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Biomedical subjects

T Uede

Publications and source records attributed to T Uede.

At least 91 records · Page 5Linked to original sources
PubMed1996

Molecular cloning and characterization of guinea pig Fc gamma RIII: expression but not function is independent of the gamma chain of Fc epsilon RI.

We have isolated two cDNA clones encoding the guinea pig receptor for the Fc portion of IgG2 (Fc gamma 2R) from a guinea pig peritoneal macrophage cDNA library. Analysis of the predicted amino acid sequence of the one cDNA clone indicated that the guinea pig Fc gamma 2R is a type I transmembrane protein and has approximately 72% DNA sequence homology and approximately 57% protein sequence homology with the human Fc gamma RIII. Therefore, we propose that the guinea pig Fc gamma 2R is referred to as guinea pig Fc gamma RIII. The most important finding in this report is that the obtained cDNA directed the cell surface expression of the Fc gamma 2R on COS-7 cells without association with the gamma chain of the high-affinity IgE receptor (Fc epsilon RI gamma) which is required for human and mouse Fc gamma RIII to be expressed on the cell surface. Furthermore, we demonstrated that the endocytosis activity of Fc gamma RIII is dependent upon the association with Fc epsilon RI gamma, suggesting that Fc epsilon RI gamma is involved in the functions of guinea pig Fc gamma RIII. The other clone was found to lack the sequence encoding transmembrane and cytoplasmic domains, suggesting the presence of a soluble form of guinea pig Fc gamma RIII. Northern blot analysis and RT-PCR showed that a transmembrane form of guinea pig Fc gamma RIII was expressed in peritoneal macrophages, but not in neutrophils in spite of the fact that they express Fc gamma 2R, indicating that the Fc gamma 2R on neutrophils is a product of a distinct gene.

Amino Acid Sequence↗
PubMed1996

Long-term acceptance of major histocompatibility complex-mismatched cardiac allograft induced by a low dose of CTLA4IgM plus FK506.

The immunosuppressant FK506 prolongs allograft survival. However, at therapeutic doses it has significant side effects. A fusion protein consisting of the extracellular portion of CTLA4 and the Fc portion of human IgG (CTLA4IgG) also prolongs allograft survival, but large doses of CTLA4IgG are required for the induction of cardiac allograft acceptance. Therefore, we constructed a pentameric form of a new CTLA4 fusion protein, CTLA4IgM. We tested whether low doses of CTLA4IgG or CTLA4IgM in combination with subtherapeutic doses of FK506 can prolong allograft survival in a synergistic fashion. C57BL/6 (H-2b) neonatal hearts were transplanted to CBA/J (H-2b) mice in a heterotopic, nonvascularized cardiac allograft model. The findings demonstrate that a combination of low doses of FK506 plus a pentameric form of CTLA4Ig, CTLA4IgM, leads to significant graft survival, while a combination of FK506 plus CTLA4IgG does not.

Abatacept↗
PubMed1996

Cerebral venous sinus thrombosis associated with systemic multiple hemangiomas manifesting as chronic subdural hematoma--case report.

A 35-year-old male was admitted with headache, nausea, and vomiting persisting for 2 days. Computed tomography (CT) revealed a left chronic subdural hematoma. Cerebral angiography demonstrated cerebral venous sinus thrombosis (CVST). He had presented with a subcutaneous mass involving the neck at age 2 years, which was shown to be a cavernous angioma, and thereafter shown signs of consumptive coagulopathy with systemic multiple hemangiomas. Burr hole aspiration of the hematoma was performed. Seventy-two-hours later, he developed clouding of consciousness and right hemiparesis. CT revealed a fresh hematoma in the operated subdural cavity and hemorrhagic diathesis manifested. A frontotemporoparietal large craniotomy was performed to remove the hematoma. Extensive electrocauterization was required. He had a satisfactory postoperative course. Collateral venous pathways, resulting from the CVST due to systemic multiple hemangiomas, may have caused hemodynamic stress in the bridging veins which subsequently induced chronic subdural hematoma.

Adult↗
PubMed1996

A case of calcification of the cervical ligamentum flavum.

We report a case of cervical myelopathy caused by the calcification of the cervical ligamentum flavum. A 42-year-old woman with gait disturbance and an episode of dysuria was transferred to our hospital on June 30, 1994. Neurological examination revealed only a mild right hemiparesis. A plain neck X-ray and a tomogram revealed a nodular calcification in the posterior part of the spinal canal at the level of C5/6. Three dimensional computed tomography clearly demonstrated that the mass consisted of three nodular structures on the vertebral lamina. Magnetic resonance images demonstrated severe compression of the spinal cord by the mass whose intensity was low. The mass was removed en bloc together with the ligamentum flavum and C5 and C6 lamina. The mass showed no continuity to the dura mater. The calcification was confined within the ligament. The patient's neurological deficits were resolved two weeks after the surgery. X-ray diffraction study demonstrated the component of the mass was found to be pure hydroxyapatite. Clinical features of calcification of the ligamentum flavum are reviewed from 85 reported cases including ours, and the difference between this calcification and the ossification of the ligament is emphasized. Calcification of the ligamentum flaum is a distinct clinical entity.

Adult↗
PubMed1996

[Surgical approach for cervical dumbbell type neurinoma: posterior approach by partial hemilaminectomy with preservation of a facet joint].

We report on a case harboring a cervical dumbbell type neurinoma. The tumor was completely removed by a modified posterior approach, consisting of partial hemilaminectomies of C2 and C3 with preservation of the facet joint. The operative field under microscope was limited by the preserved facet joint of C2/3. However, sufficient bulk reduction of the epidural and paravertebral mass enabled us to obtain a good operative field. The paravertebral mass, which extended anteriorly to just beside the posterior aspect of the carotid sheath, was removed through the lateral space. The operative field was easily widened beside the right facet joint of C2/3 with partial removal of the posterior part of the transverse process of C2 and C3. The transit portion of the tumor to the normal nerve fiber was also identified through this space. The intracanalicular mass was removed by the partial hemilaminectomies of C2 and C3 without compressing the dural sac. Following sufficient reduction of the bulk, the right vertebral artery was identified at the anteromedial margin of the enlarged intervertebral foramen. Finally the intradural part of the tumor was removed through this space. Our modified posterior approach is a less invasive method to the bony elements of the cervical vertebrae and may minimize the incidence of postoperative instability and angular deformity. This approach also eliminates the necessity of long postoperative immobilization using a rigid cervicothoracic brace.

Cervical Vertebrae↗
PubMed1996

[Distinctions of petroclival meningioma with perifocal edema on adjacent brain stem].

Although the most frequent benign tumor of the central nervous system, meningioma may be associated with extensive peritumoral edema. Whereas, peritumoral edema in the brain stem along the tumor in the infratentorial region has not been given sufficient recognition. Among 44 meningiomas attached to the petrous bone, 25 cerebellopontine angle meningiomas and 17 petroclival meningiomas, peritumoral edema in the brain stem along the tumor were clearly demonstrated on T2 weighted images of MRI in three petroclival meningiomas (6.8% of all clival and 17.6% of petroclival meningiomas). Attempts were made to surgically remove all of these tumors. However, during surgery an arachnoid/pial layer between the tumor and brain stem was destroyed completely and small perforating arteries were found to be encased in the tumor at the level of the associated edema. So surgical dissection of the tumors from the brain stem was quite difficult. By attempting radical removal of the tumor in the first case, even meticulous dissections caused direct surgical damage in the brain stem due to the obliteration of small perforating vessels. In the second case, a thin layer of the tumor remnant beside the brain stem was left intentionally, but a severe damage of the brain stem also occurred due to the obliteration of small perforating vessels. In the third case, only bulk reduction of the tumor was attempted to minimize the mass effect to the brain stem and the tumor located beside the brain stem with edema and encasing the cranial nerves and the perforating arteries from the vertebrobasilar artery was left untouched. This surgical attempt caused a transient worsening of a swallowing disturbance, but was not associated with the brain stem damage in this case. In meningiomas attached to the clivus, existence of associated peritumoral edema in the adjacent brain stem on T2 weighted images on MRI may be caused by the destruction of a arachnoid/pial layer and the encasement of small perforating vessels. The attempt at tumor dissection from the brain stem at the level of the edema was very difficult and led to serious surgical complications due to direct damage to the brain stem. In such cases, the surgery should aim at achieving a simple bulk reduction and the tumor beside the brain stem with edema should be left untouched.

Aged↗
PubMed1996

[Evaluation of carotid artery stenosis with three-dimensional CT angiography and surgical revascularization].

The accuracy of three-dimensional CT angiography (3D-CTA) for delineating atherosclerotic carotid stenosis was examined in comparison with digital subtraction angiography (DSA) in symptomatic patients. In cases undergoing carotid endarterectomy (CEA), the clinical usefulness of 3D-CTA for surgical planning was also evaluated in the light of intraoperative findings. From July 1992 to June 1995, 52 patients suffering from internal carotid ischemia and/or presenting carotid bruit were evaluated to detect carotid bifurcation stenosis by 3D-CTA. Shaded surface reconstruction (SSR) for three-dimensional display and maximum intensity projection (MIP) were employed in multiple projection to evaluate sites of stenosis. DSA was performed in 18 out of 31 patients having atherosclerotic carotid stenosis shown by 3D-CTA. MIP reconstructions accurately delineated sites of stenosis close to DSA and allowed precise depiction of ulcerated plaque and intramural calcification. The percentage of carotid stenosis was determined by comparing the narrowest point to the internal carotid artery (ICA) beyond the bulb on both 3D-CTA and DSA. Assessment of carotid stenosis was highly correlated between 3D-CTA and DSA (r = 0.987, p < 0.0001). In this series, 9 carotid arteries in 8 patients underwent CEA for severe stenosis. 3 patients with ICA occlusion and 1 patient with elongated severe stenosis underwent STA-MCA anastomosis. Using MIP reconstructions and two-dimensional original images it was found that ICA occlusion was apparently distinguished from high grade ICA stenosis. SSR provided valuable informations during CEA for atherosclerotic plaque regarding anatomical relationship with the internal jugular vein and bony structures. This advanced means of 3D-CTA can be adequate as a screening method to detect carotid stenosis in symptomatic patients and useful for surgical planning of CEA and post-operative follow-up examination.

Angiography, Digital Subtraction↗
PubMed1996

[Prognosis after total removal of craniopharyngiomas via the frontobasal interhemispheric approach].

Prognosis after total removal of craniopharyngiomas via the frontobasal interhemispheric approach is reviewed. Seventeen patients with craniopharyngiomas were operated on in Sapporo Medical University Hospital between January, 1985 and December, 1993. In eleven patients, lamina terminalis was incised and in the last six patients, it was left intact. Tumors were completely resected in all patients. After removal of the tumor, hypothalmic--pituitary functions, visual functions and psychometric functions were examined. Two of the 17 cases showed hypernaturemia and fourteen (82%) had permanent DI. Fourteen patients are receiving DDAVP and all are receiving endocrine replacement. Of fourteen patients who had disturbance of their visual acuity, nine (64%) improved. Five of six patients (83%) who presented visual field defect showed improvement in their deficits. Thirteen patients had a psychometric assessment at the time of follow-up examination. Full-scale intelligence quotient scores were distributed as follows: three above 120, five between 90 and 109, three between 70 and 79 and two below 69. Four (32%) had some impairment of memory. Concerning the QOL after total removal of craniopharyngiomas via the frontobasal interhemispheric approach, thirteen patients (76%) are leading normal lives, and three (18%) are leading nearly normal lives but require some help to overcome mild deficits. One (6%) has suffered a significant handicap.

Adolescent↗
PubMed1996

[Hearing preservation and tinnitus following removal of acoustic neurinomas].

Thirty-five cases of unilateral acoustic neurinomas were analyzed with special reference to the postoperative eighth cranial nerve function. An additional three cases of bilateral acoustic neurinomas associated with neurofibromatosis were also analyzed. Out of a total of 40 neurinomas in all, 38 cases were retrospectively reviewed. The thirty-five cases of unilateral acoustic neurinomas were summarized as follows. The patients' age ranged from 23 to 69 years old. The tumor size varied as follows; 7 cases were confined to the internal acoustic meatus, 4 cases were 20 mm or less in their maximum diameter, 13 cases were 30 mm or less, and 11 cases were more than 30 mm. The consistency of the tumor was classified as being solid in 27 cases, and being cystic in 8 cases. Hearing had been maintained in 27 cases on admission, serviceable in 17 cases, unserviceable in 10 cases and deaf in 8 cases. Operations were performed via the retromastoid suboccipital approach in all cases. The facial nerve was anatomically preserved in all cases. On the other hand, the cochlear nerve was anatomically preserved in 14 out of 35 cases (40%). The preservation ratio of the cochlear nerve showed a negative correlation to the tumor size. In 17 cases with preoperative serviceable hearing, preservation of the cochlear nerve was attempted, which resulted in a 65% anatomical preservation. However, hearing was preserved in 4 cases (36%). Serviceable hearing was preserved in only 2 cases. Tinnitus developed in 20 cases preoperatively, and then occurred postoperatively in 11 cases. Tinnitus was prominently aggravated in 2 cases in which the cochlear nerves were preserved, which resulted in unserviceable hearing. There was a statistically significant correlation between cochlear nerve preservation and the postoperative presence of tinnitus (Fisher's exact probability test: P = 0.0106 < 0.05). Tinnitus was aggravated just after the operation. However, it gradually improved and vanished as the hearing showed a recovery to a slight degree in one case. Three cases of bilateral acoustic neurinomas in neurofibromatosis were also summarized. One case received the operation only on the unilateral side. The remaining two cases were operated bilaterally. To preserve serviceable hearing on at least one side, partial removal of the tumor was performed under the monitoring of auditory brain stem response and/or cochlear microphonic potential. Serviceable hearing on at least one side was maintained in all three cases. In conclusion, hearing preservation can be expected after removal of the acoustic neurinomas under the following situations; hearing acuity of less than 50-60dB in preoperative pure tone audiogram, tumor size of less than 20 mm in maximum diameter, cases with preservation of cochlear nerve and of the internal auditory artery during the operation, and no injury to the labyrinth during the operation. In some cases, tinnitus becomes aggravated in the case with cochlear nerve preservation associated with unserviceable hearing. Furthermore, the degree of tinnitus shows a decrease as postoperative hearing improves in some cases.

Adult↗
PubMed1996

[Characteristics of visual impairment complicated with planum sphenoidale and tuberculum sellae meningiomas and their surgical results].

It is well known that it is difficult to remove the planum sphenoidale and tuberculum sellae meningioma without damaging the optic nerves. The visual outcome after this operation has been unacceptable in such tumors, especially in large ones. This review propounds a strategy to secure visual acuity through operation. A total of eight cases are summarized. In five midline symmetrical meningiomas, the tumors compressed the nerves at the portion of the optic chiasma, causing a typical bitemporal hemianopsia. Four large tumors were resected by the frontobasal interhemispheric approach to minimize the intraoperative damage to the optic chiasma, and a small one was removed by the pterional approach. Visual deficits were recovered immediately after the operation in all cases without any surgical complications. Three meningiomas were attached to the lateral part of the planum sphenoidale or tuberculum sella. Although the sizes were relatively small in all cases, they caused ipsilateral severe visual loss by direct compression to optic nerves. MRI and three-dimensional CT angiography showed the tumor extension into the optic canal. The ipsilateral pterional approach was selected in these cases. To avoid additional nerve damage, we tried to reduce the tension of nerves which were compressed by the tumors. We removed the anterior clinoid process and opened the optic canal before surgical manipulation of the tumor. In two cases, tumors severely compressed the optic nerves from the medial side, and nerves were stretched laterally. Great care was required to separate the optic nerves from tumors in those two cases. In contrast, the resection seemed to be very easy in one of the cases where the optic nerve was displaced infero-medially. Visual symptoms were improved in all cases, although one case became worse temporarily. Although planum sphenoidale and tuberculum sellae meningiomas are still troublesome, appropriate preoperative management would allow us to expect an excellent visual outcome. Especially, selection of the surgical approach should be based on the anatomical analysis of the nerve displacement.

Adult↗
PubMed1995

Angiotensin-converting enzyme gene polymorphism in Japanese patients with hypertrophic cardiomyopathy.

To examine the contribution of the angiotensin-converting enzyme (ACE) gene to hypertrophic cardiomyopathy (HCM), we determined the ACE insertion/deletion (I/D) polymorphism in 80 patients with HCM and 88 of their unaffected siblings and children. Patients were divided into familial or solitary HCM (FHCM or SHCM) groups with or without affected family members. Genotypes were identified by the polymerase chain reaction (PCR) with oligonucleotide primers flanking the polymorphic region in intron 16 of the ACE gene to amplify template DNA prepared from peripheral leukocytes. D-allele frequencies were 0.38 in all subjects, 0.42 in patients with HCM, and 0.35 in relatives (p < 0.05). The probability ratios were 1.98, 1.46, and 2.97 in patients with HCM, FHCM, and SHCM, respectively. The D allele frequency was higher in SHCM than in FHCM (p < 0.05). The findings suggest that HCM, especially in solitary cases, is partially determined by genetic disposition. Findings imply that the ACE D allele is one of the genetic contributing factors associated with cardiac hypertrophy in HCM.

Aged↗
PubMed1995

Protective effect of monoclonal antibodies against LFA-1 and ICAM-1 on myocardial reperfusion injury following global ischemia in rat hearts.

The effects of anti-LFA-1 and anti-ICAM-1 monoclonal antibodies (MAbs) on the reperfusion injury of rat cardiac tissues after global ischemia were studied. Studies were performed using an isolated blood perfused heart preparation in which hearts were subjected to 30 min of global ischemia followed by 40 min of reperfusion. Isolated rat hearts were perfused with blood from an anesthetized support rat with or without anti-LFA-1 or anti-ICAM-1 monoclonal antibody administration (n = 10 in each group). Ventricular function, myocardial tissue water content and myocardial energy status were evaluated in this model. In the control group, ischemia and reperfusion of isolated hearts resulted in a 63.6 +/- 2.7% recovery of left ventricular developed pressure (LVDP) and a 44 +/- 7% increase in coronary vascular resistance compared with pre-ischemic baseline values. Treatment with anti-LFA-1 MAb or anti-ICAM-1 MAb resulted in a 77.2 +/- 1.5% and a 80.4 +/- 3.0% recovery of LVDP, respectively. In addition, increase in coronary vascular resistance was only 23 +/- 7% and 13 +/- 6% in anti-LFA-1 and anti-ICAM-1-treated groups, respectively. Values are significantly different between the control group and MAb-treated groups. Ischemia and reperfusion resulted in a 16% increase of myocardial tissue water content (3.71 +/- 0.03 in pre-ischemic baseline versus 4.29 +/- 0.08 ml/g dry weight) in the control group, whereas that resulted in only 3.0 and 5.7% increase in anti-LFA and anti-ICAM-1-treated groups, respectively. The difference between the control group and MAb-treated groups was significant. Cardiac energy status as assessed by adenosine triphosphate (ATP) concentration was markedly reduced in the control group at 40 min of reperfusion compared with pre-ischemic baseline values (5.70 +/- 0.27 vs. 14.92 +/- 0.48 mumol/g dry weight). In contrast, the reduction of myocardial ATP concentration at 40 min of reperfusion was significantly inhibited by anti-LFA-1 and anti-ICAM-1 monoclonal antibody treatment (5.70 +/- 0.27 vs. 8.96 +/- 0.52 and 8.10 +/- 0.47 mumol/g dry weight, respectively). These results suggest that a LFA-1/ICAM-1 pathway plays a critical role in the pathogenesis of postischemic myocardial injury during early reperfusion period.

Animals↗
PubMed1995

Neutrophil-independent myocardial dysfunction during an early stage of global ischemia and reperfusion of isolated hearts.

The effect of global ischemia and reperfusion on the expression of cytokine genes and cell adhesion molecules by myocardial tissues and neutrophils was studied by using the Langendorff model. Although cardiac function deteriorated after reperfusion of ischemic hearts, there was no evidence of inflammation and myocardial degeneration, which is in contrast to previous findings that neutrophil-mediated inflammation is a critical step in post-ischemic reperfusion injury in regional ischemia. Flow cytometry analysis demonstrated that the global ischemia and reperfusion did not affect the expression of adhesion molecules on neutrophils. We also examined the expression of various cytokines which are involved in inflammatory responses. Only interleukin 1 alpha was induced after the reperfusion of the ischemic hearts. These results suggest that neutrophils barely contribute to the myocardial dysfunction and IL-1 alpha may play a role in post-ischemic myocardial dysfunction during the early stage of reperfusion.

Animals↗
PubMed1995

The rat neutrophil low-affinity Fc receptor for IgG: molecular cloning and functional characterization.

A complementary DNA (cDNA) clone encoding rat Fc gamma receptor II (Fc gamma RII) was isolated from rat neutrophils and characterized. The cDNA encodes a type I transmembrane protein with 285 amino acids having an extracellular domain consisting of two immunoglobulin-like domains (179 amino acids), a transmembrane domain (26 amino acids), and a cytoplasmic domain (47 amino acids). The nucleotide sequences are identical to that of recently cloned Fc gamma RII from rat mast cells. This protein was expressed on FcR-negative Chinese hamster ovary (CHO) cells. The characterization of cDNA-transfected CHO cells clearly indicated that the protein encoded by the cDNA clone binds guinea-pig IgG1 and IgG2 complexes and unexpectedly binds monomeric rat IgG1, but not IgG2. Furthermore, the affinity for immune complexes was significantly augmented by protease treatment of transfectants. In addition, endocytosis of immune complex was noted in transfectants.

Animals↗
PubMed1995

CD23 molecule acts as a galactose-binding lectin in the cell aggregation of EBV-transformed human B-cell lines.

Epstein-Barr virus (EBV)-transformed human B-cell lines, L-KT9 and DH3 cells express CD23 antigen, and grow in a mixture of single and aggregated cells. The CD23 molecule has high amino acid sequence homology with C-type lectin and recently we have shown that the solubilized CD23 molecule can really interact with galactose residues on glycoproteins. In this study, therefore, we tested whether CD23 antigen on the cell surface really acts as a galactose-binding lectin in the aggregation of these cells. The EBV-transformed cells (L-KT9) were separated into an aggregated-cell-rich fraction and a single-cell-rich fraction. Aggregated cells disaggregated after removal of galactose by beta-galactosidase treatment, whereas single cells made large aggregation on sialidase treatment, and this aggregation was inhibited in the presence of asialo-fetuin. On the other hand, naturally aggregated cells become single cells with anti-CD23 monoclonal antibody (mAB) as well as the soluble form of CD23, but not with anti-CD21 mAB. In addition, L-KT9 and DH3 cells bound to asialo-fetuin-coupled Sepharose (ASF-Sepharose) and this binding was significantly inhibited by pre-treatment of cells with anti-CD23, but not with anti-CD21 or other anti-adhesion molecules. From these results, we conclude that the naturally aggregated state of EBV-transformed cells occurs mainly through the interaction of CD23 as a lectin molecule and galactose residues as its ligand.

Antibodies, Monoclonal↗
PubMed1995

[Diagnosis of ruptured and unruptured cerebral aneurysms with three-dimensional CT angiography (3D-CTA)].

Three-dimensional CT angiography (3D-CTA) is a new, minimally invasive technique for the diagnosis of cerebral aneurysms. The purpose of this study is to compare the diagnostic value of 3D-CTA for ruptured and unruptured cerebral aneurysms with that of MR angiography (MRA) and digital subtraction angiography (DSA). Forty-one cases consisting of 11 cases of ruptured aneurysms and 30 cases of unruptured aneurysms, with a total of 67 cerebral aneurysms, were included in this study. 3D-CTA was performed with a bolus injection of nonionic contrast medium on the SOMATOM PLUS-S scanner and the ProSeed Accell scanner. Three-dimensional images were obtained by both shaded surface reconstruction (SSR) method and maximum intensity projection (MIP) method. The CT values of cisternal clot in cases of ruptured cerebral aneurysms did not exceed 90HU in any of the cases. The effect of SAH was, therefore, eliminated in the SSR images through a threshold level processing of a CT value of 150HU. All the cerebral aneurysms were visualized by this process. With regard to the detectability of cerebral aneurysms, 3D-CTA was able to demonstrate cerebral aneurysms with diameters of larger than 1mm as well as giant aneurysms which MRA would sometimes fail to reveal. 3D-CTA was superior to MRA and DSA in making diagnosis of small aneurysms such as those with diameters of less than 3mm.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗