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Biomedical subjects

H Sakamoto

Publications and source records attributed to H Sakamoto.

At least 343 records · Page 19Linked to original sources
PubMed1997

Significant correlation between symptom score and IgG4 antibody titer following long-term immunotherapy for perennial allergic rhinitis.

Although there is evidence of some measure of clinical benefit as well as immunologic change during the early phase of immunotherapy, a sustained clinical response is only possible with prolonged therapy. Immunotherapy has to be administered for about 3 to 5 years for such sustained clinical efficacy. This study aimed at investigating the dynamics of IgE and IgG4 antibodies after more than 5 years of immunotherapy, to examine the statistical correlation between these antibodies and symptom scores. Our study demonstrated that the allergen-specific IgE antibody level significantly decreases and the IgG4 antibody level significantly increases following immunotherapy. However, the percent decrease in IgE antibodies did not correlate with the percent decrease in symptom scores. On the other hand, the percent increase in IgG4 antibodies correlated with the percent decrease in symptom scores. We infer that an elevation of IgG4 antibodies is not simply an epiphenomenon unrelated to the underlying working mechanism of clinically successful immunotherapy, but probably makes an active contribution to symptom relief.

Adolescent↗
PubMed1997

Effect of immunotherapy on serum levels of eosinophil cationic protein in perennial allergic rhinitis.

Eosinophil cationic protein (ECP) levels in the serum of clotted blood could reflect the rate of activation of circulating eosinophils. We investigated the serum ECP levels in patients with perennial allergic rhinitis, with special reference to the effect of immunotherapy on the serum ECP levels. Serum ECP levels in untreated patients with perennial allergic rhinitis are significantly higher than those of nonatopic volunteers. Therefore, this elevation in the untreated patients represents an ongoing inflammation occurring in allergic rhinitis. The mean serum ECP level of a 1-year immunotherapy group was significantly higher than that of the nonatopic group, and was not different from that of the untreated group. In contrast, the mean serum ECP level in patients who had more than 2 years of immunotherapy was significantly lower than that of the untreated group, and was not different from that of the nonatopic group. Additionally, serum ECP levels were significantly correlated with the duration of immunotherapy. These findings suggest that activation of circulating eosinophils decreases gradually during immunotherapy, but this inhibition becomes apparent only after 2 years of immunotherapy. The control of circulating eosinophil activation might be one of the important working mechanisms behind the clinical effect of immunotherapy.

Adolescent↗
PubMed1997

Polysaccharides in fungi. XXXVIII. Anti-diabetic activity and structural feature of a galactomannan elaborated by Pestalotiopsis species.

A fungus of Pestalotiopsis species produced an extracellular, water-soluble polysaccharide (PS-N). PS-N exhibited significant hypoglycemic activity in streptozotocin-induced diabetic mice following intraperitoneal administration and had an effect on oral glucose tolerance in normal mice following oral administration. PS-N ([alpha]D +34.5 degrees in water) was homogeneous on gel chromatography, it is composed of galactose and mannose in a molar ratio of 1:9, and its molecular weight was estimated by gel chromatography to be about 24,000. Its structure was investigated by a combination of chemical and spectroscopic methods. The results indicated that PS-N, a highly branched galactomannan, is composed of beta-(1-->3)-linked D-galactofuranosyl and non-reducing terminal beta-D-galactofuranosyl residues, in addition to alpha-D-mannopyranosyl residues of a yeast mannan type.

Animals↗
PubMed1997

The effects of medetomidine on maternal and fetal cardiovascular and pulmonary function, intrauterine pressure and uterine blood flow in pregnant goats.

To investigate the effects of medetomidine on late pregnant goats, medetomidine induced changes in maternal or fetal circulation and acid-base balance, as well as changes in intrauterine pressure (IUP) and uterine blood flow (UBF), were studied. Intramuscular administration of medetomidine (40 micrograms/kg b.w.) decreased the heart rate (HR) and arterial blood pressure (ABP) of the mother, and the change in HR was significant statistically (p < 0.05). In the fetus, HR and ABP showed a transient decrease and increase (p < 0.05), respectively. A decrease in maternal arterial blood pH and oxygen partial pressure (PO2) and an increase in carbon dioxide partial pressure (PCO2) were recorded after the injection, but none was significant. In the fetus, arterial blood PO2 decreased significantly (p < 0.05) after 5 min of administration, and a significant metabolic acidemia supported by a decrease in base excess was observed. Within 1 to 4 min after the administration of medetomidine, IUP began to rise and remained high for 10 to 14 min. Thereafter, the rise in IUP was frequent and periodical. After the injection, UBF significantly (p < 0.05) decreased, and the fall in UBF was associated with a rise in IUP. The maternal and fetal serum medetomidine concentration increased remarkably after the injection of medetomidine into the mother. These observations in late pregnant goats suggested that medetomidine induced a decrease in maternal cardiac output, a decrease in UBF arising from the induction of uterine contractions, and transplacental medetomidine can have a suppressive effect on the fetus.

Adrenergic alpha-Agonists↗
PubMed1997

Pathogenesis of Chiari malformation: a morphometric study of the posterior cranial fossa.

To investigate overcrowding in the posterior cranial fossa as the pathogenesis of adult-type Chiari malformation, the authors studied the morphology of the brainstem and cerebellum within the posterior cranial fossa (neural structures consisting of the midbrain, pons, cerebellum, and medulla oblongata) as well as the base of the skull while taking into consideration their embryological development. Thirty patients with Chiari malformation and 50 normal control subjects were prospectively studied using neuroimaging. To estimate overcrowding, the authors used a "volume ratio" in which volume of the posterior fossa brain (consisting of the midbrain, pons, cerebellum, and medulla oblongata within the posterior cranial fossa) was placed in a ratio with the volume of the posterior fossa cranium encircled by bony and tentorial structures. Compared to the control group, in the Chiari group there was a significantly larger volume ratio, the two occipital enchondral parts (the exocciput and supraocciput) were significantly smaller, and the tentorium was pronouncedly steeper. There was no significant difference in the posterior fossa brain volume or in the axial lengths of the hindbrain (the brainstem and cerebellum). In six patients with basilar invagination the medulla oblongata was herniated, all three occipital enchondral parts (the basiocciput, exocciput, and supraocciput) were significantly smaller than in the control group, and the volume ratio was significantly larger than that in the Chiari group without basilar invagination. These results suggest that in adult-type Chiari malformation an underdeveloped occipital bone, possibly due to underdevelopment of the occipital somite originating from the paraxial mesoderm, induces overcrowding in the posterior cranial fossa, which contains the normally developed hindbrain. Basilar invagination is associated with a more severe downward herniation of the hindbrain due to the more severely underdeveloped occipital enchondrium, which further exacerbates overcrowding of the posterior cranial fossa.

Adolescent↗
PubMed1997

Osteoblastoma of the nasal cavity invading the anterior skull base in a young child. Case report.

The benign osteoblastoma is rarely seen as a tumor of the facial bone in infancy or early childhood. Only five cases with nasal involvement have been reported in the literature. The authors present a case of osteoblastoma of the nasal cavity, the nasal bone, the ethmoid sinus, and the anterior cranial base. This 3-year-old girl presented with a tumor surrounding the left medial canthus. Imaging studies, including x-ray films, computerized tomography scans, magnetic resonance images, a (99m)Tc-scintigram, and angiograms, confirmed the location of the tumor. A biopsy specimen of tumor was obtained intranasally and the pathological diagnosis was an osteoblastic tumor suggestive of osteoblastoma. Although the tumor margin was well defined on the radiological images, it was difficult to determine the exact margin during the operation. Therefore, it is important to show how to excise the tumor completely under direct view. With the use of a "dismasking flap," it was possible to resect the benign osteoblastoma completely from the nasal cavity, even though it extended into the orbit, the maxilla, and the anterior cranial base.

Angiography↗
PubMed1997

[Intraoperative aneurysmal rupture at the neck].

Intraoperative rupture of an aneurysm can lead to disastrous results when the rupture occurs at the neck. The authors have encountered eight cases (5%) of intraoperative rupture in a series of 155 patients. All patients were operated on in the acute stage by one of the authors of this paper (T.Y.). In six cases, the aneurysm ruptured at the dome and in two, at the neck. We report these two patients with intraoperative rupture at the neck. The first case, a 50-year-old female, developed SAH, but a 4-vessel study failed to show an aneurysm. The second series of angiograms obtained ten days later showed a broad-based, left proximal A1 aneurysm. It was decided to employ a right pterional approach. The aneurysm was arising from the right A1 segment just proximal to the anterior communicating artery. The neck was wide, with thin walls. Thus, it seemed better to apply a clip parallel to the A1 segment axis than to apply it from a direction perpendicular to the A1 segment axis. However, the right pterional approach precluded a parallel clipping, so the blades of a clip were applied perpendicularly. The clip seemed not to be completely across the neck of the aneurysm. After applying a temporary clip to the A1 segment proximal to the aneurysm, the clip blades were opened and advanced just when bursting of the sac at the base occurred and microvascular suture repair was required to control the bleeding. The second case, a 57-year-old female, underwent clipping of a right IC-PC aneurysm. However, two years postoperatively, the patient again suffered SAH. Cerebral angiography at this time revealed a relatively large recurrent IC-PC aneurysm in which the old clip was situated on the dome of the aneurysm. Aneurysmal clipping was performed on the day of rupture. Tough granular tissue was removed from the ICA, PcomA, aneurysmal neck, and the old clip. After the true neck was identified, a straight clip was applied to the neck parallel to the ICA. Soon after the clipping, arterial bleeding occurred near the neck. The ruptured aneurysm was trapped using two temporary clips. A curved clip was applied to the ruptured neck, including the wall of the ICA, to control the bleeding. This clipping caused a substantial stenosis of the ICA. Both patients demonstrated postoperative neurological deficits due to ischemia caused by temporary clipping. These encounters dramatically demonstrated that a very thin-walled aneurysm or a recurrent aneurysm has a fragile neck. In surgical treatment of these unusual aneurysms, a clip should be placed on the neck parallel to the parent artery. Furthermore, temporary clipping is advisable when dissecting the neck or applying the clip to the neck to reduce the damage to the neck.

Aneurysm, Ruptured↗
PubMed1997

Effective prevention of thrombocytopenia using adenovirus-mediated transfer of HST-11FGF-4 gene: in vivo and in vitro studies.

A novel biological function of HST-1 protein (FGF-4) was investigated by constructing an adenovirus vector containing the HST-1 cDNA and applied for thrombocytopenia as a gene therapy. A single intraperitoneal injection of the replication-deficient adenovirus containing the HST-1 gene (Adex1HST-1) into mice caused a two-fold increase in peripheral platelet count for 30 days, and effectively prevented experimentally induced thrombocytopenia. Studies of Adex1HST-1-infected or HST-1 protein-treated megakaryocytic Dami cells suggested that HST-1 protein promotes megakaryocyte maturation, and increases cytokine secretion from megakaryocyte and adhesive interactions between megakaryocyte and endothelial cells. Colony assay revealed that HST-1 protein stimulated CFU-MK (colony-forming unit of megakaryocyte) not alone but synergistically with early-acting cytokines such as IL-3 or Tpo (c-mpl ligand) as a megakaryocyte potentiating factor. These results have important implications for clinical application of the Adex1HST-1 for thrombocytopenia.

Adenoviridae↗
PubMed1997

[Replacement of the aortic root with woven and knitted Dacron composite graft].

Some of the patients with annuloaortic ectasia or Stanford type A require aortic root replacement. If conventional Bentall procedure is employed in such cases, aortic root will become a cylindrical shape totally lacking sinus of Valsalva because the procedure utilizes a straight tube. The sinuses of Valsalva support an important role in opening and closing the valvar leaflets, and opening of the coronary arteries, together with the interleaflet triangles and the sinutubular junction. In this study, we performed aortic root replacement with composite graft which consisted of two types of graft including 30 mm Knitted Dacron Graft (Gelsoft) with different dilation rates and 30 mm Woven Dacron Graft (Hemashield) as well as bioprosthesis (27 mm Carpentier-Edwards), in order to reconstruct sinus of Valsalva. Post-operative angiography revealed an excellent diastolic coronary flow, as evidenced by proximal Knitted graft of 37 mm in diameter, distal Woven graft of 30.3 mm in diameter and Doppler flow DSVR (Diastolic/Systolic Velocity Ration) of 2.2 measured at the left coronary orifice. Since it is difficult to obtain homograft at present, this procedure would be worth trying during aortic root replacement.

Aged↗
PubMed1997

[Rupture of previously documented asymptomatic saccular intracranial aneurysms].

The authors report four cases of patients with documented asymptomatic intact aneurysms that subsequently ruptured. Case 1 involves a 64-year-old woman who had two unruptured aneurysms, i.e., an anterior communicating artery aneurysm and a posterior inferior cerebellar aneurysm, both were discovered during evaluation of cerebral ischemic symptoms. At that time, only the posterior inferior cerebellar aneurysm was clipped. Seven years later, the patient bled fatally from a 5-mm untreated anterior communicating artery aneurysm that had measured approximately 3 mm on an angiogram obtained 7 years earlier. Case 2 is that of a 50-year-old woman who bled from an anterior communicating artery aneurysm that had been discovered 6 years earlier when she suffered subarachnoid hemorrhage (SAH) from a left middle cerebral artery aneurysm. At that time, she had refused surgery for the anterior communicating artery aneurysm. She recovered well from the second SAH. Case 3 is that of a 74-year-old woman who bled from a left paraclinoid internal carotid artery aneurysm that had been discovered incidentally 3 years earlier during evaluation of vertigo. She had not agreed to have a clipping at that time the aneurysm was first discovered because of her age and the difficult location of the aneurysm. She eventually made an uneventful recovery. In the fourth case, during evaluation of cerebral ischemic symptoms, a 59-year-old man was discovered to have a large basilar bifurcation aneurysm. He underwent a craniotomy for clipping of the aneurysm. The aneurysm, however, was unclippable and was instead coated with Bemsheet. Four months later, the patient bled from the aneurysm and entered a vegetative state. The indications for surgery on unruptured asymptomatic cerebral aneurysms are still unclear. The cases reported herein show that asymptomatic aneurysms, especially anterior communicating aneurysms and aneurysms once exposed surgically, do carry a certain risk for future hemorrhage and should not be dismissed as innocuous. Neurosurgeons have recognized the importance of considering life expectancy in managing patients with asymptomatic, unruptured, intracranial aneurysms. With the rapid aging of the population, withholding aneurysm surgery merely because a patient is elderly may not necessarily be the most appropriate decision.

Aged↗
PubMed1997

[Management of subarachnoid hemorrhages without detectable aneurysm].

In this study, 21 patients with subarachnoid hemorrhage (SAH) but negative angiography were evaluated. Angiography was performed twice on each patient, that is, on admission and at 2 weeks following admission. All patients had severe headache of sudden onset, a characteristic manifestation of SAH. Clinical grades on admission (Hunt and Kosnik classification) were generally good: 17 patients were in grade I or II and 4 patients were in grade III. SAH was confirmed by the presence of subarachnoid clot on CT in all cases. Based on the distribution of SAH, CT findings were classified into two patterns, i.e., perimesencephalic and non-perimesencephalic patterns. Four patients showed the perimesencephalic pattern and the remaining 17 the non-perimesencephalic. The period of follow-up ranged from 20 days to 11 years 6 months, with a mean of 6 years 10 months. Except for three recent cases, the mean follow-up period in 8 years 9 months. Exploratory craniotomies probing for aneurysms have been performed in four patients, but no aneurysms have been found in any of these cases. Clinical deterioration associated with vasospasm was observed in one patient. A communicating hydrocephalus requiring a shunting procedure was observed in three patients showing the non-perimesencephalic type CT pattern. Rebleeding occurred in one patient who subsequently died of what may be a dissecting aneurysm of the vertebral artery. One patient who was able to return to full activity experienced symptoms attributable to SAH such as frequent headaches and increased fatigability. Complete recovery was observed in the remaining 19 patients. Two of them, however, later died due to myocardial infarction and aging, respectively. Given these generally positive outcomes, it should be possible to inform such patients of the benignity of their condition. Angiography may not demonstrate a ruptured aneurysm on initial examination in all cases of aneurysmal SAH. Serial angiography, however, can provide a definite diagnosis of the dissecting aneurysm. Therefore, repeat angiography, particularly, when possible, digital subtraction angiography, is necessary to rule out aneurysmal SAH. While small aneurysms or microaneurysms are often found through exploratory craniotomy, we do not agree with the opinion that surgery may be appropriate for certain patients with SAH but with negative angiography. The natural history concerning rebleeding in such cases, as well as morbidity and mortality associated with hemorrhage, remains to be defined. Furthermore, there are reservations regarding whether coagulation of these abnormalities with bipolar cautery constitutes definitive treatment.

Adult↗
PubMed1997

Reversible pontine ischemia caused by acetazolamide challenge.

We report the findings in a patient with a midbasilar artery stenosis in whom reversible ischemic neurologic deficits developed during cerebral blood flow imaging with acetazolamide challenge. The potential for ischemic complications from acetazolamide challenge is discussed.

Acetazolamide↗
PubMed1997

Direct extracranial-intracranial bypass for children with moyamoya disease.

To improve cerebral hypoperfusion in the ischemic type of Moyamoya disease, we have applied superficial temporal artery-middle cerebral artery (STA-MCA) double anastomoses in combination with encephalo-myo-synangiosis (EMS) for 19 hemispheres of 10 children (age from 5 to 11 years at surgery). Two branches of the STA were anastomosed to the two cortical arteries which were selected in the watershed area of the cerebral hemisphere estimated as a hypoperfusion area on the preoperative angiograms. Before surgery transient ischemic attacks (TIAs) developed from every month to every 6 months in association with hyperventilation or sobbing. No perioperative completed stroke or wound complications was observed, although single TIA developed in four patients within 1 month after surgery. Postoperative angiogram demonstrated that, not only the preoperative watershed area, but also the most of the middle cerebral artery territory was oppacified via the 2 branches of the STA in all 19 hemispheres. In a mean follow-up period of 4 years, no ischemic episode was induced by hyperventilation, and there was no mental or neurological deterioration. STA-MCA double anastomoses, to the cerebral watershed area, in combination with EMS are safe and effective even for younger children with Moyamoya disease.

Anastomosis, Surgical↗
PubMed1997

Potential role of 5-HT2 and D2 receptor interaction in the atypical antipsychotic action of the novel succimide derivative, perospirone.

The pharmacological profile of the novel serotonin-dopamine antagonists (SDA)-type antipsychotic, perospirone, was compared with other SDA and typical antipsychotics, and a potential role of 5-HT2 and D2 receptor interaction in the atypical antipsychotic property of SDA was discussed based on the findings with selective 5-HT2 antagonists. Our study revealed that perospirone, like other SDA, differed from the typical antipsychotics by exhibiting 1) putative anxiolytic and/or antidepressant actions in some animal models (e.g., conditioned fear stress-induced freezing model and rat social interaction), 2) reduced extrapyramidal side effects (EPS) liability (catalepsy and bradykinesia induction), 3) weaker blocking actions at striatal D2 receptors as revealed by c-fos expression and dopamine turnover and 4) lower propensity to induce supersensitivity of dopamine receptors after repeated treatments (e.g., dopamine agonist-induced stereotyped behavior and vacuous chewing movement). The 5-HT2 antagonists mimicked the action of SDA antipsychotics in the animal models of mood disorder. In addition, combined treatments of 5-HT2 antagonists with typical antipsychotic could attenuate EPS induction and striatal c-fos expression associated with D2 receptor blockade, and could prevent the sensitization of D1 receptor function after repeated treatments. These findings suggest that the blockage of 5-HT2 receptors contributes to the broad efficacy profile of SDA (i.e., antipsychotic and mood stabilizing actions) and may counteract the D2 (and/or D1) blocking activities of antipsychotics in the striatum to reduce EPS.

Animals↗
PubMed1997

Immunosuppressive drugs inhibit the production of interleukin-6 and interleukin-8 in cultured cardiac myxoma cells.

Cardiac myxoma cells produce large amounts of interleukin (IL)-6 and IL-8. To determine whether immunosuppressive agents could be used to treat cardiac myxoma, we tested the effects of dexamethasone and three of the newer second-generation immunosuppressive drugs, cyclosporin A, tacrolimus, and deoxyspergualin, on the production of IL-6 and IL-8 in these cells. Cultured cardiac myxoma cells were used as in vitro model of cardiac myxoma. Cells were tested for 24 hours with 10(-7) M dexamethasone, 10(-6) M cyclosporin A, 10(-8) M tacrolimus, and 10(-6) M 15-deoxyspergualin, with aliquots of conditioned medium being assayed for cytokine levels at 0, 6, 12, and 24 hours. Cardiac myxoma cells isolated from 4 patients all produced quantities of IL-6 and IL-8. The concentrations of IL-6 in the medium after 7 days in culture ranged from 79,000 to 2,740,000 pg/ml, and the concentrations of IL-8 ranged from 40,000 to 1,000,000 pg/ml. Exposure of cyclosporin A and dexamethasone almost completely inhibited the production of IL-6 and IL-8 after 24 hours of treatment. Tacrolimus inhibited the production of both cytokines by 55%, while 15-deoxyspergualin reduced IL-6 levels by 24% and IL-8 levels by 48% after separate 24 hour treatments. These results suggest that these newer immunosuppressive agents may be useful in reducing the production of IL-6 and IL-8 in patients with cardiac myxoma.

Aged↗
PubMed1997

[Relationship between subjective cognition and observed life-style in nursing students].

Complex interactions between long-standing lifestyles and genetic factors are strongly involved in the pathologenesis of adult diseases or chronic degenerative diseases. We usually use a questionnaire to obtain life-style information from subjects in a health survey. However, the response to questionnaires is a subjective recognition, therefore, it does not always precisely correspond to the actual situation. The purpose of this research is to compare the response to the questionnaire about life-styles with facts that can be objectively observed. Furthermore, each aspect of life-styles was examined on a mutual influence grade. The subjects were ninety-eight nursing college students aged from 18 to 23 years old, in good health. Subjective symptoms and daily life practices were investigated by a 15-item questionnaire, as the first step. Therefore, we asked them to record their behavior on a time chart, everyday for ten days. Seven days of serial records were obtained from sixty-four subjects (65.3% of 98 persons). 1) The response "yes" to the questionnaire "Do you sleep well?" and "Do you fall asleep, easily?" was influenced by the hours of sleep, rather than what time the subjects "go-to-bed" or "get-up". The response to "Do you wake up often during the night?" expressed an actual situation, well. 2) For subjective cognition regarding excretion, the answer for "constipation" was associated with the number of defecation per week, though the answer for "diarrhea" was not. 3) The answer to "Do you eat breakfast?" reflected the actual situation. However, the answer for "Do you eat between meals?" did not express the actual situation, that is, even the subjects who answered "occasionally" or "I don't eat between meals" had eaten between meals 6.1 times per week, on average. 4) There were mutual influences among sleeping, eating breakfast and excretion.

Adult↗
PubMed1997

[A case of multifocal Langerhans cell granulomatosis: a BAL follow up study].

Langerhans cell granulomatosis, once called histiocytosis X, is a rare disease. A case of multifocal Langerhans cell granulomatosis in the bone, lymph nodes, skin and lungs of an 18-year-old man is described. Head CT and MRI showed a soft tissue mass of the left temporal bone. Lymph node and skin biopsies substantiated a diagnosis of Langerhans cell granulomatosis. A High resolution CT scan of the lung revealed a small cystic lesion, and bronchoalveolar lavage (BAL) showed an increased number of S-100 positive cells. Steroid therapy resulted in complete resolution, and no S-100 positive cells were obtained in the follow-up BAL study.

Adolescent↗