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Biomedical subjects

H Kikuchi

Publications and source records attributed to H Kikuchi.

At least 757 records · Page 42Linked to original sources
PubMed1986

Reduction of the buried intrachain disulfide bond of the constant fragment of the immunoglobulin light chain: global unfolding under physiological conditions.

The constant (CL) fragment of the immunoglobulin light chain contains only one intrachain disulfide bond buried in the interior of the molecule. The kinetics of reduction with dithiothreitol of the disulfide bond were studied at various concentrations of guanidine hydrochloride at pH 8.0 and 25 degrees C. It was found that the disulfide bond is reduced even in the absence of guanidine hydrochloride. The results of the reduction kinetics were compared with those of the unfolding and refolding kinetics of the CL fragment previously reported [Goto, Y., & Hamaguchi, K. (1982) J. Mol. Biol. 156, 891-910]. It was shown that the reduction of the disulfide bond proceeds through a species with a conformation very similar to that of the fully unfolded one and that the CL fragment undergoes global unfolding transition even in water.

Disulfides↗
PubMed1986

Autolysis of the granular layer of the cerebellar cortex in brain death.

In a study of duration of brain death, granular layer autolysis (GLA) of the cerebellar cortex was analyzed in 45 patients who died of acute cerebrovascular diseases (CVDs). Twelve patients who died of causes other than intracranial disease served as controls. Tonsillar herniation occurred in all who died of acute CVDs. More advanced GLA was seen in the central folia adjacent to the central white medullary body of the cerebellum as compared with the peripheral folia. Widespread GLA involving the most of the peripheral folia was found solely in patients in whom brain death had been present over 18 h. Of the 12 control patients, 4 showed GLA only in the central folia. Although GLA of the central folia might develop during immersion fixation of the brain, the alteration of the peripheral folia is assumed to develop in the period of brain death. Widespread GLA extending to the peripheral folia could be a pathological finding characteristic of brain death, where intracranial blood flow could be absent or significantly reduced. Brain death for little less than 1 day would be necessary for GLA to develop.

Adult↗
PubMed1986

Traumatic stenosis of the internal carotid artery in children.

Two cases of stenosis of the internal carotid artery after blunt craniocervical trauma in children are described. Their neurological symptoms developed a few hours after the injury. A superficial temporal artery-middle cerebral artery anastomosis was performed in one, and the other was conservatively treated because of the spontaneous resolution of the stenosis. The pathophysiology and treatment of this clinical entity, especially in children, are discussed.

Accidents, Home↗
PubMed1986

Effect of auranofin on autoimmune disease in a mouse model.

The effect of an oral gold preparation, auranofin, on the autoimmune disease mouse MRL/l was examined. Oral administration of auranofin on consecutive days from 6 weeks of age reduced anti-DNA antibody production, IgM rheumatoid factor production, hypergammaglobulinemia, polyclonal B cell activation and renal disease, but did not prevent massive lymphadenopathy or restore the low level of either IL-2 production or mitogen response associated with 1pr gene. In contrast to the effect on autoantibody production, little suppressive activity on the immune response to exogenous antigen SRBC was observed. These results indicate that autoimmune disease in MRL/l mice can be prevented without abrogation of T cell abnormalities and that autoimmune-selective suppression can be induced by chemical compound(s) like auranofin.

Animals↗
PubMed1986

Hemorrhagic infarction after vasospasm due to ruptured cerebral aneurysm.

Hemorrhagic infarction after vasospasm is a rare condition in patients with aneurysmal subarachnoid hemorrhage (SAH). Induced hypertensive therapy is used for patients with vasospasm, but this treatment has a risk of inducing hemorrhagic infarction. A total of 221 patients whose first computed tomographic (CT) scans were examined within 2 weeks after SAH were investigated for this study. There was symptomatic vasospasm in 99 (45%), cerebral infarction in 37 (17%), and hemorrhagic infarction in 13 (6%). Hemorrhagic infarction usually occurred 20 to 30 days after aneurysmal rupture; this period corresponds with the remission stage of the vasospasm. On CT scans, the hemorrhagic infarction was revealed as a leaky hemorrhage in a low density area in 11 cases, and a massive hemorrhage with mass effect was seen in 2 cases. These findings suggest that hemorrhagic infarction after vasospasm may sometimes be fatal. Cerebral blood flow autoregulation in patients with vasospasm was normal or of a hypertensive type during the remission stage of vasospasm, when hemorrhagic infarction usually appeared. This finding shows that induced hypertension therapy is ineffective during this stage; it should be stopped by this stage because it is ineffective and also may aggravate hemorrhagic infarction.

Adult↗
PubMed1986

Nizofenone administration in the acute stage following subarachnoid hemorrhage. Results of a multi-center controlled double-blind clinical study.

A multi-center controlled double-blind clinical study was carried out to evaluate the effects of nizofenone in patients with subarachnoid hemorrhage who were treated within 2 weeks of the ictus. The test drug was administered as an addition to conventional therapy, which was maintained during the study. Of 208 patients studied, 102 were treated with nizofenone and 106 with placebo. Treatment with nizofenone was significantly more effective (p less than 0.05) than that with placebo based on functional recovery and other clinical findings. Although no significant difference was found in mortality rate between the nizofenone- and placebo-treated groups, a higher percentage of survivors in the former group exhibited a good outcome (p less than 0.05). The effects of nizofenone administration were found to be especially notable in patients with delayed ischemic symptoms, moderately severe preoperative deficits (Hunt and Hess Grade II or III), and diffuse high-density areas in pre- and postoperative computerized tomography scans. No significant side effects were observed.

Adult↗
PubMed1986

Study of the posterior circulation in moyamoya disease. Part 2: Visual disturbances and surgical treatment.

The involvement of the posterior circulation in moyamoya disease was studied in 178 patients. Forty-three had several types of disturbance such as visual field defect, decreased visual acuity, episodes of blindness, and scintillating scotomata. Most of these symptoms were attributed to occlusive lesions in the posterior circulation. Visual disturbances were seen more often in patients with a juvenile onset than in cases of adult onset. Superficial temporal artery (STA) to middle cerebral artery (MCA) anastomosis and encephalomyosynangiosis (EMS) improved the cerebral perfusion both in the anterior and posterior circulation by redistribution of blood. In most cases, the visual symptoms subsided or were stabilized after STA-MCA anastomosis and EMS. These surgical procedures did not, however, lead to direct revascularization in cases of ischemia in the visual cortex. In five patients with impending blindness, transplantation of the omentum to the occipital lobe led to improved vision.

Adolescent↗
PubMed1986

Synergism of cephalosporins at subinhibitory concentrations and polymorphonuclear leukocytes on phagocytic killing of Escherichia coli and its mode of action.

The interactions between subinhibitory concentrations of cephalosporins and polymorphonuclear leukocytes in the killing of a strain of Escherichia coli are described and an attempt is made to define the responsible mechanism. Ceftizoxime was the most potent agent tested. Pretreatment of the E. coli strain with subinhibitory concentrations of ceftizoxime increased the susceptibility to both; phagocytic killing activity of the polymorphonuclear leukocytes and bactericidal activities of the oxygen metabolites and the granule extracts. A most interesting result was the increased susceptibility of the ceftizoxime-treated E. coli to killing by beta-glucuronidase which normally is not bactericidal. It is suggested that the augmented killing could be due to bacteriolysis by beta-glucuronidase.

Animals↗