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Biomedical subjects

M Tsuru

Publications and source records attributed to M Tsuru.

170 records · Page 10Linked to original sources
PubMedDate not supplied

Electron microscopic observation of established chondrocytes derived from human intervertebral disc hernia (KTN-1) and role of macrophages in spontaneous regression of degenerated tissues.

BACKGROUND CONTEXT: Biological and pathological cell processes during the degeneration of intervertebral discs are as yet poorly understood. PURPOSE: An electron microscope was used to observe disc hernia degeneration at the cellular level as expressed in extruded tissue from a human intervertebral disc and in cultured chondrocytes. The mechanism of spontaneous regression was analyzed in order to investigate the effects of homologous macrophages, and the results of this analysis may be developed into a clinical therapy. STUDY DESIGN/SETTING: Extruded tissue specimens excised during surgery on human intervertebral disc hernia and cultured chondrocytes isolated from the excised tissue were observed by means of electron microscopy. Extracellular matrix metalloproteinase-3 (MMP-3) and its antagonist, tissue inhibitor of metalloproteinases-1 (TIMP-1), were observed by means of immune electron microscopy. Macrophages confirmed by CD68 immunostaining were added to the chondrocyte culture and observed by means of electron microscopy. PATIENT SAMPLE: All control subjects and patients gave written consent to the study. OUTCOME MEASURES: KTN-1 was directly observed without culture, and nuclei degeneration, the development of chromatin granules, changes in the osmotic pressure of the nuclear membrane and rough-surfaced endoplasmic reticulum, and the development of fat droplets were observed. METHODS: Tissues excised during surgery were divided, a part of the tissues were fixed in various fixatives for electron microscopy and immune electron microscopy analysis, and the other part was treated with collagenase. In addition, chondrocytes were isolated and cultured. Human peripheral blood mononuclear cells were separated using the Ficoll method. After culturing the cells, macrophages were collected, added to the chondrocyte culture, and observed under an electron microscope. CD68 positivity of the macrophages was confirmed by CD68 immunostaining. RESULTS: Freshly isolated chondrocytes in the hernia's extruded region differed markedly from cultured chondrocytes. By means of immunoelectron microscopy, MMP-3 and TIMP-1 were localized at the endoplasmic reticulum of the cultured chondrocytes. Infiltration of macrophages among the chondrocytes was observed in the mixed culture. CONCLUSIONS: The tissue extruded from the intervertebral disc showed obvious signs of degeneration, such as changes in osmotic pressure. Macrophages were observed to be the mechanism of spontaneous regression.

Cell Line↗
PubMedDate not supplied

Effects of mild hypercapnia on somatosensory evoked potentials in experimental cerebral ischemia.

In a previous report, the authors demonstrated the effectiveness of mild hypercapnia in enhancing decreased perfusion flow in ischemic, non-infarcted brain tissues. However, the previous work lacked in verification of improvement of suppressed brain function. Therefore, this report was attempted to evaluate the effect of hypercapnia on somatosensory evoked potential (SEP), using the similar ischemic model as previously. The results showed that mild hypercapnia of 43 to 55 mm Hg range was beneficial not only for enhancing decreased perfusion flow but also for restoring suppressed SEP. This report seems to be the first publication which verifies a presence of correlation between local cortical blood flow (LCBF) and SEP under mild hypercapnia in mildly to moderately ischemic brain tissues.

Animals↗
PubMedDate not supplied

Nationwide co-operative study of intracranial aneurysm surgery in Japan.

A cooperative study was made of 4750 intracranial aneurysm cases collected from 133 neurosurgical clinics in Japan by letter inquiry for the period of 2 years from January 1974 to December 1975. Among them, 4124 cases (87%) had a single aneurysm, and 626 cases (13%) had multiple ones. Direct radical surgery was done in 78% of all cases, carotid ligation in 2% and non-surgical treatment in 17%. Direct surgery in a mortality rate of 15% for ruptured aneurysm cases and 7% for nonruptured cases. Radical surgery within 24 hours after rupture had a mortality of 51%, while those within 1 week and 2 weeks were 39% and 30% respectively; grade I or II patients, however, showed much better surgical results even in early operations. The neurosurgical clinics included in this study were spread throughout most of Japan. Micro-surgical technic was already in use of aneurysm surgery at the time of this study in Japan.

Adolescent↗
PubMedDate not supplied

Evaluation of the brainstem with high-resolution CT in cerebellar atrophic processes.

The authors studied the usefulness of computed tomography (CT) for evaluation of the brainstem in cerebellar atrophic processes. Twenty adult subjects without posterior fossa lesion were used for normal CT measurements of the brainstem. The measured values with CT corresponded to those with pneumotomography. Also reviewed were 49 patients with cerebellar atrophy which included spinocerebellar degeneration (25 patients), Shy-Drager syndrome (five), progressive supranuclear palsy (three), chronic phenytoin usage (10), and chronic alcoholism (six). All but the chronic alcoholism group showed atrophy of the brainstem at all locations of measurement when compared with normal controls (p less than 0.05). In addition, the patients with progressive supranuclear palsy had significantly more pronounced midbrain atrophy. In the chronic alcoholism group the measurements of the brachium pontis, the medulla, and the fourth ventricle differed significantly from those of normal controls (p less than 0.05).

Adolescent↗
PubMedDate not supplied

Myelopathy due to ossification or calcification of the ligamentum flavum: radiologic and histologic evaluations.

The clinical, radiologic, and histologic features of ossification and calcification of the ligamentum flavum were studied in 18 patients. Ossification (15 patients) usually occurred in the lower thoracic spine in men of various ages, while calcification (three patients) was found exclusively in the cervical region of older women. Histologic examinations of ossification showed mature lamellar bone associated with proliferated cartilage replacing the ligamentum flavum (endochondral ossification). This corresponded well with radiographic and computed tomographic (CT) appearances. In the cases with calcification of the ligamentum flavum, calcification within the degenerated ligamentous fibers was observed on histologic examination, and correlated well with an oval nodular density on radiographs and CT. The two conditions differ in clinical, radiologic, and histologic considerations. Pathomechanisms in the development of these lesions and clinical significance are also discussed.

Adult↗