Induction of smooth muscle cells in the fibrous capsule of human hepatocellular carcinoma but not in the septa of hepatic cirrhosis

We examined the expression of smooth muscle cytoskeleton in spindle-shaped cells in the capsule of hepatocellular carcinoma (HCC) and the septa of liver cirrhosis (LC). Serial sections of livers resected from 11 patients were stained with monoclonal antibodies against vimentin, desmin, smooth muscle actin (1A4, HHF35, CGA7) and smooth muscle myosin heavy chain isoforms (SM1, SM2). Capsular spindle-shaped cells exhibited a cytoskeletal feature indicative of intermediately differentiated smooth muscle cells. Computer-assisted morphometry revealed that the proportions of 1A4-, HHF35-, CGA7- and SM1- positive areas to vimentin-positive area were 88.0+/-11.0%, 50.8+/-17.4%, 25.3+/-16.4% and 19.4+/-12.4% (n=11) in main tumours and 86.6+/-9.4%, 50.9+/-18.7%, 21.1+/-12.3% and 17.6+/-9.7% (n=12) in daughter tumours, indicating that spindle-shaped cells are heterogeneous in cytoskeletal expression. Septal spindle-shaped cells in LC lacked the cytoskeletal proteins specific to differentiated smooth muscle cells (CGA7, SM1, SM2 and desmin). Electron microscopically, capsular spindle-shaped cells contained more microfilaments and less rough endoplasmic reticulum than do septal cells. Intermediately differentiated smooth muscle cells are induced in the capsule of HCC but not in the septa of LC, suggesting a role for stromal interaction by tumour cells in the induction of smooth muscle cells.

[A successful case report of a patient who had severe aortic stenosis with cardiac arrest: bridge use of percutaneous cardiopulmonary support system (PCPS)]

A 62-year-old female with chronic renal failure was transferred to our unit for the purpose of surgical treatment. During hemodialysis, cardiac arrest occurred suddenly. Cardiac resuscitation was not effective, necessitating PCPS. She successfully underwent an emergent aortic valve replacement. She had no brain damage and was discharged on foot on the 45th postoperative day.

[A case of myotonic dystrophy showing proximal dominant muscle involvement but not myotonia]

A 45-year-old female had progressive difficulty in climbing stairs and standing from a chair for 10 years. She had binocular cataracts which were operated at the age of 42 years. On examination, she had marked muscle wasting in the proximal limbs, scapular and sternomastoid muscles. She presented as marked muscle weakness in the proximal portion of the lower extremities and moderate in the upper extremities and the legs. Deep tendon reflexes were absent in all limbs. There was no grip myotonia, or percussion myotonia of the thenar muscle and tongue. Myotonia was not elucidated even after the hands were exposed to cold water. Moreover, none of the examined muscles revealed insertion myotonic discharge on electromyography. Serum CK level was normal and IgG value decreased to 546 mg/dl. Muscle biopsy of the left biceps muscle showed the variation in fiber size, increased central nuclei and many fiber with pyknotic nuclear clumps on HE staining. Sarcoplasmic mass and ring fibers were also found on HE staining. There were a few percents of ragged-red fibers on Gomori-trichrome staining, and type 1 fiber atrophy was found on pH 4.5 ATP-ase staining. The expansion of lymphocyte CTG trinucleotide repeats in the myotonin protein kinase gene was about 733, so that she was diagnosed as having myotonic dystrophy (MD). MRI of skeletal muscles exhibited marked atrophy especially in the femoral region and the biceps muscle. This patient had the proximal dominant muscle weakness, and absent myotonia even on electromyographic examination, which are unusual clinical features of adult onset MD.

Biomechanical analysis of anterior versus circumferential spinal reconstruction for various anatomic stages of tumor lesions

STUDY DESIGN

Spinal reconstruction procedures for metastasis evaluated biomechanically using human cadaver specimens.

OBJECTIVE

To investigate the stiffness of anterior versus circumferential spinal reconstructions for different anatomic stages of tumor lesions.

SUMMARY OF BACKGROUND DATA

Metastatic tumors predominantly involve the vertebral bodies. Although anterior instrumentation and strut grafts provide excellent stability, it remains unclear to what extent vertebral destruction requires anterior reconstructions alone versus combined anterior and posterior procedures.

METHODS

Ten human cadaveric thoracolumbar spines were used. The L1 vertebral body and posterior elements were resected sequentially based on Weinstein's anatomic zone classification for tumor lesions. Anterior reconstruction was performed between T12 and L2 using an iliac strut graft and the Kaneda SR system (AcroMed, Cleveland, OH). For circumferential reconstruction, the Cotrel-Dubousset hook and rod system was combined with the anterior reconstruction procedure. Experimental groups included the intact condition and five reconstruction stages: anterior reconstructions for corpectomy, subtotal and total spondylectomies, and circumferential reconstructions for subtotal and total spondylectomies. Nondestructive biomechanical testing was performed under four different loading modes.

RESULTS

All the reconstruction groups except anterior instrumentation alone for total spondylectomy returned stiffness to a level equivalent or higher to that of the intact spine. There were no statistical differences observed between anterior and circumferential reconstruction for subtotal spondylectomy. Anterior instrumentation alone for total spondylectomy did not restore stiffness to the intact level, and demonstrated significantly lower stiffness than that of circumferential reconstruction.

CONCLUSIONS

For corpectomy or subtotal spondylectomy, anterior reconstruction alone can provide stiffness equivalent to circumferential reconstruction. However, total spondylectomy significantly reduces the anterior reconstruction stiffness, suggesting the need for combined anterior and posterior procedures.

[A successful surgical case of giant arch aneurysm with severe pulmonary dysfunction and angina pectoris]

A 70-year-old female was admitted to our unit with chief complaints of dyspnea on effort and angina pectoris. She had suffered from chronic bronchitis. Chest CT scan demonstrated a giant arch aneurysm which strongly attached to the left anterior chest wall. Coronary angiogram showed two vessels disease. She successfully underwent coronary artery bypass grafting and total arch replacement under selective cerebral perfusion. She needed long respiratory care because of her pulmonary dysfunction. But she could wean from the ventilator under intensive respiratory care on 46th postoperative days and was discharged on foot.

In vivo activation of langerhans cells and dendritic epidermal T cells in the elicitation phase of murine contact hypersensitivity

Langerhans cells (LCs) and dendritic epidermal T cells (DETCs) constitute the skin immune system. To demonstrate the kinetics of in vivo activation of murine LCs and DETCs in the elicitation phase of contact hypersensitivity, we measured the cell area positively stained for I-A and gammadeltaT-cell receptor (or Thy-1.2), respectively, under a fluorescence microscope at various time intervals after topical application of dinitrofluorobenzene. The fluorescence-positive area of LCs increased in parallel with that of DETCs at 1 h and 24 h, indicating the biphasic activation of LCs and DETCs. Early activation was hapten-specific and often exhibited close LC-to-DETC apposition. Experiments with in vivo administration of neutralizing anticytokine antibodies revealed that none of interferon (IFN)-gamma, tumour necrosis factor (TNF)-alpha and interleukin (IL)-1beta were involved in the induction of early activation of LCs and DETCs, while TNF-alpha and IL-1beta mediated late activation of LCs, and IFN-gamma and IL-1beta mediated that of DETCs. Our results indicate that LCs and DETCs are synchronously and biphasically activated in the epidermis during the elicitation phase of contact hypersensitivity and suggest that different mechanisms may control early and late activation.

[Surgical treatment of acute massive pulmonary embolism: report of two cases]

We experienced two cases of acute massive pulmonary embolism. Both of the patients required emergent surgical procedures under cardiopulmonary bypass after cardiopulmonary resuscitation. Postoperative courses of them were uneventful. In severe cases with acute massive pulmonary thrombosis, there is no time to choose medical treatment alternative to pulmonary embolectomy. The diagnosis should be made promptly, and immediate decision of operation is very important.

High expression of macrophage migration inhibitory factor in the synovial tissues of rheumatoid joints

Macrophage migration inhibitory factor (MIF) plays an important role in inflammation and immunity via autocrine/paracrine and endocrine routes. We examined the presence of MIF in the synovial fluids of rheumatoid arthritis (RA) patients. The content of MIF in the synovial fluid was quantitated by enzyme-linked immunosorbent assay which revealed that the concentration of MIF for RA patients was 85. 7+/-35.2 ng/ml (mean+/-SD) (n=25). In comparison, the concentrations for osteoarthritis patients and normal volunteers were 19.5+/-5.3 ng/ml (n=12) and 10.4+/-1.1 ng/ml (n=5), respectively. The expression of MIF mRNA and presence of MIF protein in the synovial tissues of RA were demonstrated by Northern blot and Western blot analyses, respectively. Immunohistochemical analysis revealed that positive staining was largely observed in the cytoplasm of infiltrating T lymphocytes, which might be the major source of MIF detected in the synovial fluids. The pathophysiological role of MIF in RA remains to be elucidated; however, the present results for the first time suggest the possibility that MIF is involved in the potentiation of inflammatory and immunological responses in rheumatoid joints.

Dynamic motion analysis of normal and unstable cervical spines using cineradiography. An in vivo study

STUDY DESIGN

Cervical motion patterns were analyzed in a normal population and in patients with cervical instability by using cineradiography.

OBJECTIVES

To determine normal and pathologic motion patterns in the cervical spine through an in vivo continuous motion analysis.

SUMMARY OF BACKGROUND DATA

Cineradiographic techniques have been used in a limited number of studies to quantify spinal motion. There is a paucity of information regarding dynamic motion patterns in normal and pathologic cervical spines.

METHODS

Ten healthy subjects and 12 patients with unstable cervical spines (C1-C2 subluxation caused by rheumatoid arthritis, n = 10; instability below C2, n = 2) were studied. Cervical motion during flexion from the maximum extension position was recorded using cineradiography. Cervical segmental motions (C1-C2 to C5-C6) were continuously measured through quantifying cineradiographic images projected on a digitizer.

RESULTS

Normal cervical spines showed a well-regulated stepwise motion pattern that initiated at C1-C2 and transmitted to the lower segments with time lags. Pathologic spines showed a different order of onset of segmental motion. In patients with rheumatoid arthritis who had atlantoaxial subluxation, C1-C2 motion initiated significantly earlier than C2-C3 motion. In patients with segmental instability below C2, motion in the unstable segments preceded that in the upper intact segments.

CONCLUSIONS

Different motion patterns were observed between normal and pathologic cervical spines. Cineradiographic motion analysis is a valuable adjunctive technique, especially in diagnosis or evaluation of conditions that cannot be identified through conventional radiographic examination.

Identification of macrophage migration inhibitory factor (MIF) in rat peripheral nerves: its possible involvement in nerve regeneration

Macrophage migration inhibitory factor (MIF) is known as a pluripotent immunoregulatory cytokine involved in T-cell activation and inflammatory responses; however, no study on this protein in the peripheral nervous systems has been carried out. We here demonstrated for the first time expression of MIF mRNA and MIF protein in rat sciatic nerves by reverse transcription-polymerase chain reaction, Western blotting, and immunohistochemistry. Immunohistochemical analysis revealed positive staining of MIF, which was largely observed in Schwann cells. Furthermore, we examined MIF mRNA expression in the sciatic nerves by Northern blot analysis in the case of nerve transection. In both proximal and distal segments, the level of MIF mRNA started to increase 12 h after the nerve transection. The level remained high from 24 h up to day 7 after the injury. During the period from days 14 to 21, MIF mRNA sharply decreased to the pre-transection level. In immunohistochemistry, positive staining of MIF was largely observed in axons as well as non-neuronal cells in proximal segments at day 4 after transection. In the distal segments, contrastingly, endoneurial fibroblasts or Schwann cells migrating into neuronal fibers showed positive staining with Wallerian degeneration. Although the precise functions of MIF in the peripheral nerves remain to be elucidated, the present results could represent a major departure from the current state of knowledge, revealing a novel function in the degenerative-regenerative process.

Apoptotic DNA fragmentation and upregulation of Bax induced by transient ischemia of the rat retina

This study was performed to examine the involvement of apoptosis and the expression of bcl-2 family genes in ischemia-induced retinal injury. Retinal ischemia was induced in adult rats by raising the intraocular pressure to 130 mmHg for 45 min. Selective damage to the inner retina was observed 7 days after ischemia. No terminal deoxynucleotidyl-transferase (TdT)-mediated dUTP nick end-labeling (TUNEL) positive cells were observed in the normal retina, but there was a significant number of TUNEL positive cells 6-48 h after transient ischemia followed by a decrease at 96 and 168 h. The number of TUNEL positive cells reached a maximum at 24 h after ischemia. DNA laddering was observed on agarose gel electrophoresis with the retinas 24 and 48 h after ischemia but not in the normal retina. Semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) revealed that bax gene expression did not change immediately after cessation of ischemia, but gradually increased as early as 6 h, reached a peak at 24 h, then decreased to near baseline levels at 168 h. On the other hand, bcl-2 gene expression showed no obvious changes at any time after transient ischemia. Moreover, intense Bax protein immunoreactivity was detected in the retinal sections at 24 h after ischemia although little immunoreactivity was present in the normal sections. These results suggest that apoptosis associated with the expression of Bax is involved in retinal cell loss after ischemic insult.

One-stage posterior decompression and reconstruction of the cervical spine by using pedicle screw fixation systems

OBJECT

This retrospective study was conducted to analyze the results of one-stage posterior decompression and reconstruction of the cervical spine by using pedicle screw fixation systems in 46 patients.

METHODS

Causes of cervical myelopathy in these 46 patients included spondylosis or ossification of the posterior longitudinal ligament, rheumatoid arthritis, metastatic or primary vertebral tumors, cervical spinal injuries, and spinal cord tumor. Thirty-three patients underwent this one-stage procedure as primary surgery. In the remaining 13 patients who had previously undergone laminectomies, the one-stage procedure was performed as salvage surgery. Cervical pedicle screws were inserted into the pedicles after probing and tapping. Graft bone was placed on the bilateral lateral masses, and pedicle screws were interconnected longitudinally by either plates or rods. Postoperatively, 26 patients showed improved neurological status (at least one grade improvement on Frankel's functional classification). There were no cases of neurological deterioration postoperatively. Solid bony fusion was obtained in all patients, except in seven patients with metastatic tumor who did not receive bone grafts. Correction of kyphosis was satisfactory. Postoperative radiological evaluation revealed that 10 (5.3%) of 190 screws inserted into the cervical vertebrae had perforated the cortex of the pedicles; however, no neurovascular complications were caused by the perforations.

CONCLUSIONS

The pedicle screw fixation procedure, which does not require the lamina to be used as a stabilizing anchor, has proven to be valuable when performing one-stage posterior decompressive and reconstructive surgery in the cervical spine. The risk to neurovascular structures in this procedure, however, cannot be completely eliminated. Thorough knowledge of local anatomy and application of established surgical techniques are essential for this procedure.

The effects of wrist distraction on carpal kinematics

Changes in carpal kinematics under wrist distraction were studied in fresh cadaveric specimens. A magnetic tracking device measured kinematic motions of the scaphoid, lunate, and third metacarpal relative to the fixed radius in 3 planes of passive motion (coronal, sagittal, and "dart throwers") under progressive distraction loads. The change in percent contribution of the radiocarpal and midcarpal joints was calculated. Radiocarpal motion during extension was decreased as increasing traction was applied, but it increased with flexion. Motion of the scaphoid relative to the lunate was smaller in the oblique plane, resulting in less radiocarpal motion than in the sagittal plane. In the coronal plane, traction had little effect on radial deviation, but ulnar angulation of the scaphoid was greater with ulnar deviation of the wrist. These results suggest that different degrees of tension exist in the palmar and dorsal ligaments with the wrist under traction and during different planes of wrist motion. If wrist motion is desired during fixed traction, such as used clinically with external fixation, the dart-throwers motion (wrist extension with radial deviation and wrist flexion with ulnar deviation) appears to have the least impact on radiocarpal motion. If greater radiocarpal motion is desired, however, such as during postoperative mobilization, flexion-extension and radioulnar deviation will create more radiocarpal motion than the dart-thrower's motion.

A double-masked multicenter comparative study between alendronate and alfacalcidol in Japanese patients with osteoporosis. The Alendronate Phase III Osteoporosis Treatment Research Group

To evaluate the efficacy and safety of alendronate, a double-masked, active (alfacalcidol) controlled comparative study for 48 weeks was carried out in a total of 210 Japanese patients with osteoporosis. The doses of alendronate and alfacalcidol were 5 mg/day and 1 microgram/day, respectively. The lumbar bone mineral density (LBMD) values observed at 12, 24, 36 and 48 weeks after the initiation of alendronate treatment were 3.53 +/- 0.53%, 5.37 +/- 0.62%, 5.87 +/- 0.74% and 6.21 +/- 0.59% (mean +/- SE), respectively, higher than the baseline value. Corresponding values in the alfacalcidol group were 1.50 +/- 0.43%, 0.69 +/- 0.63%, 1.12 +/- 0.60% and 1.36 +/- 0. 63%, respectively. There was a significant difference between the two groups at each time point (p<0.05 or p<0.001). The bone turnover markers were depressed during treatment in the alendronate group: -32.2% for alkaline phosphatase, -53.7% for N-terminal osteocalcin and -45.0% for urinary deoxypyridinoline compared with the corresponding baseline values. On the contrary, no notable changes in these parameters were observed in the alfacalcidol group. Treatment with alendronate caused a transient decrease in serum calcium concentrations associated with an increase in the serum level of intact parathyroid hormone. In contrast, treatment with alfacalcidol resulted in a tendency of these parameters to change in the opposite direction. No difference in fracture incidence between the two groups was observed. The overall safety of alendronate was comparable to that of alfacalcidol. In conclusion, although it was a relatively short-term study of 48 weeks, the results of the present study indicate that alendronate at the daily dose of 5 mg was effective in increasing LBMD and that no serious drug-related adverse events were observed in the alendronate-treated patients. Alendronate is more efficacious than alfacalcidol in increasing bone mineral density, although the mechanisms of the actions of the two drugs are apparently different.

[Surgical treatment of the Palmaz-Schatz stent trapped in the left coronary ostium]

A 72-year-old male with failed delivery of the Palmaz-Schatz stent to the coronary dissection following percutaneous transluminal coronary angioplasty (PTCA) was admitted to our hospital. He was very sick and required an emergent surgical procedures. We successfully carried out the bypass grafting to the LAD and removed the stent through the aortotomy. Besides his respiratory care, postoperative course was uneventful.

Prognosis of early stage avascular necrosis of the femoral head

Seventy-two femoral heads in 63 patients in whom avascular necrosis of the femoral head was in the early stage were followed up prospectively for a mean period of 6 years 1 month. All of the necrotic lesions were confirmed by magnetic resonance imaging. At the time of final outcome, 46 (64%) of the 72 hips were symptomatic. Necrotic lesions greater than 2/3 of the weightbearing portion on T1 weighted central coronal images indicated a high risk of clinical deterioration. Fifty-nine of the 72 hips initially had necrotic lesions greater than 2/3 of the weightbearing portion, and 44 (75%) of these 59 hips were symptomatic at the final outcome. However, in the radiographic assessment of 15 (25%) asymptomatic hips, even when the necrotic lesions were greater than 2/3 of the weightbearing portion as shown by magnetic resonance imaging, the continuous absence of any radiographic abnormality indicated the possibility of a continuous asymptomatic stage for at least several years.

Expression of cellular prion protein in activated hepatic stellate cells

Suppression subtractive hybridization was used to clone genes associated with the activation of hepatic stellate cells and 13 genes were found to be dominantly expressed in activated stellate cells. Among them, one was identical to the 421-837th base pairs of cDNA sequence reported for rat prion-related protein (PrP). In cultured stellate cells, PrP mRNA expression increased in a time-dependent manner in parallel with smooth muscle (SM) alpha-actin mRNA expression. In situ hybridization demonstrated that PrP mRNA was localized in and around the fibrous septa of carbon tetrachloride (CCl4)-treated liver. Cellular PrP (PrPc) was produced by culture-activated stellate cells, and immunohistochemically detected in the fibrous septa of CCl4-damaged liver and sinusoidal linings of common bile duct-ligated liver, consistent with the localization of SM alpha-actin. Immunoelectron microscopy revealed that PrPc resided on the plasma membrane of stellate cells. These results indicate that PrP expression is closely related to stellate cell activation associated with fibrogenic stimuli.

[An emergent surgical treatment of recurrent Stanford type A thrombosed aortic dissection]

A 71-year-old male was admitted to our hospital with a chief complaint of back pain. Chest CT scan showed so-called Stanford type A thrombosed aortic dissection. Aortography revealed no ulcer like projection. At first, conservative treatment was carried out. But about two hours later, he had another back pain. Repeat chest CT scan demonstrated an enlarged dissecting lumen, necessitating emergent graft replacement. Postoperative course was uneventful and he was discharged on the 33rd postoperative days.

[An emergent coronary artery bypass grafting to total occlusion of all three coronary arteries in a patient with severe hyperbilirubinemia]

A 69-year-old man was transferred to our hospital because of chest pain and dyspnea. He had been very ill due to acute hepatitis and hyperbilirubinemia. Coronary angiography showed total occlusion of all three coronary arteries. An emergent coronary artery bypass grafting was successfully performed after insertion of IABP. Even though total bilirubin levels rose to 20.5 mg/dl, it gradually decreased without plasmapheresis. He had no hepatic failure and was discharged on foot on the 24th postoperative days.

[Accumulation of a photosensitizer ATX-S 10 Na (II) to experimental corneal neovascularization]

In order to determine the most appropriate time point for laser irradiation in photodynamic therapy with a new photosensitizer, ATX-S 10 Na (II), which produces selective occlusion of new vessels, we investigated the time course of plasma levels of ATX-S 10 Na (II) after intravenous administration and degree of dye accumulation in the corneal neovascularization in rabbit eyes. Plasma ATX-S 10 Na (II) concentration decreased rapidly after injection and become virtually undetectable at 24 h, indicating rapid excretion from the body. Nitrogen-pulsed laser spectrofluorometry demonstrated that the amount of ATX-S 10 Na (II) in new corneal vessels increased and reached a maximal level 2 to 4 hours after dye injection. Under a fluorescence microscope, ATX-S 10 Na (II) was localized in the wall new corneal vessels and in extravascular tissue 2 to 4 hours after dye injection. These results indicate that the appropriate time for laser irradiation in selective PDT is between 2 and 4 hours after dye injection, when a larger amount of dye is accumulated in neovasculature tissue compared to normal tissue.

Mechanism of the pathogenesis of glutamate neurotoxicity in retinal ischemia

PURPOSE

This study was carried out to examine the involvement of glutamate and nitric oxide neurotoxicity in ischemia/reperfusion-induced retinal injury in vivo.

METHODS

We monitored glutamate release from in vivo cat retina during and after pressure-induced ischemia using a microdialysis technique. Morphometric studies were performed to study the effects of MK-801 (dizocilpine), L-NAME (N omega-nitro-L-arginine methyl ester), and D-NAME (N omega-nitro-D-arginine methyl ester) on the histological changes in the rat retina induced by ischemia or intravitreal injection of NMDA (N-methyl-D-aspartate; 200 nmol).

RESULTS

A large release of glutamate occurred during ischemia, followed by a marked release after reperfusion. Histological changes occurred selectively in the inner part of the retina after ischemia as well as intravitreal injection of NMDA. Pretreatment with intravenous injection of MK-801 or L-NAME significantly inhibited the ischemic injury of the inner retina. Intravitreal injection of L-NAME inhibited NMDA-induced neurotoxicity in the retina.

CONCLUSION

These findings indicate that nitric oxide mediates neurotoxic actions of glutamate which are responsible for ischemic injury in the retina.

Pathologic features of spinal disorders in patients treated with long-term hemodialysis

STUDY DESIGN

Pathologic features of hemodialysis-associated spinal disorders were evaluated using preoperative radiographic images and histologic findings of the spinal lesions resected during surgery.

OBJECTIVES

To investigate the pathology of hemodialysis-related spinal disorders and to determine the role of amyloidosis in the establishment of severe destruction of the spine.

SUMMARY OF BACKGROUND DATA

The pathologic events leading to hemodialysis-associated spinal disorders are poorly understood. The distribution of amyloid deposits in the spine also has not been clarified.

METHODS

Twenty patients with hemodialysis-associated spinal disorders were investigated regarding pathologic features of neural compression and spinal destruction. Preoperative radiographic images such as plain radiography, tomography, computed tomography, magnetic resonance imaging, and scintigraphy were assessed for the existence of an intracanal mass, hypertrophy of the ligamentum flavum, and destructive changes of the spinal components. Histologic examination also was conducted by light microscopy and scanning electron microscopy to determine the distribution pattern of amyloid deposits in the spinal components.

RESULTS

Six patients with no destructive changes in the spine showed spinal canal stenosis. In the cervical spine, a main factor associated with spinal canal stenosis was the presence of intracanal amyloid deposits in three patients. In the lumbar spine, a main factor associated with spinal canal stenosis was hypertrophied ligamentum flavum in three patients. Destructive changes of the facet joints, intervertebral disc, and vertebral body were seen in the other 14 patients. Amyloid deposits were densely distributed at the enthesis of capsular fibers to the bone and in anular tears in the intervertebral discs. Vertebral end plates were destroyed by penetration of amyloid granulation into the vertebral body. Osteoclast activity in the destroyed vertebral bodies was enhanced, with no evidence of new bone formation.

CONCLUSIONS

Amyloid deposits played an important role in the progression of spinal destruction and severe instability.

Morphometric and ultrastructural analyses of in vivo-activated murine Langerhans cells induced by administration of a streptococcal preparation (OK-432)

Langerhans cells (LCs) are activated in the epidermis by external and internal stimuli, such as antigens and cytokines, respectively. To reveal the morphologic and functional properties of in vivo-activated LCs during inflammation, we injected the streptococcal preparation OK-432 intradermally into the earskin of mice and performed time-course analyses by immunofluorescence and electron microscopy. Cellular infiltrate appeared in the dermis at 6 h after OK-432 injection and had progressively extended to the dermoepidermal junction at 12 and 24 h. Immunostaining for class II antigen revealed that LCs were enlarged and extended long dendrites during inflammation. Acidic compartments such as lysosomes and multivesicular bodies also increased in number and Golgi apparatuses developed as demonstrated by electron microscopy and morphometric analysis. Birbeck granules, although not showing numerical changes, were translocated from the Golgi area to the subplasmalemmal area. After epicutaneous application of cationic ferritin, LCs often contained endosomes as the result of engulfment by the cytoplasmic projections. The present results indicate that nonspecifically induced dermal inflammation is capable of inducing activation of LCs in vivo, and that in vivo-activated LCs have the capacity for active endocytosis and intracellular digestion or processing.

Compensatory muscle activity in the posterior cruciate ligament-deficient knee during isokinetic knee motion

We performed electromyographic analyses in 12 patients with posterior cruciate ligament-deficient knees to compare electrical activity in the quadriceps, hamstring, and gastrocnemius muscles between the uninjured and involved limbs. Each patient performed concentric isokinetic knee motion at 30 and 60 deg/sec in both limbs separately. Torques in knee extension and flexion and surface electromyograms from the quadriceps, medial hamstring, and medial gastrocnemius muscles were simultaneously recorded. The uninjured limb served as a control for each patient. Before generation of flexion torque, the gastrocnemius muscle was electrically activated significantly earlier in posterior cruciate ligament-deficient knees than in uninjured knees at each velocity. However, we could not find any significant differences between the posterior cruciate ligament-deficient and uninjured knees in torque curves and electromyelograms of the quadriceps and hamstring muscles. This study suggests that early contraction of the gastrocnemius muscle may be a part of a compensatory mechanism in posterior cruciate ligament-deficient knees.

[Pulmonary edema associated with the Chinese medicine shosaikoto]

A 45-year-old Japanese woman presented with a high fever, a nonproductive coughing, and severe dyspnea, and was admitted to another hospital. During the week prior to hospitalization, she had been given Shosaikoto for treatment of liver dysfunction of unknown etiology. Mycoplasma pneumonitis was initially suspected, so she was treated with antibiotics (clindamycin and minocycline) and received oxygen therapy. Pulmonary insufficiency worsened rapidly, and she was transferred to our hospital. On admission, a chest roentgenogram revealed bilateral alveolar infiltrates predominantly in the medial lung fields. Furosemide and high-dose methylprednisolone were immediately administered, but hypoxemia increased. When the PaO2 was 55.7 Torr while the patient breathed 100% oxygen, mechanical ventilation with positive end-expiratory pressure (PEEP) was started. Arterial blood-gas values improved dramatically, and the chest roentgenogram became clear. Our diagnosis of noncardiogenic pulmonary edema is based on the chest-roentgenographic findings, infiltration of inflammatory cells as seen in two lung-biopsy specimens and bronchoalveolar lavage fluid, the lack of findings of heart failure on physical examination and electrocardiography, and the good clinical response to PEEP. A positive lymphocyte stimulation test in response to Shosaikoto implicated this non-traditional herbal medicine as an etiologic factor in the non-cardiogenic pulmonary edema. Shosaikoto has been identified as the cause of interstitial pneumonia or eosinophilic pneumonia, but pulmonary edema associated with Shosaikoto has not been previously described. This case suggests that methylprednisolone treatment may be insufficient for Shosaikoto-induced pulmonary edema, and that mechanical ventilation with PEEP is very effective.

Photodynamic effect of a new photosensitizer ATX-S10 on corneal neovascularization

In order to elucidate the mechanism by which a new photosensitizer ATX-S10 causes the photodynamic effect on neovasculature, we investigated the kinetics and localization of dye accumulation in the neovascular cornea of rats after systemic administration and the development of vascular injury induced by subsequent laser irradiation, compared to those in the normal iris. Under a fluorescence microscope, the neovascular cornea always exhibited more intense fluorescence than the iris between 0.5 and 4 hr after ATX-S10 administration, indicating the preferential deposit of dye in the former tissue. The fluorescence was found inside the vascular lumen at the earliest time period and thereafter in the vascular lining cells, interstitial tissue and infiltrating neutrophils until 6 hr. As observed using light and electron microscopy, laser irradiation performed 2.5 hr after ATX-S10 injection caused extensive vascular thrombosis with endothelial destruction, which persisted for at least 3 days. The proportion of thrombosed vessels at 6 hr after laser irradiation in the neovascular cornea (64+/-5%; n=3) was significantly (P<0.01) higher than that in the normal iris (44+/-8%; n=3). In the non-thrombosed vessels from heparinized rats, in which thrombosis-related ischemic effect was excluded, mitochondrial vacuolation was the pathologic change commonly seen in the endothelial cells, pericytes and neutrophils. Morphometric analysis revealed that the mitochondria of endothelial cells in the corneal new vessels were more severely injured than those in the iris vessels. The present results indicate that ATX-S10 is a potent photosensitizer which induces photodynamic occlusion particularly of new vessels probably due to the preferential biodistribution of dye in the neovascular tissue.

Acellular calcified columns in the normal growth plate of mouse vertebrae

The present study aims to demonstrate the calcified columnar structures of the growth plate of mouse vertebrae and to show their age related changes. For light microscopy, paraffin sections of decalcified lumbar spines were stained with hematoxylin-eosin or toluidine blue; methacrylate sections of undecalcified specimens were stained to detect calcium precipitate. For scanning electron microscopy, lumbar spines treated with 5% NaClO solution were dehydrated by acetone and metal-coated. Light microscopy of hematoxylin-eosin stained sections revealed that the acellular columnar structures appeared between the chondrocyte stacks in the growth plate. These structures were stained more densely by toluidine blue. The methacrylate-embedded sections for calcium staining showed calcium deposition in the columns. Scanning electron microscopy of NaClO-treated specimens enabled the direct observation of the columns on both the epiphyseal and diaphyseal bone surfaces facing the cartilaginous growth plate. Numerous projections on each surface were distributed in mirror images ; the corresponding projections were similar in size and shape, indicating that the projections bonded with each other and formed calcified columns in the cartilaginous growth plate. Longitudinal sections of the spine confirmed these findings. The calcified columns first appeared about 2 or 3 weeks of age and increased in number with time. While increasing in number, they also grew in size fusing with the neighboring ones. The proportional area of the columns occupying the surface facing the growth plate also increased with age. These findings indicate that the calcified column ultimately concerns the cessation of the bone growth.

Combination of low back pain and previous low back pain and shoulder stiffness in construction employees

A postal questionnaire for the prevalence of low back pain was studied with relevance to stiffness of that shoulder and a history of low back disorders in construction employees. The percentage of clerical employees with low back pain was 31.3% and of field workers was 30.3%. Odds ratios representing a relative risk factor for low back pain relating to each age group showed 2.35 in the clerical and 2.10 in the field workers at the age of 30-34 years, and 3.34 and 2.58 at the age of 35-39 years, respectively. In the persons with positive previous low back pain, the prevalence rate of low back pain was 52.6% in the clerical, and 50.2% in the field workers. Odds ratios for low back pain relating to previous low back pain significantly exceeded unity for the clerical employees (OR = 9.53) and the field workers (OR = 10.28), compared to those without a history of previous low back pain. The incidence of stiffness of the shoulder was 48.2% in the clerical and 45.2% in the field workers, and the prevalence rate of low back pain among those with stiffness of the shoulder was 68.5% in the clerical and 65.8% in the field workers. Odds ratio were 3.03 in both groups. Among each age group, the prevalence rate of stiffness of the shoulder with low back pain increased gradually to a maximum in the 45-49 age group of 19%, and then dropped. In those with a history of low back pain and/or stiffness of the shoulder, the prevalence of low back pain showed significantly greater value than other risk factors.

Morphological and functional alterations to sinusoidal endothelial cells in the early phase of endotoxin-induced liver failure after partial hepatectomy in rats

Liver failure following major hepatectomy is characterized pathologically by massive hepatic necrosis, which is thought to begin with injury of sinusoidal endothelial cells (SECs). To examine the early events of SECs leading to hepatic damage, we performed time-course analyses of the morphological and functional perturbation of SECs after endotoxin administration to hepatectomized rats. At 1.5 h after endotoxin injection, when hepatocellular damage was not yet evident, SECs showed augmented expression of intercellular adhesion molecule-1, with frequent adherence of infiltrating leucocytes and ultrastructural features of defenestration and hypertrophied cytoplasm enriched with cell organelles. The serum level of hyaluronate, as an indicator of the functional state of SECs, was significantly elevated. At 3 h, SECs underwent necrosis and disruption, accompanied by fibrin deposits with concomitant hepatocellular necrosis. The morphological and functional alterations of SECs precede necrotic changes in hepatocytes and SECs in endotoxin-induced liver failure after partial hepatectomy.

Establishment of chimerism in donor liver with recipient-type bone marrow cells prior to liver transplantation produces marked suppression of allograft rejection in rats

In this study, we investigated whether establishment of chimerism in donor liver with recipient-type bone marrow cells (BMCs) prior to liver transplantation could prolong the liver allograft survival. Donor female ACI rats were inoculated with recipient-type BMCs of male LEW rats via the portal vein, with or without irradiation as cytoablation, followed by intramuscular administration of FK506 for 5 days. At 1-2 months later, livers were harvested and transplanted into naive female LEW rats. No immunosuppressants were used. Chimerism in donor rats was confirmed by primers specific for the sex determinant Y chromosome of rats. With livers from rats pretreated with recipient-type BMCs, survival of liver allografts was significantly extended, irrespective of irradiation. These results showed that modification of the donor liver by intraportal injection of recipient-type BMCs and concomitant administration of FK506 prior to liver transplantation prolonged liver allograft survival in rats.

The role of anteromedial foraminotomy and the uncovertebral joints in the stability of the cervical spine. A biomechanical study

STUDY DESIGN

The biomechanical role of the cervical uncovertebral joint was investigated using human cadaveric spines. Sequential resection of cervical uncovertebral joints, including clinical anteromedial foraminotomy, was conducted, followed by biomechanical testing after each stage of resection.

OBJECTIVES

To clarify the biomechanical role of uncovertebral joints and clinical anteromedial foraminotomy in the cervical spine and their effects on interbody bone graft stability.

SUMMARY OF BACKGROUND DATA

Although the biomechanical role of the cervical uncovertebral joints has been considered to be that of a guiding mechanism in flexion and extension and a limiting mechanism in posterior translation and lateral bending, there have been no studies quantifying this role. According to results in quantitative anatomic studies, anatomic variations exist in uncovertebral joints, depending on the vertebral level, articular angulation, and relative height of the joints.

METHODS

Fourteen human functional spinal units at C3-C4 and C6-C7 underwent sequential uncovertebral joint resection, with each stage of resection followed by biomechanical testing. The uncovertebral joint was divided anatomically into three parts on each side: the posterior foraminal part, the posterior half, and the anterior half. The loading modes included torsion, flexion, extension, and lateral bending. A simulated anterior bone graft construct was also tested after each uncovertebral joint resection procedure.

RESULTS

Significant changes in stability were observed after sequential uncovertebral joint resection in all loading modes (P < 0.05). The biomechanical contribution of uncovertebral joints decreased in the following order: the posterior foraminal part, the posterior half, and the anterior half. Unilateral and bilateral foraminotomy most affected the stability of the functional spinal unit during extension, causing a 30% and 36% decrease in stiffness of the functional spinal unit, respectively. The effect was less in torsion and lateral bending. After sequential resection, there was a statistically significant difference between decreases in torsional stiffness at C3-C4 and C6-C7 (P < 0.05). The stiffness of the simulated bone graft construct decreased progressively during flexion and lateral bending after each foraminotomy (P < 0.05). Increased bone graft height of 79% returned stability to the preforaminotomy level.

CONCLUSIONS

This is the first study to quantitate the biomechanical role of uncovertebral joints in cervical segmental stability and the effect at each intervertebral level. The effect differs because of anatomic variations in uncovertebral joints. The major biomechanical function of uncovertebral joints includes the regulation of extension and lateral bending motion, followed by torsion, which is mainly provided by the posterior uncovertebral joints. This study highlights the clinical assessment of additional segmental instability attributed to destruction of the uncovertebral joints during surgical procedures or by neoplastic lesions.

Stability of posterior spinal instrumentation and its effects on adjacent motion segments in the lumbosacral spine

STUDY DESIGN

An in vitro biomechanical analysis of three anterior instability patterns was performed using calf lumbosacral spines. Stiffness of the constructs was compared, and segmental motion analyses were performed.

OBJECTIVES

To clarify the factors that alter the stability of the spinal instrumentation and to evaluate the influence of instrumentation on the residual intact motion segments.

SUMMARY OF BACKGROUND DATA

Recently, many adverse effects have been reported in fusion augmented with rigid instrumentation. Only few reports are available regarding biomechanical effects of stability provided by spinal instrumentation and its effects on residual adjacent motion segments in the lumbar-lumbosacral spine.

METHODS

Eighteen calf lumbosacral spine specimens were divided into three groups according to instability patterns--one-level, two-level, and three-level disc dissections. Six constructs were cyclically tested in rotation, flexion-extension, and lateral bending of intact spines, of destabilized spine, and of spines with four segmental posterior instrumentation systems used to extend the levels of instability (Cotrel-Dubousset compression hook and three transpedicular screw fixation systems). During each test, stiffness values and segmental displacements were measured.

RESULTS

The rigidity of the instrumented construct increased as the fixation range became more extensive. Although application of the instrumentation effectively reduced the segmental motion of the destabilized vertebral level, the motion at the destabilized level tended to increase as the number of unstable vertebral levels increased, and the fixation range of the instrumentation became more extensive. Instrumented constructs produced higher segmental displacement values at the upper residual intact motion segment when compared with those of the intact spine. In contrast, the instrumented constructs decreased their segmental displacement values at the lower residual intact motion segment with higher magnitude of the translational (shear) motion taking place compared with the intact spine in flexion-extension and lateral bending. These changes in the motion pattern became more distinct as the fixation range became more extensive.

CONCLUSIONS

As segmental spinal instrumentation progresses from one level to three levels, the overall torsional and flexural rigidity of the system increases. However, segmental displacement at the site of simulated instability becomes more obvious. Application of segmental instrumentation changes the motion pattern of the residual intact motion segments, and the changes in the motion pattern become more distinct as the fixation range becomes more extensive and as the rigidity of the construct increases.

Four-Channel, 8 x 8 Bit, Two-Dimensional Parallel Transmission by use of Space-Code-Division Multiple-Access Encoder and Decoder Modules

We experimentally demonstrate four-channel multiplexing of 64-bit (8 x 8) two-dimensional (2-D) parallel data links on the basis of optical space-code-division multiple access (CDMA) by using new modules of optical spatial encoders and a decoder with a new high-contrast 9-m-long image fiber with 3 x 10(4) cores. Each 8 x 8 bit plane (64-bit parallel data) is optically encoded with an 8 x 8, 2-D optical orthogonal signature pattern. The encoded bit planes are spatially multiplexed and transmitted through an image fiber. A receiver can recover the intended input bit plane by means of an optical decoding process. This result should encourage the application of optical space-CDMA to future high-throughput 2-D parallel data links connecting massively parallel processors.

[Vesico-vaginal fistula with a giant vesico-vaginal stone: a case report]

The patient, a 73-year-old woman, had undergone hysterectomy and irradiation therapy 26 years ago. On September 4, 1997, the patient was referred to our hospital, and presented with low grade fever and lower abdominal dull pain of a one-month duration. Radiologic and vaginal examinations revealed bilateral hydronephrosis and a giant stone lying down between the bladder and vagina. Vaginal incontinence showed the presence of the vesico-vaginal fistula. She underwent bilateral ureterocutaneostomy and cystolithotomy. A giant vesico-vaginal stone was removed by using a hammer and chisel. It weighed 180 g. The stone was composed of calcium phosphate and magnesium ammonium phosphate. Persistent infection of the bladder and the vagina may have been a possible etiological factor of the vesico-vaginal stone formation. Three weeks after the operation, bilateral hydronephrosis was improved.

Stimulation of bone formation in vivo by insulin-like growth factor-II in rats

Insulin-like growth factor-II (IGF-II) plays an important role in skeletal remodeling, however, little is known about its effect on bone formation in vivo. In our study of the stimulation of bone formation in vivo by IGF II we injected recombinant human IGF-II into the parietal bones of neonatal rats once a day for 12 days. The bone mineral density measured by dual energy X-ray absorptiometry and the thickness of IGF-II-injected parietal bones increased in a dose-dependent manner. The layers of osteoblasts were observed along the IGF-II-injected side.

Clinical features and management of traumatic posterior interosseous nerve palsy

The clinical features and results of treatment were reviewed in 17 traumatic palsies of the posterior interosseous nerve. Variations in clinical features depended on whether the recurrent branch or descending branch of the posterior interosseous nerve was injured. Seven patients had nerve repair, and two were treated by tendon transfers. Eight patients were treated conservatively. Sixteen of 17 patients recovered to more than M4 motor power at final follow-up. Associated muscle damage worsened the functional result.

Protective effects of FK506 against glutamate-induced neurotoxicity in retinal cell culture

PURPOSE

To examine the effects of FK506 on glutamate neurotoxicity in cultured retinal neurons.

METHODS

Experiments were performed with primary retinal cultures obtained from 17- to 19-day-old rat fetuses. To assess the effects of FK506 and other drugs on glutamate neurotoxicity, cultures were treated with a drug beginning 10 minutes before application of glutamate and continuing during the subsequent 10 minutes of glutamate exposure. The treated cells were then incubated for 1 hour in a drug-free and glutamate-free medium. After a 1-hour incubation, cell viability was quantitatively measured by the trypan blue exclusion method.

RESULTS

Brief exposure to glutamate markedly decreased cell viability. FK506 protected against glutamate neurotoxicity in a dose-dependent manner. Rapamycin is a competitive inhibitor of FK506 that binds FK506 binding protein. Simultaneous application of rapamycin and FK506 negated the protective effects of FK506. Cyclosporin A, which binds and inhibits calcineurin, mimicked the protective effects of FK506. Treatment with FK506 did not affect the intracellular maximum Ca2+ concentration induced by glutamate application. Although FK506 exhibited protective action against Ca2+ ionophore-induced neurotoxicity, it had no effect on nitric oxide-induced neurotoxicity. Treatment with FK506 reduced the activity of nitric oxide synthase (NOS).

CONCLUSION

FK506 protected against glutamate neurotoxicity by inhibiting NOS activity in cultured retinal neurons.

A case of intraductal papilloma of breast in advanced age

Breast tumors have their various biological characteristics as to advanced age of patients. Intraductal papilloma is a benign tumor of the breast which is known to occur in the premenopausal young females. Tumors of the breast in the senile females are found mainly to be breast cancers. No any cases of intraductal papilloma over 80-years were reported in Japan to date. We have recognized mammary tumors in old aged patients to be cancers, but it is necessary to put it into mind there are a few intraductal papillomas even if advanced in age. In this report, we present the most senile case with intraductal papilloma in our institute.

Infectivity and arthritis induction of Borrelia japonica on SCID mice and immune competent mice: possible role of galactosylceramide binding activity on initiation of infection

We investigated the relationship between the binding activity to galactosylceramide (GalCer) and the arthritis induction activity of Borrelia japonica. The B. japonica strains maintained the ability to induce arthritis in inbred C3H/HeN and immunodeficient SCID mice, but the ability was lower than that of Borrelia burgdorferi sensu stricto virulent strain 297. Histopathological changes were restricted to the joints, and a marked effusion of polymorphonuclear neutrophils into the joint space was found. The binding activity of B. japonica strains to GalCer was lower than that of the virulent strain 297 but higher than that of the high-passage strain 297. The lower infectivity and virulence of B. japonica may explain its lower binding ability to GalCer.

Force transmission through the wrist joint in Kienböck's disease: a two-dimensional theoretical study

This study quantifies the changes in force and pressure distributions across the wrist joint in different stages of Kienböck's disease using a 2-dimensional computer simulation model. Twenty-four cases classified as Lichtman's stage II, IIIA, or IIIB (8 cases in each category) were analyzed using the rigid body spring model technique. A 2-dimensional model in the posteroanterior plane of the wrist was loaded through the metacarpals under a total force of 142 N. The joint forces, peak pressures, and ligament tensions calculated on the involved side were normalized against the contralateral normal side values of the same patient. The results demonstrated that significant changes of the force transmission across the wrist joint occurred only from stage IIIA to IIIB, in which scaphoid rotation was prominent. On the basis of this study, scaphoid rotation plays an important role in affecting the wrist joint contact pressure distribution. This may be responsible for the progression of Kienböck's disease.

Imaging and modelling from serial microscopic sections for the study of anatomy

A system is considered for segmenting noisy intensity images and consequent three-dimensional object reconstruction from a set of planar contours. A new semi-automatic method for the extraction of contours from a sequence of cross-sectional images based on an active contour model (ACM) is proposed. The dynamic ACM proceeds along the sequence of cross-sections following a non-rigid motion, in accordance with the organ boundary. Image texture information is also employed in the model. Problems associated with topological reconstruction from planar contours are addressed, and several criteria promoting semi-automatic topological reconstruction are introduced. The proposed system is successfully applied to the processing of real data related to animal embryonic organs, proving that the system allows detailed modelling of irregular objects. The reconstructed models can be observed in wire-frame, solid, transparent or stereoscopic semi-transparent format. The human-computer interaction implemented in the procedure assists with problems of feature identification and object manipulation about an arbitrary axis.

Detrimental effect of a non-selective nitric oxide synthase inhibitor on the energy state of the liver following acute endotoxemia in rabbits

BACKGROUND

The effect of nitric oxide synthase (NOS) inhibitors in septic shock is very controversial. It is known that the administration of NOS inhibitors to normal subjects itself increases pulmonary vascular resistance with a concomitant decrease of cardiac output. Therefore, the hypothesis was tested that the detrimental effects of a non-selective NOS inhibitor on liver energetics in a rodent model of endotoxemia are mediated by the adverse pulmonary circulatory effect of the drug itself.

METHODS

Twenty anesthetized rabbits were instrumented and two separate experiments (a magnetic resonance spectroscopic study and a hemodynamic study) were performed under similar conditions. Animals were assigned randomly to either a control group (group 1; animals received lipopolysaccharide (LPS) at a dose of 400 microg/kg alone) or a treatment group (group 2; animals received NG-nitro-L-arginine methyl ester (L-NAME) at a dose of 7.5 mg/kg, 75 min after administration of LPS).

RESULTS

In group 1, slight decreases in hepatic adenosine triphosphate (ATP) value were observed. In group 2, the decreases in ATP values were more prominent than those observed in group 1. LPS produced an acute drop in mean arterial pressure (MAP) with a concomitant increase in pulmonary vascular resistance (PVR) and a reduction in the cardiac output (CO) at 30 min after LPS. The administration of L-NAME caused a transient increase in MAP with a concomitant increase in systemic vascular resistance at 2 h after LPS. However, these changes in PVR and CO were more prominent than in group 1.

CONCLUSION

These results suggest that alterations within the pulmonary circulation may be a contributing factor which was responsible for the non-selective NOS inhibitor-induced acute hepatic energy derangement after LPS.

Diagnosis of synovial sarcoma with the reverse transcriptase-polymerase chain reaction: analyses of 84 soft tissue and bone tumors

The chimeric transcript SYT-SSX is generated as a result of reciprocal translocation t(X;18), which is the primary cytogenetic abnormality found in, and appears to be specific for, synovial sarcoma. We performed a reverse transcriptase-polymerase chain reaction (RT-PCR) for SYT-SSX transcripts in a series of 84 tumors (61 soft tissue tumors and 23 bone tumors), including a variety of histologic types, to assess its usefulness in molecular diagnosis. Ten synovial sarcomas, three tumors initially unclassified, and one malignant peripheral nerve sheath tumor contained the chimeric transcripts. A review of the original slides and additional examination showed that a diagnosis of synovial sarcoma was appropriate for these cases. Additionally, in situ hybridization with an SSX1 probe indicated that the chimeric transcripts exist not only in the cells of special components but also in cells showing a variety of histologic patterns. Therefore, RT-PCR can be considered a useful molecular biological technique that can provide objective evidence for diagnosis of synovial sarcoma. Northern blot analysis with an SSX1 probe also detected chimeric SYT-SSX transcripts in the synovial sarcoma cases. The additional smaller bands, however, were also detected in six peripheral primitive neuroectodermal tumors (pPNETs) and one embryonal rhabdomyosarcoma. In five of these pPNETs, other bands ranging in size from 2.0 to 2.2 kb were also found, and it seems possible that these bands might represent novel karyotypic aberrations and/or splicing variants of SSX.