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S Okajima

Publications and source records attributed to S Okajima.

At least 37 records · Page 2Linked to original sources
PubMed1999

Up-regulated uridine kinase gene identified by RLCS in the ventral horn after crush injury to rat sciatic nerves.

Rat sciatic nerve crush injury is one of the models commonly employed for studying the mechanisms of nerve regeneration. In this study, we analyzed the temporal change of gene expression after injury in this model, to elucidate the molecular mechanisms involved in nerve regeneration. First, a cDNA analysis method, Restriction Landmark cDNA Scanning (RLCS), was applied to cells in the ventral horn of the spinal cord during a 7-day period after the crush injury. A total of 1991 cDNA species were detected as spots on gels, and 37 of these were shown to change after the injury. Temporally changed patterns were classified into three categories: the continuously up-regulated type (10 species), the transiently up-regulated type (22 species), and the down-regulated type (5 species). These complex patterns of gene expression demonstrated after the injury suggest that precise regulation in molecular pathways is required for accomplishing nerve regeneration. Secondly, the rat homologue of uridine kinase gene was identified as one of the up-regulated genes. Northern blot analysis on rat ventral horn tissue and brain revealed that the UK gene had three transcripts with different sizes (4.3, 1. 4, and 1.35 kb, respectively). All of the transcripts, especially the 4.3 kb one, were up-regulated mainly in a bimodal fashion during the 28-day period after the injury. The RLCS method that we employed in the present study shows promise as a means to fully analyze molecular changes in nerve regeneration in detail.

Animals↗
PubMed1999

Distribution of synaptosomal-associated protein 25 in nerve growth cones and reduction of neurite outgrowth by botulinum neurotoxin A without altering growth cone morphology in dorsal root ganglion neurons and PC-12 cells.

Synaptosomal-associated protein 25 has been regarded as one of the target-associated soluble N-ethylmaleimide-sensitive fusion attachment protein receptors essential for exocytosis of vesicles in synapses. We have previously reported that cleavage of syntaxin, which is another target-associated soluble N-ethylmaleimide-sensitive fusion attachment protein receptor, with botulinum neurotoxin C1 resulted in inhibition of neurite extension and morphological changes including growth cone collapse and large vacuole formation. As an attempt to explore the mechanism of growth cone extension, we examined the ultrastructural localization of synaptosomal-associated protein 25 in growth cones with or without treatment of botulinum neurotoxin A, which cleaves synaptosomal-associated protein 25. In dorsal root ganglion neurons, light microscopy demonstrated synaptosomal-associated protein 25 immunoreactivity throughout the neurons, including the cell bodies, neurites and growth cones. Using electron microscopy, gold signals immunoreactive for synaptosomal-associated protein 25 were identified diffusely in the cytoplasm of the growth cones. In contrast, in PC-12 cells, a large number of gold signals were localized on the plasma membranes. High levels of signal were also found in the cytoplasm in the central region of the growth cones. We also confirmed that botulinum neurotoxin A treatment reduced neurite extension by about 50%. However, both in dorsal root ganglion neurons and in PC-12 cells we found no differences in the ultrastructure nor in the localization of synaptosomal-associated protein 25 between growth cones with and without toxin treatment. These results indicate that cleavage of synaptosomal-associated protein 25 inhibits growth cone extension in a manner different than that of syntaxin cleavage. The results of this study suggest the possibility that synaptosomal-associated protein 25 is involved in growth cone extension through a process independent of vesicle fusion.

Animals↗
PubMed1999

Factors influencing pulmonary surfactant protein A levels in cord blood, maternal blood and amniotic fluid.

The purpose of this study was to evaluate factors that influence pulmonary surfactant protein A (SP-A) levels in cord blood, maternal blood and amniotic fluid, as well as to establish the normal range of serum SP-A. Labor significantly influenced cord blood SP-A levels. The SP-A levels in maternal blood after delivery were correlated with, but higher than those before delivery. There was a correlation between SP-A levels in amniotic fluid and cord blood. Neonatal serum SP-A was not correlated with maternal SP-A levels. The normal range of SP-A in cord blood was 2.7-21.7 ng/ml following cesarean section without labor, 4.8-50.2 ng/ml after labor at gestational weeks 36-38, and 12.2-44.6 ng/ml at gestational weeks 39-41. SP-A levels in maternal blood before and after delivery and amniotic fluid were 6. 0-74.0, 9.6-73.6 and 403.4-24,540 ng/ml, respectively.

Amniotic Fluid↗
PubMed1999

Differential expression of gap junction proteins connexin26, 32, and 43 in normal and crush-injured rat sciatic nerves. Close relationship between connexin43 and occludin in the perineurium.

We immunohistochemically and morphometrically examined the expression of gap junction protein connexin (Cx) in normal and crush-injured rat sciatic nerves using confocal laser scanning microscopy. Cx26 was localized in the perineurium and Cx43 was present in the perineurium and the epineurium, whereas Cx32 was confined to the paranodal regions of the nodes of Ranvier. Double labeling for connexins and laminin revealed that Cx43 was localized in multiple layers of the perineurium, whereas Cx26 was confined to the innermost layer. Double labeling for connexins and a tight junction protein, occludin, showed that occludin frequently coexisted with Cx43 but existed separately from Cx26 in the perineurium. After crush injury, the pattern of normal Cx32 expression was initially lost but recovered, whereas Cx43 rapidly appeared in the endoneurium and its expression was subsequently attenuated. Although crush injury produced no apparent alteration in Cx43 and occludin in the perineurium, a rapid increase and a subsequent decrease in the frequency of Cx26-positive spots during nerve regeneration were shown by morphometric analysis. These results indicate that Cx26, Cx32, and Cx43 are expressed differently in various types of cells in peripheral nerves and that their expressions are differentially regulated after injury. The expression of connexins and occludin in the perineurium suggests that perineurial cells are not uniform in type and that the regulation of gap junctions and tight junctions is closely related in the perineurium.

Animals↗
PubMed1999

[A case of multiple bone metastases from advanced breast cancer effectively treated with pamidronate].

A 57-year-old woman, with bone, lymph node and skin metastases underwent mastectomy and extirpation of skin tumors. Chemoenderine-therapy was performed from the 15th day after operation, with a toremifene and CEF regimen consisting of cyclophosphamide, epirubicin and 5-fluorouracil. She had nausea and neurological symptoms from hypercalcemia (21.5 mg/dl) on the 28th day after operation. Her serum PTHrP level was found to be high at 214 pmol/l. We administered pamidronate in a dose of 45 mg biweekly, and she improved. The CEF regimen and pamidronate therapy was continued for 6 cycles and the regions of bone metastases were reduced on the bone scintography. Thereafter she has been administered pamidronate 30 mg/4 weeks as an outpatient with no further symptoms, and serum Ca and PTHrP have remained normal. In conclusion, pamidronate combined with chemotherapy can be a therapeutic option for not only hypercalcemia but also bone metastases of breast cancer.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1999

[Evaluation of intermittent hepatic arterial infusion chemotherapy for multiple liver metastasis of colorectal cancer].

Five patients with synchronous multiple hepatic metastasis of colorectal cancer were treated with hepatic arterial infusion chemotherapy. All cases received intermittent 5-FU infusion (5-FU 250-1,000 mg/2-3 hrs/1-2 weeks) on an outpatient basis. In the evaluation of 5 cases, 3 PR and 1 NC were observed. One case administered arterial infusion for adjuvant chemotherapy has no recurrence in liver. In two patients, extra-hepatic metastases were found. In conclusion, this therapy was effective and useful for hepatic metastasis. Moreover, other forms of treatment for extra-hepatic metastasis must be used.

Adult↗
PubMed1999

[Intraperitoneal cisplatinum chemotherapy in patients with carcinomatous peritonitis due to colorectal scirrhous cancer--case report].

Two patients received intraperitoneal cisplatinum chemotherapy for carcinomatous ascites due to colorectal cancer recurrence. The patients were a 47-year-old man who had rectal cancer and 51-year-old woman who had colon cancer. They had received the operation and adjuvant chemoradiation therapy and chemotherapy respectively. However, five months and two years after resection, respectively, they presented massive ascites due to carcinomatous peritonitis and were given cisplatin injection intraperitoneally. The amount of ascites was significantly diminished. One patient had been discharged and been able to stay at home, and the other patient underwent gastrostomy for ileus. The results suggested that intraperitoneal cisplatinum chemotherapy may be useful for the patient with carcinomatous ascites due to colorectal cancer.

Adenocarcinoma, Scirrhous↗
PubMed1999

[Palliative chemo-radiotherapy for abdominal recurrence of esophageal carcinoma--case report].

A 71-year-old man with stage IV esophageal carcinoma was treated by chemo-radiotherapy (5-FU 500 mg/day + CDDP 10 mg/day for 4 weeks and 67.6 Gy of RT). The esophageal tumor showed a complete response to the treatment. Six months later, he had obstructive jaundice due to an abdominal recurrent mass. A secondary (palliative) CRT was performed (5-FU 500 mg/day + CDDP 10 mg/day for 3 weeks and 45 Gy of RT). The abdominal tumor became remarkably smaller and jaundice disappeared. Though the patient died from pulmonary carcinomatous lymphangitis, the primary lesion showed CR. CRT was very effective for local treatment and for palliative therapy.

Aged↗
PubMed1998

Localization of tyrosine-phosphorylated proteins in cultured mouse dorsal root ganglion neurons.

The present study, using confocal laser scanning microscopy and immunoelectron microscopy, examined the intracellular localization of tyrosine-phosphorylated proteins in cultured mouse dorsal root ganglion neurons with special reference to their growth cones. The growth cone is the specialized structure formed at the growing tip of the axon; characteristically highly motile with filopodia on the surface, it is responsible for the extension and guidance of the neurites to the appropriate targets during nerve regeneration. It has been suggested that protein-tyrosine phosphorylation plays an important role in the intracellular signal transduction that regulates the extension and motility of growth cones. By fluorescence immunocytochemistry, phosphotyrosine immunoreactivity was found in the growth cones and neurites. Some of the filopodia exhibited strong immunoreactivity at their tips. By immunoelectron microscopy, a large number of immunogold particles (gold particles conjugated to the secondary antibody) were seen to be distributed in the cytoplasm and some were observed on the plasma membrane in the growth cones, whereas in the neurites the density of immunogold particles was the same in the axoplasm as on the plasma membranes. These findings suggest that in the growth cones phosphotyrosines might mainly be involved in intracellular signaling for maintaining their high motility whereas in the neurites they might mostly be associated with the receptor proteins at the plasma membrane for adhesion as well as for growth of neurites. Thus, tyrosine phosphorylation might contribute to different functions for growth cones and neurites.

Animals↗
PubMed1998

Ultrastructure and cellular biology of nerve regeneration.

Hippocrates provided the first written description of the peripheral nervous system (PNS), as early as the 4th century B.C., and later Herophilus identified nerves as such, distinguished them from tendons; he also traced nerves to the spinal cord. The traditional Hippocratic teaching of the time, however, doubted that nerve healing occurred. Through the subsequent centuries, several papers were written about the PNS but, without sufficient understanding of anatomy, physiology, and the regenerative capacity of the PNS, it is not difficult to comprehend the frustration that might have been encountered by surgeons in dealing with nerve injuries and their subsequent repair. This was probably the reason why nerve repair was rarely actually undertaken prior to the 19th century. A plethora of studies on the PNS and its regeneration has been reported over the last 150 years and has provided us with current knowledge. It is important, before describing the most recent developments in the area of peripheral nerve regeneration, to briefly outline the major advances over the last century. Currently, the therapeutic approaches taken toward the patient with peripheral nerve injury change continuously. Sophisticated advances in technology, cellular and molecular neurobiology, and electron microscopy will doubtless optimize reconstructive strategies in treating nerve injury. A greater awareness and understanding of the nerve ultrastructure, as well as the underlying mechanisms of the regenerative process and those factors detrimental to nerve regeneration, will assist in the successful repair of nerve injury. This paper reviews the cellular, biochemical, and ultrastructural elements of nerve injury and repair, and the rationale for current reconstructive strategies and techniques.

Animals↗
PubMed1997

Immunocytochemical distribution of Ca(2+)-independent protein kinase C subtypes (delta, epsilon, and zeta) in regenerating axonal growth cones of rat peripheral nerve.

In the peripheral nerve, regenerating axonal sprouts usually emanate at nodes of Ranvier, and extend as growth cones along the inner surface of Schwann cells and/or through Schwann cell columns in the distal nerve segment. In order to elucidate the significance of Ca(2+)-independent protein kinase C in nerve regeneration, localizations of delta, epsilon and zeta subtypes were examined immunocytochemically in sprouts and growth cones of regenerating axons, as well as in normal intact nerves in the rat sciatic nerve. In normal nerves, intense immunoreactivities of delta, epsilon and zeta subtypes were present in axons of both myelinated and unmyelinated fibres. Subcellularly, the distribution of these subtypes in the axoplasm was patchy, and discontinuous in the axolemma and subaxolemmal peripheral zones of myelinated nerves. Some thin myelinated axons showed no immunoreactivity for epsilon subtype. Schwann cells of both myelinated and unmyelinated fibres had moderate immunoreactivities for each subtype. In areas of nerve regeneration, axonal sprouts at nodes of Ranvier, and growth cones extending along Schwann cell basal laminae, had intense immunoreactivities for delta, epsilon and zeta subtypes which are distributed diffusely throughout the axoplasm, and on the entire axolemma. In the sprouts, immunoreactivity for epsilon subtype was strong on the axolemma, but weak or almost absent in the axoplasm. These data, together with those of our previous study, indicate that Ca(2+)-independent protein kinase C subtypes (delta, epsilon and zeta) have basically the same distribution patterns as those of Ca(2+)-dependent subtypes in sprouts and growth cones of regenerating axons, as well as in normal intact axons; albeit epsilon subtype is somewhat different in distribution and intensity from delta and zeta subtypes. It is suggested that Ca(2+)-independent subtypes are involved in maintaining growth cone activities along with the Ca(2+)-dependent subtypes.

Amino Acid Sequence↗
PubMed1997

[Spinal cord ischemia caused by dissecting aortic aneurysm in a patient with acute exacerbation of pulmonary emphysema].

A 61-year-old man with pulmonary emphysema was admitted due to acute exacerbation of chronic respiratory failure and a complaint of chest pain. A chest CT scan on admission showed aneurysmal dissection from the ascending aorta to the descending aorta. Analgesia was noted below the fourth thoracic vertebra, which supplies the accessory respiratory muscles including the intercostal muscles. Even after recovery from circulatory failure, his chest muscles were weak and he could not be removed from mechanical ventilation. An autopsy revealed ischemia of the spinal cord at the T4 level. In contrast, The C3 level of the spinal cord, which supplies the diaphragm, was intact. Paralysis of accessory respiratory muscles including intercostal muscles may have caused the continuation of the respiratory failure. This case shows the importance of accessory respiratory muscles in maintaining chest wall movement in patients with chronic pulmonary emphysema.

Acute Disease↗
PubMed1996

[Study of erythrocyte sedimentation rate in patients with pulmonary tuberculosis].

We studied the erythrocyte sedimentation rate (ERS) and related factors that influence ESR in 326 patients with Pulmonary tuberculosis. The ESR tended to be higher for aged subjects and showed a difference between patients under 59 years old and patients over 60 years old. Besides, patients under 30 years old tended to present lower ESR. It is suggested that they may be under the influence of inapparent infection. For The Japanese Society for Tuberculosis Classification, a significant difference was noted in the extent, but there was no difference about the presence of cavity. A significant correlation was detected between ESE and Gaffky scale, ESR and CRP, and ESR and period until sputum culture became negative. But CRP negative cases were observed in about 28%. CRP alone was not sufficient for the evaluation of the morbid condition of Mycobacterium infection. Receiver-Operator Characteristic curve analysis confirmed that ESR is useful among patients with pulmonary tuberculosis. Therefore evaluation of ESR together with CRP was needed.

Adult↗
PubMed1995

Distribution of protein kinase C (alpha, beta, gamma subtypes) in normal nerve fibers and in regenerating growth cones of the rat peripheral nervous system.

The distribution of protein kinase C (alpha, beta, gamma subtypes) was studied using immunocytochemical techniques in normal nerve fibers and in regenerating sprouts (growth cones) from the nodes of Ranvier following crush injuries to the rat peripheral nervous system. In normal nerves, for each protein kinase C subtype, immunoreactivity was present in both myelinated and unmyelinated axons. In myelinated axons, immunoreactivity for all three subtypes was patchy in the axoplasm and diffuse in the subaxolemmal peripheral zones. No immunoreactivity was found in the microtubule and neurofilament (cytoskeletal) domain. In contrast, in unmyelinated axons, immunoreactivity was distributed diffusely in the axoplasm. Schwann cells of myelinated fibers exhibited protein kinase C immunoreactivity, but those of unmyelinated fibers did not. In regenerating nerves, early sprouts and growth cones extending through the crushed site along Schwann cell basal laminae exhibited intense immunoreactivity for all three subtypes. Immunoreactivity was distributed diffusely throughout the axoplasm of the regenerating sprouts (growth cones), in which microtubules and neurofilaments were very rare. Thus, the subcellular localization of the protein kinase C immunoreactivity in growth cones of early regenerating nerves differed from that of normal parent axons. These findings suggest that protein kinase C (alpha, beta and gamma subtypes), whose subcellular distribution becomes more extensive in regenerating axons, may have important functional roles in axonal sprouting and in the regulation of growth cone activity in the peripheral nervous system.

Animals↗
PubMed1994

137Cs concentration among children in areas contaminated with radioactive fallout from the Chernobyl accident: Mogilev and Gomel oblasts, Belarus.

The level of radiation exposure in children in Belarus caused by the Chernobyl accident was investigated on the basis of whole body 137Cs count. The subjects were 10,062 children (4,762 boys and 5,300 girls) in Mogilev and Gomel, Belarus, who received Chernobyl Sasakawa Health and Medical Cooperation Project health examinations from May 1991 to December 1992 and who were 5-16 y old at the time of examination. The median whole body 137Cs count per body weight varied from 21-48 Bq kg-1 and from 28-126 Bq kg-1 in Mogilev oblast and Gomel oblast, respectively. (The "oblast" is the largest administrative district constituting the country. Belarus consists of 6 oblasts). Corresponding annual effective dose equivalents were all less than the public dose limit of 1 mSv y-1, but the observed levels in the children were considerably higher than the average level of 2.3 Bq kg-1 reported in the past for the former Soviet Union.

Accidents↗
PubMed1994

Motor axon terminal regeneration as studied by protein gene product 9.5 immunohistochemistry in the rat.

Normal intact and regenerating axon terminals up to 30 days after nerve crushing were studied in the rat flexor carpi ulnaris muscle by confocal laser scanning microscopy (CLSM) and electron microscopy using immunohistochemistry for protein gene product 9.5 (PGP 9.5). The motor axons were intensely and homogeneously stained along their entire length. "Three dimensional" organizations of elaborate axon terminals were clearly demonstrated by reconstructing serial optical images obtained by CLSM in normal neuromuscular junctions. In the injured nerve, the earliest regenerating axons could be identified at endplate regions six days after nerve crushing as intensely immunoreactive thin processes which bifurcated in T-shape and formed delicate lace-like terminals. Such lace-like terminals were composed of fine thread-like portions 0.2-0.8 microm in diameter and expanded portions of 2-3 microm in diameter. Electron microscopy revealed that all the axon terminals in the cytoplasm were stained almost homogeneously by PGP 9.5 immunohistochemistry up to their extreme tips. Axon terminals were in direct contact with the basal lamina of the postsynaptic folds, and showed occasional branching. The thin thread-like portions contained no mitochondria but only a few vesicles, where as the expanded portions, abundant mitochondria. And preterminal axons and some expanded portions were abutted by Schwann cells, while thin thread-like portions were exposed with no association with Schwann cells. Twenty to 30 days after crushing injury, regenerating motor axon terminals resumed their mature form in terms of branching elaborations and ultrastructural features. Thus, CLSM of PGP 9.5 immunocytochemistry combined with electron microscopy was able to demonstrate the "three-dimensional" organization of elaborate axon terminals at high resolution in the normal and regenerating neuromuscular junctions. Using this technique, extremely fine processes of axonal terminals were identifiable at the earliest stage of reinnervation.

Animals↗
PubMed1993

Synaptophysin immunocytochemistry in the regenerating sprouts from the nodes of Ranvier in injured rat sciatic nerve.

Following crush injury of rat sciatic nerve, strong synaptophysin immunoreactivity was demonstrated in the regenerating sprouts that emerged from the proximal nodes of Ranvier and in their growth cones that extended through the space between Schwann cell basal lamina and myelin sheath of the parent axon. These findings suggest that synaptophysin is involved in the growth regulation of regenerating sprouts.

Animals↗