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Biomedical subjects

A Hashimoto

Publications and source records attributed to A Hashimoto.

At least 289 records · Page 16Linked to original sources
PubMed1992

[A case report on the sliding commissuroplasty for mitral regurgitation due to posterior commissural chordal rupture].

We have performed a mitral valve reconstruction on a 31-year-old man who suffered from infective endocarditis four years ago. Severe mitral regurgitation and posterior commissural chordal rupture were noted. The mitral valve was repaired by Carpentier's sliding commissuroplasty and ring annuloplasty. The postoperative course was uneventful, and mitral regurgitation completely disappeared. It appears that Carpentier's sliding commissuroplasty is a superior new reconstructive technique for mitral regurgitation due to commissural chordal rupture.

Adult↗
PubMed1992

[A clinical assessment of efficacy in continuous retrograde cerebral perfusion method].

From November 1990 to June 1991, 8 patients underwent surgical repair using continuous retrograde cerebral perfusion (CRCP). We evaluated the effect of CRCP from these 8 cases. As a method of CRCP, we perfused with oxygenated blood from SVC canulae with a internal jugular vein pressure of 30-40 cmH2O. Simultaneously systemic perfusion from femoral arterial canulae was performed. At nasopharyngeal temperature of 15-21 degrees C, CRCP time was 46-115 minute. SVC perfusion flow was 280-900 ml/min, and femoral arterial perfusion flow was 450-1,200 ml/min. At 30 minute after starting CRCP, oxygen tension of the blood which was returned to aortic arch was 11-23 mmHg, whereas oxygen tension of the SVC perfusion blood was 210-398 mmHg. In only one patient, transient involuntary movement was seen after operation, but prolonged emergence from anesthesia was not seen. In conclusion, CRCP is considered as an useful method in the operation of the aortic arch.

Aorta, Thoracic↗
PubMed1992

[Surgical repair of distal aortic arch aneurysm using "elephant trunk" technique].

We present a surgical case of 61-year-old man with distal aortic arch aneurysm. Under selective cerebral perfusion in deep hypothermia, we approached to the aneurysm through median sternotomy. Dilated distal aortic arch and proximal descending aorta with mural thrombus in the aneurysmal lumen were found. The aortic occlusion balloon catheter was inserted into the descending aorta. A Cooley woven Dacron graft (26 mm in diameter) was anastomosed at 5 cm above its distal end loosely to the descending aorta with five interrupted mattress sutures, and the distal portion of the graft was pushed down into the distal aorta ("elephant trunk" technique). Postoperative course was uneventful and the dead space around the graft in aneurysm was filled with thrombus. Six months later, however, emergent operation was performed because of compression of the bronchus and the esophagus by enlargement of the aneurysm due to leakage. The second operation was approached through 5th left intercostal thoracotomy and median sternotomy. The aneurysm was opened, and the thrombus was amounted to 500 g. The distal end of the graft was anastomosed end-to-end to the mid-portion of the descending thoracic aorta. Postoperative course was uneventful and the patient was discharged. It is concluded that Elephant trunk technique is effective and the postoperative control of hypertension is very important.

Aorta, Thoracic↗
PubMed1992

[A case report of thrombosed St. Jude Medical valve in a patient with macroglobulinemia].

A 66-year-old man who had undergone MVR using a ST. Jude Medical valve entered the hospital with acute heart failure and cardiogenic shock 3 months after surgery. He had had a symptom of petechiae due to macrogloburinemia after initial MVR and had been in the poor control of anticoagulation therapy because of presence of petechiae. He was diagnosed as prosthetic valve thrombosis using echocardiography and underwent emergency re-MVR using a Central Open Bioprosthesis (COB) which was developed by our department. He was doing well 8 month after re-MVR. Selection of prosthetic valve should be performed carefully in the patient with hemorrhagic disease, and careful observation and proper anticoagulant therapy should be carried out after valve replacement.

Aged↗
PubMed1992

[Classification of congenitally bicuspid aortic valve and its angiographic and surgical significance].

From January, 1978 to December, 1990, 85 patients with congenital bicuspid aortic valve underwent aortic valve replacements (AVR) with St. Jude Medical valve prosthesis. We classified congenital bicuspid aortic valve into four types. Type I (44.7%): Two cusps are situated right and left, a coronary artery arises from each related sinus of valsalva. Type II (22.4%): Type I + raphe in the right cusp. Type III (3.5%): one cusp is located anteriorly, the other posteriorly and both coronary arteries arise from anterior cusp. Type IV (29.4%): Type III + raphe in the anterior cusp. Regarding to preoperative diagnosis, aortic stenosis dominated in Type I (78.8%) and aortic regurgitation dominated in Type IV (72.0%). Implanted valve sizes were 22.2 +/- 1.8 (Type I), 23.4 +/- 1.6 (Type II) and 24.0 +/- 2.2 (Type IV). There was a significant difference between Type I and Type II, same as Type I and Type IV. Babb's method and outflow measurement method were utilized to predict the aortic annular size. However, both of them were not reliable for estimating the size of the aortic annulus in cases of aortic stenosis undergoing AVR with a 21 mm prosthesis.

Adolescent↗
PubMed1992

[A useful method for the surgical treatment of active infective endocarditis--a case report using the Teflon felt reinforcing method].

In the surgical treatment for active infective endocarditis (IE), perivalvular leakage is the most severe complication. We had a 42-year-old man who had active IE and a giant vegetation in the aortic valve, and a small mycotic aneurysm in the left ventricular outflow tract. Other operative observations included slight redness and a decrease in the reflex of the annular endocardium. We made a patch closure of the mycotic aneurysm, and aortic valve replacement using the Teflon felt reinforcing method. In the postoperative course, he had a pacemaker implantation with complete AV block. Postoperative pathological examination revealed inflammatory cells and plasma infiltration, and edematous change of the interstitial tissue around the cusp surface and annular side of the resected valve. These pathological changes could explain the redness and the decrease in the reflex of the annular endocardium. The edematous changes of the annular tissue might be the cause of postoperative perivalvular leakage. Reinforcement of the prosthetic valve with Teflon felt might be a useful method to prevent perivalvular leakage. There is, however, the possibility of acceleration or elongation of infective endocarditis. In our experiences of the surgical treatment for active IE, we performed valve replacement using Teflon felt in 6 patients, and not using in 27 patients. The mean period until CRP had been normalized was no significant difference between both groups (mean days using Teflon felt were 63.5 days, and not using were 75 days).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Influence of adjuvants on the antibody specificity to the Plasmodium falciparum major merozoite surface protein, gp195.

The effect of adjuvants on the specificity of immune responses to the Plasmodium falciparum gp195 protein was investigated using adjuvant formulations based on synthetic muramyl dipeptide and monophosphoryl lipid A derivatives, in parallel with CFA and alum. Although these immunomodulators were as effective as CFA in inducing an antibody response to gp195, there were distinct differences in the recognition of B cell epitopes by these antibody populations. We have also demonstrated that MHC control of antibody specificity can be related to the adjuvant used for immunization. In general, the potency of adjuvants, their ability to induce antibodies of a particular specificity, or their ability to overcome MHC control of immune responsiveness varied independently. These findings suggest a critical role of adjuvants in the determination of the specificity of the immune response to protein Ag. Thus, the influence of adjuvants should be a major consideration in studies on immunologic recognition, as well as in the design of modern subunit vaccines.

Adjuvants, Immunologic↗
PubMed1991

Stereoselective inhibition by D- and L-alanine of phencyclidine-induced locomotor stimulation in the rat.

Bilateral injection of D-alanine, but not L-alanine, (10-100 micrograms per side for each amino acid) into the lateral ventricle reduced the increasing effect of phencyclidine (PCP, 10 mg/kg, given intraperitoneally) on locomotor activity in the rat in a dose dependent manner. This stereoselectivity agrees with the potency of these agents as agonists for the strychnine-insensitive glycine receptor in the N-methyl-D-aspartate receptor complex, suggesting that stimulation of the allosteric regulation site may antagonize the ability of PCP to produce hyperactivity.

Alanine↗
PubMed1991

D-alanine inhibits methamphetamine-induced hyperactivity in rats.

Bilateral intracerebroventricular injection of D-alanine (200-600 micrograms/rat) antagonized the ability of methamphetamine (1.0 mg/kg s.c.) to induce locomotor stimulation in the rat. In contrast, L-alanine (600 micrograms/rat) failed to affect the behavioral change induced by methamphetamine. The stereoselectivity parallels the potency of these amino acids as agonists for the strychnine-insensitive glycine binding site within the NMDA receptor complex. These results support the view that reduced excitatory amino acidergic neurotransmission may be involved in methamphetamine-induced hyperactivity.

Alanine↗
PubMed1991

Whole-cell K+ current activation in response to voltages and carbachol in gastric parietal cells isolated from guinea pig.

Patch-clamp studies of whole-cell ionic currents were carried out in parietal cells obtained by collagenase digestion of the gastric fundus of the guinea pig stomach. Applications of positive command pulses induced outward currents. The conductance became progressively augmented with increasing command voltages, exhibiting an outwardly rectifying current-voltage relation. The current displayed a slow time course for activation. In contrast, inward currents were activated upon hyperpolarizing voltage applications at more negative potentials than the equilibrium potential to K+ (EK). The inward currents showed time-dependent inactivation and an inwardly rectifying current-voltage relation. Tail currents elicited by voltage steps which had activated either outward or inward currents reversed at near EK, indicating that both time-dependent and voltage-gated currents were due to K+ conductances. Both outward and inward K+ currents were suppressed by extracellular application of Ba2+, but little affected by quinine. Tetraethylammonium inhibited the outward current without impairing the inward current, whereas Cs+ blocked the inward current but not the outward current. The conductance of inward K+ currents, but not outward K+ currents, became larger with increasing extracellular K+ concentration. A Ca(2+)-mobilizing acid secretagogue, carbachol, and a Ca2+ ionophore, ionomycin, brought about activation of another type of outward K+ currents and voltage-independent cation currents. Both currents were abolished by cytosolic Ca2+ chelation. Quinine preferentially inhibited this K+ current. It is concluded that resting parietal cells of the guinea pig have two distinct types of voltage-dependent K+ channels, inward rectifier and outward rectifier, and that the cells have Ca(2+)-activated K+ channels which might be involved in acid secretion under stimulation by Ca(2+)-mobilizing secretagogues.

Animals↗
PubMed1991

Fluoromethylated and hydroxymethylated derivatives of N-methyl-D-aspartate receptor antagonist 1-[1-(2-thienyl)cyclohexyl]piperidine.

Derivatives with fluoromethyl and hydroxymethyl groups on the cyclohexyl ring of 1-[1-(2-thienyl)cyclohexyl]piperidine (TCP), a noncompetitive antagonist of N-methyl-D-aspartate (NMDA) receptor, were tested in a radioligand binding assay to evaluate their ability to inhibit [3H]TCP binding by rat brain homogenates. The potencies of these compounds as antagonists of NMDA and L-glutamate responses were also compared using a rat cortical slice preparation. One of the analogs, cis-2-hydroxymethyl-r-1-(N-piperidyl)-1-(2-thienyl) cyclohexane (5) was found to show a high affinity (IC50 = 16 nM) for the phencyclidine (PCP) binding sites, very close to that of TCP, and to be 38-fold more potent in binding than its trans isomer. Fluoromethyl and hydroxymethyl substitutions at C4 position of the cyclohexyl ring of TCP clearly reduced the affinity by at least one order of magnitude relative to TCP.

Animals↗
PubMed1991

Natural histories of atrial septal defect with pulmonary hypertension, and ventricular septal defect with pulmonary hypertension.

A study of the natural history of 51 adult patients with atrial septal defect with pulmonary hypertension (ASD + PH) was performed. ASD + PH of less than 14 Um2 of pulmonary artery resistance (PVR) was considered an indication for surgery. The prognosis of surgically treated patients was favorable, but that of medically treated patients was poor. For patients with ventricular septal defect with pulmonary hypertension (VSD + PH), surgery was considered for pulmonary-systemic vascular resistance ratio (Rp/Rs) less than 0.5, and for patients under than 10 years and, ideally, under 2 years of age.

Adult↗
PubMed1991

Acute aortic dissection. A comparison between the results of medical and surgical treatments.

Over the last ten years 96 patients with aortic dissection were encountered in our Institute, of whom 51 had type A dissection, and 45 had type B dissection. In the patients with type A dissection the long-term survival rate was poor if they were not operated upon without delay, and the cause of death was usually rupture of the aneurysms. In the patients with acute type B dissection the surgical indication was limited and, generally speaking the long-term survival rate of the medically treated patients was more favorable.

Acute Disease↗
PubMed1991

Site-related difference in the prevalence of mitral valve prolapse. Relation to the prevalence and severity of mitral regurgitation.

In this study, 431 consecutive patients with mitral valve prolapse (MVP) diagnosed by two-dimensional echocardiography were employed to further investigate the site-related difference in the prevalence of MVP. Following echocardiographic determination of the site and severity of MVP, a pulsed-Doppler technique was further performed to assess the existence and severity of mitral regurgitation (MR) in all patients. These patients were then classified by age in 10-year groups with patients older than 60 years being enrolled in one group. The younger groups accounted for a large number of the patients with MVP in our study, with the number of patients being reduced with age. In addition, female patients tended to predominate up until the 50s, but not in the 50 and older groups. The prevalence of MVP at the centro-medial site of the anterior mitral leaflet (AML) predominated in all age groups, gradually decreasing with age, except for a peak in the 40s, before continuing to decline in the 50 and older groups. On the other hand, the prevalence of MVP at the lateral site of the AML and at the posterior mitral leaflet (PML) increased with age. In the 50 and older age groups, the prevalence of MVP at these sites increased steeply with age. However, the prevalence of MVP at both the lateral site of the AML and PML did not significantly increase with age. The trend shown above was not significantly different for gender. The number of patients with MR increased with age independent of the site of MVP. However, the prevalence and severity of MR associated with MVP at the lateral site of the AML and/or at the PML were significantly greater than at the other sites up until the 50s (p less than 0.05). When patients were older than 50 years, this significant site-related difference in the prevalence of MR was not observed because of the higher prevalence of MR in the older patients in this study. Forty-one patients could be followed for 2 to almost 5 years. Three of the 41 patients were observed to have MVP at the centro-medial site of the AML in the initial examination, but the site of MVP had extended to the lateral side of the AML in the final examination. Two patients with MVP at all 3 sites of the AML demonstrated an increase in the severity of MVP. However, there were no newly documented cases of MR among those patients.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1991

[A case report of chronic traumatic dissecting aneurysm of the thoracic aorta].

A 63-year-old male, who sustained a blunt chest trauma in a traffic accident, was referred to our hospital for his traumatic aneurysm. An operative repair was undertaken 3 months after the trauma. The descending aorta was dissected along 5 cm, and its diameter was about 6 cm. Graft replacement was performed under the left heart bypass by using the BioMedicus centrifugal pump. He is doing well 3 years after the operation.

Accidents, Traffic↗