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  • Author or Editor: Kazushi Asano x
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Abstract

OBJECTIVE

To evaluate the clinical impact on quantitative analysis of contrast-enhanced ultrasound (CEUS) on single extrahepatic portosystemic shunt (PSS) in dogs.

ANIMALS

21 client-owned dogs with single extrahepatic PSS and 5 healthy Beagles.

PROCEDURES

In all dogs, CEUS was performed to calculate the rising time (RT), rising rate (RR), and portal vein-to-hepatic parenchyma transit time (ΔHP-PV) from the time-intensity curve obtained in the hepatic parenchyma and portal vein. All dogs in the PSS group underwent preoperative CT angiography (CTA) and surgery. The CEUS variables in the PSS group were compared with those in the healthy dogs (control group) and were analyzed for shunt types and grades of intrahepatic portal venous branches based on CTA findings, intraoperative portal pressure, and surgical procedures.

RESULTS

All 3 CEUS variables showed no significant differences between the PSS and control groups. The RT and ΔHP-PV in the left gastrophrenic shunt group were significantly longer than in the other shunt types. In the intrahepatic portal vascularity, the RT in grade 1 was significantly shorter than in grades 3 and 4, and the RR in grade 1 was significantly higher than in grade 4. The RT and ΔHP-PV were significantly correlated with portal pressure variables. The RT in dogs with partial ligation was significantly shorter than in dogs with complete ligation and percutaneous transvenous coil embolization.

CLINICAL RELEVANCE

Quantitative assessments of CEUS may be useful for estimating intrahepatic portal vascularity in dogs with single extrahepatic PSS.

Open access
in American Journal of Veterinary Research

Abstract

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.

Open access
in American Journal of Veterinary Research

Abstract

OBJECTIVE

To describe the clinical, diagnostic, and pathological features and postoperative prognosis of canine combined hepatocellular-cholangiocarcinoma (cHCC-CCA).

ANIMALS

14 privately owned dogs that underwent surgical treatment.

PROCEDURES

The medical records, including signalment, clinical signs, blood test, urine analysis, computed tomography (CT) findings, intraoperative findings, and pathological findings, were retrospectively reviewed in the dogs with cHCC-CCA.

RESULTS

Of 306 dogs that underwent surgical removal of hepatic masses, 14 dogs (4.6%) were pathologically confirmed to have cHCC-CCA. Median age and body weight were 11.3 years and 7.3 kg, respectively. There were no specific clinicopathological findings for cHCC-CCA. CT revealed a massive hepatic mass in all dogs and the inclusion of cyst-like lesions within the mass in 13 dogs. Intrahepatic metastases were found at time of surgery in 2 dogs (14.3%). Of the residual 12 dogs, 1 dog showed postoperative formation of intrahepatic nodules suggestive of metastases and another had intrahepatic and pulmonary nodules and a forelimb skin mass, suggesting postoperative metastases. The median survival time of the patients with cHCC-CCA was 700 days (range, 10 to 869 days) after surgery.

CLINICAL RELEVANCE

To the authors’ knowledge, this is the first study to describe the clinical, diagnostic, and pathological features and postoperative prognosis of canine cHCC-CCA. The clinical and diagnostic features of canine cHCC-CCA might be more similar to those of HCC rather than to those of CCA, but the preoperative diagnosis differentiating between HCC and cHCC-CCA was challenging. Our study suggests that the postoperative prognosis of canine patients with cHCC-CCA is similar to that of dogs with HCC.

Restricted access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To investigate the relationship between myocardial performance index (MPI; also known as the Tei index) and cardiac function in anesthetized cats administered dobutamine.

Animals—6 adult cats.

Procedures—Cats were anesthetized by administration of propofol (6 mg/kg, IV), and anesthesia was maintained by administration of isoflurane. Heart rate and systolic arterial pressure (SAP) were monitored. Stroke volume, cardiac output, and aortic blood flow (ABF) were measured by use of transesophageal ultrasonography. Left ventricular fractional shortening (LVFS), mitral E-wave velocity-to-A-wave velocity (E:A) ratio, and ejection time were measured by use of transthoracic echocardiography. Dobutamine was administrated via a cephalic vein at rates of 2.5, 5.0, and 10 μg/kg/min.

Results—Heart rate, SAP, cardiac output, and ABF increased with dobutamine administration, whereas stroke volume significantly decreased. The LVFS significantly increased, and the E:A ratio significantly decreased. Total isovolumic time and the MPI significantly decreased. The MPI was negatively correlated (r = −0.63) with LVFS. Conversely, the MPI was positively correlated with the E:A ratio (r = 0.47), stroke volume (r = 0.66), and total isovolumic time (r = 0.95). However, the MPI was not significantly correlated with heart rate, SAP, cardiac output, or ABF.

Conclusion and Clinical Relevance—Analysis suggested that the MPI provides a sensitive clinical assessment of cardiac response to medication in cats, which may be similar to the usefulness of the MPI reported in humans.

Full access
in American Journal of Veterinary Research

Abstract

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.

Restricted access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To investigate the in vitro differentiation of canine bone marrow stromal cells (BMSCs) into functional, mature neurons.

Sample—Bone marrow from 6 adult dogs.

Procedures—BMSCs were isolated from bone marrow and chemically induced to develop into neurons. The morphology of the BMSCs during neuronal induction was monitored, and immunocytochemical analyses for neuron markers were performed after the induction. Real-time PCR methods were used to evaluate the mRNA expression levels of markers for neural stem or progenitor cells, neurons, and ion channels, and western blotting was used to assess the expression of neuronal proteins before and after neuronal induction. The electrophysiological properties of the neuron-like cells induced from canine BMSCs were evaluated with fluorescent dye to monitor Ca2+ influx.

Results—Canine BMSCs developed a neuron-like morphology after neuronal induction. Immunocytochemical analysis revealed that these neuron-like cells were positive for neuron markers. After induction, the cells’ mRNA expression levels of almost all neuron and ion channel markers increased, and the protein expression levels of nestin and neurofilament-L increased significantly. However, the neuron-like cells derived from canine BMSCs did not have the Ca2+ influx characteristic of spiking neurons.

Conclusions and Clinical Relevance—Although canine BMSCs had neuron-like morphological and biochemical properties after induction, they did not develop the electrophysiological characteristics of neurons. Thus, these results have suggested that canine BMSCs could have the capacity to differentiate into a neuronal lineage, but the differentiation protocol used may have been insufficient to induce development into functional neurons.

Full access
in American Journal of Veterinary Research