PubMed Health⌕ Search

Biomedical subjects

R Teshima

Publications and source records attributed to R Teshima.

At least 19 recordsLinked to original sources
PubMed2002

Re-aggravation of myelopathy due to intramedullary lesion with spinal cord enlargement after posterior decompression for cervical spondylotic myelopathy: serial magnetic resonance evaluation.

STUDY DESIGN: A case report. OBJECTIVES: To report a case of swelling of the spinal cord and an intramedullary lesion occurring after expansive laminoplasty for cervical spondylotic myelopathy. SETTING: A university hospital in Japan. METHODS: Clinical evaluation, radiography, MR imaging. RESULTS: A 65-year-old man with a cervical spondylotic myelopathy in whom symptoms were improved immediately after expansive laminoplasty, but became aggravated 2 weeks later. Magnetic resonance images demonstrated swelling of the spinal cord and an intramedullary lesion that extended from the medulla oblongata to C7. Nine months after surgery, the lesion was reduced to C2-6, but neurological deterioration had not improved. Six years after surgery, the patient remains confined to bed. CONCLUSION: Patients with such disease conditions are rare, and it is difficult to predict postoperative swelling of the spinal cord before surgery. Spine surgeons should be aware of such rare disease conditions involving the spinal cord.

Aged↗
PubMed2002

Measurement of periprosthetic bone mineral density by dual-energy x-ray absorptiometry is useful for estimating fixation between the bone and the prosthesis in an early stage.

Periprosthetic bone mineral density (BMD) was measured with dual-energy x-ray absorptiometry in 37 hips after cementless hip arthroplasty. Changes in BMD were evaluated longitudinally from 1 to 36 months. Stem fixation was evaluated at 5 years after surgery and was classified into a stable fixation group (30 hips) and an unstable fixation group (7 hips). On plain radiographs, distinct reactive lines around the proximal stem were detected at an average of 35 months after surgery in the unstable fixation group. In the unstable fixation group, the BMD decrease in the calcar region peaked 6 months after surgery, and BMD increased thereafter. In the stable fixation group, BMD continued to decrease until 36 months after surgery; a significant difference was observed between the 2 groups 24 months after surgery. Measurement of periprosthetic BMD is useful for estimating fixation between the bone and the prosthesis in an early stage.

Absorptiometry, Photon↗
PubMed2001

Examination of oral sensitization with ovalbumin in Brown Norway rats and three strains of mice.

We studied the conditions needed to sensitize animals to the oral feeding of food allergens, without induction of tolerance, in order to investigate the allergenicity of orally ingested food proteins. Brown Norway (BN) rats were sensitized by daily OVA (ovalbumin)-gavage or by drinking OVA containing water ad libitum and the ASA (active systemic anaphylaxis) response, as the immediate hypersensitivity response to antigen stimulation after oral sensitization, was examined. The oral administration of OVA by gavage produced a higher OVA-specific IgE response and an increase in serum histamine after antigen challenge, as compared to those produced by drinking water. Next, we examined the effect of murine age, the oral feeding technique and the oral feeding dose on sensitization using BALB/c, B10A and ASK mice. Twenty-week-old mice showed the strongest OVA-specific IgE and IgG1 responses and ASA-associated serum histamine contents increased with gavage in the three different age groups of BALB/c mice. Administering 0.1 mg of OVA by gavage daily for 9 weeks appeared to induce a higher response than administering 1 mg of OVA, in terms of OVA-specific IgE and IgG1 antibody responses and ASA responses. Among the three strains of mice, B10A mice exhibited the highest response in terms of OVA-specific IgE and IgG1 antibody and ASA responses. These findings suggested BN rats and B10A mice were suitable models for oral sensitization with antigen protein and that oral sensitization in mice requires low dose, intermittent antigen intakes.

Administration, Oral↗
PubMed2001

2,5-Di-tert-butyl-1,4-hydroquinone enhances cell transformation accompanied by an increase in intracellular free calcium ion concentration.

Two hydroquinones with similar structures, 2,5-di-tert-butyl-1,4-hydroquinone (DTBHQ) and 2-tert-butyl-1,4-hydroquinone (MTBHQ), are used as antioxidants in the environment. DTBHQ and MTBHQ were examined for their ability to induce cell transformation using BALB/3T3 cells. DTBHQ at concentrations of 2.5-15 microM enhanced cell transformation initiated by a subthreshold dose (0.75 microM) of 3-methylcholanthrene (MCA) in a two-stage cell transformation assay, which mimics a two-stage carcinogenicity test in experimental animals. Because DTBHQ is known to act as a calcium ion mobilizing agent in other cells, we examined the effects of DTBHQ on intracellular free calcium ion concentration ([Ca(2+)]i) in BALB/3T3 cells. DTBHQ elevated [Ca(2+)]i with a dose dependency similar to that of its enhancing effect on the MCA-initiated cell transformation. MTBHQ neither enhanced cell transformation nor induced increase of [Ca(2+)]i. Aberrant calcium signaling produced by DTBHQ might contribute to the enhancement of MCA-initiated transformation in BALB/3T3 cells.

3T3 Cells↗
PubMed2001

Correlation between operative outcomes of cervical compression myelopathy and mri of the spinal cord.

STUDY DESIGN: Magnetic resonance images of cervical compression myelopathy were retrospectively analyzed in comparison with surgical outcomes. OBJECTIVES: To investigate which magnetic resonance findings in patients with cervical compression myelopathy reflect the clinical symptoms and prognosis, and to determine the radiographic and clinical factors that correlate with the prognosis. SUMMARY OF BACKGROUND DATA: Signal intensity changes of the spinal cord on magnetic resonance imaging in chronic cervical myelopathy are thought to be indicative of the prognosis. However, the prognostic significance of signal intensity change remains controversial. METHODS: The participants in this study were 73 patients who underwent cervical expansive laminoplasty for cervical compression myelopathy. Their mean age was 64 years, and the mean postoperative follow-up period was 3.4 years. The pathologic conditions were cervical spondylotic myelopathy in 42 patients and ossification of the posterior longitudinal ligament in 31 patients. Magnetic resonance imaging (spin-echo sequence) was performed in all the patients. The transverse area of the spinal cord at the site of maximal compression was computed, and spinal cord signal intensity changes were evaluated before and after surgery. Three patterns of spinal cord signal intensity changes on T1-weighted sequences/T2-weighted sequences were detected as follows: normal/normal, normal/high-signal intensity changes, and low-signal/high-signal intensity changes. Surgical outcomes were compared among these three groups. The most useful combination of parameters for predicting prognosis was determined using a stepwise regression analysis. RESULTS: The findings showed 2 patients with normal/normal, 67 patients with normal/high-signal, and 4 patients with low-signal/high-signal change patterns before surgery. Regarding postoperative recovery, the preoperative low-signal/high-signal group was significantly inferior to the preoperative normal/high-signal group. There was no significant difference between the transverse area of the spinal cord at the site of maximal compression in the normal/high-signal group and the low-signal/high-signal group. A stepwise regression analysis showed that the best combination of surgical outcome predictors included age (correlation coefficient R = -0.348), preoperative signal pattern, and duration of symptoms (correlation coefficient R = -0.231). CONCLUSIONS: The low-signal intensity changes on T1-weighted sequences indicated a poor prognosis. The authors speculate that high-signal intensity changes on T2 weighted images include a broad spectrum of compressive myelomalacic pathologies and reflect a broad spectrum of spinal cord recuperative potentials. Predictors of surgical outcomes are preoperative signal intensity change pattern of the spinal cord on radiologic evaluations, age at the time of surgery, and chronicity of the disease.

Adult↗
PubMed2001

Sacral cyst managed with cyst-subarachnoid shunt: a technical case report.

STUDY DESIGN: This report describes the cyst-subarachnoid shunt, a novel surgical treatment, for sacral cysts. OBJECTIVE: To introduce a new surgical technique for sacral cysts. SUMMARY OF BACKGROUND DATA: There is no consensus on the appropriate treatment for symptomatic sacral cysts. The hydrostatic and pulsatile forces of cerebrospinal fluid are attributed to the growth of the cyst and their becoming symptomatic. METHODS: The clinical and radiologic features of a 41-year-old man with a symptomatic sacral cyst are detailed. A cyst-subarachnoid shunt was set to equalize the cerebrospinal fluid pressure between the cephalad thecal sac and the cyst. RESULTS: Immediately after surgery, the patient had no pain in his left leg and was free of pain at 2 years. Magnetic resonance imaging 1 year after surgery showed a decrease in the size of the cyst. CONCLUSION: Although this is a preliminary study, a cyst-subarachnoid shunt can be a useful alternative for symptomatic sacral cysts.

Adult↗
PubMed2001

Correlation between cytosolic calcium concentration and degranulation in RBL-2H3 cells in the presence of various concentrations of antigen-specific IgEs.

We studied the dependence of beta-hexosaminidase release from RBL-2H3 cells on the antigen-specific IgE concentrations. The cells were sensitized with DNP-specific IgE (0.5-5000 ng/ml) or OVA-specific IgE (5-50 ng/ml) and stimulated with DNP(35)-HSA (10(-2)-100 ng/ml) or OVA (10(-1) ng/ml-10 microg/ml). It was found that the beta-hexosaminidase release increased in a dose-dependent manner with the concentration of the IgEs and antigens added to the mast-cell suspension. We also studied the correlation between the intracellular calcium concentration ([Ca(2+)]i) and degranulation in RBL-2H3 cells. The percentage of beta-hexosaminidase release from the cells was well correlated with [Ca(2+)](i) increase, and the correlation coefficient was 0.88 for DNP-specific IgE and 0.99 for OVA-specific IgE. The minimum [Ca(2+)](i) required to induce the beta-hexosaminidase release was 100 nM for DNP-specific IgE, and 70 nM for OVA-specific IgE. Therefore, the [Ca(2+)](i) monitoring system is a sensitive marker of degranulation from RBL-2H3 cells and can be used to measure even low amounts of antigen-specific IgE.

Animals↗
PubMed2001

No neurological involvement for more than 40 years in Klippel-Feil syndrome with severe hypermobility of the upper cervical spine.

We report the case of a 42-year-old woman with Klippel-Feil syndrome, who showed severe hypermobility of the upper cervical spine without neurological involvement for more than 40 years. Radiographs revealed the presence of the odontoid bone and fusion of the atlas, odontoid bone, and occiput. Congenital fusion was present from the axis to C5 as a block vertebra. Lateral flexion-extension radiographs revealed severe hypermobility at the junction between the odontoid bone and the axis. Prophylactic surgical stabilization has been recommended in patients with severe hypermobility, but adjacent disc problems may possibly occur at the unfused levels in the future. We believe that early prophylactic stabilization should not be indicated for Klippel-Feil syndrome without neurological involvement only because of hypermobility.

Adult↗
PubMed2001

Effect of parathyroid hormone on cortical bone response to in vivo external loading of the rat tibia.

Cortical bone responses following administration of parathyroid hormone (PTH) were evaluated using a four-point bending device to clarify the relationship between the effect of PTH and mechanical loading. Female Wistar rats, 6-months-old, [corrected] were used. Rats were randomized into three groups (n = 10/group), namely PTH-5 (5 microgram PTH/kg body weight), PTH-30 (30 microgram PTH/kg body weight), and PTH-v (vehicle). PTH (human PTH (1-34)) was injected subcutaneously three times/week for 3 weeks. Loads on the right tibia were applied in vivo at 29.1 +/- 0.3 N for 36 cycles at 2 Hz 3 days/week for 3 weeks using four-point bending. The administration of PTH and tibial mechanical loading were performed on the same day. After calcein double labeling, rats were killed and tibial cross-sections were prepared from the region with maximal bending at the central diaphysis. Histomorphometry was performed over the entire periosteal and endocortical surfaces of the tibiae, dividing the periosteum into lateral and medial surfaces. The in vivo average peak tibial strains (predicted) on the lateral periosteal surface were 1392.4, 1421.8 and 1384.7 (mu)strain in PTH-v, PTH-5 and PTH-30 groups, respectively, showing no significant difference among the three groups. Significant loading-related increases in the bone formation surface, mineral apposition rate, and bone formation rate were observed at the periosteal and endocortical surfaces. Significant differences between PTH groups were also seen. Interaction between mechanical loading and PTH was significant at both periosteal and endocortical surfaces. It is concluded that PTH has a synergistic effect on the cortical bone response to mechanical loading.

Animals↗
PubMed2001

1H-NMR studies of cerebrospinal fluid: endogenous ethanol in patients with cervical myelopathy.

Endogenous ethanol was observed by nuclear magnetic resonance spectroscopy in the course of screening for cerebrospinal fluid of the patients with cervical myelopathy. Ethanol was detected in 10 out of 20 patients. It seems likely that the presence of endogenous ethanol is related to the severity of myelopathy. Also, the concentration of ethanol was correlated with that of lactate in the cerebrospinal fluid. This implies that ethanol may be formed as the end product of glycolysis or in an unknown pathway in the case of severely insulted myelonic tissues.

Adult↗
PubMed2001

Bone mass changes of tibial and vertebral bones in young and adult rats with collagen-induced arthritis.

To study the effect of arthritis on bone mass, bone mineral density (BMD) of cancellous and cortical bone in the tibial metaphysis and diaphysis in 2- and 7-month-old rats with collagen-induced arthritis (CIA) was serially measured using peripheral quantitative computed tomography (pQCT). BMD in the fourth lumbar vertebra in 7-month-old CIA rats was also measured by pQCT. The fourth lumbar vertebral body, distal femur, and proximal tibia in 7-month-old CIA rats were analyzed histomorphometrically. Changes in BMD differed between 2-month-old (young) and 7-month-old (adult) CIA rats. Although the BMD for the proximal tibia (2 mm and 5 mm distal from the growth cartilage) in young CIA rats decreased compared with that in control rats, the values exceeded the initial value during the arthritis course. On the other hand, bone loss in adult CIA rats occurred predominantly in the cancellous bone of the periarticular region of the tibia (2 mm distal from the growth cartilage), in which the enhancement of bone resorption and reduced bone formation were observed histomorphometrically. No remarkable changes were demonstrated in BMD or histomorphometrical analysis for the lumbar vertebra during the experimental course. These results suggest that bone loss in adult CIA rats resembles the osteoporosis that develops during the early stage of human rheumatoid arthritis. We conclude that adult CIA rats are more appropriate than young CIA rats as an experimental model of secondary osteoporosis due to rheumatoid arthritis.

Age Factors↗
PubMed2001

Effects of ovariectomy and estrogen replacement therapy on arthritis and bone mineral density in rats with collagen-induced arthritis.

We investigated the effects of ovariectomy (ovx) and estrogen replacement therapy (ERT) on bone mineral density (BMD) and arthritis severity in rats with collagen-induced arthritis (CIA). Seven-month-old female Sprague-Dawley rats were separated into a sham group (n = 8), CIA group (n = 14), ovx group (n = 10), CIA + ovx group (n = 11), and CIA + ovx + ERT group (n = 14). In these groups, ovx was performed at 7 days, and ERT (17beta-estradiol at 20 microg/kg three times per week) was initiated 8 days after sensitization. Every 2 weeks, until 8 weeks after sensitization, arthritis score and hind paw thickness were evaluated, and BMD of the trabecular and cortical bones in the metaphysis and diaphysis of the tibia were measured by peripheral quantitative computed tomography. The arthritis score was highest in the CIA + ovx group at all timepoints after sensitization. The hind paw thickness was significantly higher in the CIA + ovx group than in the CIA group at 8 weeks after sensitization (p < 0.05). Both the arthritis score and hind paw thickness were lower in the CIA + ovx + ERT group than in the CIA + ovx group. BMD in the metaphysis was significantly decreased in both the trabecular and cortical bones in the CIA + ovx group compared with those in the CIA group at 4, 6, and 8 weeks after sensitization. In the CIA + ovx group, trabecular BMD was changed by -34 +/- 11%, and cortical BMD changed by -14 +/- 7% in the metaphysis at 8 weeks compared with those at 0 week. In the CIA group, changes of BMD in the metaphysis were -7 +/- 11% in trabecular bone and 0 +/- 7% in cortical bone. These differences of trabecular and cortical bone loss in the metaphysis were significant (both p < 0.01). BMD reduction was significantly less in the CIA + ovx + ERT group than in the CIA + ovx group at 6 and 8 weeks after sensitization. Although BMD in the diaphysis was also reduced in the groups with CIA, the degree of reduction was smaller than in the metaphysis. We conclude that ovx in CIA rats could enhance the severity of arthritis and bone loss, and that ERT could suppress arthritis and bone loss.

Animals↗
PubMed2001

Regulation of mouse mast cell surface Fc epsilon RI expression by dexamethasone.

It is now clear that the mast cell's functional response to IgE-dependent stimulation can be influenced significantly by the level of expression of the high-affinity IgE receptor (Fc epsilon RI) on the cell's surface. Thus, modulation of Fc epsilon RI surface expression represents a potentially important mechanism for regulating mast cell activity in allergic reactions. In this study, we examined whether a glucocorticoid, dexamethasone (DEX), can influence levels of mast cell Fc epsilon RI expression either in the presence or absence of IgE, an up-regulator of the mast cell surface Fc epsilon RI level. In the absence of IgE, DEX decreased the surface Fc epsilon RI levels in mouse peritoneal mast cells, mouse bone marrow-derived cultured mast cells and a mouse mast cell line, Cl.MC/C57.1. Moreover, DEX also partially suppressed the ability of IgE to enhance surface expression of Fc epsilon RI in these cells. Three different glucocorticoids, DEX, methylprednisolone and hydrocortisone, suppressed Fc epsilon RI expression in mast cells, whereas sex steroids, i.e. estradiol, progesterone and testosterone, did not, indicating that the Fc epsilon RI-suppressing effect is glucocorticoid specific. On the other hand, DEX did not affect levels of Fc epsilon RI alpha, beta or gamma mRNA, suggesting that its ability to decrease surface Fc epsilon RI reflects a post-transcriptional mechanism. Finally, DEX-treated mast cells showed a reduced degranulation response to antigenic stimulation through down-regulation of surface Fc epsilon RI expression in addition to DEX-induced changes in downstream signals. These results show that mast cell surface Fc epsilon RI expression is suppressed by glucocorticoids in both the presence and absence of IgE, and suggest that reduction of mast cell surface Fc epsilon RI levels may be one of the favorable anti-allergic actions of glucocorticoids.

Animals↗
PubMed2001

Tensile properties of rat anterior cruciate ligament in collagen induced arthritis.

OBJECTIVES: To investigate the effects of collagen induced arthritis (CIA) on the tensile properties of rat anterior cruciate ligament (ACL). METHODS: The tensile strength, bone mineral density (BMD), and histology of ACL units from rats with CIA were investigated. RESULTS: The tensile strength of the ACL unit was significantly lower in the rats with CIA at 10 weeks after immunisation (ultimate failure load, 74.9% of the control; stiffness, 62.0% of the control). The major mode of failure was femoral avulsion, and the BMD was significantly lower in the rats with CIA. A histological examination of the ligament insertion in rats with CIA showed resorption of the cortical bone beneath the ACL insertion and an enlarged mineralised fibrocartilage zone. CONCLUSIONS: These findings indicate that the decrease in tensile strength of ACL units correlated with histological changes in the ligament-bone attachment, such as bone resorption beneath the ligament insertion site and an enlargement of the mineralised fibrocartilage zone.

Analysis of Variance↗
PubMed2001

Calcium signals in rat basophilic leukemia (RBL-2H3) cells primed with the neuropeptide substance P.

Communication between nerves and mast cells is a prototypic demonstration of neuroimmune interaction. We have recently shown that direct nerve-mast cell cross-talk can occur in the absence of an intermediary transducing cell and that the neuropeptide substance P is an important mediator of this communication. Here we study the calcium signals in rat basophilic leukemia cells (RBL-2H3; mucosal-type mast cells) primed with substance P. RBL cells responded only slightly to stimulation with compound 48/80, however they responded to the stimulation when the cells had been primed with substance P (0.5 microM) for one week. The present results provide a foundation to study the neuroimmune cross-talk in a co-culture system.

Animals↗
PubMed2001

Bi-directional relationship of in vitro mast cell-nerve communication observed by confocal laser scanning microscopy.

Communication between nerves and mast cells is a prototypic demonstration of neuro-immune interaction. Recently, we used an in vitro co-culture approach comprising cultured murine superior cervical ganglia (SCG) and rat basophilic leukemia (RBL) cells to study this interaction. Previously, we concentrated mainly on the activation signal from neurites to mast cells (RBL). However, it is proposed that mast cell-nerve communication is not a one-sided relationship but a bi-directional one. In the present work, we studied the communication from mast cells to neurites. We observed that binding of anti-IgE receptor antibodies to mast cells increases calcium ion concentration [Ca2+]i in SCG neurites. This indicates that mast cell-nerve communication is bi-directional. Confocal fluorescence microscopic images indicated that [Ca2+]i in neurites increased after an increase of [Ca2+]i in mast cells. The lag-time of neurite activation was several times longer than that of mast cell activation. The correlation coefficient between the lag-times for mast cell and nerve activation was calculated to be 0.81. In addition, the fluorescence images showed that calcium signals in SCG neurites were able to extend to a long distance (100-200 microm) from the site where mast cells (RBL) attached to neurites.

Animals↗
PubMed2001

[Hypersensitivity about environmental chemicals--mainly about food allergy].

The hypersensitivity of environmental chemicals and natural products has been reviewed. Among environmental chemicals, small molecular weight molecules work as hapten and cause immediate-type and delayed-type hypersensitivity. Among natural products, relatively lower molecular weight protein or glycoprotein (MW 10,000-70,000 kDa) work as allergen and cause mainly immediate-type hypersensitivity. In recent years, amino acid sequence of important natural allergens have been determined, and three-dimensional structure and IgE epitopes of some of these allergens have also been determined. The characteristics of both inhalation and food allergens have been summarized. As for food allergens, the stability of these proteins in simulated gastric fluid(SGF) was one of the most important characteristics. In the last parts, the approach to the assessment of allergenic potential of genetically modified foods has been summarized.

Allergens↗