Near-Infrared Spectral Results of Asteroid Itokawa from the Hayabusa Spacecraft

The near-infrared spectrometer on board the Japanese Hayabusa spacecraft found a variation of more than 10% in albedo and absorption band depth in the surface reflectance of asteroid 25143 Itokawa. Spectral shape over the 1-micrometer absorption band indicates that the surface of this body has an olivine-rich mineral assemblage potentially similar to that of LL5 or LL6 chondrites. Diversity in the physical condition of Itokawa's surface appears to be larger than for other S-type asteroids previously explored by spacecraft, such as 433 Eros.

Construction of a genetic linkage map of Japanese quail (Coturnix japonica) based on AFLP and microsatellite markers

The Japanese quail (Coturnix japonica) is a notably valuable egg and meat producer but has also been used as a laboratory animal. In the present study, we constructed a Japanese quail linkage map with 1735 polymorphic amplified fragment length polymorphisms markers, and nine chicken microsatellite (MS) markers, as well as sex and phenotypes of two genetic diseases; a muscular disorder (LWC) and neurofilament-deficient mutant (Quv). Linkage analysis revealed 578 independent loci. The resulting linkage map contained 44 multipoint linkage groups covering 2597.8 cM and an additional 218.2 cM was contained in 21 two-point linkage groups. The total map was 2816 cM in length with an average marker interval of 5.5 cM. The Quv locus was located on linkage group 5, but linkage was not found between the LWC locus and any of the markers. Comparative mapping with chicken using orthologous markers revealed chromosomal assignments of the quail linkage group 1 to chicken chromosome 2 (GGA2), 5 to GGA22, 2 to GGA5, 8 to GGA7, 27 to GGA11, 29 to GGA1 and 45 to GGA4.

Sex identification by male-specific growth hormone pseudogene (GH-psi) in Oncorhynchus masou complex and a related hybrid

It is often difficult to identify sexes of many fish species by conventional cytological method because of the lack of heteromorphic sex chromosomes. Isolation of sex-specific molecular markers is thus important for sexing and for understanding sex chromosome evolution in these species. We have identified genetic sexes by PCR-based male-specificity of a growth hormone pseudogene (GH-psi) in masu and Biwa salmon, two subspecies of the Oncorhynchus masou complex, and their hybrid Honmasu. PCRs with primers designed from sequences of chinook salmon GH genes amplified GH-I and GH-II fragments in both sexes, but a third GH-psi fragment was detected in predominant proportion of males and very few phenotypic females. The consistency of phenotypic sex with genetic sex identified by GH-psi for masu salmon, Biwa salmon and Honmasu was 93.1, 96.7 and 94%, respectively. The remaining individuals showed inconsistency or deviation from sex-specificity: a few phenotypic males lacked the GH-psi, whereas a few phenotypic females possessed the GH-psi. Sequence of the putative GH-psi fragment from such females was identical to that from genetic males, and shared about 95% homology with the corresponding GH-psi fragment from chinook salmon. This result confirmed that these females were really GH-psi-bearing individuals. PCR analyses with primers designed from masu salmon GH-psi gave identical results, indicating that the absence of GH-psi in a few males was not resulted from primer mismatching. These GH-psi-bearing females and GH-psi-absent males were more likely to originate from spontaneous sex reversion than from crossing-over between GH-psi and the sex determination gene/region.

Improved fish lymphocyte culture for chromosome preparation

Cytogenetic methodology is still underdeveloped in fishes compared with mammals. Culture condition for fish lymphocytes was optimized to improve chromosome preparation using the rainbow trout (Oncorhynchus mykiss) as a model after changing the combination of parameters such as mitogens, incubation periods, media, cell components, and freshness of blood. The optimized culture condition included isolation of lymphocytes from fresh blood by a stirring method, their culture in medium 199 supplemented with 10% FBS, 18 microg/ml of phytohemagglutinin (PHA-W) and 100 microg/ml of lipopolysaccharide (LPS) as mitogens, and harvested at 6 days after culture. This condition provided a notably increased mitotic index (MI) of 4.3-10.0% in rainbow trout lymphocytes. In addition, the condition was highly reproducible as shown by the similar level of MI in cultured lymphocytes from 181 individuals without failure. Applicability of this method in a wide range of fish groups was also proven with Ml of 1.1-13.3% in cultured lymphocytes from other 16 freshwater species of Acipenseridae, Anguillidae, Solmonidae, Cyprinidae, and Centrarchidae, and five marine species of Sparidae, Kyphosidae, Paralichthyidae, and Scorpaenidae. Chromosome preparations of improved quality by the present method were successfully applied for the replication R-banding with incorporation of 5-bromo-2'-deoxyuridine and direct R-banding fluorescence in situ hybridization.

Activation of caspases in intestinal villus epithelial cells of normal and nematode infected rats

BACKGROUND

Small intestinal epithelial cells (IEC) show apoptosis in physiological turnover of cells and in certain inflammatory diseases.

AIMS

To investigate the role of caspases in the progression of IEC apoptosis in vivo.

METHODS

IEC were separated along the villus-crypt axis from the jejunum of normal and Nippostrongylus brasiliensis infected rats at 4 degrees C. Caspases were examined by a fluorometric assay method, histochemistry, and immunoblotting.

RESULTS

Villus cell rich IEC from normal rats exhibited a high level of caspase-3-like activity whereas activities of caspase-1, -8, and -9 were negligible. Immunoblotting analysis of villus cell rich IEC revealed partial cleavage of procaspase-3 into a 17 kDa molecule as well as cleavage of a caspase-3 substrate, poly(ADP-ribose) polymerase (PARP), whereas in crypt cell rich IEC, caspase-3 cleavage was less significant. Caspase-3 activity was also observed histochemically in villus epithelium on frozen sections of the normal small intestine. IEC prepared at 4 degrees C did not reveal nuclear degradation whereas subsequent incubation in a suspension at 37 degrees C induced intense nuclear degradation within one hour in accordance with increases in active caspase-3. This apoptosis was partially suppressed by the caspase inhibitor Z-VAD-fmk. Nematode infected animals showed villus atrophy together with significant increases in levels of caspase-3 in IEC but not of caspase-1, -8, or -9.

CONCLUSION

Caspase-3 may have an important role in the physiological replacement of IEC as well as in progression of IEC apoptosis induced by nematode infection.

Intracerebral hematoma due to ruptured nontraumatic middle meningeal artery aneurysm--case report

A 77-year-old woman suddenly lost consciousness and presented with right hemiparesis. Computed tomography showed a large subcortical hematoma in her left frontal lobe associated with subarachnoid hemorrhage. The first impression was hemorrhage due to a ruptured aneurysm of the middle cerebral or the internal carotid artery on the left. Left internal carotid angiography showed no aneurysm or vascular anomaly, but back flow of contrast medium into the external carotid artery disclosed two saccular aneurysms arising from the anterior branch of the left middle meningeal artery (MMA). Emergent surgical intervention confirmed that the hematoma was due to ruptured MMA aneurysm. Nontraumatic MMA aneurysm should be recognized as a possible causative lesion of intracranial hemorrhage despite the extremely low incidence. External carotid angiography should be performed in patients with intracranial hemorrhage in whom no vascular cause can be detected in the internal carotid system.

Therapeutic effects of azathioprine in combination with low-dose prednisolone in patients with intractable autoimmune hepatitis type 1

This study evaluated the effects of azathioprine in combination with low-dose prednisolone in the management of patients with intractable autoimmune hepatitis. Thirteen patients with intractable autoimmune hepatitis who had an incomplete or arrested response to conventional prednisolone therapy, or who relapsed during prednisolone maintenance therapy were additionally administered 50 or 100 mg/day of azathioprine in combination with prednisolone. This regimen reliably induced complete remission in 12 of 13 patients, and these 12 remained in remission during the follow-up period with maintenance therapy of 50 mg/day of azathioprine in combination with 5 mg/day of prednisolone. The findings of the current study indicate that the azathioprine and low-dose prednisolone combined therapy may offer a satisfactory alternative therapy for patients with intractable autoimmune hepatitis who have an incomplete or arrested response to conventional prednisolone therapy, or who relapse during prednisolone maintenance therapy.

Biomechanical evaluation of diagonal fixation in pedicle screw instrumentation

STUDY DESIGN

Flexibility tests and finite element analyses were performed for the biomechanical evaluation of diagonal transfixation in pedicle screw instrumentation.

OBJECTIVE

To assess the biomechanical advantages of diagonal transfixation compared with conventional horizontal transfixation.

SUMMARY AND BACKGROUND DATA

A few pedicle screw instrumentation systems allow the use of cross-links in the diagonal direction. Such a diagonal transfixation is anticipated to improve the surgical construct stability, but its biomechanical qualities have not been completely evaluated.

METHODS

Flexibility tests were performed on 10 calf lumbar spines (L2-L5). Specimens were subjected to pure moments up to 8.2 Nm in flexion, extension, lateral bending, and extension while the resulting movements of L3 and L4 were measured by a three-dimensional motion analysis system. The tested cases included (1) intact, (2) pedicle screw fixation without transfixation after total removal of the L3-L4 disc, (3) pedicle screw fixation with diagonal transfixation, and (4) pedicle screw fixation with horizontal transfixation. Three-dimensional finite element models of the tested surgical constructs were also developed by use of three-dimensional beam elements to investigate the effect of diagonal transfixation and horizontal transfixation on the construct stability and the corresponding stress changes in the screws.

RESULTS

When compared with no transfixation, horizontal transfixation significantly improved the lateral bending and axial rotation stability by 15.7% and 13.9%, respectively, but there was no improvement of stability in flexion and extension. By contrast, diagonal transfixation significantly improved the flexion and extension stability by 12% and 10.7%, respectively, but not the lateral bending and axial rotation stability in comparison with no transfixation. Comparison between horizontal transfixation and diagonal transfixation showed that the stabilizing effect of diagonal transfixation was greater in flexion and extension (13% and 11%, P < 0.01) than that of horizontal transfixation but smaller in lateral bending (11%, P < 0.05) and axial rotation (6.6%, P > 0.1). Finite element model predictions of the motion changes were similar to the changes observed in flexibility tests. In horizontal transfixation, the load changes, compared with no transfixion, were a 0.02% increase in flexion-extension, a 27.5% increase in lateral bending, and a 58% decrease in axial rotation, and the magnitudes of the moments applied on both the right and left pedicle screws were identical. However, when diagonal transfixation was achieved by connecting the left superior screw and the right inferior screw, the loads in the left screw were increased by 11.5% in flexion-extension, 43.6% in lateral bending, and 7.9% in axial rotation, whereas the loads in the right screw were decreased by 10.9% in flexion-extension, increased by 0.06% in lateral bending, and decreased by 18.1% in axial rotation.

CONCLUSIONS

The results of this study showed that diagonal transfixation provides more rigid fixation in flexion and extension but less in lateral bending and axial rotation in comparison with horizontal transfixation. Furthermore, greater stresses in the pedicle screws were predicted in the diagonal transfixation model. These limitations of diagonal transfixation should be considered carefully for clinical application.

Reduced IP3 sensitivity of IP3 receptor in Purkinje neurons

The inositol 1,4,5-trisphosphate receptor (IP3R) is highly expressed in Purkinje neurons (PNs) and is thought to be essential for the induction of long-term depression at parallel-fiber-PN synapses. Here, by imaging the fluorescence intensity of the low-affinity Ca2+ indicator inside the Ca2+ stores in the permeabilized single PNs, we analyzed the kinetics of Ca2+ release via the IP3R in controlled cytoplasmic environments. The rate of Ca2+ release is dependent on the IP3 concentration with an EC50 of 25.8 microM, which is > 20-fold greater than that of the IP3R in the isolated preparations or in peripheral cells. This property would be advantageous in inducing the release of Ca2+ in a localized space adjacent to the site of synaptic inputs.

Direct measurement of HDL cholesterol: method eliminating apolipoprotein E-rich particles

It has been reported that the existing direct method of high density lipoprotein (HDL) cholesterol measures particles enriched with apolipoprotein E (apoE). The aim of our study was to investigate a new analytical protocol to directly measure HDL cholesterol that eliminates apoE-rich particles. The interactions of four lipoproteins (HDL(3), HDL(2), LDL, and VLDL + chylomicron) with surfactants, divalent cations, sugars, and lectins were investigated. By analyzing sera, HDL(3), and HDL(2), we examined the relationships among the measurements obtained by our protocol, a precipitation method using heparin-MnCl(2), and a commercially available kit for this direct method. A significant difference was found between the direct method and the heparin-MnCl(2) method, but not between our protocol and the heparin-MnCl(2) method. Multiple regression analysis showed that the difference between the direct method and the heparin MnCl(2) method is dependent on sources of apoE-rich HDL. In conclusion, our protocol enables a direct measurement of HDL cholesterol that eliminates apoE-rich particles.

Morphologic changes in the lumbar intervertebral foramen due to flexion-extension, lateral bending, and axial rotation: an in vitro anatomic and biomechanical study

STUDY DESIGN

A biomechanical and anatomic study with human cadaveric lumbar spine.

OBJECTIVES

The purpose of this study is to examine the morphologic changes in the intervertebral foramen during flexion, extension, lateral bending, and axial rotation of the lumbar spine and to correlate these changes with the flexibility of the spinal motion segments.

SUMMARY OF BACKGROUND DATA

Previous studies showed morphologic changes in the intervertebral foramen during flexion and extension; however, those changes during lateral bending and axial rotation were not well known.

METHODS

There were 81 motion segments obtained from 39 human cadaveric lumbar spines (mean age 69 years). The motion segments were imaged with CT scanner with 1-mm thick consecutive sections. For biomechanical testing each motion segment was applied with incremental pure moments of flexion, extension, lateral bending, and axial rotation. Rotational movements of the motion segment were measured using VICON cameras. After application of the last load, the specimens were frozen under load, and then CT was performed with the same technique described above. Six parameters of the intervertebral foramen were measured, including foraminal width (maximum and minimum), foraminal height, disc bulging, thickness of ligamentum flavum, and cross-sectional area of the foramen.

RESULTS

Flexion increased the foraminal width (maximum and minimum), height, and area significantly while significantly decreasing the disc bulging and thickness of ligamentum flavum (P < 0.05). However, extension decreased the foraminal width (maximum and minimum), height, and area significantly. Lateral bending significantly decreased the foraminal width (maximum and minimum), height, and area at the bending side, whereas lateral bending significantly increased the foraminal width (minimum), height, and area at the opposite side of bending. Likewise, axial rotation decreased the foraminal width (minimum) and area at the rotation side significantly while significantly increasing the foraminal height and foraminal area at the opposite side. The percent change in the foraminal area was found significantly correlated with the amount of segmental spinal motion except for the extension motion.

CONCLUSIONS

This study showed that the intervertebral foramen of the lumbar spine changed significantly not only on flexion-extension but also on lateral bending and axial rotation. The percent change in cross-sectional foraminal area was correlated with the amount of segmental motion except for extension motions. Further studies are needed to assess the morphologic changes in the intervertebral foramen in vivo and to correlate clinically.

Modulation of doxorubicin sensitivity by cyclosporine A in hepatocellular carcinoma cells and their doxorubicin-resistant sublines

BACKGROUND AND AIMS

Cyclosporine A (Cys) and verapamil (Ver) sensitize multidrug-resistant (MDR) cells to various anticancer drugs by interacting with membrane glycoproteins involved in the drug efflux. In the present study, we assessed the effect of Cys on the modulation of doxorubicin (DOR) sensitivity in hepatocellular carcinoma (HCC) cell lines, and their DOR-resistant sublines.

METHODS

The sensitivity to DOR and the chemosensitizing effects of Cys were assessed by using two human HCC cell lines, PLC/PRF/5 and Hep-3B, and their DOR-resistant sublines, PLC/DOR and 3B/DOR. The expression of multidrug resistance 1 (MDR1) and multidrug resistance-associated protein (MRP) mRNA in these cells were detected by using a RT-PCR. The HCC cell lines grown in individual wells of 24-well plates were incubated with DOR that were sequentially diluted in culture medium in combination with 5 micromol/L Cys for 24 h. The cell viability in each well was measured by using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay.

RESULTS

The mRNA of MDR1 and that of MRP were readily detectable in the HCC cell lines by RT-PCR. When 5 micromol/L Cys was added to the culture, the 50% inhibiting concentration (IC50) of DOR was reduced from 0.93 +/- 0.29 microg/mL to 0.32 +/- 0.10 microg/mL in PLC/PRF/5, and from 0.25 +/- 0.07 microg/mL to 0.09 +/- 0.04 microg/mL in Hep-3B. Furthermore, in the presence of 5 micromol/L Cys, the IC50 of DOR was reduced from 48.63 +/- 17.04 microg/mL to 0.49 +/- 0.14 microg/mL in PLC/DOR, and from 4.60 +/- 1.22 microg/mL to 0.15 +/- 0.06 microg/mL in 3B/DOR. The amounts of PCR products of MDR1 mRNA in PLC/DOR and 3B/DOR were greater than those in PLC/PRF/5 and Hep-3B, respectively.

CONCLUSIONS

In HCC, the amplification of MDR1 mRNA is probably the main mechanism underlying acquired DOR resistance. Cyclosporine is also indicated to be highly active in potentiating the anticancer activity of DOR in HCC cells and their DOR-resistant sublines.

Orientation and osteoarthritis of the lumbar facet joint

Several studies have shown an association between sagittal orientation of the facet joint and degenerative spondylolisthesis. There is currently no information available on the association between orientation of the facet joint and osteoarthritis. This study examined the association between orientation and osteoarthritis of the lumbar facet joints. One hundred eleven consecutive patients underwent plain radiography and magnetic resonance imaging. These patients were divided into two groups: No Degenerative Spondylolisthesis Group (98 patients) and Degenerative Spondylolisthesis Group (13 patients). In the No Degenerative Spondylolisthesis Group, segments with higher grades of osteoarthritis showed more sagittal orientation of the facetjoints at the L3-L4 and L4-L5 levels. The facet joint was oriented significantly more sagittally in the Degenerative Spondylolisthesis Group than in the No Degenerative Spondylolisthesis Group at the L4-L5 and L5-S1 levels. The severity of facet joint osteoarthritis was significantly higher in the Degenerative Spondylolisthesis Group than in the No Degenerative Spondylolisthesis Group at the L3-L4, L4-L5, and L5-S1 levels. A significant association was found between sagittal orientation and osteoarthritis of the lumbar facet joints, even in patients without degenerative spondylolisthesis. Facet joint osteoarthritis, rather than spondylolisthesis, is the pathoanatomic feature that is associated with sagittal orientation of the facet joints in patients with degenerative spondylolisthesis.

Effects of Ca2+ on flavin-linked complex enzymes in mitochondria isolated from eggs and embryos of sea urchin

Mitochondria isolated from sea urchin embryos in early development show almost the same activities of cytochrome c oxidase and flavin-linked complex enzymes, which are estimated by cytochrome c reductases as in those isolated from unfertilized eggs. The activities of these cytochrome c reductases are inhibited by Ca2+ at above 10-5 M more strongly than cytochrome c oxidase. To investigate the changes in intramitochondrial Ca2+ concentration at fertilization, the activity of pyruvate dehydrogenase, another mitochondrial enzyme, was measured. The activity of this enzyme was controlled by phosphorylation and Ca2+-dependent dephosphorylation of the catalytic unit. The enzyme activity increased for 30 min after fertilization, decreased and became close to zero within ~60 min. Then, the activity appreciably increased again after hatching. This seems to reflect changes in the intramitochondrial Ca2+ concentration. The enzyme activity was enhanced by pre-incubation with Ca2+ at concentrations up to 10-5 M but was made quite low at above 10-4 M Ca2+ and 10-3 M adenosine triphosphate. Although the changes in pyruvate dehydrogenase activity observed at fertilization will reflect the changes in the intramitochondrial calcium concentration, the intramitochondrial Ca2+ concentration of unfertilized eggs cannot be estimated from these results because high (> 10-4 M) or low (10-6 M) Ca2+ can inhibit the enzyme. Measurement of respiration of a single egg showed that injection of ethyleneglycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid released the mitochondrial electron transport in the unfertilized egg. The possibility that changes in intramitochondrial calcium concentration occur at fertilization is discussed in relation to activation of both mitochondrial respiration and pyruvate dehydrogenase.

Manipulation of elementary charge in a silicon charge-coupled device

The ultimate limit in the operation of an electronic device is the manipulation of a single charge. Such a limit has been achieved in single-electron tunnelling devices. However, these devices are based on multiple tunnel barriers and conductive islands, which are complex structures to fabricate. Here we demonstrate another type of device that can also manipulate elementary charge, but which is more suitable for large-scale integration. The device consists of two closely packed silicon wire-MOSFETs, which are commonly used building blocks of electronic circuits. We have developed a scheme to generate and store holes in the channels of either of these MOSFETs. Subsequently, holes can be transferred between the two MOSFETs at the level of an elementary charge, and their exact position can be monitored. This single-charge transfer device, which is operated at 25 K, is in effect a charge-coupled device. This is also the first realization of a silicon-based device that manipulates elementary charge.

The relationship between disc degeneration and flexibility of the lumbar spine

BACKGROUND CONTEXT

A relationship between degenerative changes of the intervertebral disc and biomechanical functions of the lumbar spine has been suggested. However, the exact relationship between the grade of disc degeneration and the flexibility of the motion segment is not known.

PURPOSE

To investigate the relationship between degenerative grades of the intervertebral disc and three-dimensional (3-D) biomechanical characteristics of the motion segment under multidirectional loading conditions.

STUDY DESIGN/SETTING

A biomechanical and imaging study of human cadaveric spinal motion segments.

METHODS

One hundred fourteen lumbar motion segments from T12-L1 to L5-S1 taken from 47 fresh cadaver spines (average age at death, 68 years; range, 39 to 87 years) were used in this study. The severity of degeneration (grades I to V according to Thomson's system) was determined using magnetic resonance (MR) images and cryomicrotome sections. Pure unconstrained moments with dead weights were applied to the motion segments in six load steps. The directions of loading included flexion, extension, right and left axial rotation, and right and left lateral bending.

RESULTS

When the MR images were graded, 2 segments had grade I disc degeneration; 45, grade II; 20, grade III; 26, grade IV; and 21, grade V. When the cryomicrotome sections were graded, 14 segments had grade I disc degeneration; 31, grade II; 22, grade III; 26, grade IV; and 21, grade V. Segments from the upper lumbar levels (T12-L1 to L3-4) tended to have greater rotational movement in flexion, extension, and axial rotation with disc degeneration up to grade IV, whereas the motion decreased when the disc degenerated to grade V. In the lower lumbar spine at L4-5 and L5-S1, motion in axial rotation and lateral bending was increased in grade III.

CONCLUSIONS

These results suggest that kinematic properties of the lumbar spine are related to disc degeneration. Greater motion generally was found with disc degeneration, particularly in grades III and IV, in which radial tears of the annulus fibrosus are found. Disc space collapse and osteophyte formation as found in grade V resulted in stabilization of the motion segments.

The effect of disc degeneration and facet joint osteoarthritis on the segmental flexibility of the lumbar spine

STUDY DESIGN

A biomechanical and imaging study of human cadaveric spinal motion segments.

OBJECTIVE

To investigate the effect of both disc degeneration and facet joint osteoarthritis on lumbar segmental motion.

SUMMARY OF BACKGROUND DATA

Spinal degeneration includes the osteoarthritic changes of the facet joint as well as disc degeneration. Disc degeneration has been reported to be associated with spinal motion. The association of facet joint osteoarthritis with lumbar segmental motion characteristics and the combined influence of disc degeneration and facet osteoarthritis has not yet been investigated.

METHODS

A total of 110 lumbar motion segments (52 female, 58 male) from 44 human lumbar spines were studied (mean age = 69 years). Magnetic resonance images were used to assess the disc degeneration from Grade I (normal) to Grade V (advanced) and the osteoarthritic changes in the facet joints in terms of cartilage degeneration, subchondral sclerosis, and osteophytes. Disc height, endplate size, and facet joint orientation and width also were measured from the computed tomographic images. Rotational movements of the motion segment in response to the flexion, extension, lateral bending, and axial rotational moments were measured using a three-dimensional motion analysis system.

RESULTS

Female motion segments showed significantly greater motion (lateral bending: P < 0. 001, flexion: P < 0.01, extension: P < 0.05) and smaller endplate size (P < 0.001) than male ones. The segmental motion increased with increasing severity of disc degeneration up to Grade IV, but decreased in both genders when the disc degeneration advanced to Grade V. In male segments, the disc degeneration-related motion changes were significant in axial rotation (P < 0.001), lateral bending (P < 0.05), and flexion (P < 0.05), whereas female segments showed significant changes only in axial rotation (P < 0.001). With cartilage degeneration of the facet joints, the axial rotational motion increased, whereas the lateral bending and flexion motion decreased in female segments. In male segments, however, motion in all directions increased with Grade 3 cartilage degeneration and decreased with Grade 4 cartilage degeneration. Subchondral sclerosis significantly decreased the motion (female: axial rotation, P < 0. 05; extension, P < 0.05 vs.- male:flexion,P < 0.05). Severity of osteophytes had no significant association with the segmental motion.

CONCLUSION

Axial rotational motion was most affected by disc degeneration, and the effects of disc degeneration on the motion were similar between genders. Facet joint osteoarthritis also affected segmental motion, and the influence differed for male and female spines. Further studies are needed to clarify whether the degenerative process of facet joint osteoarthritis differs between genders and how facet joint osteoarthritis affects the stability of the spinal motion segment.