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Biomedical subjects

H Kajiwara

Publications and source records attributed to H Kajiwara.

At least 55 records · Page 3Linked to original sources
PubMed1995

A new cardiac wall substitute made of Dacron fabric prosthesis sealed with autologous tissue fragments: comparative studies of neointima formation and bleeding resistant property against fibrinolysis phenomenon with those of a preclotted sealing graft.

A cardiac wall substitute made of a Dacron fabric prosthesis sealed with minced-autologous tissue fragments was developed. An animal study showed rapid neointima formation on the graft luminal surface and no bleeding problem under load test with tissue plasminogen activator (tPA) administration. To evaluate the efficacy of the sealing method, a special substitute that was sealed with tissue fragments in one half and preclotted with fresh blood in the other half was prepared. The grafts were implanted into the right ventricular outflow tract in 14 dogs. During a load test with administration of tPA intravenously, the preclotted area bled quite remarkably; however, the area sealed with tissue fragments did not bleed. Two weeks after implantation, red thrombus adhered on the preclotted area, while a white, glistening surface was noticed on the tissue fragments area. Light microscopical observation showed complete neointima formation in the tissue fragmented area but a thrombus layer in the preclotted area. These results indicated that the tissue fragmentation was a superior method compared with preclotting for creating a cardiac wall substitute.

Adipose Tissue↗
PubMed1995

Cloning and nucleotide sequence of the gene encoding dimethyl sulfoxide reductase from Rhodobacter sphaeroides f. sp. denitrificans.

The gene encoding dimethyl sulfoxide (DMSO) reductase, which contains a molybdenum cofactor, of the phototrophic bacterium Rhodobacter sphaeroides f. sp. denitrificans was isolated using an oligonucleotide probe, which was synthesized based on a internal amino acid sequence of the purified enzyme. The DMSO reductase gene coded for 822 amino acids (2466 base pairs, M(r) = 89,206) as a precursor form having a signal peptide of 42 amino acids. The deduced amino acid sequence had high homology with those of some enzymes containing a molybdenum cofactor: trimethyl amine N-oxide reductase (48%), biotin sulfoxide reductase (44%), and DMSO reductase (29%) of Escherichia coli.

Amino Acid Sequence↗
PubMed1995

Influence of boiling water treatment on surface roughness and surface microstructure of set gypsum (dental stone).

The influence of boiling water treatment on the surface roughness and surface microstructure of set gypsums was investigated. Typical surfaces before and after immersion in boiling water were compared by means of SEM observation, the Knoop hardness test, and a surface roughness test. The surfaces of set gypsums were rougher than that of an acrylic resin plate, and after immersion in boiling water, highly roughened surfaces and thinner crystal bodies were observed on each specimen under SEM. The knoop hardness of set gypsums was considerably lowered after boiling water immersion. That of die stones was the same or lower than set dental stones. The results showed that even brief immersion in boiling water had profound effects on the dental stone cast, resulting in rougher surfaces and lower hardness of set gypsums.

Calcium Sulfate↗
PubMed1994

Banding a hemodialysis arteriovenous fistula to decrease blood flow and resolve high output cardiac failure: report of a case.

We report herein the successful surgical treatment of a patient with high-output cardiac failure which developed from a high-flow hemodialysis arteriovenous fistula of the Brescia-Cimino type. Banding correction of the venous limb of the fistula with a woven Dacron prosthesis resulted in marked improvement of the cardiac failure. An ultrasonic study showed the fistula flow of 3.2 l/min to be as high as 40% of the resting cardiac output, or 8.0 l/min, before banding, while an intraoperative electromagnetic study was useful for controlling the degree of banding and showing the decrease of fistula flow from 3.7 l/min to 1.4 l/min.

Aortic Aneurysm, Abdominal↗
PubMed1994

Proton magnetic resonance spectroscopy of brain tumors: an in vitro study.

The ability of proton magnetic resonance spectroscopy (1H MRS) to diagnose brain tumors was investigated using in vitro high-resolution spectra. Fifty-eight surgically excised samples of brain tumors (12 glioblastomas, 4 anaplastic astrocytomas, 6 astrocytomas, 12 meningiomas, 6 neurinomas, 4 chordomas, 3 craniopharyngiomas, 2 pituitary adenomas, 2 malignant lymphomas, 1 ependymoma, 1 medulloblastoma, and metastatic brain tumors including 3 pulmonary adenocarcinomas, a hepatocellular carcinoma, and a renal cell carcinoma) and 4 nontumorous lobectomized brains were examined by in vitro 1H MRS. N-Acetyl-aspartate was demonstrated in normal tissues but could not be detected in nonneuroectodermal tumors. Total creatine was decreased in all brain tumors in comparison with normal brain tissues, but was relatively higher in neuroectodermal tumors than in other brain tumors. Choline-containing compounds were present in all tumors except craniopharyngioma, and their concentrations were particularly high in a metastatic brain tumor from hepatocellular carcinoma. The concentration of glycine was high in neuroectodermal tumors, whereas that of taurine was high in medulloblastoma, pituitary adenoma, and renal cell carcinoma. Alanine was increased in meningioma, glioma, and pituitary adenoma. Neurinoma had the largest inositol content among the tumors examined. Thus each type of brain tumor exhibited a characteristic MR spectrum. These data suggested that in vivo 1H MRS might provide clinically useful information about tumor metabolism and aid in the differential diagnosis of tumors. Although excellent anatomical localization of tumors can be readily obtained by MR imaging, MRS may provide additional information in cases in which the differential diagnosis of tumors by MR imaging is difficult.

Adolescent↗
PubMed1994

[Surgical treatment of active infective endocarditis].

From January, 1978, through December, 1990, surgical treatment for active infective endocarditis was performed in 11 patients. There were 8 men and 3 women who ranged in age from 19 to 54 years with a mean age of 38.8 years. Two patients had ventricular septal defects and 1 patient had rheumatic valve disease. In all patients, the infecting organism was isolated from blood, including streptococcus in 7, staphylococcus in 2, and gram-negative rods in 2. The indication for operation at the active phase was uncontrolled infection in 7 and progressive heart failure in 4. The operation was performed at 7 to 150 days with a mean of 53 days after diagnosis. Operative findings showed vegetations in all cases and perforations of the valve in 6. There were no operative deaths. Perioperative complications developed in 5, whose indication for operation was uncontrolled infection. Complications consisted of 1 prosthetic valve endocarditis, 1 pulmonary suppuration, 1 ruptured mycotic aneurysm of the hepatic artery, 1 ruptured mycotic aneurysm of the popliteal artery, and 1 pyogenic spondylitis. All were successfully treated surgically or with antibiotic therapy. There were no complications in patients whose indication for operation was progressive heart failure. We conclude that the risk of embolism is high in patients undergoing surgery at the active phase of infective endocarditis because of uncontrolled infection; thus, such patients should be carefully monitored for emboli.

Adult↗
PubMed1993

Microsequence analysis of the N-terminally blocked proteins immobilized on polyvinylidene difluoride membrane by western blotting.

A technique has been developed for efficient deblocking and subsequent microsequencing of N-terminally blocked proteins immobilized on a polyvinylidene difluoride (PVDF) membrane at the picomole levels. In this technique, proteins were first separated by polyacrylamide gel electrophoresis and then transferred onto a PVDF membrane by Western blotting. The electroblotted proteins with N-terminal acetylserine or acetylthreonine could be deblocked on-membrane by treatment with trifluoroacetic acid vapor and sequenced by a gas-phase protein sequencer. Similarly, N-formylated proteins could be deblocked on-membrane in HC1 solution and then directly sequenced from the N-terminal amino acid. Proteins with N-terminal pyroglutamic acid were enzymatically deblocked by in situ pyroglutamyl peptidase digestion, and N-acetylated proteins were also enzymatically deblocked with acylamino acid-releasing enzyme (AARE) after on-membrane digestion with trypsin to generate the N-terminal peptide fragment. This tryptic digestion was required since AARE can remove the acetylamino acid only from a short peptide. Based on these four deblocking methods, we present a strategy for sequential deblocking and subsequent N-terminal sequence analysis of N-blocked protein immobilized on PVDF membrane.

Acetylation↗
PubMed1993

Proton magnetic resonance spectroscopy of astrocytic tumors: an in vitro study.

Water-soluble metabolites extracted from 20 astrocytic tumors (11 glioblastomas, 3 anaplastic astrocytomas, and 6 low-grade astrocytomas) and four normal brains were measured qualitatively and quantitatively using in vitro high-resolution proton magnetic resonance (1H-MR) spectroscopy. MR spectra from tumors exhibited characteristic patterns according to malignancy, presumably reflecting the metabolism of gliomas. Concentrations of choline-containing compounds, inositol, alanine, and glycine increased according to the malignancy, while that of total creatine decreased. In particular, glycine concentration was very high in glioblastoma, and an immunohistochemical study using anti-glycine antibody demonstrated that glycine was mainly distributed in glioma cells, not in proliferative endothelial cells. The ratios of choline-containing compounds and glycine to total creatine are useful parameters for grading gliomas, and the ratio of glycine to total creatine is useful for the differential diagnosis of glioblastoma from metastatic tumor. Such indications appearing in in vivo 1H-MR spectroscopy might provide clinically useful information on tumor metabolism and malignancy, and help assess the effects of radiation therapy and chemotherapy on gliomas.

Antibodies, Monoclonal↗
PubMed1993

[External work of canine latissimus dorsi muscle after vascular delay].

The first purpose of this study was to estimate physiological performance of skeletal muscle for circulatory assist. External work in the form of linear dynamic contraction was studied in canine latissimus dorsi muscle (LDM). The second purpose was to relate the effect of vascular delay of the LDM to the physiological performance. The left LDM with vascular delay (VD) were compared to the right control LDM (CTR) without vascular delay. Simultaneous dynamic contraction of both VD and CTR LDM were studied under various settings of the preloads and the afterloads. Maximal external work per single contraction were 136 +/- 38 mJ in VD and 81 +/- 21 mJ in CTR. Maximal total work, which includes external work and preload work, were 578 +/- 195 mJ in VD and 407 +/- 146 mJ in CTR. Maximal fractional shortenings of the LDMs were 22.8 +/- 4.7% in VD and 17.5 +/- 2.6% in CTR. The maximal external work of VD was 81% of canine LV stroke work and 620% of canine RV stroke work. The maximal total work of VD was 340% of canine LV stroke work. The fractional shortenings, external work and total work of VD were higher than those of CTR under all loading conditions. The physiologic performance of canine LDM was improved after vascular delay.

Animals↗
PubMed1993

[Clinical assessment of cerebral infarction, complicated with aortic arch replacement under selective cerebral perfusion].

Since October 1984 to December 1992, 47 aortic arch replacements were performed under selective cerebral perfusion (SCP). Patient age ranged from 19 to 81 years, with an average of 60.2 years. Thirty one patients were male and 16 female. Twenty patients were diagnosed with dissecting aneurysms, 27 true aneurysms. The operative mortality was 14 out of 47 (29.8%) over all. The mortality of dissecting aneurysm related acuity that is 5 of 9 (55.6%) for patients in acute phase, against none in chronic. The operative mortality of true aneurysms was 6 out of 11 (54.5%) for patients who had emergency operation, against 3 out of 16 (18.8%) scheduled, extensive surgery. Cerebral disorders developed on 8 patients out of 44 (18.2%, except 3 operative deaths). The mortality rate of cerebral disorder was 6 out of 8 (75.0%). Six patients with true aneurysm had cerebral infarctions after the surgery. Two patients had already cerebral disorders in advance the surgery. The cause of cerebral infarction was resumed by atherosclerotic materials. Our operative results indicate that cerebral disorder subsequently affects the mortality of aortic arch replacement. For the prevention of cerebral infarction, we modified the method of SCP. We start the SCP at the initiation of total cardiopulmonary bypass, routinely associated to an aortic clamp and cardiac arrest under myocardial protective procedure that is the use of perfusion cooling (30 degrees C, monitored at the esophagus), topical cooling and cold Saint Thomas solution infused in the coronary arteries. When aortic arch replacement is done, we need to make sure a good restarting of the heart and a good recovery of the systemic circulation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

[Long-term results of closed mitral commissurotomy--comparative study of closed mitral commissurotomy (CMC), open mitral commissurotomy (OMC) and mitral valve replacement (MVR)].

As the technique of open heart surgery has improved, CMC has been abandoned in favor of OMC and MVR. We evaluated and compared the results of CMC, OMC and MVR. METHOD. Between 1965 and 1978, 141 patients with mitral stenosis (MS) underwent CMC, and late follow-up obtained in 117 (83%) of them (CMC group). Between 1980 and 1989, 72 patients and 37 patients underwent OMC (OMC group) and MVR (MVR group), respectively. Cumulative follow-up periods were 1982, 632 and 200 patient-years in the CMC, OMC and MVR groups, respectively. RESULTS. (1) Survival rate; In the CMC group there were 2 operative deaths due to severe mitral regurgitation (MR). There were 17 late deaths, due to reoperations in 4 patients, cerebral infarction in 4 patients, congestive heart failure in 3 patients, myocardial infarction in 2 patients and unknown causes in 4 patients. The survival rate was 95%, 91% and 86% at 5, 10 and 15 years, respectively, in the CMC group. In the OMC and MVR groups there was no death. (2) The event free rate was 89%, 79% and 58% at 5, 10 and 15 years, respectively, in the CMC group, 97% and 97% at 5 and 10 years in the OMC group, and 95% and 90% at 4 and 5 years in the MVR group. (3) Reoperations; In the CMC group of 40 patients (34%) required reoperations in an average of 10.4 years after the initial operation, due to re-MS in 22 patients, MR in 10 patients and MRS in the 8 patients. Reoperative findings consisted of clefts in the mitral leaflets in 7 patients. There were pulmonary hypertension in 15 patients and tricuspid regurgitation in 22 patients. Fourteen patients underwent tricuspid anuloplasty and one patient underwent a tricuspid valve replacement. In the OMC group one patient required a reoperation due to MR; in the MVR group one patient required a reoperation due to a thrombosed valve. CONCLUSION. In the CMC group the survival rate and the event free rate were lower, and the rate of reoperation was higher than in the other two groups.

Adult↗
PubMed1993

[A case of mitral regurgitation caused by total rupture of the posterior papillary muscle after acute myocardial infarction].

We observed a case of severe mitral regurgitation caused by total rupture of the posterior papillary muscle 13 days after acute myocardial infarction. The patient was a 76-year-old man who suddenly felt anterior chest pain. He was admitted to another hospital with the diagnosis of acute myocardial infarction. Electrocardiogram suggested a posterior infarction. He did well during the first 12 days of hospitalization, but at noon on the 13th day he developed anterior chest pain and dyspnea. Echocardiography demonstrated rupture of the posterior papillary muscle. He was subsequently transferred to our hospital with acute heart failure. He was initially treated with an intra-aortic balloon pump. Cardiac catheterization demonstrated 99% stenosis of segment 2 of the right coronary artery and mitral regurgitation, Sellers' stage IV. Intraoperative findings included total rupture of the posterior papillary muscle. Mitral valve replacement was performed using a Carbomedics prosthetic valve. The patient was discharged 53 days after surgery without heart failure or angina pectoris. This case represents the 6th successful operation of total papillary muscle rupture in Japan.

Aged↗
PubMed1992

Repeated intracerebral hemorrhage associated with impaired platelet aggregation--report of two cases.

The authors report two cases of hypertensive intracerebral hemorrhage (ICH) repeated at the same site within 1 or 2 days causing death in a 53-year-old male and a 48-year-old female. In both cases, platelet aggregation was significantly impaired. Acquired platelet dysfunction may be important in the expansion of hemorrhage in patients with repeated hypertensive ICH. In such cases administration of normal platelets may be required to prevent devastating hemorrhage.

Blood Platelet Disorders↗
PubMed1992

[Pulmonary arteriovenous malformation with systemic blood supply].

A forty-eight year-old woman who had suffered from exertional dyspnea and cyanosis since her youth was found to have abnormal shadow in her right lower lung at the roentgenographic examination. Pulmonary angiography showed cavernous network between pulmonary artery and vein of the 8th, 9th, and 10th segments. Bronchial artery was dilated, supplying the cavernous lesion. From these findings this lesion was diagnosed as pulmonary arteriovenous malformation feeded by bronchial artery. Right lower lobectomy was performed. The effect of resection was confirmed by intraoperative arterial gas analysis before and after the excision. She has been doing well without any signs of recurrence for 3 years after the surgery.

Arteries↗
PubMed1992

[Recurrent thromboses of the Björk-Shiley valve in a patient with gout].

A 56-year-old male, who had mitral stenosis and gout, underwent mitral valve replacement with the Björk-Shiley valve prosthesis. Four years after the surgery, the patient suddenly became dyspneic on exercise due to malfunctioning valve. Thrombosis was found on the prosthesis, which was replaced again by Björk-Shiley valve. Thrombotest value had been satisfactorily controlled at 12.8 +/- 4.2% with warfarin since the first surgery. Dilazep chlorate also had been prescribed. Hyperuricemia had been controlled with allopurinol. In spite of these combined medical therapy, thrombosed valve recurred. Clotted prosthesis was superseded by Carpentier-Edwards Bioprosthesis. Enhancement of platelet function of the patients with gout and hyperuricemia has been reported. Gout in this case might have influence on the recurrent episodes of thrombosis. Monitoring of platelet function would be necessary in follow-up of a patients with gout and valve replacement.

Equipment Failure↗
PubMed1991

[Arteriovenous malformation associated with meningioma].

A case of arteriovenous malformation (AVM) associated with a meningioma is reported. A 28-year-old woman was hospitalized for generalized convulsion. CT scan and right carotid angiogram revealed AVM in the right parietal lobe extending to the wall of the lateral ventricle. At the time of surgery an intraventricular meningioma attached to the choroid plexus was found in the excised cavity of the AVM. It is suggested that the meningioma might have been caused by chronic irritation due to an increased blood flow in the arteries supplying the AVM, because the AVM and the meningioma exist in the same lesion and share the same blood supply.

Adult↗
PubMed1991

Experimental irradiation of femoral arteries by carbon dioxide (CO2) laser: morphologic changes under transmission electron microscope (T.E.M.) examination.

In order to study the morphologic changes after CO2 laser irradiation, 42 rat femoral arteries were irradiated under various conditions at different time intervals from zero to three weeks. The arteries were examined under transmission electron microscope (T.E.M.), and 30 mW power and 0.3 to 0.5 mm/sec velocity were considered to be the most suitable for a CO2 anastomosis of small femoral arteries.

Animals↗