and nonenhanced three dimensional time-of-flight magnetic resonance angiography findings between dogs with meningioma and dogs with intracranial histiocytic sarcoma: 19 cases (2010-2014)

OBJECTIVE To compare conventional MRI and nonenhanced 3-D time-of-flight (TOF) magnetic resonance angiography (MRA) findings between dogs with meningioma and dogs with intracranial histiocytic sarcoma (IHS). DESIGN Retrospective case series. ANIMALS 14 dogs with meningioma and 5 dogs with IHS. PROCEDURES Medical records of dogs with meningioma or IHS that were examined at a tertiary veterinary hospital from 2010 through 2014 and underwent 3-D TOF MRA in conjunction with conventional MRI were reviewed. Findings for conventional MRI and 3-D TOF MRA were compared between the 2 groups of dogs to evaluate whether there were any characteristics that could be used to differentiate meningioma from IHS. RESULTS Tumor type was significantly associated with signal intensity on conventional T2-weighted and fluid-attenuated inversion recovery MRI images; most meningiomas were hyperintense, and most IHSs were isointense or hypointense on those images. Tumor type was not associated with signal uniformity, tumor location, tumor origin, or the presence of edema, midline shift, or brain herniation. On MRA, blood vessels adjacent to the tumor were identified and characterized for 9 of 14 dogs with meningioma and all 5 dogs with IHS. Vessels adjacent to meningiomas were displaced in 8 of 9 dogs, whereas vessels adjacent to IHSs were not displaced. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated nonenhanced 3-D TOF MRA findings provided additional information that can be assessed in conjunction with conventional MRI findings to help differentiate meningiomas from IHSs in dogs.

Preoperative Differential Diagnosis of Canine Adrenal Tumors Using Triple-Phase Helical Computed Tomography

OBJECTIVE

To characterize the computed tomography (CT) findings for canine adrenal tumors, including cortical adenoma, cortical adenocarcinoma, and pheochromocytoma, and to evaluate the feasibility and usefulness of preoperative triple-phase helical CT for differentiation of tumor types and surgical planning.

STUDY DESIGN

Retrospective study.

ANIMALS

Dogs with adrenal tumors (n=36).

METHODS

All dogs underwent triple-phase helical CT, followed by adrenalectomy and histopathological diagnosis of the resected mass. Precontrast images, arterial, venous, and delayed phase images were obtained. In all cases, morphological characteristics and CT values and calculations, including the percentage enhancement washout ratio, relative percentage washout, enhancement washin, and enhancement washout, were analyzed and compared among the tumor types.

RESULTS

Of the 36 dogs with adrenal masses, cortical adenocarcinoma was most commonly diagnosed (16 dogs), followed by pheochromocytoma (13 dogs), and cortical adenoma (7 dogs). The precontrast minimum CT value and enhancement washout between venous and delayed phases in the cortical adenoma were significantly higher than those in the cortical adenocarcinoma. The maximum CT values of the precontrast image and arterial and venous phases, the enhancement washin and washouts, percentage enhancement washout ratio, and relative percentage washout in the pheochromocytomas were significantly higher than those in cortical adenocarcinoma.

CONCLUSION

The differential diagnosis of canine adrenal tumors was feasible based on triple-phase CT findings, including morphological features, CT values, and intratumoral contrast attenuation. Preoperative diagnosis using triple-phase helical CT may be useful for surgical planning in dogs with adrenal tumors.

Effects of diet-induced obesity and voluntary exercise in a tauopathy mouse model: implications of persistent hyperleptinemia and enhanced astrocytic leptin receptor expression

The number of patients with Alzheimer's disease (AD) is increasing worldwide, and available drugs have shown limited efficacy. Hence, preventive interventions and treatments for presymptomatic AD are currently considered very important. Obesity rates have also been increasing dramatically and it is an independent risk factor of AD. Therefore, for the prevention of AD, it is important to elucidate the pathomechanism between obesity and AD. We generated high calorie diet (HCD)-induced obese tauopathy model mice (PS19), which showed hyperleptinemia but limited insulin resistance. HCD enhanced tau pathology and glial activation. Conversely, voluntary exercise with a running wheel normalized the serum leptin concentration without reducing body weight, and restored the pathological changes induced by HCD. Thus, we speculated that persistent hyperleptinemia played an important role in accelerating pathological changes in PS19 mice. Leptin primarily regulates food intake and body weight via leptin receptor b (LepRb). Interestingly, the nuclear staining for p-STAT3, which was activated by LepRb, was decreased in hippocampal neurons in HCD PS19 mice, indicating leptin resistance. Meanwhile, astroglial activation and the astrocytic expression of a short LepR isoform, LepRa, were enhanced in the hippocampus of HCD PS19 mice. Real-time PCR analysis demonstrated that leptin increased mRNA levels for pro-inflammatory cytokines including IL-1β and TNF-α in primary cultured astrocytes from wild type and LepRb-deficient mice. These observations suggest that persistent hyperleptinemia caused by obesity induces astrocytic activation, astrocytic leptin hypersensitivity with enhanced LepRa expression, and enhanced inflammation, consequently accelerating tau pathology in PS19 mice.

Neurite Outgrowth-Stimulating Peptide Derived from Bovine κ-Casein

We found a novel peptide that stimulates neurite outgrowth in Neuro-2a mouse neuroblastoma cells, from the pepsin-pancreatin digest of bovine kappa-casein. The amino acid sequence of this peptide is Phe-Leu-Pro-Tyr-Pro-Tyr (FLPYPY), corresponding to peptidic sequence 76-81 of bovine kappa-casein. The neurite outgrowth-stimulating activity of FLPYPY was seen over 10(-9) M. On the other hand, FLPYP and FLPYPYY, which corresponded to sequences 76-80 and 76-82 of bovine kappa-casein respectively, were ineffective.

Anti-inflammatory action of donepezil ameliorates tau pathology, synaptic loss, and neurodegeneration in a tauopathy mouse model

Acetylcholinesterase inhibitors (AChEIs) are widely used to compensate for acetylcholine (ACh) depletion in the Alzheimer's disease (AD) brain. Some clinical and experimental studies, however, have suggested that AChEIs also provide neuroprotection. To assess the effect of AChEIs on neurodegeneration, donepezil (DZ), an AChEI, was administered to FTDP-17 model mice with a P301S tau mutation (line PS19). Eight months of DZ treatment resulted in amelioration of neuroinflammation, tau pathology, synaptic loss, and neuronal loss, as well as decreased tau insolubility and phosphorylation. Tau kinase activity analysis demonstrated significantly suppressed c-Jun N-terminal kinase (JNK) in the brains of DZ-treated PS19 mice. Recently, ACh has been shown to suppress inflammation, which plays a role in neurodegeneration. To confirm the anti-inflammatory effect of DZ, PS19 mice were injected with lipopolysaccharide, in combination with or without DZ, for one month. Results demonstrated that DZ suppressed IL-1β and COX-2 expression in the brain, as well as the spleen, suggesting that DZ directly prevents systemic inflammation. These data indicated that ACh did not act just as a cognition-linking neurotransmitter, but might suppress pathological mechanisms of neurodegeneration via anti-inflammatory action.

Effects of clenbuterol, a β₂-adrenergic agonist, on sizes of masseter, temporalis, digastric, and tongue muscles

We compared the hypertrophic effects of clenbuterol, a β₂-adrenergic agonist, on the masseter, digastric, and temporalis with those on the tongue, tibialis anterior, soleus, diaphragm, and heart. The weights of masseter, digastric and temporalis in the clenbuterol group were 36 ~ 56% greater than those in the control group, whereas those of the tibialis anterior, diaphragm, and heart weights in the clenbuterol group were 9 ~ 33% greater than those in the control group. No significant difference in the weights of the soleus and tongue was found between the control and clenbuterol groups. Taken together with our present and previously reported results, it is suggested that the hypertrophic effects of clenbuterol on the masseter, digastric, and temporalis are greater than those on the limb, trunk, and heart.

A case of obstructive sleep apnoea with anterior cervical osteophytes

Osteophytes of the cervical spine are usually seen in elderly adults. When prominent, they have been blamed for dysphagia, cough, dysphonia and dyspnoea. This paper reports on an obstructive sleep apnoea (OSA) patient with cervical spinal osteophytes, one cause of airway obstruction. A 75-year-old male complained of pronounced snoring. The diagnosis was mild OSA, apnoea hypopnoea index was 9.4. Patient reported no restrictions in neck movements, experiences of neck pain or neck trauma. Previously, patient underwent a tonsillectomy due to discomfort in the pharyngeal region. A lateral cephalometric image was taken to observe airway before oral appliance therapy. The image revealed the presence of large osteophytes or sclerotic enthesopathy, lying on anterior surfaces from the fourth to seventh cervical vertebrae. A computed tomography (CT) image revealed the relationship of airway position to the spine. In the reconstructed three-dimensional (3D) image, the airway appeared displaced to the right of the craniomandiblar bone, with the hyoid bone similarly displaced in a manner to that of the airway. The spine also appeared displaced to the left side ofcraniomandiblar bone. Additionally, the 3D image revealed calcification of the stylohyoideum ligament and ligamentum nuchae. This present case highlights the necessity of CT examination for OSA patients. There were several ligament calcifications in the head and neck region. Cervical spine osteophytes, as a component of Forestier's or cervical spine disease, have been associated with dysphagia and dysphonia. It was reported that bilateral vocal cord paralysis was caused by osteophytes compressing the post-cricoid area of larynx.

Human Mena associates with Rac1 small GTPase in glioblastoma cell lines

Mammarian enabled (Mena), a member of the Enabled (Ena)/Vasodilator-stimulated phosphoprotein (VASP) family of proteins, has been implicated in cell motility through regulation of the actin cytoskeleton assembly, including lamellipodial protrusion. Rac1, a member of the Rho family GTPases, also plays a pivotal role in the formation of lamellipodia. Here we report that human Mena (hMena) colocalizes with Rac1 in lamellipodia, and using an unmixing assisted acceptor depletion fluorescence resonance energy transfer (u-adFRET) analysis that hMena associates with Rac1 in vivo in the glioblastoma cell line U251MG. Depletion of hMena by siRNA causes cells to be highly spread with the formation of lamellipodia. This cellular phenotype is canceled by introduction of a dominant negative form of Rac1. A Rac activity assay and FRET analysis showed that hMena knock-down cells increased the activation of Rac1 at the lamellipodia. These results suggest that hMena possesses properties which help to regulate the formation of lamellipodia through the modulation of the activity of Rac1.

Validity and reliability of patient satisfaction questionnaires in a dental school in Japan

PURPOSE

The purpose of this study was to construct questionnaires for the dental school setting from freely given patient answers with the aid of text mining, and to confirm the structure, reliability and validity of the questionnaires.

METHODS

Using these questionnaires, we carried out a survey of the satisfaction of patients treated at the Dental Hospital of the Tsurumi University School of Dental Medicine. A total of 3394 patients participated in the study. To confirm the reliability of inter-item correlations and construct validity, factor analysis was carried out, and items belonging to each factor and Cronbach's alpha coefficients were calculated.

RESULTS

Four factors were extracted and 64.0% of the variance was explained by these four factors. All correlation coefficients were >0.85. These four factors were: 'Treatment', 'Communication', 'Facilities' and 'Appearances'. From structural equation modelling, we determined that overall satisfaction was >0.75 and was statistically significant.

CONCLUSION

The questionnaires used in this study are useful for measuring patient satisfaction in the dental school hospital setting.

Impaired circadian rhythm of gastric myoelectrical activity in patients with multiple system atrophy

In order to evaluate gastric motility and its circadian rhythm in patients with multiple system atrophy (MSA) and healthy control subjects, we measured gastric myoelectrical activity (GMA) for 24 hours using a cutaneous electrogastrogram (EGG) recorder in 14 MSA patients and 9 age-matched controls. We analyzed six 10-minute segments of EGG before and after each meal and two 20-minute EGG segments during sleep; three parameters were used for the analysis: dominant frequency (DF), instability coefficient of dominant frequency (ICDF), and dominant power (DP). DF increased during daytime and decreased during sleep in the control, while this circadian variation was blunted in the patients with MSA. The average DF of the eight segments in the MSA patients did not differ from that of the control. Both MSA patients and control subjects did not show the circadian variation of ICDF and DP. The average ICDF of the eight segments in the patients with MSA was significantly decreased when compared with that of the control (p < 0.01). No differences were observed in DP between the two groups. This study indicates that the healthy subjects appear to have a circadian rhythm of DF, and the patients with MSA appear to have impaired circadian rhythm of DF and decreased ICDF possibly due to the degeneration of the central autonomic neurons.

Organotropic chemopreventive effects of n-3 unsaturated fatty acids in a rat multi-organ carcinogenesis model

Organotropic chemopreventive effects of n-3 unsaturated fatty acids were studied using a multi-organ carcinogenesis model in male rats. Rats were treated with diethylnitrosamine (DEN), N-methyl-N-nitrosourea (MNU), N-butyl-N-4-hydroxybutylnitrosamine (BBN), 1,2-dimethylhydrazine (DMH) and dihydroxy-di-n-propylnitrosamine (DHPN) during the first 7 weeks, and then given unsaturated fatty acid (UFAs), docosahexaenoic acid (n-3, C(22:6)) (DHA), eicosapentaenoic acid (n-3, C(20:5)) (EPA), linoleic acid (n-6, C(18:2)) (LA) or oleic acid (n-9, C(18:1)) (OA) at a dose of 1.0 ml/rat, 3 times a week by gavage for the consecutive 30 weeks. All rats were fed a low LA basal diet throughout the experiment and a calorie-restricted basal diet during the period of UFAs feeding administration. DHA significantly reduced tumor size and numbers in the large intestine as compared to OA treatment. Furthermore, DHA showed a tendency to inhibit carcinogenesis in the small intestine and lung. EPA also showed a tendency to inhibit intestinal carcinogenesis. On the other hand, LA showed a tendency to inhibit lung carcinogenesis, but to promote large intestinal carcinogenesis. However these UFAs did not influence preneoplastic and neoplastic lesion development in the liver, kidney, and urinary bladder. Levels of the administered fatty acids were clearly increased in the serum and organs. In contrast, arachidonic acid (AA) levels in the large and small intestines and liver were markedly decreased by treatment with DHA and EPA. Decreased levels of AA in the large intestine correlated well with tumor incidence, although the number of glutathione S-transferase-positive (GST-P(+)) foci showed an inverse correlation with AA levels. The data thus provide evidence that an organotropism exists with regard to the influence of UFAs on carcinogenesis, which correlates with reduction of tissue AA levels in the target organs.

A new analytical method for the detection of anti-tumor promoters using flow cytometry

Flow cytometry analysis was applied to the measurement of Epstein-Barr virus (EBV) induction which is used as a short term assay for anti-tumor promoters. The data obtained by measurement with flow cytometry were parallel with those of the fluorescence microscopic method. Flow cytometry is rapid, quantitative and should be applicable for the EBV activating test.

Phorbol ester-induced production of prostaglandin E2 from phosphatidylcholine through the activation of phospholipase D in UMR-106 cells

To determine the effects of 12-O-tetradecanoylphorbol-13-acetate (TPA) on phospholipase D (PLD) activity in osteoblast-like UMR-106 cells, we used cells prelabeled with [3H] myristic acid or [3H] arachidonic acid, which were preferentially incorporated to phosphatidylcholine. The treatment of [3H] myristate-labeled cells with TPA in the presence of 1% ethanol caused a dose-dependent formation of [3H] phosphatidylethanol (PEt), a product specific to PLD, suggesting an activation of this enzyme. Pretreatment of the cells with protein kinase C (PKC) inhibitors (GF109203X, staurosporine or H-7) abolished the TPA-dependent formation of PEt. The PEt formation in response to TPA treatment was not observed after the pretreatment of the cells with TPA to downregulate PKC. These results suggest the involvement of PKC in the TPA-induced activation of PLD. With [3H] arachidonate-labeled cells, TPA treatment in the absence of ethanol resulted in the liberation of [3H] arachidonic acid, which was gradually converted to prostaglandin E2 (PGE2), but the accumulations of [3H] phosphatidic acid (PA) and [3H] diacylglycerol (DAG) were very small and temporary. In contrast, PA was linearly accumulated following TPA treatment, when the cells were pretreated with an inhibitor of phosphatidate phosphohydrolase (PAP), propranolol, with no accumulation of either DAG or arachidonic acid. The TPA treatment of the cells pretreated with a DAG lipase inhibitor, RHC-80267, caused the generation of DAG after a lag period of approximately 5 min, with a very small and temporary accumulation of PA. The TPA treatment of cells pretreated with a cyclooxygenase (COX) inhibitor, indomethacin, blocked the PGE2 production. The TPA-induced PGE2 production was not affected by the pretreatment of cells with a phospholipase A2 inhibitor, p-bromophenacylbromide, or with a phospholipase C inhibitor, D-609. TPA also stimulated PGE2 production in osteoblastic cells that were enzymatically isolated from adult rat calvaria, and the experiments with lipid metabolizing enzyme inhibitors gave the same profile of inhibition of TPA-induced PGE2 production as was observed in UMR-106 cells. These results suggest that PA formed as a consequence of the activation of PLD by TPA is rapidly converted to arachidonic acid via a PAP/DAG lipase pathway, followed by a gradual conversion of arachidonic acid to PGE2 by COX in both UMR-106 cells and isolated adult osteoblastic cells, and that neither phospholipase A2 nor phospholipase C is involved in the TPA-induced PGE2 production. To the best of our knowledge, this is the first report that shows that the activation of PKC in osteoblastic cells leads to the production of PGE2 via a PLD/PAP/DAG lipase/COX pathway.

Modulation of eosinophil chemotactic activities to leukotriene B4 by n-3 polyunsaturated fatty acids

Eosinophil accumulation induced by leukotriene B4 appears to be involved in the pathogenesis of allergic diseases. We evaluated the effects of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) on chemotaxis to leukotriene B4 in guinea pig peritoneal eosinophils. Guinea pigs that were sensitized to polymyxin B were administered an intraperitoneal injection of polymyxin B (1 mg/animal) alone or combined with DHA (15 or 50 mg/kg, i.p.), EPA (50 or 100 mg/kg, i.p.), or with linoleic acid (LA) (100 mg/kg, i.p.). Forty hours later, eosinophils were obtained from the intraperitoneal lavage fluid and purified. The chemotactic and chemokinetic responses of eosinophils to leukotriene B4 were measured using a 96-well microchemotaxis chamber. DHA significantly decreased the chemotactic and chemokinetic responses of eosinophils in a dose-dependent fashion. A higher dose of EPA also significantly inhibited both of those responses, whereas LA had no effect. Our results suggested a possible mechanism for the improvement of allergic diseases by dietary supplementation with n-3 PUFA.

Inhibitory effects of oleic and docosahexaenoic acids on lung metastasis by colon-carcinoma-26 cells are associated with reduced matrix metalloproteinase-2 and -9 activities

In order to determine the effects of single unsaturated fatty acids (UFAs) or combinations on establishment of lung metastatic colonies, UFAs were administered orally to CDF1 mice bearing s.c. implants of the highly metastatic colon carcinoma 26. Oleic acid (OA), docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) demonstrated significant inhibition. In the case of DHA, this inhibitory potential was markedly reduced by co-administration of linoleic acid (LA) or EPA. Furthermore, while tumor cells treated with DHA showed a very low potential for lung colony formation when injected i.v., this again being partially reversed by co-administration of EPA. UFAs were found to be well absorbed into tumor tissues after oral administration, causing marked changes in relative levels, the arachidonic acid (AA) content, in particular, being markedly decreased by treatment with DHA or EPA, but not with DHA plus EPA or with DHA plus LA. Investigation of the gelatinolytic activity of the 57-kDa and 92-kDa isoforms of type-IV collagenase (MMP-2 and MMP-9, respectively) showed a clear reduction in the former by treatment with OA, while DHA, but not DHA plus LA or EPA, caused a decrease in the 92-kDa isoform, which was well correlated with AA content in tumor tissues (r = 0.900, p < 0.001). These results suggest that inhibition of metastasis due to treatment with OA and DHA might be due to depressed type-IV collagenase activity.

Lipid and fatty acid compositions of a novel docosahexaenoic acid-producing marine bacterium

An unidentified bacterial strain, SCRC-21406, isolated from the intestine of a marine fish, Glossanodon semifasciatus, produced docosahexaenoic acid at 23% (mol/mol) [= 28% (w/w)] of total fatty acids in a medium containing 0.5% (wt/vol) peptone and 0.1% (wt/vol) yeast extract at 12 degrees C under atmospheric pressure. The cell yield was 0.43 g/L. The major lipids of the strain were phosphatidylethanolamine and phophatidylglycerol. Docosahexaenoic acid was localized at the sn-2 positions of both phospholipids. The amounts of polyunsaturated fatty acids other than docosahexaenoic acid were extremely small [< 3% (mol/mol)]. Monounsaturated fatty acids of the cis-7, cis-9 and cis-11 types were detected.

Relationship between progression of gastric mucosal atrophy and Helicobacter pylori infection: retrospective long-term endoscopic follow-up study

A retrospective long-term endoscopic follow-up study was designed to examine atrophic changes in the gastric mucosa over time in Helicobacter pylori-positive patients. Over a period of 8-17 years (mean, 13.4 years) 22 subjects (5 men, 17 women, mean age, 55 years) without localized gastroduodenal lesions underwent serial endoscopic examinations and serological and microbiological assessments of H. pylori infection. The extent of atrophic mucosa in the gastric body was expressed using the Kimura-Takemoto classification of atrophic pattern. Atrophic patterns were unchanged over time in 7 H. pylori-seronegative and culture-negative subjects with normal stomach, and in 1 seropositive and culture-negative subject with severe atrophy. Seven of 10 H. pylori culture-positive subjects not including three with the O-3 pattern, i.e., open type atrophic pattern, exhibited a cephalad shift of atrophic pattern. The cumulative progression rates of atrophy in the culture-positive subjects excluding O-3 subjects, were 10% after 2 years, 20% after 4 years, 50% after 6 years, and 70% after 8 years. The increases in the extent of the atrophic area were discontinuous, in terms of age, in the H. pylori-positive individuals and occasionally advanced rapidly within periods of several years with no relation to age.

Inhibitory effects of docosahexaenoic acid on colon carcinoma 26 metastasis to the lung

Unsaturated fatty acids, including n-3 polyunsaturated fatty acids (PUFAs) such as docosahexaenoic acid (C22:6, DHA) and eicosapentaenoic acid (C20:5, EPA), and a series of n-6 PUFAs were investigated for their anti-tumour and antimetastatic effects in a subcutaneous (s.c.) implanted highly metastatic colon carcinoma 26 (Co 26Lu) model. EPA and DHA exerted significant inhibitory effects on tumour growth at the implantation site and significantly decreased the numbers of lung metastatic nodules. Oleic acid also significantly inhibited lung metastatic nodules. Treatment with arachidonic acid showed a tendency for reduction in colonization. However, treatment with high doses of fatty acids, especially linoleic acid, increased the numbers of lung metastatic nodules. DHA and EPA only inhibited lung colonizations when administered together with the tumour cells, suggesting that their incorporation is necessary for an influence to be exerted. Chromatography confirmed that contents of fatty acids in both tumour tissues and plasma were indeed affected by the treatments. Tumour cells pretreated with fatty acids in vivo, in particular DHA, also showed a low potential for lung colony formation when transferred to new hosts. Thus, DHA treatment exerted marked antimetastatic activity associated with pronounced change in the fatty acid component of tumour cells. The results indicate that uptake of DHA into tumour cells results in altered tumour cell membrane characteristics and a decreased ability to metastasize.

Cytoplasmic calcium level and membrane fluidity of platelets contacting poly(acrylamide-co-methacrylic acid) particles with different surface properties

Changes in cytoplasmic free calcium levels and membrane fluidity of platelets in contact with poly(acrylamide-co-methacrylic acid) (PAAmMAc) particles were examined to analyze the mechanistic aspect of regulating platelet function. Our previous studies demonstrated interesting features of PAAmMAc particles during interaction with platelets: (1) PAAmMAc particles induce no calcium increase but enhance membrane fluidity of platelets: (2) thrombin induces no calcium increase in platelets when the platelets were mixed previously with PAAmMAc particles; and (3) PAAmMAc particles induce a calcium increase in platelets when they were treated previously with sodium azide (NaN3). These results suggest the possibility that PAAmMAc surfaces may regulate the calcium level by influencing platelet metabolism. In this study, non-cross-linked PAAmMAc solution with the same chemical composition as the particles showed a suppressive effect on thrombin-induced calcium increase, but, no influence on membrane fluidity. This result indicates that aggregated macromolecular surface assemblies of PAAmMAc may dominate the increase in membrane fluidity of platelets although the calcium change is induced by discrete molecular level interaction between the PAAmMAc and platelet membranes. It was also revealed that the suppression of thrombin-induced calcium increase and the membrane fluidity increase in platelets by PAAmMAc particles were reduced by albumin-treatment of the particles. This result suggests that such phenomena may be due to a decrease in any physicochemical interaction of PAAmMAc surfaces with albumin, rather than platelet metabolic change. PAAmMAc particle surfaces with higher carboxyl groups exhibited a more suppressive effect on thrombin-induced calcium increase, whereas those with lower carboxyl groups derived a higher calcium increase when the platelets were treated previously with NaN3. These results suggest the importance of electrostatic and any other physicochemical interaction of PAAmMAc chains on regulating cytoplasmic calcium levels.

Prevention of 1,2-dimethylhydrazine-induced colon tumorigenesis by HMG-CoA reductase inhibitors, pravastatin and simvastatin, in ICR mice

3-Hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, pravastatin (Pr) and simvastatin (Si), suppressed 1,2-dimethylhydrazine (DMH)-induced colon cancer development in female ICR mice. All mice received an i.p. injection of 10 mg DMH/kg body wt once weekly for 15 weeks. Pr was administered at 0.01, 0.005 and 0.001% levels in drinking water, and Si at 0.01 and 0.002% levels in the diet. All animals had access to Pr or Si throughout the experiments which were terminated at weeks 25 or 30. Histologically most of the tumors were well-differentiated adenocarcinomas. The incidence of colon tumors examined at weeks 25 or 30 was reduced by 67% in the 0.01% Pr group, by 30% in the 0.005% Pr and 0.01% Si groups, and by 24% in the 0.001% Pr and 0.002% Si groups, compared with their respective controls. However, the differences did not reach statistical significance. The number of tumors per mouse was significantly reduced in all groups administered Pr and Si except the 0.001% Pr group as compared to their respective controls. The results from those three independent experiments seem to suggest that HMG-CoA reductase inhibitors may prevent colon tumorigenesis in laboratory animal model.

Colon cancer prevention with a small amount of dietary perilla oil high in alpha-linolenic acid in an animal model

BACKGROUND

Epidemiologic and experimental studies suggest that dietary fish oil and vegetable oil high in omega-3 polyunsaturated fatty acids (PUFAs) suppress the risk of colon cancer. The optimal amount to prevent colon carcinogenesis with perilla oil high in omega-3 PUFA alpha-linolenic acid in a 12% medium-fat diet was investigated in female F344 rats. For comparison, safflower oil high in omega-6 PUFA linoleic acid was used.

METHODS

Thirty or 25 rats at 7 weeks of age in each group received an intrarectal dose of 2 mg N-methyl-N-nitrosourea 3 times weekly in weeks 1 and 2 and were fed the diets with various levels of perilla oil and safflower oil throughout the experiment.

RESULTS

The incidence of colon cancer at the termination of the experiment at week 35 was 40%, 48% and 32% in the rats fed the diets with 3% perilla oil plus 9% safflower oil, 6% perilla oil plus 6% safflower oil, and 12% perilla oil plus 0% safflower oil, respectively, whereas it was 67% in the rats fed the control diet with 0% perilla oil plus 12% safflower oil. The amount of diet consumed and the body weight gain were identical in all of the dietary groups. The ratios of omega-3 PUFA to omega-6 PUFA in the serum and the colonic mucosa at week 35 were increased in parallel to the increased intake of perilla oil.

CONCLUSIONS

The results suggest that a relatively small fraction of perilla oil, 25% of total dietary fat, may provide an appreciable beneficial effect in lowering the risk of colon cancer.

Intracellular calcium response to directly applied mechanical shearing force in cultured vascular endothelial cells

We studied the responses of cultured endothelial cells to mechanical shearing force directly applied to those cells in vitro to determine changes in the concentration of intracellular calcium ion (Ca++), one of the factors that transfers information within the cell. Cultured bovine fetal aortic endothelial cells containing the Ca++ fluorescence indicator, Fura-2, were rubbed with a latex balloon in a specially designed system, and changes in the fluorescence of Fura-2 caused by this shear stimulation were determined by photometric fluorescence microscopy. Immediately after shear stimulation, the concentration of Ca++ in the cells was increased and reached a peak (511 +/- 165 nM, n = 12) within 15 seconds after stimulation. After the peak, the concentration was gradually restored to the resting level (55 +/- 17 nM, n = 12). The magnitude of the Ca++ response was dependent on the intensity of the shear force applied. Analysis of fluorescence images of Fura-2 revealed that the cells showed this Ca++ reaction without being injured or desquamated, although there were slight differences in the degree and duration of reaction among cells. This reaction appeared even when the cells were placed in the air with no contact with the fluid. This result suggests that neither the fluid flow associated with the balloon movement nor chemical substances in the fluid are involved in the reaction, but that pure physical force alone is responsible for the Ca++ reaction. Further, it suggests that endothelial cells have the ability to perceive such physical stimulation as shear force and to transfer this information to the interior of the cell via changes in the intracellular Ca++ concentration.