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Biomedical subjects

K Kusumoto

Publications and source records attributed to K Kusumoto.

At least 19 recordsLinked to original sources
PubMed1992

Inhibition of nitric oxide synthesis does not reduce infarct volume in a rat model of focal cerebral ischaemia.

The effect of the nitric oxide (NO) synthesis inhibitor Ng-nitro-L-arginine methylester (L-NAME) on ischaemic brain damage was determined in a rat model of focal cerebral ischaemia. Ischaemia was induced by permanent occlusion of the left middle cerebral artery (MCA) and infarction assessed 4 h post-occlusion by quantitative histopathology. L-NAME (30 mg/kg s.c.), administered 30 min pre- and 30 min post-MCA occlusion, did not significantly alter the volume of ischaemic damage in the cerebral hemisphere, neocortex or caudate nucleus compared with saline controls. This result provides no support for the view that NO generation is a key component in the post-ischaemic cascade leading to acute neuronal death.

Animals↗
PubMed1992

The effect of the kappa-opioid receptor agonist CI-977 in a rat model of focal cerebral ischaemia.

The effect of a novel, highly potent and selective kappa-opioid receptor agonist CI-977 upon ischaemic brain damage and brain swelling has been examined in a rat model of focal cerebral ischaemia. Focal ischaemia was produced by the permanent occlusion of the left middle cerebral artery (MCA) during a brief period of halothane anaesthesia. The animals were sacrificed 24 h after MCA occlusion and the amount of ischaemic brain damage and swelling was assessed in coronal sections at 8 predetermined stereotactic planes. Treatment with CI-977 (0.03, 0.3 or 3 mg/kg), initiated 30 min prior to MCA occlusion (and at multiple times thereafter) produced dose-dependent reductions in the volumes of infarction and of brain swelling, with the most marked reductions being noted with CI-977 (0.3 mg/kg) in both infarction (reduced by 38% from controls; P less than 0.02) and swelling (reduced by 31%; P less than 0.002). There was an excellent correlation between the volume of brain swelling and ischaemic damage which was similar with saline-treated and CI-977-treated animals (overall correlation coefficient r = 0.896). These results indicate that CI-977 is effective in reducing infarction in a model of focal cerebral ischaemia, and that the reduction in brain swelling occurs in parallel with the reduction in ischaemic damage.

Animals↗
PubMed1992

[Transorbital penetrating brain injury].

Transorbital penetrating brain injury is rare during this time of peace. In our paper, we reported seven cases of these injuries and discussed the mechanism and treatment of intracranial complications. Transorbital penetrating brain injuries were caused by thin, long and relative hard objects such as chop-stick (case 3), pencil (case 6), bamboo stick (case 1, 2, 7) and a piece of metal (case 4, 5). CT scan, MRI and angiography demonstrated a large variety of intracranial complications. For instance, intracerebral hematoma, cerebral contusion, intraventricular hemorrhage, pneumocephalus, brain stem injury and carotid cavernous sinus fistula. We had no case of infectious complications such as meningitis and brain abscess. If the direction of the injuring object runs parallel to the orbital roof, it penetrates the cranial cavity commonly via the superior orbital fissure or the optic canal, which routes provide direct access without bone fracture. This direction will cause critical intracranial complications such as CCF or brain stem injury. If the injuring object runs upward and across the orbital roof which has thin bone and therefore offers little resistance, the frontal lobe will be easily damaged, and it will cause intracerebral hematoma. But the prognosis for this type of injury is not so poor because we can easily remove the hematoma and the foreign body. With our treatment policy of "pull and see", all our cases but one recovered well. The one exception was a case in which a large intracerebral hematoma was over-looked in an ophthalmological clinic. This patient died. Nowadays, CT scan and MRI give clear information about the anatomical location of injuring objects and intracranial complications.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

Reconstruction of both eyelids following electrical burn.

A case of severe electrical burn of the unilateral upper and lower eyelids is reported, together with the surgical technique of reconstruction. A 25-year-old man suffered an electrical burn on his left eyelids. On admission, his left upper and lower eyelids were subtotally necrotic. Total eyelid reconstruction was performed 2 1/2 months later. A chondromucosal graft taken from the nasal septum was utilized as the deep layer of the upper eyelid, which was covered by sliding down the remaining levator muscle and connective tissues to maintain the blood supply to the composite graft. The outer layer of the upper lid was reconstructed with a free split-thickness skin graft. The lower lid was reconstructed with a local flap lined with a free mucosal graft. This sandwich method using the levator muscle as a core was found useful for reconstructing both the upper and lower eyelids.

Adult↗
PubMed1991

Impairment of grafts by short-term warm ischemia in rat liver transplantation.

The mechanism of warm ischemic damage was investigated by assessing hepatic energy metabolism, mitochondrial functions, and lipid peroxidation (LP) of transplanted liver grafts in rats. Donor livers were stored ischemically either for 90 min at 4 degrees C (control) or for 20 min at 37 degrees C and 70 min at 4 degrees C (warm ischemia). In the control group, adenosine 5'-triphosphate (ATP) recovered within 8 min to 86% of the normal preischemic value (10.30, SEM 0.26 mumol/g dw). Total adenine nucleotides (TAN) recovered to 14.83 (SEM 0.22) mumol/g dw within 30 min, as compared with a normal level of 15.44 (SEM 0.36) mumol/g dw. The energy charge potential (ECP) immediately recovered to 0.79 (SEM 0.01) within 8 min (normal, 0.81, SEM 0.01). Mitochondrial phosphorylation rate (PR) was not significantly altered. LP averaged 451 (SEM 10) nmol/g dw in normal livers and did not change even during reperfusion (504, SEM 79, nmol/g dw, at 15 min). In contrast, in the warm ischemic group, ATP recovered only to 65% of the normal value even at 30 min (P less than 0.01), and TAN remained significantly lower than the control value (12.39, SEM 0.47, mumol/g dw, P less than 0.001). PR was normal at the end of warm ischemia, was significantly reduced at the end of the total ischemic period (P less than 0.001 and P less than 0.01, as compared with control and normal values, respectively), and gradually recovered over 30 min. LP increased and reached the maximum of 795 (SEM 84) nmol/g dw at 15-min reperfusion (P less than 0.05). In grafts treated with 50 mg/kg bw allopurinol (i.v.) 10 min prior to the onset of warm ischemia, ATP and ECP recovered to normal values at 30 min, and TAN was significantly higher than in the warm ischemic group (13.28, SEM 0.28, mumol/g dw, P less than 0.05). PR was maintained at normal values, and LP was increased but to a lesser degree than in the ischemic group. It is concluded that the delayed recovery of ATP metabolism in the warm ischemic group might be due to the loss of adenine nucleotides and the decreased PR, and that allopurinol has a protective effect against warm ischemic damage.

Allopurinol↗
PubMed1990

Unusual intra- and extracranial arteriovenous communication--case report.

The authors report an unusual case of arteriovenous communication between extracranial and intracranial vessels, accompanied by incidentally detected bilateral arachnoid cysts of the middle cranial fossa. A 52-year-old male was admitted with a sudden onset of headache, vomiting, and conjunctival hyperemia of the right eye followed by progressive chemosis and proptosis. He had undergone a craniotomy for hypertensive right putaminal hemorrhage 4 months previously. Angiography showed the main feeding artery to be the superficial temporal artery and the draining veins to be the superficial Sylvian veins and the basal vein of Rosenthal. Partial obstruction of the right cavernous sinus was also shown. At surgery, granulation tissue continued to the dura mater through the skull aperture of previous craniotomy and adhered to the underlying damaged cerebrum. The extremely unusual nature of the communication, the operative findings, and the atypical fistulous figures suggested that communication had occurred postoperatively via newly generated vessels in granulation tissue.

Arachnoid Cysts↗
PubMed1989

Positive inotropic and vasoconstrictive effects of endothelin-1 in in vivo and in vitro experiments: characteristics and the role of L-type calcium channels.

Cardiac and vascular effects of endothelin-1 (ET-1) were studied in hemodynamic models in vivo and in isolated artery and heart tissues. The hemodynamic changes induced by ET-1 (30-300 pmol/kg i.v.) in dogs were increases in blood pressure, cardiac output, and ventricular contractility. Ring preparations of canine coronary artery and rabbit thoracic aorta showed vasoconstrictive responses to ET-1 (10(-10) M and over) with an EC50 of 3-10 x 10(-9) M. Nifedipine 10(-5) M did not reverse these effects completely. ET-1 had positive inotropic effects from 10(-10) M in rabbit papillary muscles. It lengthened the action potential duration by 16% and increased the developed tension by 180% (10(-8) M). In contrast, Bay K 8644 (10(-7) M) produced similar lengthening (17%) in the duration with only a 37% increase in the tension. This suggests a difference in the mechanisms of the positive inotropic effects between these two agents. We conclude that ET-1 has positive inotropic and vasoconstrictive effects, and that these ET-1-induced contractions in ventricular muscles and arteries cannot be explained thoroughly by the increase in currents through voltage-dependent calcium channels.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗
PubMed1989

Mating-type control in Saccharomyces cerevisiae: isolation and characterization of mutants defective in repression by a1-alpha 2.

The alpha 2 protein, the product of the MAT alpha 2 cistron, represses various genes specific to the a mating type (alpha 2 repression), and when combined with the MATa1 gene product, it represses MAT alpha 1 and various haploid-specific genes (a1-alpha 2 repression). One target of a1-alpha 2 repression is RME1, which is a negative regulator of a/alpha-specific genes. We have isolated 13 recessive mutants whose a1-alpha 2 repression is defective but which retain alpha 2 repression in a genetic background of ho MATa HML alpha HMRa sir3 or ho MAT alpha HMRa HMRa sir3. These mutations can be divided into three different classes. One class contains a missense mutation, designated hml alpha 2-102, in the alpha 2 cistron of HML, and another class contains two mat alpha 2-202, in the MAT alpha locus. These three mutants each have an amino acid substitution of tyrosine or acid substitution of tyrosine or phenylalanine for cysteine at the 33rd codon from the translation initiation codon in the alpha 2 cistron of HML alpha or MAT alpha. The remaining 10 mutants make up the third class and form a single complementation group, having mutations designated aar1 (a1-alpha 2 repression), at a gene other than MAT, HML, HMR, RME1, or the four SIR genes. Although a diploid cell homozygous for the aarl and sir3 mutations and for the MATa, HML alpha, and HMRa alleles showed alpha mating type, it could sporulate and gave rise to asci containing four alpha mating-type spores. These facts indicate that the domain for alpha2 repression is separable from that for a1-alpha2 protein interaction or complex formation in the alpha2 protein and that an additional regulation gene, AAR1, is associated with the a1-alpha2 repression of the alpha1 cistron and haploid-specific genes.

Amino Acid Sequence↗
PubMed1988

A case of large intestinal malignant lymphoma.

Primary malignant lymphoma of gastrointestinal tract is relatively rare and the most of it are seen in stomach or small intestine, and in Japan only 130 cases of primary large intestinal malignant lymphoma were reported from the accumulating results of the postoperative cases in the 11th Congress of the Japanese Research Society for Cancer of the Colon and Rectum. This paper describes the case report of the primary malignant lymphoma originated from the cecum, and the review of the literature. The patient was 63 year-old female, who came to this hospital for slight fever and right lower abdominal pain that was gradually increasing. After the investigation by using barium enema and the intrapelvic CT, cecum tumor was detected. The ileocecal excision was performed, and revealed the 4 X 4.5 cm tumorous type lesion of which surface was slightly irregular. Histopathologically the tumor was follicular lymphoma (partial type), medium sized cell type by the Lymphoma-leukemia Study Group (LSG) classification. After discharge, cyclophosphamide was administered by 100 mg/day for six weeks, and the sign of the recurrence has not been observed.

Cecal Neoplasms↗
PubMed1987

Immunoelectron microscopic study of glomerular lesions using a postembedding method with a protein A-gold complex.

Renal biopsy tissue from 33 children with various glomerular diseases has been investigated by electron microscopy using a postembedding immunostaining technique with a protein A-gold complex in order to establish more precise correlations between immunopathologic and morphologic findings in glomeruli. This technique could detect immunoglobulins (IgG, IgA, and IgM), complement factor (C3c), and fibrinogen-related antigen. The immunoreactivity of these antigens was essentially confined to the mesangial, paramesangial, subendothelial, and subepithelial 'electron-dense deposits' in the glomeruli. Except for IgM and C3c in the case of glomerular sclerosis, the distribution of the mentioned factors was even in the electron-dense deposits, as could be shown by 'double-immunolabeling'. From the above-mentioned findings one can conclude that several of the localized factors are associated with the formation of electron-dense deposits, the ultrastructural hallmarks of glomerular disease.

Antigens↗