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Biomedical subjects

Y Hashizume

Publications and source records attributed to Y Hashizume.

At least 235 records · Page 13Linked to original sources
PubMed1984

Ultrastructure of early calcification in cervical ossification of the posterior longitudinal ligament.

A case of ossification of the cervical posterior longitudinal ligament was investigated with the electron microscope. The posterior longitudinal ligament was composed of bundles of collagen fibers intermingled with occasional fibroblasts and rare blood vessels. Some ligaments contained matrix vesicles in the vicinity of degenerated cells. Hydroxyapatite crystals were frequently precipitated within the matrix vesicles. These findings are similar to the fine structure of the early stage of calcification in normal and pathological calcifying tissues described previously. In this study, the calcification process of the posterior longitudinal ligament suggests that matrix vesicles originate from degenerated cells, and acquire hydroxyapatite crystal deposits. Some eventually coalesce to form a large calcifying mass. Substantial amounts of collagen fibers comprising the ligament may serve an important role in orienting apatite crystal precipitation.

Humans↗
PubMed1984

Occlusion of the basilar artery. A clinical and pathological study of thirteen autopsied cases.

The present report dealt with thirteen autopsied cases of basilar artery occlusion. The age of the patients ranged from fifty one to seventy six years with a mean age of fifty six years, and there were eleven males and two females. Basilar artery occlusion was found in one in every 160 autopsies. The average length of the clinical course of the disease was five months. Many patients had a history of hypertension, diabetes mellitus, and cerebrovascular attacks. The neurological signs and symptoms of basilar artery occlusion extremely varied and were complicated. In our series, occular bobbing, palatal myoclonus, Foville syndrome, and Millard - Gubler syndrome are significant. Arteriosclerotic thrombosis is the most important etiologic factor. The site of occlusion was most frequently encountered in the lower third of the basilar artery. Areas of softening were prominent in the midbrain and the pons. In the cerebellum, softenings were present particularly in the areas supplied by the superior cerebellar artery. Infarcts in the thalamus and the temporo-occipital lobes supplied by the posterior cerebral artery were observed very frequently. The distribution of softening was related to the site of occlusion of the basilar artery and the collateral circulation through the Willis ring.

Aged↗
PubMed1983

Amyotrophic lateral sclerosis. Lack of central chromatolytic response of motor neurocytons corresponding to active axonal degeneration.

Ventral spinal roots and anterior horn cells in the lateral nuclear group of the fourth lumbar segment from 21 patients with amyotrophic lateral sclerosis (ALS) and 23 control patients were morphometrically analyzed. The number of large myelinated fibers was remarkably decreased, while small myelinated fibers were well preserved. The population of large myelinated fibers significantly correlated with the population of anterior horn cells. Numerous axonal degenerations were observed in the ventral spinal roots of patients with ALS, even in patients with severe loss of neurons and axons. In spite of this high frequency of active axonal degeneration, the incidence of central chromatolysis of anterior horn cells remained at the control level.

Adult↗
PubMed1983

Intramedullary spinal cord metastasis. Pathologic findings in five autopsy cases.

This report describes the pathologic findings in five autopsy cases with intramedullary spinal cord metastasis. In an autopsy series over a 30-year period, the incidence of intramedullary metastasis among the metastatic tumors to the spine was 3.5%, and the incidence among the central nervous system (CNS) metastasis was 4.2%. Primary site of tumor was the lung in four cases, and cancer of the thyroid was suspected in one case. On transverse section, the tumor was located mainly in the ventral part of the posterior horn and the medial part of the lateral column. Involvement was focal extending over one to six segments. In two cases, secondary hemorrhage occurred in the posterior horn or the posterior column. In three cases, central ischemic infarction was noted cephalad and caudad to the tumor metastasis. The mode of tumor spread to the spinal cord is not clear, but the autopsy findings in our series suggest that intramedullary tumor may result from hematogenous spread via the arterial circulation.

Adult↗
PubMed1983

Pencil-shaped softening of the spinal cord. Pathologic study in 12 autopsy cases.

This report describes pathologic findings of pencil-shaped softening in 12 autopsy cases. Nine cases were associated with extradural metastasis of malignant tumor and three were observed in brain death. The cavity of the pencil-shaped softening containing necrotic debris and abundant macrophages was located mainly in the ventral part of the posterior column or the dorsal horn. It extended longitudinally over several segments of the cord, predominantly in an upward direction, and had a very clear demarcated margin from the compressed surrounding tissue. Reactive change of the surrounding tissue was very rare. Pencil-shaped softening was found most often in the level of the thoracic cord. The cavity was always continuous with an area of transverse necrosis or and area of patchy necrosis. In previous reports, the factor of circulatory disturbance was considered important for the pathogenesis of pencil-shaped softening. In addition, we believe that mechanical compression is also an important factor.

Adult↗
PubMed1981

Spinal and cranial motor nerve roots in amyotrophic lateral sclerosis and X-linked recessive bulbospinal muscular atrophy: morphometric and teased-fiber study.

Amyotrophic lateral sclerosis (ALS) and adult onset X-linked recessive bulbospinal muscular atrophy (SPMA), constituting the category of adult onset form of motor neuron disease, were analyzed on motor nerve roots. The results of morphometric analysis on ventral spinal roots (VSR) of all spinal segments from ALS and SPMA revealed the following three findings: (1) the large-myelinated alpha-motoneuron fibers were markedly decreased in number throughout all segments; (2) thin-myelinated autonomic preganglionic fibers were almost completely preserved; (3) small-intermediate-myelinated fibers which are considered to correspond to gamma-motoneuron fibers were generally well preserved in ALS, but decreased by one-half to one-third in SPMA. However, all the components of the nerve roots of the oculomotor, trochlear, and abducent nerves were completely preserved in both ALS and SPMA. Moreover, the teased-fiber study showed that the regenerating-sprouting process rarely occurred in the VSR of ALS and SPMA. The present study suggested that the site of the primary lesion seems to be in the alpha-motoneuron fibers in motor neuron diseases, such as ALS or SPMA. However, the marked discrepancy in the pathologic change in the alpha-motoneuron fibers in the VSR and the nerve roots innervating the external ocular muscles was noteworthy.

Amyotrophic Lateral Sclerosis↗
PubMed1980

Pathological studies on the ossification of the posterior longitudinal ligament (opll).

Ossification of the posterior longitudinal ligament (OPLL), which causes marked spinal cord compression, occurs more frequently in Japan than in other parts of the world. To investigate the mechanism of this ossification, we examined two cases of mixed type of OPLL inducing severe neurological signs due to spinal cord compression and three cases of segmental OPLL type without neurological signs. Ossification of the ligament begins at the upper end of posterior margin of the vertebral body and distends mainly downward along the posterior longitudinal ligament (PLL) and finally replaces the PLL completely. Ossification consists of compact bones with lamellar structures. In the upper end of the posterior margin of the vertebral body, where the PLL fuses with the cortical bone of vertebral body, ossification always has a direct contact with cortical bone and in this portion proliferation of cartilaginous tissue and calcification were observed. Proliferation of cartilaginous tissue plays a key role in the formation of OPLL and occurs mainly by an enchondral ossification. In three among twenty one cases of cervical vertebrae examined as the control, small foci of ossification were observed which might be related to the initial phase of OPLL. Spinal cords of case 1 and 2 showed marked indentation and flattening with the loss of nerve cells, severe fibrous gliosis of the gray matter and demyelination of the anterior column. Venous congestion due to compression and vulnerability of gray matter to anoxia is important for the histological changes of spinal cord.

Adult↗