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Biomedical subjects

H Imagawa

Publications and source records attributed to H Imagawa.

At least 37 records · Page 2Linked to original sources

Venereal infection of mares by equine arteritis virus and use of killed vaccine against the infection.

Venereal infection with equine arteritis virus (EAV) was established in each of seven mares by inoculation via the cervix with 20 ml of viral suspension (> or = 8 x 10(6) plaque-forming units; PFU), following treatment with prostaglandin and oestradiol. A dose of < or = 8 x 10(5) PFU produced infection in only five of eight mares. Serum neutralizing antibody developed in mares manifesting clinical signs of equine viral arteritis (EVA), and a weak antibody was detectable in one apparently healthy mare inoculated with 8 x 10(5) PFU. Virus isolation was demonstrated not only in the buffy coat but also in nasal swabs of infected mares. EAV was isolated frequently from the body tissues of the mares (killed 10 to 34 days post-inoculation) up to day 12, but rarely from the reproductive tissues later than day 12. The virus persisted longest in the splenic and deep inguinal lymph nodes, followed by the spleen and internal iliac lymph nodes. Four mares immunized with a killed vaccine for EVA showed no clinical disease after venereal challenge with EAV; the virus was recovered from the buffy coat of three mares and from the nasal swab of one of them, but not from the remaining animal.

Animals↗

Idiopathic iliac arterial aneurysms in a child.

Arterial aneurysms are very rare in children, especially those who have no history of cardiac or vascular malformation, connective tissue disorder, or trauma. We describe a 3-year-old boy who had multiple arterial aneurysms of the left external iliac artery with a maximal diameter of 67 mm, with no history of these disorders. The iliac artery distal to the aneurysm and superficial femoral artery were occluded causing the growth disturbances of his left leg. He underwent graft replacement of the left iliac artery using a ringed Gore-Tex graft (6 mm in diameter). Postoperative angiogram showed a patent graft without any residual aneurysm in the left iliac artery. His ankleibrachial index improve from 0.2 to 0.6 after surgery.

Anastomosis, Surgical↗

Saccular aneurysm in the right-sided aortic arch: a successfully corrected case.

We report the surgical treatment of a rare case of true aortic aneurysm in a right-sided aortic arch. A 49-year-old female patient with obstructive respiratory problems demonstrated a true aneurysm with a diameter of 58 mm located at the right-sided aortic arch between the right carotid artery and right subclavian artery. Surgery was successfully performed by replacing the arch including the aneurysm with a prosthetic graft. The positions of true aneurysms in the right-sided aortic arch can be divided into two subtypes: first, the transverse arch between the right carotid artery and right subclavian artery, and second, the base of the subclavian artery, the Kommerell's diverticulum. The region is informative for consideration of the surgical approach toward aneurysms of this entity.

Angiography, Digital Subtraction↗

[David's operation for aortic regurgitation associated with annulo-aortic ectasia].

A 54-year-old man with AR due to AAE underwent the replacement of ascending aorta by sparing an aortic valve (David operation). Under cardiopulmonary bypass, the aneurysmal aorta and the all three sinuses of valsalva were excised, leaving 5 mm of arterial wall attached to the aortic valve. The aortic valve was reimplanted inside a Dacron graft (28 mm Hemashield) which was calculated by aortic valve leaflet height as well as from the size of LVOT. The patient has survived the operative procedure and showed uneventful recovery. We believe this new procedure preserving the native aortic valve is useful for preventing from some complications associated with an artificial heart valve and improvement of QOL of patient.

Aorta↗

[Noninvasive hemodynamic assessment of internal thoracic artery grafts using duplex echocardiography from supraclavicular fossa--a comparison with Doppler catheter method].

We evaluated the usefulness of noninvasive hemodynamic assessment of internal thoracic artery grafts (ITAGs) using duplex Doppler echocardiography from the supraclavicular fossa (transcutaneous pulsed Doppler method: PD method). Eighteen ITAGs were examined by PD method in comparison with Doppler catheter method using Doppler flowire (DC method). The hemodynamic indices used were the diastolic/systolic peak velocity ratio (DSVR) and the diastolic fraction of time-velocity integral (DF) in the ITAGs. A significant linear correlation was seen both in DSVR and DF between these two methods (p < 0.01). The subjects were assigned to two groups according to angiographic findings Group A (Gr-A: 5 grafts) with string sign including significant graft stenosis and group B (Gr-B 13 grafts) with good patency. In both PD and DC methods, DSVR and DF were significantly lower in Gr-A than in Gr-B (p < 0.01). The blood flow pattern was thus systolic dominant in the grafts with string sign, while it was diastolic dominant in the grafts with good patency. In some grafts in Gr-B, however, both DSVR ad DF were as low as that in Gr-A. Responding to pacing, Gr-B further increased both DSVR and DF, but Gr-A did not. As a result, the difference between both groups was further distinguished. In summary, ITAG function can be assessed by the noninvasive PD method. Interventions such as exercise, dobutamine infusion may make it more accurate, particularly in evaluating borderline data.

Aged↗

Survey of equine rotaviruses shows conservation of one P genotype in background of two G genotypes.

DIG-labelled ssRNA probes were prepared from variable regions of VP4 and VP7 cognate genes, and used in hybridization assays for P and G genotyping of group A cell culture-adapted equine rotaviruses and fecal samples collected from foals with and without diarrhea. The probes confirmed known P and G serotypes of sixteen cell culture-adapted strains. From one-hundred and twenty-one rotavirus-positive samples, 83 reacted when tested for their P and G genotype specific probes. From these, 71 were found to contain G3 P12 genotypes, and 11 G14 P12 genotypes. No sample reacted with H1 or L338 P and G genotype probes. This suggests that the equine rotavirus population is conservative, containing predominantly one P genotype and two G genotypes. One isolate (26/94) whose dsRNA was visualized in an agarose gel did not react with any of the equine probes, and was found to belong to G8 and P1 genotypes. This is the fourth example of a single unique equine isolate (after H1, L338, and R-22). The remaining thirty-eight untypable field isolates had no detectable dsRNA after storage for 1 to 3 years.

Animals↗

Repair of postinfarction ventricular septal defect on a beating heart.

Two elderly patients with postinfarction ventricular septal defect underwent repair by endocardial patch with infarct exclusion on a beating heart under normothermic cardiopulmonary bypass with ultra-short-acting beta-blocker infusion. Their hemodynamic states soon recovered, and postoperative angiographic studies showed improvement of cardiac function and no residual shunt. Ultra-short-acting beta-blocker has the potential to facilitate safe repair of postinfarction ventricular septal defect on a beating heart, and this operative approach can be beneficial for myocardial protection.

Adrenergic beta-Antagonists↗

Late true aneurysm after bypass grafting for long aortic coarctation.

Two adolescent patients who underwent a repair of long aortic coarctation using bypass grafting with subsequent late true aneurysm formation are reported. To our knowledge, only 1 case of late true aneurysm formation after bypass grafting has been reported in the English-language literature.

Adolescent↗

[Coronary artery bypass grafting under bradycardia induced by ultra-short acting beta blocker].

From Dec. 1993 to May, 1994, coronary artery bypass grafting (CABG) was performed in 7 patients under bradycardia induced by an ultra-short acting beta blocker (esmolol). The ages ranged from 51 to 68 years. There was one patient with low ejection fraction (EF = 31%) and two patients with porcelain aorta. A tepid temperature was maintained during cardiopulmonary bypass (CPB). A high flow rate of 2.2-2.6 liter/min/m2 was applied to control perfusion pressure above 50 mmHg during CPB. After CPB was started, a high dose of esomolol was added (10-30 mg/kg intravenous bolus followed by a continuous infusion of 1-4 mg/kg/min). Severe bradycardia was achieved by the initial loading of esmolol. The mean heart rate was significantly (p < 0.01) decreased from 78 +/- 12 bpm to 49 +/- 7 bpm by the loading. Altogether, 25 anastomoses (11 ITA, 6 GEA, 8 SVG) were performed to LAD (10), Cx (7) and RCA (8), with an average of 3.6 +/- 0.9 anastomoses/patient. IABP was required for 2 patients postoperatively. There was no operative death, but one hospital death due to aspiration pneumonia 3 months later. Postoperative max CPK-MB was low (17.4 +/- 9.7 IU/L) in 6 patients. The postoperative angiography was performed in all patients with a patency rate of 88%. It was considered that esmolol facilitated CABG under beating heart and this technique is suitable for patients with severe atheromatous disease of the ascending aorta or patients with a low ejection fraction to avoid aortic cross-clamping.

Adrenergic beta-Antagonists↗

[A case of ventricular septal defect closure in patient with cytomegalo virus hepatitis].

Cytomegalovirus (CMV) infection has been reported to cause serious event in nonimmunocompromised patients after major surgery. Particularly in active case, the indication of surgical intervention is a difficult issue. A 7-months-old boy with ventricular septaldefect (VSD) has been diagnosed with CMV hepatitis. As his heart failure was not controlled with medication, he underwent closure of VSD at 9 months of age while CMV was still detected in the urine and serum by polymerase chain reaction method. During post operative course, he was treated with ganciclovir and intravenous CMV hyperimmune grobiln, and CMV in the serum became negative and he develops no aggravation of the CMV infection postoperatively.

Antiviral Agents↗

Use of the serum neutralisation test for equine viral arteritis with different virus strains.

Serum cross neutralisation tests were conducted with a recent American isolate (84KY-A1) and a European isolate, (Wroclaw-2) and compared with the prototype and modified viruses of the Bucyrus strain of equine arteritis virus by using virus specific immune horse sera. The modified Bucyrus strain was neutralised and showed high neutralisation titres with all the immune sera. The prototype Bucyrus strain was also substantially neutralised, followed by the 84KY-A1 strain. As a result of the tests with the modified Bucyrus strain as the antigen, 20 seropositive horses were discovered among home-bred horses which had no previous record of clinical equine viral arteritis. Heat inactivation of the sera at 62 degrees C for 30 minutes caused the disappearance of all but the most positive reactions. When the prototype Bucyrus strain was used instead of the modified virus, no positive reactions were detectable. A serological survey, using the Bucyrus strain in a microtitre neutralisation test, was conducted with 1656 horse sera collected between 1988 and 1990 in Japan. The test disclosed only eight foreign-bred horses positive to the virus; they had been imported as competition horses. No circumstantial evidence of an effect of such horses as a source of infection for horse populations free of the virus was obtained.

Animals↗

Rapid detection of African horsesickness virus by the reverse transcriptase polymerase chain reaction (RT-PCR) using the amplimer for segment 3 (VP3 gene).

The complete sequence of the major core protein (VP3) gene of African horsesickness virus serotype 4 (AHSV-4; vaccine strain) was determined by analysis of a complete cDNA clone representing segment 3. The RNA was 2,789 bp long and a comparison of its sequence with that of bluetongue virus serotype 10 (BTV-10) revealed 58% nucleotide similarity. Based on these data, the reverse transcriptase-polymerase chain reaction (RT-PCR) technique was applied to the specific detection of AHSV using a pair of primers designed for AHSV-4 VP3 gene. Approximately 230 bp of PCR products were amplified by RT-PCR from the total RNA extracts (mRNA and dsRNA) of Vero cells infected with eight serotypes of AHSV. No product was observed analogous to other orbiviruses. The supernatant of the infected cell culture fluid without any RNA purification was also suitable as a template for RT-PCR after being denatured at 94 degrees C for 5 min. The sensitivity of this method was between 10(0) and 10(1) TCID50 when viral RNA from the supernatant of infected cell culture was subjected to RT-PCR. The whole procedure for detecting the virus RNA by RT-PCR could be carried out within 5 h. The RT-PCR with AHSV VP3 gene as a target was found to be a simple, highly specific and sensitive assay for AHSV.

African Horse Sickness Virus↗

Cardiac hemangiopericytoma growing in the left atrium.

A 49-year-old woman was seen because of exertional dyspnea. Two-dimensional echocardiography revealed the presence of a large mass in the left atrium. An urgent operation was performed because the tumor suddenly stuck in the mitral orifice. The lesion, which occupied the entire left atrium, was resected during cardiopulmonary bypass. Histologic analysis revealed malignant hemangiopericytoma.

Female↗

Genetic analysis of equine rotavirus by RNA-RNA hybridization.

Serotype G3 equine rotaviruses isolated in Japan made up a common genogroup and were classified into two different genotypes. The genomes of serotype G3 equine rotaviruses with an identical electropherotype (isolated from 1982 to 1989) were very closely related to each other regardless of the year in which they were isolated. Serotype G3 equine rotavirus BI originating from England belonged to the same genogroup of serotype G3 equine rotaviruses isolated in Japan, although BI was classified as having a different genotype. The genomes of both serotype G10 equine rotavirus R-22 and serotype G10 calf rotavirus were closely related to each other.

Animals↗