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Biomedical subjects

K Seki

Publications and source records attributed to K Seki.

At least 235 records · Page 13Linked to original sources
PubMed1994

[Definitive diagnosis of Alzheimer's disease using olfactory mucosal biopsy].

Characteristic changes appearing in the biopsied olfactory mucosa of Alzheimer's disease (AD) patients were investigated using immunohistochemical staining. Specimens were obtained from 6 patients who were clinically diagnosed with AD, 2 patients with cerebrovascular dementia and 5 age-matched patients with olfactory disturbance without dementia. In most AD cases, polyclonal tau protein immunoreactivity was seen in the dendrites, perikarya of the olfactory receptor cells in the olfactory epithelium and the olfactory nerve bundles in the lamina propria. In a few cases, tau protein immunoreactivity was found in the extracellular mass in the epithelium. Ubiquitin immunoreactivity was seen is the dendrites of olfactory receptor cells. On the other hand, in control cases, only dendrites and olfactory nerve bundles reacted to anti-polyclonal tau protein antiserum in a few cases. These results indicate that the neurofibrillary tangle-like tau protein immunoreactivity in the perikarya senile plaque-like extracellular mass and ubiquitin immunoreactivity in the olfactory epithelium were characteristic changes in AD, and olfactory mucosal biopsy is a useful method for the definitive diagnosis of AD.

Aged↗
PubMed1994

Characteristics of the health conditions of old patients with spinal cord injury.

The state of health of old patients with spinal cord injury (SCI) was investigated to clarify the disorders that they are presently suffering from. A questionnaire was sent by mail to 668 patients with SCI living in western Japan. Valid answers were returned from 448 (67%), and they were divided into a young group (160 patients aged 18-39 years), middle-aged group (193 patients aged 40-59 years), and elderly group (95 patients aged 60-73). About 30% in the young group answered that they were ill or worrying about their health. This percentage was about 60% in the middle-aged and elderly groups. According to disease types, none of the young group had urological diseases except urological impairment or cardiovascular diseases, but many of the elderly group had urological tract infection, kidney diseases, cardiovascular diseases, and digestive diseases. Decubitus ulcer was reported in all groups. Urological diseases and decubitus ulcer were considered to be characteristic ailments of individuals with SCI. The elderly group was also characterized by a high incidence of adult diseases such as hypertension and diabetes mellitus. Therefore, the types of diseases and their frequency are considered to be different in older patients with SCI compared with the aged population in general because of the characteristic conditions of SCI in addition to adult diseases.

Adolescent↗
PubMed1994

Specific reactivity of human monoclonal antibody AE6F4 against cancer cells in tissues and sputa from lung cancer patients.

In vitro immunization of normal human peripheral lymphocytes by the co-cultivation with A549 cells (a human lung adenocarcinoma cell line), followed by the hybridization with the partner cell line A4H12, resulted in the efficient generation of hybridomas which produce human monoclonal antibodies of IgG or IgM isotype. Immunohistochemical and immunocytological studies showed that one of those monoclonal antibodies, termed AE6F4, was specifically reactive to lung cancer tissues as well as cancer cells in sputa.

Antibodies, Monoclonal↗
PubMed1994

[Whole head measurement of auditory evoked magnetic field using a MR-linked helmet shaped MEG system].

Authors compared MR anatomy and magneto-encephalographic (MEG) functional methods in locating auditory cortex in 20 normal volunteers and 56 patients with intracranial structural lesions. Auditory evoked response was measured over the entire head, using a helmet shaped 64 channel MEG system. In each subject, three dimensional MR image was obtained with identical coordinate system of MEG. Best fit sphere to each subject's head was calculated from MRI data. Signal source of auditory evoked MEG was estimated using a two dipole model in the best fit sphere. Position and orientation of dipoles were superimposed on each subject's MRI. Both left and right dipolar patterns appeared about 100 ms after unilateral auditory stimuli (N100m) in 19 normal subjects and 47 patients. These dipolar patterns overlap each other across the midline. A two dipole model successfully localized bilateral N100m dipoles in the upper surface of superior temporal planes. N100m response was missing unilaterally in 1 normal subjects and 9 patients inspite of normal audiometry findings, suggesting sub-clinical auditory dysfunction. The MR-linked whole head MEG is a non-invasive tool to localize source of auditory evoked N100m response even in the case with intracranial structural lesions.

Acoustic Stimulation↗
PubMed1994

[Aortic dissection with giant pseudoaneurysm as a rare late complication of aortic valve replacement--a case report].

A 60-year-old man who had received aortic valve replacement for aortic regurgitation at 47 years of age developed sudden syncope and shock on Mar. 28, 1991. Close examination including CT scan and aortography revealed DeBakey type I aortic dissection with giant pseudoaneurysm which compressed superior vena cava and right pulmonary artery and caused superior vena cava syndrome. He underwent elective ascending aortic replacement under profound hypothermic cardiopulmonary bypass and circulatory arrest on Jun. 17, 1991. The giant pseudoaneurysm was present posterolaterally to the ascending aorta. It communicated with the false lumen and contained massive thrombi. The intimal tear of the ascending aorta existed along the suture line of previous aortotomy.

Aortic Dissection↗
PubMed1994

[Adjunctive methods for surgery of descending thoracic aortic aneurysm].

During the last 6 years, we employed partial extracorporeal circulation (PEC) in 7 cases and left heart bypass (LHB) in 9 cases as adjunctive methods for surgery of descending thoracic aortic aneurysm. During the aortic clamping, systemic heparinization was performed to keep an ACT more than 400 seconds in a PEC group, while it was kept from 200 to 250 seconds in LHB group. The bypass flow was controlled to maintain the distal arterial pressure over 50 mmHg in both groups. Hemodynamics during the aortic clamping were stable in both groups and significant differences were not found between them. However, ventricular fibrillation occurred in one case of LHB group, who suffered from coronary artery disease, and required subsequent PEC to maintain systemic circulation. Both PEC and LHB provided adequate intraoperative hemodynamics and postoperative serum biochemistries. But we preferred to adopt PEC to maintain the diatal perfusion in cases with heart disease, who are likely to develop circulatory deterioration under the aortic clamping.

Adult↗
PubMed1994

[Locating the central sulcus using three dimensional image fusion system of helmet shaped whole head MEG and MRI].

We compared MR anatomy and magnetoencephalographic (MEG) functional methods in locating the central sulcus. In 20 normal volunteers and 58 patients with intracranial structural lesions, the short latency somatosensory evoked magnetic fields for median nerve and posterior tibial nerve stimuli were measured over the entire head, using a helmet shaped MEG system. The dipole positions estimated by a single current dipole model were projected onto the three dimensional MRI. In 94% of a total of 156 hemispheres, N20m dipole positions for median nerve stimuli coincided with the central sulcus defined by MR anatomical image only. For posterior tibial nerve stimuli, the P38m dipole positions were estimated as being near the medial end of the anatomical central sulcus. MRI and MEG are complementary in locating the central sulcus, even in cases of intracranial structural lesions.

Adolescent↗
PubMed1994

[Total aortic replacement in a patient with extensive thoracoabdominal aortic aneurysm--a case report].

A 35-year-old woman with a form fruste of Marfan's syndrome, presented the extensive thoracoabdominal aortic aneurysm. CT scan, MRI and aortogram revealed that she had a true aneurysm of ascending aorta and aortic arch and chronic DeBakey IIIb dissecting aneurysm extending throughout the descending thoracic and abdominal aorta. The surgical treatment was consisting of two staged operations. At the first operation, ascending aorta and aortic arch were reconstructed under cardiopulmonary bypass and selective cerebral perfusion. Elephant trunk method was employed for the second operation. The second operation was performed by graft replacement of the entire descending thoracic and abdominal aorta with reattachment of intercostal and visceral arteries. She discharged the hospital without any complication including paraplegia.

Adult↗
PubMed1994

[Conduction disturbances after coronary artery bypass grafting with retrograde cardioplegia].

We studied forty-six cases, who had undergone coronary artery bypass grafting with retrograde cold blood cardioplegia for myocardial protection, to manifest the frequency and causative factors of postoperative conduction disturbances. We obtained the following conclusions. 1) Postoperative conduction disturbances developed in nineteen cases (41.3%), all of which were right bundle branch blocks, but these were usually transient and were not associated with further complications in the follow-up period. 2) There were no significant differences in many factors, including number of grafts, aortic cross-clamp times, or peak CK-MB between cases with and without postoperative conduction disturbances.

Adult↗
PubMed1994

[Postlaminectomy kyphosis of the cervical spine complicating spinal cord tumor in the foramen magnum].

Postlaminectomy kyphosis is rarely encountered as a sequela of decompression of the upper cervical spine, especially in adults. We present a case of disabling cervical kyphosis which developed after laminectomy for excision of a foramen magnum tumor and was treated successfully by occipito-vertebral fusion. A sixty-one-year old female was treated by laminectomy of the first through to the third cervical spine for a foramen magnum meningioma. One year later, the laminectomy was extended downward to include the fourth through to the seventh cervical spine because of neurological deterioration. Seven years after the first laminectomy, she was referred to our spinal service because of severe neck pain, numbness and muscle weakness of both upper extremities. Lateral X-ray of her cervical spine presented a severe kyphosis. Roentgenogram two months after the first laminectomy already showed slight deformity and, timewise, it corresponded with the time when the patient experienced neurological deterioration. Subsequent X-rays showed progression of kyphosis. After we confirmed a lessening of the pain and improvement of the neurological symptoms during an axial traction using a halo-vest, posterior occipito-cervico-thoracic fusion was performed using Luque segmental spinal instrumentation and autogenous bone graft. After surgery the pain decreased and neurological symptoms improved. It is important to be aware of the complication of kyphotic deformity after laminectomy and once it has developed, it is recommended to stabilize the progression by early spinal fusion.

Cervical Vertebrae↗
PubMed1994

[Mitral valve aneurysm in a patient with mitral regurgitation: a case report].

A 66-year-old man admitted to our hospital complaining of severe dyspnea. Echocardiography demonstrated severe mitral regurgitation and an abnormal echo at the anterior leaflet of the mitral valve. It was a persistent bulge that protruded toward the left atrium throughout systole and diastole. Left ventriculography also demonstrated the same abnormal shadow of the mitral valve. At the operation, it was seen that two of the chordae tendineae of the anterior leaflet had ruptured and a small aneurysm, approximately 10 mm in length, originated from the lateral part of the leaflet. The aneurysm protruded into the left atrium and had neither rupture nor perforation. Because the aneurysm of the mitral valve was too large to resect and repair the valve, it was replaced with St. Jude Medical Valve (29 M). IABP was needed at the weaning from cardiopulmonary bypass, but he recovered gradually well afterwards. The excised anterior leaflet showed myxomatous degeneration, but had no vegetation and rheumatic change. Microscopic examination of the valve aslo revealed myxomatous degeneration and no signs of the inflammation.

Aged↗
PubMed1993

Absence of linkage disequilibrium at amyloid precursor protein gene locus in Japanese familial Alzheimer's disease with 717Val-->Ile mutation.

To date, eleven independent FAD pedigrees with the 717Val-->Ile mutation have been identified. Interestingly, five pedigrees were of Japanese origin and four were of British origin. The apparent ethnic prediction of this mutation raises the possibility that there is a founder effect in these two island nations. We did not observe any significant linkage disequilibrium in any locus of APP and GT12 loci in the five Japanese FAD pedigrees with the 717Val-->Ile mutation. A founder effect would probably not be present in Japanese FAD pedgrees with the 717Val-->Ile mutation.

Alleles↗
PubMed1993

Secretory cell immunoscreening assay--a highly sensitive screening method for secretory cells.

We have developed a rapid and sensitive screening method to detect the secretory product from transformed secretory cells. Polyclonal antibodies against the target secretory protein are first adsorbed onto a nitrocellulose membrane and are then called solid-phase antibodies. Then this membrane is placed on top of target protein-secreting adherent animal cell colonies. After trapping the secreted protein on the membrane, the protein is detected using the highly sensitive enhanced chemiluminescence detection system. Thus, this method is named the secretory cell immunoscreening assay (SCISA). We have screened recombinant BHK-21 cells, which secrete human interleukin-6 (hIL-6) for highly productive clones. With the SCISA method, it is possible to detect less than 100 pg of hIL-6 secreted by a single colony. We are also able to select highly productive colonies rapidly and easily from a large sample population of transformed cell colonies.

Animals↗
PubMed1993

Identification of hybrid-type carbohydrate chains on the light chain of human monoclonal antibody specific to lung adenocarcinoma.

The carbohydrate chains on the light chains of human monoclonal antibody HB4C5 reactive to human lung adenocarcinoma tissue have been characterized. The HB4C5 antibody consists of two kinds of light chains (30 kDa and 32 kDa). Each chain has different carbohydrates of varying molecular masses linked to the variable regions. The 30 kDa light chain has been confirmed to be the active species for antibody binding. The carbohydrates on the light chains were characterized by lectin blot analysis combined with glycosidase treatment. A carbohydrate chain linked to the active 30 kDa light-chain species, and one of a few carbohydrate phenotypes on the 32 kDa light-chain species is characterized as "hybrid type". A sialylated complex-type carbohydrate could also bind to the 32 kDa light-chain species. Nucleotide sequence analysis revealed that one potential N-glycosylation site is located in the complementarity determining region 1 of the light chain, although no such site was found in the variable region of the heavy chain.

Adenocarcinoma↗
PubMed1993

[Clinical trial of IVC filter to temporary placement].

We developed a new inferior vena caval filter to prevent pulmonary embolism for a patient with IVC thrombus. This filter made by covering top half of Dotter Intravascular Retriever catheter with Dacron mesh sheet, was placed in IVC through a 10 F sheath from right jugular vein. In one case, after anticoagulant therapy and thrombectomy using balloon catheter, many free-floating thrombus were trapped in this filter and were taken out from the IVC. This filter was useful for preventing pulmonary embolism when removing thrombus in IVC, iliac and lower extremity veins. We propose to call this device "Hino's filter".

Adolescent↗
PubMed1993

Transforming growth factor alpha and CD68 immunoreactivity in giant cell tumours of bone: a study on the nature of stromal and giant cells, and their interrelations.

To clarify the nature of neoplastic cells, 17 giant cell tumours of bone were studied histologically and immunohistochemically. L1 antigen and S-100 protein were not detected in the tumour giant cells and stromal cells, although present in non-neoplastic macrophages. The giant cells in all the lesions, some stromal cells, and osteoclasts in the normal bone showed CD68 and transforming growth factor alpha (TGF alpha) immunoreactivity. Fibrohistiocytic antigen, factor XIIIa, was expressed in large numbers of stromal cells in all lesions. Some stromal cells expressed alpha-smooth muscle actin and osteocalcin. These immunohistochemical results suggested that the stromal cells of giant cell tumours of bone showed histiocytic and occasional myofibroblastic and osteoblastic differentiation. Proliferating cell nuclear antigen was demonstrated in the nuclei of the stromal cells only, indicating that these were the sole proliferating elements. TGF alpha produced by the giant cells and some stromal cells may play a role as a mediator for the attraction and/or proliferation of the precursor cells, and may suppress the activity of osteoblastic stromal cells, resulting in restricted bone formation in giant cell tumours.

Adolescent↗