Biomedical subjects

K Hamano

Publications and source records attributed to K Hamano.

At least 91 records · Page 5Linked to original sources

PubMed1999

Coronary bypass surgery after renal transplantation.

We report, herein, cases of two renal transplantation patients who underwent coronary artery bypass grafting and discuss the perioperative management of this clinical situation. The first case was a 43-year-old male who underwent coronary artery bypass grafting 50 days after renal transplantation, and the second was a chronic case of a 49-year-old male who underwent coronary artery bypass grafting 17 years after renal transplantation. Prior to the operation, the first patient was continuously administered 2 mg/kg/day of cyclosporin A with the dosage regulated according to the plasma level. The second patient was administered 50 mg/day of cyclophosphamide intravenously instead of an oral dosage of 50 mg/day of azathioprine just prior to the operation. In both patients, perfusion pressure during cardiopulmonary bypass was maintained at approximately 80 mmHg in order to obtain optimal urine output. The CD4/CD8 ratio was monitored for indication of graft rejection, but no remarkable changes were observed perioperatively in either patient. Both patients followed a good clinical course and their postoperative renal function was well maintained. The urine output during cardiopulmonary bypass was 300 ml and 650 ml, respectively. The patients were discharged 15 and 27 days after their operation, respectively. In conclusion, coronary artery bypass grafting can be safely performed in patients who have undergone renal transplantation, if there is appropriate perioperative usage of immunosuppressive agents and maintenance of perfusion pressure during cardiopulmonary bypass.

Adult↗

PubMed1999

Nitric oxide release from coronary vasculature before, during, and following cardioplegic arrest.

Nitric oxide (NO) is known as a vasodilatory molecule synthesized by vascular endothelium. The NO-dependent vasodilatory response of coronary artery is impaired after ischemia and reperfusion. In the present study, the release of NO from coronary vasculature was evaluated before and during cardioplegic arrest and after reperfusion. Nine patients undergoing heart surgery were studied. Multidose crystalloid cardioplegics were used for myocardial protection. The coronary affluent and effluent were obtained simultaneously before cardioplegic arrest, at each cardioplegic administration, and after reperfusion; and the levels of nitrite and nitrate, the stable end-products of NO, were measured. The NO release from the coronary vasculature was determined as the difference in the levels of nitrite and nitrate between the coronary effluent and affluent. The level of nitrite/nitrate release from coronary vasculature was 6.8 +/- 3.7 microM before cardioplegic arrest. During cardioplegic arrest the nitrite/nitrate release decreased, reaching 1.3 +/- 1.3 microM (p < 0.05, vs. before cardioplegic arrest) at the fourth administration of the cardioplegic. At 3 to 5 minutes after reperfusion, nitrite/nitrate release further decreased to 0.36 +/- 0.34 microM (p < 0.05, vs. before cardioplegic arrest). During cardioplegic arrest the NO release decreased and reached significance at approximately 70 minutes of cardioplegic arrest compared to that before cardioplegic arrest. After reperfusion, NO release was further reduced, with statistical significance compared to that before cardioplegic arrest. Our data may indicate that cardioplegic arrest and reperfusion cause endothelial dysfunction.

Aged↗

PubMed1999

A magnetic resonance abnormality correlating with permeability of the blood-brain barrier in a child with chemical meningitis during central nervous system prophylaxis for acute leukemia.

Chemical meningitis developed in a boy with acute lymphoblastic leukemia during central nervous system (CNS) prophylaxis. Cerebrospinal fluid examination showed pleocytosis and a high protein level. There were no malignant cytological findings. Calculated permeability of albumin across the blood-brain barrier (BBB) was more elevated than that of immunoglobulin or alfa2-macroglobulin. Magnetic resonance imaging (MRI) revealed diffuse pachymeningeal enhancement without any intracerebral lesion. Subsequent CNS prophylaxis was postponed. CSF findings and BBB permeability returned to normal, correlating well with the decrease of MRI abnormality.

Albumins↗

PubMed1999

Dumbbell-shaped trigeminal neurinoma in a child.

We experienced a case of solitary trigeminal neurinoma in a 10-year-old boy without stigmata of neurofibromatosis. This boy presented with progressive cerebellar ataxia, right abducens palsy and right hemiparesis. Magnetic resonance images (MRI) demonstrated a tumour extending into both the middle and posterior fossas forming a dumbbell-shaped mass lesion with a size of 35 x 30 x 45 mm. The tumour was successfully removed free of complications by a two-stage operation composed of right subtemporal and suboccipital retromastoid approaches. It is extremely rare for a solitary neurinoma to occur at this site in a child without neurofibromatosis. Surgical approaches in this type of tumour are discussed with a review of the literature.

Child↗

PubMed1999

The preoperative administration of lentinan ameliorated the impairment of natural killer activity after cardiopulmonary bypass.

The aim of this study was to determine whether the preoperative administration of lentinan, which is used clinically to activate T cell function in cancer patients, prevents the impairment of lymphocyte function after cardiopulmonary bypass (CPB). A total of 25 adults undergoing coronary artery bypass grafting were enrolled in this study. Lentinan (2 mg) was given to 10 randomly selected patients 7 d before surgery, while the other 15 patients were considered as a control. The white blood cell count, percentage of lymphocytes, subsets of lymphocytes, and natural killer cell activity were measured preoperatively, immediately after CPB and 1, 3, and 6 d after surgery. The white blood cell counts and the percentage of lymphocytes were not significantly different between the two groups; however, the percentage of CD4-positive cells in the lentinan group recovered to normal more rapidly than in the control group. Although natural killer cell activity was impaired in the control group after CPB, it maintained a nearly normal level in the lentinan group. The preoperative administration of lentinan for patients undergoing CPB ameliorated the impairment of natural killer activity and promoted the rapid recovery of CD4-positive cells.

Adjuvants, Immunologic↗

PubMed1999

Oocyte activation and parthenogenetic development of bovine oocytes following intracytoplasmic sperm injection.

Development of bovine oocytes after intracytoplasmic sperm injection (ICSI) was investigated. Oocytes were matured for 24-26 h in vitro and injected with isolated sperm heads. When treated with 7% ethanol (v/v) for 5 min, 71.7% of ICSI oocytes were activated as shown by the resumption of meiosis and the formation of female pronuclei. However, 41.5% of injected sperm heads remained condensed at 18-20 h after injection into the ooplasm. The incidence of decondensing sperm and that of male pronuclei at this stage were 15.1% and 26.4%, respectively. A total of 55.5% of oocytes reached the 2-cell stage following sperm head injection and 54.7% after sham-ICSI; these percentages were not significantly different from those following in vitro fertilisation (IVF) (73.1%). The percentage of 2-cell embryos reaching the 8-cell stage following ICSI was 37.5%, and 27.6% after sham-ICSI, which were significantly lower (p < 0.01) than the equivalent percentage following IVF (62.4%). The percentages of parthenogenetic embryos reaching the 2-cell, 4-cell and 8-cell stages following ICSI were 56.4%, 48.9% and 30.0%, respectively. These results indicate that the low rate of normal embryonic development of bovine oocytes following ICSI is largely due to the parthenogenetic activation of the oocytes.

Animals↗

PubMed1999

A newly designed adapter for testing an ex vivo mitral valve apparatus.

Few instruments are currently available to test mitral valve function in an ex vivo state due to the technical difficulties involved. To investigate the native ex vivo mitral valve or prosthetic mitral valve with chordae, we developed a mitral valve adapter with an annulus suturing portion and 2 papillary muscle suturing sites that can be changed in angle, direction, and length of chordae. We used this adapter to test an ex vivo mitral apparatus in beagle dogs and evaluated the morphology and function of the mitral apparatus by endoscopy. Our newly designed mitral valve adapter proved extremely useful for examining the ex vivo mitral valve anatomy and function and for testing stentless mitral prostheses with annular-papillary muscle continuity.

Animals↗

PubMed1999

Deletion polymorphism in the gene for angiotensin-converting enzyme is not a risk factor predisposing to abdominal aortic aneurysm.

OBJECTIVE: to establish whether deletion of the angiotensin-converting enzyme (ACE) gene is a risk factor predisposing to abdominal aortic aneurysm (AAA) or not. METHODS: the study included 125 patients with AAA and 153 controls randomly selected from 328 individuals. The control subjects were confirmed not to have an AAA, but matched with the AAA group for age, sex, hypertension, diabetes mellitus, and hyperlipidaemia. The presence of ACE polymorphism was detected by a polymerase chain reaction using DNA extracted from blood. RESULTS: the distribution of ACE genotypes and allele frequencies in the control and AAA groups was not significantly different. CONCLUSION: the deletion polymorphism in the ACE gene is not a risk factor for AAA.

Aged↗

PubMed1999

Gender preselection in cattle with intracytoplasmically injected, flow cytometrically sorted sperm heads.

We investigated the development to the blastocyst and subsequent live-offspring stages of in vitro-matured bovine oocytes intracytoplasmically injected with flow cytometrically sorted bull sperm heads. Bull sperm heads, prepared by ultrasound sonication, were distinguished and sorted on the basis of their relative DNA contents using a flow cytometer/cell sorter modified for sorting sperm. By fluorescence in situ hybridization, the proportion of sperm confirmed as having Y specific DNA in the fraction sorted for the Y sperm was 82%. Injection with single sorted sperm heads of in vitro-matured oocytes (cultured for 24 h) resulted in 46.6% cleavage and 6.9% blastocyst development rates. Embryo transfer of 48 blastocysts (Days 7-8) to recipients (one per recipient) resulted in 20.8% pregnancy and 20.8% normal live offspring production rates. The birth of 8 male and 2 female calves represents an 80% sex preselection accuracy rate.

Animals↗

PubMed1999

Broader clinical spectrum of Fukuyama-type congenital muscular dystrophy manifested by haplotype analysis.

Fukuyama-type congenital muscular dystrophy, Walker-Warburg syndrome, and muscle-eye-brain disease are clinically similar autosomal-recessive diseases, characterized by congenital muscular dystrophy, cobblestone lissencephaly, and eye anomalies. The classification of these disorders remains controversial. We analyzed five patients with congenital muscular dystrophy from four families who had severe eye and brain anomalies, such as retinal dysplasia and hydrocephalus, using polymorphic microsatellite markers flanking the Fukuyama-type congenital muscular dystrophy locus on chromosome 9q31. All patients were heterozygous for the Fukuyama muscular dystrophy founder haplotype with 3-kb insertion. In three cases, the other chromosome without the 3-kb insertion exhibited the same haplotype with a nonsense mutation on exon 3 of the Fukuyama gene. Thus, these three patients were compound heterozygotes for the condition. Severe eye anomalies such as retinal dysplasia or detachment and hydrocephalus could be included in the clinical spectrum of Fukuyama muscular dystrophy. The clinical spectrum of this disease is much broader than previously presumed.

Abnormalities, Multiple↗

PubMed1999

Coronary artery bypass grafting in the acute phase after renal transplantation: report of a case.

To the best of our knowledge, only 3 cases of coronary artery bypass grafting (CABG) performed under cardiopulmonary bypass (CPB) on patients in the chronic phase after renal transplantation have been reported in Japan. The first case of a patient who underwent CABG in the acute phase after renal implantation in Japan is herein described. Perioperatively, oral immunosuppressive agents were discontinued and they were given intravenously. Cyclosporin A (Cy-A) was administered via a continuous intravenous infusion in the acute phase after renal transplantation and closely monitored, because the blood concentration of Cy-A can vary a great deal during the perioperative period. This case report serves to demonstrate that as long as appropriate immunosuppressive drugs are perioperatively administered, CABG under CPB can be safely performed on patients who have undergone renal transplantation without subsequent rejection, infection, or renal damage, even during the acute phase.

Administration, Oral↗

PubMed1999

[Coronary artery bypass grafting for a patient with angina pectoris and ulcerative colitis].

The implementation of coronary artery bypass grafting for angina pectoris with ulcerative colitis has been rarely reported. A 63-year-old man has a past history of acute myocardial infarction in 1984 and ulcerative colitis since 1988. Coronary angiography and cardiac catheterization showed total obstruction of segment 2, 95% stenosis of segment 6, 75% stenosis of segment 7 and total obstruction of segment 12 with LVEF 23%. Coronary artery bypass grafting was performed under IABP support and cardiopulmonary bypass with aprotinin infusion after an inflammatory reaction of ulcerative colitis was adequately suppressed. Ulcerative colitis was controlled by administering 40 mg of predonisolone during perioperative period.

Angina Pectoris↗

PubMed1999

[A one-staged operation for mitral regurgitation and giant bulla in a patient with severe pulmonary hypertension: report of a case].

A 57-year-old woman was admitted to our hospital for the treatment of mitral regurgitation and giant bulla with severe pulmonary hypertension. A dobutamine-induced test performed preoperatively resulted in a decrease of the systolic pulmonary artery pressure by 30 mmHg. Subsequently, mitral valve replacement and bullectomy were performed concomitantly. The patient recovered from heart failure, and the pulmonary artery pressure clearly decreased during the perioperative period. This case report serves to demonstrate the effectiveness of performing a one-staged operation for mitral regurgitation and giant bulla with severe pulmonary hypertension.

Blister↗

PubMed1999

[Is left ventricular regional wall motion after CABG influenced by cardioplegic protection?].

This clinical study was conducted to determine whether different techniques of cardioplegic protection reflected left ventricular regional wall motion after CABG. A total of 43 patients with more than 90% stenosis of the LAD (seg 6 and/or 7) before CABG, who had patent grafts were allocated to two groups: namely, the crystalloid group, comprised of 23 patients given cold crystalloid cardioplegia and topical ice slush, and the blood group, comprised of 20 patients given tepid blood cardioplegia delivered intermittently antegrade. Each group was divided into two subgroups according to whether the left ventricular regional wall motion showed no change or deterioration after CABG. We also examined the relationship between the grading of the collateral artery before CABG and the postoperative ventricular regional wall motion. The number of patients who showed deterioration after CABG was higher in the crystalloid group than in the blood group (p = 0.008). Moreover, patients in the crystalloid group whose collateral artery had been graded as 0 before CABG tended to show deterioration of left ventricular local wall motion after CABG (p = 0.07). Whereas those patients in the blood group did not. In conclusion, the incidence of deterioration after CABG was higher in the crystalloid group than in the blood group.

Aged↗

PubMed1999

[Dose the administration of low-dose aprotinin contribute to an anti-inflammatory effect in coronary artery bypass grafting?].

A study was conducted to determine whether the administration of low-dose aprotinin contributed to an anti-inflammatory effect in coronary artery bypass grafting. Levels of the inflammatory cytokines; IL-6, IL-8, and GEL, were measured before and after cardiopulmonary bypass, then 1, 3 and 6 days after coronary artery bypass grafting, in a group of patients given aprotinin (n = 7) and a control group (n = 15). A comparison of the levels of all these inflammatory cytokines between the two groups revealed no significant difference at any time point. This indicates, that low-dose aprotinin did not contribute to an anti-inflammatory effect in coronary artery bypass grafting.

Aged↗

PubMed1998

An ancient retrotransposal insertion causes Fukuyama-type congenital muscular dystrophy.

Fukuyama-type congenital muscular dystrophy (FCMD), one of the most common autosomal recessive disorders in Japan (incidence is 0.7-1.2 per 10,000 births), is characterized by congenital muscular dystrophy associated with brain malformation (micropolygria) due to a defect in the migration of neurons. We previously mapped the FCMD gene to a region of less than 100 kilobases which included the marker locus D9S2107 on chromosome 9q31. We have also described a haplotype that is shared by more than 80% of FCMD chromosomes, indicating that most chromosomes bearing the FCMD mutation could be derived from a single ancestor. Here we report that there is a retrotransposal insertion of tandemly repeated sequences within this candidate-gene interval in all FCMD chromosomes carrying the founder haplotype (87%). The inserted sequence is about 3 kilobases long and is located in the 3' untranslated region of a gene encoding a new 461-amino-acid protein. This gene is expressed in various tissues in normal individuals, but not in FCMD patients who carry the insertion. Two independent point mutations confirm that mutation of this gene is responsible for FCMD. The predicted protein, which we term fukutin, contains an amino-terminal signal sequence, which together with results from transfection experiments suggests that fukutin is a secreted protein. To our knowledge, FCMD is the first human disease to be caused by an ancient retrotransposal integration.

Amino Acid Sequence↗

PubMed1998

A quantitative study of the progress of myelination in the rat central nervous system, using the immunohistochemical method for proteolipid protein.

The temporal changes in intensity of myelination of the nervous pathways in 0 to 42-day-old Wistar rats were quantitatively analyzed by immunohistochemistry with anti-proteolipid protein and compared with that obtained by immunohistochemistry with anti-myelin basic protein. Immunohistochemistry was performed on paraffin-embedded tissue according to the standard ABC technique. Intensity of myelination was examined by an image analyzing system. We analyzed nine nervous pathways: corpus callosum, optic tract, internal capsule, spinal tract of the trigeminal nerve, inferior cerebellar peduncle, cerebellar white matter, pyramidal tract, medial longitudinal fasciculus, and cuneate fasciculus. The presence of immunoreactive fibers for proteolipid protein (PLP) in the spinal tract of the trigeminal nerve, medial longitudinal fasciculus and cuneate fasciculus was noted on postnatal day 0. Those of the corpus callosum, inferior cerebellar peduncle, cerebellar white matter, pyramidal tract and internal capsule were noted on day 7, and that of optic tract on day 14. The time required to reach the intensity of myelination of day 42 was day 14 for the cuneate fasciculus, day 21 for the spinal tract of the trigeminal nerve, inferior cerebellar peduncle and medial longitudinal fasciculus, day 28 for the optic and pyramidal tracts, day 35 for the corpus callosum and day 42 for the internal capsule and cerebellar white matter. The appearance of immunoreactive fibers for PLP was usually earlier than that for myelin basic protein (MBP) and the pattern of difference between PLP and MBP can be classified into three groups: (1) their time of appearance and progress are almost the same, as in the optic tract; (2) the appearance and progress of PLP occurs earlier than those of MBP, as in the pyramidal tract; (3) the appearance of PLP occurs earlier than that of MBP, but their progress is the same. Our findings revealed that the time of appearance and progress of myelination as measured by PLP are different among the nervous pathways, and that there is also a difference between PLP and MBP. This difference between PLP and MBP may indicate a functional difference between them.

Age Factors↗

PubMed1998

Recovery after prolonged cross-clamping tepid blood cardioplegia: report of a case.

Despite a prolonged repetitive aortic cross-clamp time of 411 min, a patient who suffered a left ventricular rupture after undergoing mitral valve replacement following mitral valvuloplasty and Maze procedure recovered without any permanent residual left ventricular dysfunction. During the aortic cross-clamping we used tepid blood cardioplegia for myocardial protection. This case report serves to demonstrate the potential of tepid blood cardioplegia as an effective method of myocardial protection.

Aged↗