Biomedical subjects

Shin-ichi Kikuchi

Publications and source records attributed to Shin-ichi Kikuchi.

14 recordsLinked to original sources

PubMed2007

Effects of the mechanical load on forward bending motion of the trunk: comparison between patients with motion-induced intermittent low back pain and healthy subjects.

STUDY DESIGN: Postural changes and trunk muscle activities were examined in patients with motion-induced intermittent low back pain (MILBP) and healthy controls. OBJECTIVES: To assess the ability to maintain an upright standing position. SUMMARY OF BACKGROUND DATA: Since MILBP is not observed at rest, its pathophysiology is complicated to investigate. METHODS.: Postural changes were measured with a 3-dimensional motion analyzer, and muscle activities with a surface electromyography while 10 female patients at an average age of 76 years (MILBP group) and 10 healthy controls at an average age of 74 years (Control Group) were standing upright and loaded with 10-kg weights. RESULTS: In the Control Group, no significant forward bending motion occurred. In the MILBP group, there was a temporal increase in forward bending at various speeds and at various time phases. In the MILBP group but not in the Control Group, the rate of changes in median power frequency of erector spinae muscle declined significantly as compared with that in the Control Group (P < 0.05). CONCLUSIONS: These results indicated that fatigue of the back muscles occurred in MILBP patients and could be a pain generator in low back pain.

Abdominal Muscles↗

PubMed2006

Effects on improvement of blood flow in the chronically compressed cauda equina: comparison between a selective prostaglandin E receptor (EP4) agonist and a prostaglandin E1 derivate.

STUDY DESIGN: Vasodilatation was studied in a model of experimental chronic cauda equina compression using measurements of vessel diameter on video recordings. OBJECTIVE: The vasodilative effect was compared between a prostaglandin E2 receptor (EP) subtype agonists (EP4 agonist) and a prostaglandin E1 (PGE1) derivate. SUMMARY AND BACKGROUND DATA: Reduction of blood flow is one important pathogenic factor of neurogenic intermittent claudication (NIC) for lumbar spinal canal stenosis. It is known that PGE1 improves the mean walking distance in patients with cauda equina compression type of NIC. There are four subtypes of EP: EP1, EP2, EP3, and EP4. EP4 is located in vessels of pigs and rabbits. A highly selective EP4 agonist, which has effects on dilatation of pig and rabbit vessels, has recently been developed. One may therefore assume that this agonist may improve blood flow in the chronically compressed cauda equina. METHODS: A total of 25 dogs were used. A plastic balloon inflated to 10 mm Hg was placed under the lamina of the seventh lumbar vertebra for 1 week. OP-1206 cyclodextrin clathrate (OP-1206 CD: prostaglandin E1 derivate) and ONO-4819 CD (a highly selective EP4 agonist) were intravenously administrated. The following 5 experimental groups were assigned: animals in group OP (3) (n = 5) and Group OP (10) (n = 5) received 3 eta g/kg per minute and 10 eta g/kg per minute of OP-1206 CD, respectively; those in Group EP (3) (n = 5) and Group EP (10) (n = 5) received 3 eta g/kg per minute and 10 eta g/kg per minute of ONO-4819 CD, respectively; and those in the control group (n = 5) received saline. After 7 days, the cauda equina was exposed and blood vessels of the second or third sacral nerve root were identified using a specially designed operation microscope equipped with a video camera. The diameters of the observed blood vessels were measured on video-recordings every 10 minutes until 60 minutes after administrating OP-1206 CD or ONO-4819CD. RESULTS: In the Groups OP (3), OP (10), and EP (10), the blood vessels were dilated and blood flow increased after injection of the agents. In the Group EP (10), the vessel diameter and blood flow increased significantly compared with that in the other four groups. In contrast, the blood vessels contracted and the blood flow was reduced in the Group EP (3). CONCLUSIONS: Our results suggested that the EP4 agonist at high concentrations might be a potential therapeutic agent since it is expected to increase blood flow in nerve roots in patients with spinal canal stenosis.

Alprostadil↗

PubMed2006

Mechanical load of the lumbar spine during forward bending motion of the trunk-a biomechanical study.

STUDY DESIGN: We investigated the mechanical load of the lumbar spine caused by changes of posture and carried load. OBJECTIVE: To clarify the relationship between the actual and theoretical load of the lumbar spine with and without application of external weights. SUMMARY OF BACKGROUND DATA: There is sparse knowledge regarding the relationship between the intradiscal pressure and trunk muscle activities during forward bending motion. METHODS: The measurements of intradiscal pressure, electromyogram activities of the trunk muscles, and motion analysis of the trunk in 3 young healthy men were performed simultaneously with and without lifting a weight of 10 kg. The recorded values were compared with theoretical values based on the principle of levers. RESULTS: The load of the lumbar spine and electromyogram activities of the back muscles increased in proportion to the tilting angle with and without external weights. However, the external weights induced no significant activity in the abdominal muscles. The actual measurement values were larger than the theoretical values at all tilting angles of the trunk. CONCLUSIONS: We found that the increase of the actual spinal load during trunk flexion in healthy individuals consisted of the theoretical spinal load and load generated by the back muscle activities.

Adult↗

PubMed2005

Effects of separate application of three growth factors (TGF-beta1, EGF, and PDGF-BB) on mechanical properties of the in situ frozen-thawed anterior cruciate ligament.

OBJECTIVE: To clarify effects of a separate application of TGF-beta1, EGF, and PDGF-BB on the material properties of the in situ frozen-thawed anterior cruciate ligament. DESIGN: Twenty-eight rabbits were divided into four groups after undergoing the in situ freeze-thaw treatment in the right anterior cruciate ligament. In 3 of the 4 groups, 4 ng TGF-beta1, 20 ng EGF, and 4 microg PDGF-BB was applied to the frozen anterior cruciate ligament, respectively. In the remaining sham treatment group, only fibrin sealant as a vehicle was applied. Each animal was sacrificed at 12 weeks after surgery. BACKGROUND: If the role of growth factors in ligament healing and remodeling is understood, better therapies can be designed for ligament trauma. METHODS: The freeze-thaw treatment was performed three times using the originally developed cryo-probe. The cross-sectional area of the anterior cruciate ligament was measured by the optical non-contact method. After preconditioning, each specimen was stretched to failure. The ligament strain was determined with a video dimension analyzer. RESULTS: The tensile strength and the tangent modulus of the anterior cruciate ligament in the TGF-beta1 group was significantly higher than in the sham group, but significantly lower than in the normal control group. There were no significant differences in the strength and the modulus between the EGF group, the PDGF-BB group, and the sham group. CONCLUSIONS: In this model, an application of 4 ng TGF-beta1 significantly inhibited some of the material deterioration that occurs in the in situ frozen-thawed anterior cruciate ligament, while an application of 20 ng EGF or 4 microg PDGF-BB did not significantly affect the deterioration. RELEVANCE: This information will be useful in the future to develop a new biological therapy for ligament reconstruction to prevent the graft deterioration after transplantation.

Animals↗

PubMed2005

Endoscopic partial laminectomy for cervical myelopathy.

OBJECT: The authors report the results of endoscopic partial laminectomy performed in 10 patients with degenerative cervical compressive myelopathy. METHODS: Endoscopic partial laminectomy was performed safely in 10 patients with cervical myelopathy. All of the patients experienced symptomatic improvement with slight postoperative wound pain. The mean operative duration was 164+/-35 minutes and the mean intraoperative blood loss was 45.5+/-27 ml. CONCLUSIONS: Endoscopic partial laminectomy may be used as a minimally invasive alternative for the treatment of cervical compressive myelopathy.

Adult↗

PubMed2005

[Clinical anatomy of lumbar spine].

Three elements contribute to the neurologic symptoms of the lumbar spine or its multiplicity from an anatomical viewpoint. The first element is the problem of neural tissue. The second element is the bone or the soft tissue existing around the circumference of the neural tissue. The third element is the correlation of the above two. In other words, the neural tissue as content is too large or the adjacent tissue as container is too narrow or else an aberration in the correlation of the aforesaid is involved. Therefore, it is necessary to study those three elements to comprehend the neurologic symptoms of the lumbar spine.

Humans↗

PubMed2005

[Experimental studies of lumbar spinal stenosis].

Neurophysiologic function and ischemia causes neurogenic symptoms in lumbar spinal stenosis. Neurophysiologic function and potential therapeutic agents were investigated using a chronic cauda equina compression model that was developed according to a clinical pathogenesis. In the chronic cauda equina compression model, nerve conduction velocity and blood flow in spinal nerves decreased but mechanical allodynia was not induced. Prostaglandins and 5-HT receptor antagonist effected to improve blood flow in nerve roots after cauda equina compression;therefore, they might be potential agents for lumbar spinal stenosis.

Animals↗

PubMed2005

[Block treatment for low back pain--technical note].

Many types of block are used for treatment of low back pain. In the current paper, trigger-point block, facet block, ilio-sacral joint block, epidural block and nerve root infiltration (nerve root block), quite common procedures for treatment of low back pain, are introduced and technical notes are described. There are two important points for block treatment, one is the knowledge of anatomy and another is the knowledge of side effects. We must remember to prepare everything for side effects when block treatment is done.

Humans↗

PubMed2005

[Therapeutic effects of calcitonin on back pain in the patients with osteoporosis].

A prospective study was performed to clarify the therapeutic effect on calcitonin in the patients with osteoporosis using patient-based outcome measures. A total of 67 patients with primary osteoporosis who complained back pain were included in this study. All patients were administered calcitonin 20 Unit/week intramuscularly. The therapeutic effects were assessed using various patient-based outcome measures before treatment, 2, 4 weeks and 3 months after treatment. We used Short form 12 for measuring general well-being, Roland Morris disability questionnaire for functional status associated with back pain, and visual analogue scale for pain intensity. Statistic analysis was performed using paired-t test. Pain intensity and functional status were significantly recovered at 2 weeks follow-up time and the effects were continued at 3 months follow-up time. Physical component summary (PCS) was recovered at 3 months follow-up tme, whereas mental component summary (MCS) was improved at 2 weeks follow-up time. These facts suggest that improvement of back pain using calcitonin correlates directly with recovery in functional status, indirectly with recovery in general well being.

Aged↗

PubMed2004

Necessity of rib head resection for anterior discectomy in the thoracic spine.

STUDY DESIGN: The relation between the rib head and the thoracic disc was investigated anatomically. OBJECTIVES: To clarify the necessity of rib head resection in thoracoscopic discectomy using the anterior approach. SUMMARY OF BACKGROUND DATA: When using the transthoracic anterior approach, the rib head must often be resected. However, there are no reports in which the relation between the rib head and the interspinal disc has been investigated. METHODS: The distance between the inferior margin of the superior vertebral body and the superior margin proximal to the rib (hereafter, "rib index") was measured. RESULTS: The rib index shows negative value in T2-T9 levels, while zero in Tl0 level and positive value T11-T12. The rib index of the fifth to ninth ribs in men was significantly smaller than those in women. CONCLUSIONS: The surgeon should anticipate full removal of the rib head if operating at T9 and only partial resection below that level.

Aged↗

PubMed2004

Effects of 5-HT2A receptor antagonist on blood flow in chronically compressed nerve roots.

Neurogenic intermittent claudication (NIC) can be caused by compression of the cauda equina by spinal stenosis and is a major clinical problem. A reduction of blood flow is an important mechanism for inducing NIC and may be caused by a vasoconstrictive effect mediated by the serotonin 5-HT2A receptor in chronic cauda equina compression lesions. This study assessed the effects of the 5-HT2A receptor antagonist on nerve vasculature in chronically compressed nerve roots. A plastic balloon was placed under the lamina of L7 and inflated to 10 mmHg and left for 1 week in several cauda equina compression models. All experimental animals received an acute administration of serotonin. One group received sarpogrelate hydrochloride (5-HT2A receptor antagonist: 5-HTRA) before administration of serotonin, and another group was administered 5-HTRA after administration of serotonin. Diameters and blood flow in the vasculature of S2 or S3 nerve roots were measured after injection of serotonin. In animals without compression of the cauda equina (sham), blood vessels contracted and the blood flow was reduced after administration of serotonin. In sham and compression animals receiving both serotonin and 5-HTRA, blood vessel diameter was not reduced and was significantly larger than that in the compression group receiving only serotonin (p<0.05). Likewise, the blood flow was not reduced in sham and compression animals receiving serotonin and 5-HTRA and was significantly greater in the compression group treated only with serotonin. 5-HTRA inhibited vasoconstriction and the reduction of blood flow in chronically compressed nerve roots challenged with serotonin. This fact suggests that 5-HTRA might be effective at improving blood flow in chronically compressed nerve roots in patients with spinal canal stenosis and changes in circulation levels of serotonin.

Animals↗

PubMed2003

Correlation of low back pain with functional status, general health perception, social participation, subjective happiness, and patient satisfaction.

STUDY DESIGN: A cross-sectional and epidemiologic study investigated low back pain. OBJECTIVE: To assess the correlation among outcome measures for low back pain, including sciatica, according to a proposed low back pain-related model. SUMMARY OF BACKGROUND DATA: Various outcome measures are used in low back pain research: pain, functional status, generic health status, and patient satisfaction. Correlation among these measures has been unclear. METHODS: For this study, 816 subjects (369 men and 447 women; average age, 62 years) who underwent an adult medical examination. The patients were interviewed concerning their personal background, severity of low back pain and sciatica, functional status, general health perception, social participation, subjective happiness, and patient satisfaction. The correlation among these measures was analyzed systematically using path analysis based on a low back pain-related model hypothesizing that low back pain and sciatica worsen functional status and general health perception and then affect social participation, subjective happiness, and patient satisfaction. RESULTS: Restriction of functional status was found to be the most closely correlated with severity of low back pain. A decrease in physical health was most closely correlated with restriction of function. Social participation, subjective happiness, and patient satisfaction were closely correlated with physical health status. There was a significant correlation among outcome measures concerning physical health, which was consistent with a low back pain-related model. CONCLUSIONS: The outcome measures concerning physical health in this study were found to be correlated significantly, consistent with the proposed low back pain-related model.

Adult↗

PubMed2003

An anatomic study of the lumbar plexus with respect to retroperitoneal endoscopic surgery.

STUDY DESIGN: The distribution of the lumbar plexus was analyzed using cadavers. OBJECTIVE: To clarify the safety zone to prevent nerve injuries with respect to retroperitoneal endoscopic surgery. SUMMARY OF BACKGROUND DATA: Surgical approaches to the retroperitoneal space vary among surgeons. Recently, retroperitoneal endoscopic surgery has been applied to various spinal disorders. When the psoas major muscle is separated during retroperitoneal endoscopic surgery, there is a potential risk of injury to the lumbar plexus or nerve roots. However, there is sparse knowledge regarding the relationship between the greater psoas muscle and the lumbar plexus. METHODS: A total of 30 cadavers were analyzed. Six lumbar spines of the cadavers were cut in parallel with the lumbar disc space. Each axial section was photographed and captured into a computer. The distribution of the lumbar plexus was analyzed using computer images. The positions where the genitofemoral nerve emerged on the abdominal surface of the psoas major muscle were analyzed using 24 cadavers. RESULTS: L2/3 and above, all parts of the lumbar plexus, and nerve roots were located from the dorsal fourth of the vertebral body and dorsally. The genitofemoral nerve descends obliquely forward through the psoas major muscle, emerging on the abdominal surface between the cranial third of the L3 vertebra and the caudal third of the L4 vertebra. The safety zone of the psoas major muscle to prevent nerve injuries, excluding the genitofemoral nerve, is at L4/L5 and above. CONCLUSIONS: The safety zone, excluding the genitofemoral nerve, is at L4-L5 and above.

Cadaver↗

PubMed2002

Expression of OASIS, a CREB/ATF family transcription factor, in CNS lesion and its transcriptional activity.

We reported the expression patterns of a novel member of the CREB/ATF family, OASIS, in central nervous system (CNS) lesions and its transcriptional activity. OASIS gene expression was upregulated in the stab-injured spinal cord. Double labeling experiments revealed that the distribution of OASIS mRNA-positive cells overlapped with a population of GFAP-immunoreactive cells. This finding suggested that OASIS might regulate expression of important downstream molecules in certain subset of the reactive astrocytes (e.g. inhibitory substances in injured brain). In gel shift assays, OASIS was able to specifically bind to CRE as CREB family members were. We then examined transcriptional activity of full-length OASIS with GAL4-UAS-luciferase reporter assay in COS7 cells. OASIS protein activated transcription, but did not inhibit basal transcription driven by AdML promoter. To determine critical portion(s) of the OASIS protein in transcriptional activation, we examined the activity of various deletion constructs of OASIS gene. The assay revealed that a strong transcriptional activation domain lay in the N-terminal region where acidic amino acids clustered and a possible repression domain, which had not been reported for other CREB/ATF family members, lay in the more C-terminal region. We therefore proposed that OASIS protein positively regulated gene transcription in a subset of reactive astrocytes, and thereby influenced the reaction of injured CNS tissues.

Animals↗