Search PubMed⌕ Search

Biomedical subjects

S Fujiwara

Publications and source records attributed to S Fujiwara.

At least 271 records · Page 15Linked to original sources
PubMed1994

Levels of parathyroid hormone and calcitonin in serum among atomic bomb survivors.

To examine the potential causes of increased levels of calcium in serum with increasing dose of atomic bomb radiation, which was obtained from the previous preliminary analysis, levels of parathyroid hormone (PTH) and calcitonin in serum were examined among 1459 subjects in Hiroshima and Nagasaki. A significant effect of radiation on levels of calcium, PTH and calcitonin in serum was found, even after patients with hyperparathyroidism were excluded. The level of calcium in serum increased with radiation dose; this can be explained partly by the increase in the level of PTH with radiation dose. However, the dose effect on calcium remained even after adjustment for PTH, calcitonin and confounding factors such as renal function, serum albumin level and medication. Parathyroid hormone increased initially by 6.8% per gray, but the dose response leveled off after about 1 Gy. The level of calcitonin increased with radiation dose, probably in part due to feedback mechanisms stimulated by the increase in calcium. However, after adjustment for the level of calcium, the increase in the level of calcitonin with dose was still found. Although the etiological mechanisms of the effect of radiation on serum levels of calcium, PTH and calcitonin are unclear, radiation exposure may affect secretion of PTH and calcitonin and regulation of calcium a long time after atomic bomb exposure.

Adult↗
PubMed1993

Optico-hypothalamic glioma: an analysis of 16 cases.

We reviewed our experience of 16 patients with histologically proven optico-hypothalamic gliomas. They ranged in age from 0.3 to 15 years at the time of diagnosis. Fifteen tumors were located in the optic chiasm, optic nerve, optic tract and/or hypothalamus, while one tumor was confined to one optic nerve. All tumors were classified as low-grade astrocytomas, which were mainly composed of pilocytic astrocytes. No patient had associated neurofibromatosis. The initial treatment for tumors included surgery in 12, radiotherapy in 7, and chemotherapy in 4 patients. After treatment, visual function improved in 3 out of 14, and endocrine function improved in 1 out of 4 evaluable patients. The 5-year actuarial survival rate was 84.0%, and that at 10 years 71.1%. Our experience and the literature indicate that: (1) patients with disease limited to the optic nerve are adequately managed by resection alone; (2) chiasmal-hypothalamic gliomas behave variably, and progressive disease may occur late in the course of the illness; (3) gliomas that arise in patients under 2 years of age and involve the optic chiasm may act aggressively despite their histological benignity; (4) the beneficial effects of radiotherapy occur in about half of the patients; (5) although chemotherapy may be an effective adjuvant treatment modality, it is not an alternative to radiation therapy at present. Both surgery and irradiation therefore offer the best treatment now available for patients with progressive disease.

Adolescent↗
PubMed1993

Repeat angiography and magnetic resonance imaging (MRI) of dissecting aneurysms of the intracranial vertebral artery. Report of four cases.

We here present 4 cases with dissecting aneurysm (DA) of the intracranial vertebral artery, who were followed up by repeat cerebral angiography and MRI. The patients consisted of 2 males and 2 females, and the mean age was 43 years. Two cases were associated with polyarteritis nodosa (PN) and hypertension, respectively. Three of the cases developed subarachnoid haemorrhage (SAH), while the other one suffered from lateral medullary syndrome. In cerebral angiography, "pearl and string" signs were revealed in all cases, while a "double lumen" indicating a true diagnostic sign of DA was demonstrated in only one case. Repeat angiography showed that a bleb formation with a bulging of the aneurysmal sac was seen in 2 cases, and an irregularity of the wall in one case. On the other hand in one case, the ectatic part shrank, while the stenotic part was restored. In magnetic resonance imaging (MRI), a hyperintensity mass on T 1-weighted image (T 1-WI) adjacent to flow void suggesting either an intramural haematoma or a linear shape hyperintensity on T 1-WI were demonstrated in 3 cases. In the follow up MRI done in 2 cases, a serial change in the intensity from iso-intensity to hyperintensity on T 1-WI was observed in one case suggesting intramural haemorrhage, while an enlargement of the ectasic flow void was seen in the other case. Three of 4 cases were operated on by trapping of the aneurysms. One, who had systemic vascular diseases due to PN, and repeat angiography showed a regression of the aneurysm, was conservatively treated.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

De novo aneurysm formation and aneurysm growth following therapeutic carotid occlusion for intracranial internal carotid artery (ICA) aneurysms.

We herein report the long term results of 27 intracranial internal carotid artery (ICA) aneurysms treated by indirect surgery such as a trapping of the aneurysm or carotid ligation either with or without EC-IC bypass. These patients were then followed for a mean period of 10 years. Seventy-four percent of the aneurysms were categorized as either being giant or large. Late complications were observed in 7 patients. A rupture of newly formed aneurysms at the anterior communicating artery occurred in 2 cases 8 or 9 years after either trapping or performing a ICA ligation, respectively. In these patients, previous angiography could not reveal any abnormalities at the anterior communicating artery. A rupture of a contralateral ICA aneurysm was seen in a patient whose ipsilateral ICA was ligated for a ICA aneurysm 22 years previously. An enlargement of the contralateral giant cavernous ICA aneurysm became symptomatic 6 years after a partial ligation of the ICA combined with an EC-IC bypass for a giant cavernous carotid artery aneurysm on the other side. Two cases of sudden death occurred in a young patient and an elderly patient with a small anterior communicating artery aneurysm, 9 and 19 years respectively, after trapping of the ICA aneurysms, although the cause could not be definitely ascertained. Rebleeding occurred in one patient who died 8 years after a carotid ligation and a partial clipping of the ICA aneurysm. Haemodynamic stress may therefore play a major role in inducing new aneurysms or growing aneurysms.(ABSTRACT TRUNCATED AT 250 WORDS)

Carotid Artery Diseases↗
PubMed1993

Peduncular hallucinosis following microvascular decompression for trigeminal neuralgia: case report.

A patient with peduncular hallucinosis following microvascular decompression is reported. A 63-year-old woman with trigeminal neuralgia had microvascular decompression through a lateral suboccipital approach. When a venous hemorrhage occurred on the surface of the pons during surgery, the two main tributaries of the superior petrosal vein were sacrificed to obtain a wider operative field. On the 1st postoperative day, the patient had no problems and the pain completely disappeared, but on the 2nd day, both visual and auditory hallucinations developed, which continued until the 5th postoperative day. The nature of the hallucinations was consistent with peduncular hallucinosis. The pathogenesis of this variety of hallucination is discussed.

Female↗
PubMed1993

Structure and localization of O- and N-linked oligosaccharide chains on basement membrane protein nidogen.

The carbohydrate content of mouse nidogen predicts the occupation of two N- and about seven O-linked acceptor sites. The corresponding oligosaccharides were examined by sequential exoglycosidase digestions. The data indicate N-linked substitutions by several bi-, tri- and tetraantennary complex types of oligosaccharides which are further modified by additional lactosamines and terminal alpha-galactose and/or sialic acid. Mannose-rich oligosaccharides were of low abundance. O-linked structures included a di- and tetrasaccharide core structure that were in addition sialylated and may be similar to structures found in fetuin. Evidence is provided that the two sequence-predicted asparagine acceptors are almost fully substituted. Sequence analysis of tryptic peptides identified Thr-271, Ser-303, Thr-309, Thr-317, Thr-320, Thr-892 and Thr-905 as the most likely sites for galactosamine substitutions. These residues are located in the flexible link connecting the N-terminal globular domains G1 and G2 of nidogen and at the border between the rod and the C-terminal globe G3. Four of them showed Pro in the -1 or +3 position. All these Ser, Thr and Pro residues but not the N-linked attachment sites are identical in human nidogen.

Amino Acid Sequence↗
PubMed1993

Long-term results of endourologic treatment of urinary calculi: investigation of risk factors for recurrence or regrowth.

To evaluate the risk factors related to the long-term outcome of endourologic treatment of urinary calculi, we examined rates of recurrence and regrowth in 167 renal units. The following risk factors were examined: age; previous stone; location, number, size, and composition of stone; and procedures. In our study sample, the overall recurrence and regrowth rates were 17% and 10%, respectively. The earliest recurrence and regrowth appeared at 3 months after treatment, and 71% occurred within 2 years. In 22% of renal units that were estimated to be stone-free, stones appeared later, and 45% of inadequately fragmented stones enlarged. Stones located in a renal calix and pelvis, multiple stones, large stones (more than 20 mm), stones composed of calcium oxalate or calcium phosphate or both, and struvite stones were likely to be risk factors, but there were no significant differences statistically. Although the possibility of several risk factors was suggested in our study, thorough fragmentation of stones and complete removal of fragments, combined with extracorporeal shock wave lithotripsy or chemolysis if needed, is ultimately responsible for successful treatment of urinary calculi.

Adolescent↗
PubMed1993

A complementary DNA for an ascidian embryonic nuclear antigen Hgv2 encodes a protein closely related to the amphibian histone-binding protein N1.

We have isolated and sequenced a cDNA clone encoding an ascidian embryonic nuclear protein, Hgv2. An insert about 2 kb long covered almost the entire length of 2.3-kb Hgv2 mRNA. The amino acid sequence of Hgv2 deduced from the cDNA sequence showed that this protein is related to the amphibian karyophilic histone-binding protein N1, which is thought to be involved in nucleosome assembly. Homology between these two proteins is evident from their extremely similar amino acid compositions and hydropathy profiles. In addition, Hgv2 protein has sequences strikingly similar to the nuclear targeting signal of N1. This is therefore the first report of molecular cloning of a homologue of N1 in non-amphibian species. Putative histone-binding domains of N1 are composed of two acidic residue-rich clusters. Hgv2 polypeptide contains two highly acidic regions, but amino acid sequences of the regions are not conserved. Since Hgv2 protein exists in nuclei of every embryonic cell but disappears from nuclei of metamorphosed juvenile tissues, this protein may function as a nucleosome assembly factor during rapid embryonic cell divisions.

Amino Acid Sequence↗
PubMed1993

Role of endogenous endothelin in extension of rabbit myocardial infarction.

The role of endogenous endothelin-1 (ET-1) in myocardial infarction was investigated in a rabbit ischemia-reperfusion model and in rabbit Langendorff hearts. AwETN40, a monoclonal antibody against ET-1, at 10 mg/kg i.v. inhibited hypertension and hypotension induced by ET-1 (0.3 nmol/kg i.v.): about 70-100% inhibition lasted for 24 h. In a coronary occlusion (30 min)-reperfusion (24 h) model, AwETN40 (10 mg/kg i.v.) reduced the infarct size from 60.9 +/- 4.6% (infarct region/ischemic region in weight, IgG1 kappa control; n = 5) to 37.1 +/- 5.2% (n = 5, p < 0.05). Plasma ET-1 levels were increased significantly by coronary occlusion-reperfusion and returned to control level 24 h after reperfusion. Effects of ET-1 on the coronary vessels and cardiac contractility were studied in the Langendorff heart. ET-1 increased the perfusion pressure from concentrations as low as 10 pM, whereas the developed left ventricular pressure was not altered. These results suggest that ET-1 decreases oxygen supply to the cardiac muscles by constricting coronary vessels and that this, in turn, worsens the ischemic condition of the heart to extend the infarct size.

Animals↗
PubMed1993

Enhancer-like activity of A1gR1-binding site in alginate gene activation: positional, orientational, and sequence specificity.

Significant activation of promoters of alginate genes such as algD or algC occurs in mucoid Pseudomonas aeruginosa during its proliferation in the lungs of cystic fibrosis patients. These promoters have been shown to be responsive to environmental signals such as high osmolarity. The signaling is mediated by a so-called two-component signal transduction system, in which a soluble protein, AlgR2, undergoes autophosphorylation and transfers the phosphate to a DNA-binding response regulator protein, AlgR1. The phosphorylated form of AlgR1 has a high affinity for binding at upstream sequences of both the algC and algD promoters. Two AlgR1-binding sites (ABS) have been reported upstream of the algC gene. One of the two ABSs (algC-ABS1, located at -94 to -81) is critical for the algC activation process, while the second ABS (algC-ABS2, located at +161 to +174) is only weakly active. We now report the presence of a third ABS within the structural gene of algC, and this ABS (algC-ABS3) is also important for algC promoter activation. algC-ABS1 can be replaced functionally by algC-ABS2, algD-ABS1, or algD-ABS2 and somewhat weakly by algD-ABS3. Introduction of a half-integral turn in the DNA helix between the algC site of transcription initiation and algC-ABS1 allowed only slight reduction of promoter activity, suggesting that the binding site could be appreciably functional even when present in the opposite face of the helix. Activation of the algC promoter is independent of the relative location (upstream or downstream of the mRNA start site), the number of copies, or the orientation of algC-ABS1, suggesting that it behaves like a eukaryotic enhancer element in promoting transcription from the algC promoter.

Alginates↗
PubMed1993

Aneurysm of the posterior cerebral artery: report of eleven cases--surgical approaches and procedures.

Eleven cases of an aneurysm of the posterior cerebral artery are reported. All 11 aneurysms were saccular, and 3 were either giant or large. The aneurysms arose from the P1 segment in three patients, the P1-P2 junction in three patients, the P2 segment in three patients, and from the P3 segment in two patients. In all, 10 patients underwent surgery. All P1 and P1-P2 junction aneurysms were treated with the pterional approach. Three P2 and two P3 aneurysms were managed by the subtemporal approach. Two small aneurysms in the series were treated by coating the aneurysmal dome, two by clipping the afferent artery, and all other saccular type aneurysms were treated by clipping the aneurysmal neck. Seven patients had either an excellent or good outcome; two had poor results; and one patient died. The operative approaches and procedures are also discussed in relation to the anatomy of posterior cerebral artery aneurysms.

Adolescent↗
PubMed1993

Combined endovascular and neurosurgical approach for paraclinoid internal carotid artery aneurysms.

The authors review the surgical management of nine complex paraclinoid aneurysms treated with the endovascular balloon catheter technique. With the patient under general anesthesia, the balloon catheter was guided into the feeding artery of the aneurysm by the Seldinger technique. After the aneurysm was exposed, the balloon was inflated temporarily to prevent premature rupture and to facilitate the dissection of the aneurysm. For the larger paraclinoid aneurysm, the double-lumen catheter was introduced into the cervical internal carotid artery (ICA). After temporarily trapping the aneurysm by balloon occlusion of the cervical ICA and clipping the intracranial ICA distal to the aneurysm, retrograde aspiration was performed to collapse the aneurysm. The complete collapse of the large aneurysm by this technique allows an easier dissection of the aneurysm and a safer application of suitable clips. Such a retrograde suction decompression method was used in six large aneurysms. Intraoperative digital subtraction angiography was performed in all cases after the aneurysmal clipping; in three aneurysms, repositioning the clip was required. Only one case of embolic complication was related to the vessel catheterization in this series, which was discovered during the operation. An embolectomy was performed immediately, and there were no postoperative sequelae. We conclude that the combined endovascular and neurosurgical approach, particularly for the large ICA aneurysms, which are difficult to control proximally, can be a useful method of treatment. To prevent complications related to thrombus formation, further refinement in the balloon catheter itself is still needed.

Adult↗
PubMed1993

Prospective study on the prevention of cerebral vasospasm by intrathecal fibrinolytic therapy with tissue-type plasminogen activator.

The authors have evaluated the efficacy of postoperative intrathecal injections of tissue-type plasminogen activator (tPA) in preventing cerebral vasospasm in patients with a diffuse thick subarachnoid hemorrhage (SAH). The present study examined 105 patients who underwent direct surgery within 48 hours of SAH and whose computerized tomography (CT) findings were classified as Fisher CT Group 3. Patients showing diffuse thick subarachnoid blood clots on CT with greater than 75 Hounsfield units (HU) were included in the tPA therapy group and those with below 75 HU comprised the control group. The surgical method was the same in both groups, and both groups had cisternal drainage instituted. On the day following the operation, the tPA group was given an intrathecal injection of tPA (2 mg), and this was continued for several days until all of the cisterns exhibited low density on CT scans. Follow-up angiography showed that 26 cases (87%) in the tPA group had no vasospasm, three (10%) had moderate vasospasm, and one (3%) had severe vasospasm. All four patients showing spasm on angiography were asymptomatic, and there were no cases of delayed ischemic neurological deficits (DIND). In contrast, there were 11 cases (15%) with DIND in the control group. In the tPA group, there was one case of SAH caused by drainage catheter removal, one with a small epidural hematoma, and one with subgaleal fluid accumulation; all of these were treated conservatively with favorable results. Overall, there were no infectious complications related to cisternal drainage and intrathecal injection of tPA. These results indicate that multiple intrathecal injections of small doses of tPA are effective and safe in preventing vasospasm. On the basis of this experience, the authors conclude that injection of 2 mg of tPA daily for 5 days (a total of 10 mg) is effective in preventing the development of vasospasm.

Adult↗
PubMed1993

Intraventricular hemorrhage and cerebral ischemic attacks in the presence of lupus anticoagulant mimicking moyamoya disease.

A case of an 18-year-old female, who developed an intraventricular hemorrhage and recurrent cerebral ischemic r attacks with Moyamoya like angiographical findings was reported. Lupus Anticoagulant (LA) was present in the patient's plasma. Cerebral angiography demonstrated stenosis and occlusion of the intracranial major arteries. Hemorrhagic episodes in patient's with LA is quite rare. The mechanism of intraventricular hemorrhage and the significance of LA in the differential diagnosis of Moyamoya disease are discussed.

Adolescent↗
PubMed1993

The artificial restoration of a dental root.

Periodontal ligament (PDL) cells, osteoblasts (OB), and gingival (GIN) cells originating from human periodontium were co-cultured indirectly with human peripheral blood lymphocytes (PBL). The formation of osteoclasts (OC) from each the co-cultured PBL was compared with a standard PBL culture. A marked suppression of OC formation was observed in PBL co-cultured with PDL cells, and an enhanced OC formation was observed in PBL co-cultured with OB and GIN cells, when compared with the standard PBL culture. The suppressing activity of PDL cells and the enhancing activity of OB and GIN cells on the formation of OC derived from PBL were also found, when the co-culture fluids of PDL/PBL, OB/PBL, and GIN/PBL were added to PBL, and the numbers of OC were counted after 7 days' incubation. Furthermore, the alkaline phosphatase (ALPase) activity of PDL cells was stimulated by co-culturing them with PBL, and the ALPase activity of OB and GIN cells was inhibited by co-culturing them with PBL. When PDL cells were seeded on the surfaces of titanium discs and incubated at 37 degrees C in a 5% CO2 incubator, PDL cells could adhere faster onto titanium surfaces that were coated with a cell-and-tissue-adhesive substance than onto non-coated titanium surfaces. These cultures formed a confluent monolayer on the surfaces of titanium discs by means of an autologous serum containing alpha MEM. These results clearly suggest that the periodontal ligament is a specifically differentiated tissue whose function is to protect alveolar bone from bone resorption due to biting force.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

[Recent advances in the study on the mechanism of brain injury].

A cerebral contusion and DAI (diffuse axonal injury) are practically very important in a medico-legal case of the closed head injury. In this paper, we will report the epitome of the recent advances in the study on the mechanism of them. Coup contusion can be mainly attributed to the skull inbending and/or the skull fracture which develop in the impact region. As to the mechanism of the contrecoup contusion, several theories are reported. During rotational movement of the head, intracerebral shear strains would be produced because of brain lag (Holbourn's rotation theory). Anatomical features of the skull plays an important role (Gurdjian). Relative movement between a brain and a skull induces intracranial cavitation due to pressure gradient (Gross's cavitation theory). Brain is injured by deformation pressure induced by skull deformation and acceleration one done by a movement of the head (Lindenberg). The last one is Courville's transmitted waves of force theory. As to DAI, there is Gennarelli's theory. During a rotational movement of a brain caused by high rate of angular acceleration operating for a long period, intracerebral shear strains occur and injure a brain. As to the brain injuries which include a cerebral contusion and DAI, two theories are reported. Centripetal progression of strains to the core of a brain injuries the brain (Ommaya). Natural frequency of impact determines the nature of resulting injury to the brain (Willinger).

Biomechanical Phenomena↗
PubMed1993

Histo-pathological findings of abraded skins in the cases of automobile dragging.

We histologically examined skin which had been abraded by automobile dragging. In the first case, the victim was a 57-year-old drunken male. He was hit by a passenger car while walking on a road and dragged for a distance of 30 m. He soon died from the pelvic bone fractures. Extensive and deep abrasions were observed on both shoulders and the back. In the second case, a 20-year-old drunken male was lying on a road. He was run over by a passenger car and dragged for a distance of 800 m. During the dragging the car's underbody strongly compressed his thoraco-abdominal region and killed him by causing insufficiency in breathing. Deep abrasions were found in the right temporal region and right back at the waist. In the third case, when a 50-year-old woman was riding a moped it collided with a passenger car at an intersection and she fell to the ground. Soon after, she was run over by another passenger car and dragged for a distance of 718 m. The cause of death was profuse bleeding from the crushed right axillary artery and vein. Autopsy revealed very extensive and severe abrasions in the right upper arm, right axilla, lateral surface of the right chest and abdomen, right back, back pelvic region, and lateral surface of the right lower leg and foot. Especially in the arm, axilla and chest, the skin and soft tissues were worn away, muscles and bones were exposed, and the right axillary artery and vein were crushed.(ABSTRACT TRUNCATED AT 250 WORDS)

Accidents, Traffic↗