Biomedical subjects

Toshihiro Matsuo

Publications and source records attributed to Toshihiro Matsuo.

16 recordsLinked to original sources

PubMed2006

Inhibitory effects of a new bisphosphonate, minodronate, on proliferation and invasion of a variety of malignant bone tumor cells.

Little is known about the biological effects of bisphosphonates on primary malignant bone tumors. The purpose of this study was to investigate the antitumor effects of newly developed minodronate (MIN) on a variety of human malignant bone tumors. We examined the effects of MIN and clinically relevant incadronate (INC) on the proliferation, apoptosis, and cell cycle of two osteosarcoma (Saos-2, MG-63), two chondrosarcoma (SW1353, OUMS27), and two Ewing's sarcoma (RD-ES, SK-ES-1) cell lines. Furthermore, we investigated the anti-invasion effects of MIN on sarcoma cells and the effects of MIN on tumor growth in nude mice. MIN inhibited the viability of all six cell lines in a dose-dependent manner with IC50 values of 2.7 to 5.0 microM, which were significantly lower than those of INC. Importantly, both bisphosphonates affected the viability of normal bone marrow stromal cells much less than sarcoma cells. Both bisphosphonates induced cell cycle perturbation in all sarcoma cells tested and apoptosis in Saos-2 and SW1353 cells, although they failed to induce apoptosis in RD-ES and SK-ES-1 cells. MIN significantly suppressed invasion, even at a low concentration of 1 microM (p < 0.01). Daily injection of 5 microg of MIN inhibited the growth of SK-ES-1 xenograft sarcoma in nude mice without loss of body weight. These findings suggest that MIN may have a beneficial adjuvant role in the treatment of patients with malignant bone tumors.

Animals↗

PubMed2005

Nerve tolerance to high-dose-rate brachytherapy in patients with soft tissue sarcoma: a retrospective study.

BACKGROUND: Brachytherapy, interstitial tumor bed irradiation, following conservative surgery has been shown to provide excellent local control and limb preservation in patients with soft tissue sarcomas (STS), whereas little is known about the tolerance of peripheral nerves to brachytherapy. In particular, nerve tolerance to high-dose-rate (HDR) brachytherapy has never been properly evaluated. In this study, we examined the efficacy and radiation neurotoxicity of HDR brachytherapy in patients with STS in contact with neurovascular structures. METHODS: Between 1995 and 2000, seven patients with STS involving the neurovascular bundle were treated in our institute with limb-preserving surgery, followed by fractionated HDR brachytherapy. Pathological examination demonstrated that 6 patients had high-grade lesions with five cases of negative margins and one case with positive margins, and one patient had a low-grade lesion with a negative margin. Afterloading catheters placed within the tumor bed directly upon the preserved neurovascular structures were postoperatively loaded with Iridium-192 with a total dose of 50 Gy in 6 patients. One patient received 30 Gy of HDR brachytherapy combined with 20 Gy of adjuvant external beam radiation. RESULTS: With a median follow-up of 4 years, the 5-year actuarial overall survival, disease-free survival, and local control rates were 83.3, 68.6, and 83.3%, respectively. None of the 7 patients developed HDR brachytherapy-induced peripheral neuropathy. Of 5 survivors, 3 evaluable patients had values of motor nerve conduction velocity of the preserved peripheral nerve in the normal range. CONCLUSION: In this study, there were no practical and electrophysiological findings of neurotoxicity of HDR brachytherapy. Despite the small number of patients, our encouraging results are valuable for limb-preserving surgery of unmanageable STS involving critical neurovascular structures.

Adolescent↗

PubMed2005

Clinical outcomes of 54 pelvic osteosarcomas registered by Japanese musculoskeletal oncology group.

BACKGROUND: To determine the clinical outcomes in patients with pelvic osteosarcoma, we reviewed the experience with 54 pelvic osteosarcoma patients. METHODS: Thirty-five patients underwent surgical treatment with 30 undergoing limb salvage procedures and 5 requiring hemipelvectomies. RESULTS: Oncological outcome was continuously disease free in 12 cases, no evidence of disease in 3, alive with disease in 3, died of disease in 34 and died of other causes in 2. The 5-year survival rate was 29.5%. For the patients who underwent surgery, statistically significant prognostic factors were chemotherapy, surgical margin, tumor location in sacrum, efficacy of chemotherapy, local recurrence, metastasis and treatment for metastases. With univariate analysis, local recurrence, surgical margin and tumors resected from the sacrum were significant prognostic factors for metastasis. Surgical margin, tumor resected from sacrum and metastasis were significant prognostic factors for local recurrence. With regard to postoperative functional mobility, patients with tumors resected from the sacrum exhibited poorer functional mobility when compared with other sites. CONCLUSIONS: Patients with tumors located in the sacrum had worse prognosis, and significant prognostic factor for local recurrence and metastasis. Treatment of pelvic osteosarcoma especially located in the sacrum requires new approaches and further improvements in order to ensure successful outcomes.

Adolescent↗

PubMed2005

Recurrent pulmonary mucinous cystadenoma.

A pulmonary mucinous cyst adenoma is rare and there has been no report of the recurrence. We report a case of a 56-year-old female who had recurrent pulmonary mucinous cystadenoma. She had previously received a partial resection of the lung for a pulmonary mucinous cystadenoma 20 years ago. On this admission, a chest X-ray and CT scan revealed a large pulmonary mass, and a lung resection was performed. The resected lesion was histologically confirmed as mucinous cystadenoma. At 2 years to date after the second operation, the patient has no recurrence.

Cystadenoma, Mucinous↗

PubMed2005

Reconstructed patellar tendon length after proximal tibia prosthetic replacement.

A common problem after proximal tibia prosthetic reconstruction is insufficient extensor mechanism or extensor lag. Maintaining the reconstructed patellar tendon length is an important way to minimize extensor lag. We measured the patellar tendon length and extensor lag serially. From 1994-2003, seven consecutive patients with malignant bone tumors of the proximal tibia had prosthetic reconstruction. The extensor mechanism was reconstructed by reattachment of the patellar tendon to the prosthesis with a synthetic material and augmented by a gastrocnemius flap. The patellar tendon length was measured according to the Insall-Salvati ratio. The ratios at 30 degrees knee flexion decreased immediately postoperatively, and reverted to almost the same preoperative values within 18 months. The mean ratios at 60 degrees knee flexion are significantly greater than 30 degrees at 6 months postoperatively. These findings indicate that the patellar tendon stretched, whereas the extensor lag improved continuously for 12 months postoperatively. In the revision at 22 months postoperatively, although the patellar tendon was not reattached to the replaced prosthesis, the ratio and the extensor lag had not worsened. These results show that providing strong continuity of the patellar tendon, gastrocnemius flap, and leg extensors can decrease the extensor lag, although the patellar tendon stretches.

Adolescent↗

PubMed2004

[Evaluation of postoperative pain relief after video-assisted thoracoscopic surgery (VATS) for spontaneous pneumothorax].

BACKGROUND: We have investigated correlation between postoperative pain and chest tube insertion after video-assisted thoracoscopic surgery (VATS) for patients with spontaneous pneumothorax, and have evaluated preemptive analgesia by intercostal nerve block (ICB) using bupivacaine. METHODS: Thirty patients received VATS for spontaneous hemi-pneumothorax. There were two groups of the patients; Group CT received chest tube before the operation, and the Group NCT received no chest tube. Both groups received general anesthesia combined with ICB by 0.25% bupivacaine at the surgical region before operation. Postoperative pain was assessed using visual analogue scale (VAS scale: 0-10) and the need for additional supplemental analgesics before the operation, and at 6 and 24 hours after the operation, and at 3, 7, 14, and 30 days after the operation. RESULTS: Visual analogue scale in Group NCT before the operation, and at 24 hours, 3, 7, 14, and 30 days after the operation was significantly lower than that of Group CT. Analgesic requirements were significantly lower in the Group NCT than in the Group CT. CONCLUSIONS: We should avoid the insertion of a chest tube before the operation as much as possible. Furthermore early operation and intercostal nerve blockade before the operation were useful to prevent postoperative pain and its shift to chronic post thoracostomy pain.

Adolescent↗

PubMed2003

Injectable magnetic liposomes as a novel carrier of recombinant human BMP-2 for bone formation in a rat bone-defect model.

Small-sized magnetic liposomes with incorporated recombinant human bone morphogenetic protein-2 (rhBMP-2) were prepared, and the efficiency for bone formation after topical injection was evaluated in a rat bone-defect model. A critical-sized segmental bone defect was created in the mid-part of the femoral shaft, and a permanent magnet was attached. Topical injection onto the defects was performed with different liposomal preparations (nonmagnetic and magnetic liposomes) using different treatment modalities (different doses and different treatment timing of rhBMP-2). Weekly evaluations were made radiographically and microcomputed tomographically, histologically, and/or by mechanical testing at 9 weeks after surgery. A single topical application of magnetic liposomes with an appropriate amount of rhBMP-2 (approximately 3 microg) incorporated under magnetic induction immediately after surgery was effective for new bone formation. The combined treatment of topical magnetic rhBMP-2 liposomes and magnetic implantation at the injury site was effective for the treatment of bone defects. This injectable carrier for BMP is expected to have many advantages over solid carriers because it can be prepared easily and can be less invasively applied to the injured site at any time after surgery.

Animals↗

PubMed2003

Rapid-growth lung cancer associated with a pulmonary giant bulla: a case report.

A giant bulla of the lung is suggested as a risk factor for lung cancer. Here we report a case with lung cancer in a giant bulla, which showed rapid progression. A 57-year-old man, who had a history of heavy smoking, was admitted to our hospital due to hemoptysis. A chest X-ray revealed a giant bulla with a ground glass shadow and a high fluid level in the right upper lung. Sputum cytology was negative for malignant cells. A chest X-ray a month later showed increases of the size of the radio-opaque shadow and of the air-fluid retention, suggesting pulmonary hemorrhage from the giant bulla. Limited resection or lobectomy was indicated, but pneumonectomy was performed due to the severe air-leak. Macroscopically, a multiple nodular tumor arose from the bulla wall, which might be related to blood flow and necrotic tissue. The postoperative pathological diagnosis was papillary adenocarcinoma. Unfortunately, the patient developed a recurrence of carcinoma in the pleuroperitoneal cavity and died at 2.5 months after the operation. Based on this report and review of other cases in the literature, we should keep in mind the rapid progression of lung cancer in association with an emphysematous bulla.

Adenocarcinoma, Papillary↗

PubMed2002

Thymic basaloid carcinoma with hepatic metastasis.

A thymic basaloid carcinoma is rare, as is an unusual case with extra-thoracic metastasis. We report on a 41-year-old woman who had a thymic basaloid carcinoma with liver metastases. The patient underwent resection of the thymic basaloid carcinoma followed by curative partial hepatectomy. At 1 year later, another metastatic lesion developed in the residual liver, which was also curatively resected. The postoperative course was uneventful, and the patient is surviving without recurrence for 12 months, to date.

Adult↗

PubMed2002

Intraoperative intercostal nerve blockade for postthoracotomy pain.

BACKGROUND: Epidural analgesia is widely employed as a means to control postthoracotomy pain, but is sometimes inadequate. The purpose of this study is to evaluate the effectiveness of intraoperative, temporary, intercostal nerve blockade in addition to epidural analgesia for control of postthoracotomy pain. METHODS: Forty patients undergoing elective lobectomy through antero-axillary thoracotomy were randomized to receive epidural analgesia only (group A, n = 20) or epidural analgesia plus temporary, intraoperative intercostal nerve blockade using 0.25% bupivacaine (group B, n = 20). Postoperative pain was assessed using a subjective analogue visual scale, and with the Prince Henry pain scale. Food intake and nonsteroidal analgesic consumption were also investigated. Serum ACTH and cortisol in each group were measured before and after the operation. RESULTS: The analogue visual scale scores were significantly higher in group A than group B (p < 0.001), and were significantly higher on the day of operation and postoperative days 1, 2, and 3 (p < 0.001, p < 0.005, p < 0.005, p < 0.05, respectively). Prince Henry pain scale scores were significantly higher on the day of operation and postoperative day 1 (p < 0.05, p < 0.005, respectively). Food intake was significantly lower in group A than in group B (p < 0.05), and nonsteroidal analgesic consumption was not significantly different between groups. There was no significant difference between group A and group B in serum ACTH or in cortisol levels. CONCLUSIONS: Additional intraoperative intercostal nerve blockade provides an additive benefit for postthoracotomy pain relief, especially early after operation.

Female↗

PubMed2002

Temporary stenting for malignant tracheal stenosis due to esophageal cancer: a case report.

We present a case of a 56-year-old male with esophageal cancer who underwent successful temporary tracheal stenting followed by a surgical procedure. The trachea was obstructed owing to endotracheal metastasis and the patient had severe dyspnea. A silicone Y-stent was initially inserted into the tracheal stenosis to secure the airway, and then tumor-specific chemo-radiotherapy was applied. The tumor was reduced, the stent was removed and a pathological study indicated that the tracheal metastasis had disappeared. The patient then underwent esophagectomy and tumor-specific chemo-radiotherapy was continued after the surgery. The patient has remained alive and free of esophageal cancer for 18 months after the airway stent emplacement. These findings suggested that the silicone stent was suitable as a temporary measure and that temporary stenting combined with tumor-specific therapy was effective as part of the aggressive therapeutic strategy with which to treat the malignant airway stenosis due to esophageal cancer.

Airway Obstruction↗

PubMed1999

Deprotonation-Induced Enantioselective Aggregation and Deprotonation-Induced Ligand Rearrangement of Copper(II) Complexes Yield 1D Homochiral and Heterochiral Chains and a Cyclic Tetramer, Respectively.

The copper(II) complexes of protonated pentadentate Schiff-base ligands with [Cu(H(2)L(n))](ClO(4))(2) formula (n = 3-6, 3-6) have been synthesized and characterized (H(2)L(3) = N-((2-methylimidazol-4-yl)methylene)-3-aminpropyl-N'-((2-methylimidazol-4-yl)methylene)-4'-aminobutylamine, H(2)L(4) = N-((2-phenylimidazol-4-yl)methylene)-3-aminpropyl-N'-((2-phenyl-imidazol-4-yl)methylene)-4'-aminobutylamine, H(2)L(5) = N,N'-bis((2-phenylimidazol-4-yl)methylene)-3,3'-diaminodipropylmethylamine, H(2)L(6) = N-((2-methylimidazol-4-yl)methylene)-2-aminoethyl-N'-((2-methylimidazol-4-yl)methylene)-3'-aminopropylamine. The mono-deprotonated complexes 3', 4', and 5' contain one imidazole and one imidazolate groups per unit and are Delta (clockwise) or Lambda (anticlockwise) enantiomorphs due to the spiral arrangement of the ligand around copper(II) ion. They function as chiral building components for a self-assembly process resulting from the formation of hydrogen bonds between the imidazole and imidazolate groups of adjacent units to yield 1D zigzag-chain structures. The distance between hydrogen-bonded nitrogen atoms is 2.81(2), 2.832(9), and 2.875(9) Å for 3', 4', and 5', respectively. The crystal lattice of 3' yielded either.DeltaDeltaDelta. or.LambdaLambdaLambda. isotactic 1D zigzag-chains, while the crystal lattices of 4' and 5' yielded.DeltaLambdaDeltaLambda. syndiotactic 1D zigzag-chains. In 3', two adjacent methyl groups at the 2-position connected by hydrogen bond array in the same direction, thus allowing homochiral aggregation of the complex molecules in a 1D chain. On the other hand, in 4' and 5', two adjacent bulky phenyl groups require opposite orientations, thus allowing heterochiral aggregation. Enantioselective aggregation with homochirality or heterochirality can thus be controlled with suitable substituents. While its mononuclear precursor 6 is pentacoordinated with the N(5) donor set of the pentadentate ligand H(2)L(6), the deprotonated complex 6' has an imidazolate-bridged tetranuclear cyclic structure with a Cu-Cu distance of 6.086(2) Å. The ligand in 6' is tetradentate and includes an hexahydropyrimidine ring resulting from a deprotonation induced rearrangement reaction.

Journal Article↗

PubMed1999

pH-Dependent Monomer <--> Oligomer Interconversion of Copper(II) Complexes with N-(2-R-imidazol-4-ylmethylidene)-2-aminoethylpyridine (R = Methyl, Phenyl).

The monomer <--> oligomer interconversion of the reported metal complexes is generated by proton abstraction/supply as a common external information input. The mononuclear copper(II) complexes 1 and 2 with [CuCl(2)(HL(n)())] chemical formula have been prepared (HL(1) = N-(2-methylimidazol-4-ylmethylidene)-2-aminoethylpyridine; HL(2) = N-(2-phenylimidazol-4-ylmethylidene)-2-aminoethylpyridine). The crystal structures were determined. 1.H(2)O, C(12)H(16)N(4)OCl(2)Cu: a = 13.773(2) Å, b = 8.245(2) Å, c = 13.861(2) Å, beta = 110.10(1) degrees, monoclinic, P2(1)/n, and Z = 4. 2, C(17)H(16)N(4)Cl(2)Cu: a = 7.6659(7) Å, b = 16.287(1) Å, c = 14.103(1) Å, beta = 95.058(7) degrees, monoclinic, P2(1)/c, and Z = 4. Complexes 1.H(2)O and 2 assume a pentacoordinated square pyramidal geometry with a N(3)Cl(2) donor set consisting of the nitrogen atoms of the protonated tridentate ligand and two chloride ions in the solid state, while in aqueous solution the Cu(II) ion is tetracoordinated (N(3)Ow donor set). When 1 and 2 are treated with an equimolar amount of sodium hydroxide or triethylamine, the deprotonation of the imidazole moiety promotes a self-assembly process, arising from coordination of the imidazolate nitrogen atom to a Cu(II) ion of an adjacent unit, to yield compounds 1'.4H(2)O as the perchlorate salt, and 2'a.6H(2)O as the perchlorate salt and( )()2'b as the hexafluorophosphate salt, respectively. 1'.4H(2)O, C(12)H(15)N(4)O(5)ClCu: a = b = 13.966(2) Å, c = 33.689(3) Å, tetragonal, I4(1)/a, and Z = 16. 2'a.6H(2)O, C(51)H(51)N(12)O(15)Cl(3)Cu(3): a = 15.177(3) Å, b = 15.747(3) Å, c = 14.128(3) Å, alpha = 100.06(2) degrees, beta = 110.37(2) degrees, gamma = 63.54(1) degrees, triclinic, P&onemacr;, and Z = 2. 2'b, C(17)H(15)N(9)F(6)PCu: a = b = 29.812(5) Å, c = 11.484(3) Å, trigonal, R&thremacr;, and Z = 18. The nuclearity of the self-assembled molecules and their detailed structure were confirmed to be cyclic imidazolate-bridged tetranuclear for 1'.4H(2)O and hexanuclear for 2'a.6H(2)O and 2'b, respectively, through single-crystal X-ray analyses and FAB-MS spectra. Variable-temperature experimental magnetic susceptibility data were well reproduced by using the Heisenberg model based on a cyclic tetranuclear structure for 1' and a cyclic hexanuclear structure for 2'a and 2'b. The reversible interconversion between the protonated monomeric and deprotonated oligomeric species were confirmed by pH-dependent potentiometric and electronic spectral titrations in aqueous solution, whereas the Pd(II) complex did not show a perfect disassembly process.

Journal Article↗

PubMed1998

Synthesis, Magnetic Properties, and Incomplete Double-Cubane Structure of Manganese(III)-Metal(II) Complexes [Mn(MeOH)L(OH)M(bpy)](2) (M = Zn, Cu, Ni, and Mn; H(4)L = 1,2-Bis(2-hydroxybenzamido)benzene; bpy = 2,2'-Bipyridine).

The manganese(III) complex K[MnL(py)(2)].py (H(4)L = 1,2-bis(2-hydroxybenzamido)benzene, py = pyridine) reacted as a ligand complex at the two phenoxo oxygen atoms with metal(II) ion and 2,2'-bipyridine to give a series of heterometal complexes [Mn(MeOH)L(OH)M(bpy)](2) (M(II) = Zn (1); Cu (2); Ni (3); Mn (4)). X-ray structures were determined 1, C(68)H(74)N(8)O(18)Mn(2)Zn(2): a = 12.367(3) Å, b = 12.844(2) Å, c = 12.262(2) Å, alpha = 106.58(1) degrees, beta = 117.89(1) degrees, gamma = 78.57(2) degrees, triclinic, P&onemacr;, and Z = 1. 2, C(68)H(74)N(8)O(18)Mn(2)Cu(2): a = 13.447(1) Å, b = 12.670(2) Å, c = 21.732(1) Å, beta = 107.076(5) degrees, monoclinic, P2(1)/n, and Z =2. 3, C(68)H(74)N(8)O(18)Mn(2)Ni(2): a = 12.358(3) Å, b = 12.847(3) Å, c = 12.315(3) Å, alpha = 106.63(2) degrees, beta = 118.71(1) degrees, gamma = 78.32(2) degrees, triclinic, P&onemacr;, and Z = 1. 4, C(66)H(66)N(8)O(16)Mn(4): a = 12.511(2) Å, b = 21.129(3) Å, c = 12.811(1) Å, beta = 110.12(1) degrees, monoclinic, P2(1)/n, and Z = 2. The X-ray analyses confirmed that each of the crystals consists of an incomplete double-cubane molecule with a [Mn(2)M(2)O(6)] core, in which two M(II) ions are bridged by two hydroxo groups to form a planar dinuclear moiety bridged by di-&mgr;-hydroxo groups [(bpy)M(OH)(2)M(bpy)](2+) and the dinuclear moiety is sandwiched between two Mn(III) complexes [Mn(MeOH)L](-). The Mn(III) ion and the dinuclear M(II) moiety are triply bridged by the one hydroxo oxygen of the dinuclear moiety and two phenoxo oxygen atoms of the Mn(III) ligand complex. The two phenoxo oxygen atoms of the Mn(III) ligand complex coordinate as an axial ligand to two independent metal(II) ions of the dinuclear moiety. The magnetic susceptibilities of 1-4 were measured in the temperature range of 2-300 K. All the Mn(III) ions in these complexes are in a high-spin state of S(Mn) = 2 with a d(4) electronic configuration, and the metal(II) ions are in the spin states of S(Zn) = 0, S(Cu) = 1/2, S(Ni) = 1, and S(Mn(II)) = 1/2 (low-spin). The magnetic susceptibility data are well reproduced by the following spin Hamiltonian based on the rhombus spin coupling model with spin (S(1), S(2), S(3), S(4)) = (2, S(M), 2, S(M)), including a zero-field splitting term for the Mn(III) centers: H = g(Mn)beta(S(1) + S(3)).H + g(M)beta(S(2) + S(4)).H - 2J(S(1).S(2) + S(2).S(3) + S(3).S(4) + S(4).S(1)) - 2J'(S(2).S(4)) + D(Mn)[S(1z)(2) + S(3z)(2)], in which g(Mn) and g(M) are the g factors of the Mn(III) and M(II) ions, J and J' are the Mn(III)-M(II) and M(II)-M(II) Heisenberg coupling constants, and D is the zero-field splitting parameter of Mn(III). The calculated best-fit parameters are as follows: g(Mn) = 1.91, g(Cu) = 2.39, J = -4.5 cm(-)(1), J' = -8.1 cm(-)(1), and D(Mn) = -4.9 cm(-)(1) for 2; g(Mn) = 1.97, g(Ni) = 2.23, J = -1.5 cm(-)(1), J' = -2.6 cm(-)(1), and D(Mn) = -5.5 cm(-)(1) for 3; and g(Mn) =1.95, g(Mn(II)) = 2.29, J = -3.5 cm(-)(1), J' = -14.1 cm(-)(1), and D(Mn) = -12.0 cm(-)(1) for 4. The spin frustration due to the incomplete double-cubane structure is discussed.

Journal Article↗

PubMed1998

Zigzag-Chain and Cyclic-Tetrameric Compounds Derived by Deprotonation of Mononuclear Copper(II) Complexes with N,N'-Bis(2-substituted-imidazol-4-ylmethyl- idene)-1,4-diaminobutane (2-Substituent = H, Me): Synthesis, Characterization, Structure, Substituent Effect, and Interconvertibility.

Two copper(II) complexes with N,N'-bis(2-substituted-imidazol-4-ylmethylidene)-1,4-diaminobutane (2-substituent = H, 1; Me, 2) were synthesized, and their deprotonation assembly behavior was studied. X-ray analyses of 1 and 2 revealed that the molecules assume a butterfly shape bent by a line of N(2)-Cu-N(4) where the angle of N(3)-Cu-N(5) representing the extent of the molecular bend is 150.9(2) degrees and 105.66(8) degrees for 1 and 2, respectively. Due to the molecular bend, two imidazole moieties (sites A and B) are recognized as two inequivalent groups for the deprotonation process in which the imidazole group of site A is in an equatorial CuN(3) plane, while that of site B is in a CuN(2) plane bent from the equatorial coordination plane. 1 dissociates a proton of site B first to give an infinite zigzag-chain compound 1', while 2 dissociates a proton of site A first to give a cyclic-tetranuclear compound 2'. 2' undergoes a further deprotonation to give an electrically neutral di-deprotonated complex 2". The interconversion between the protonated monomer and the deprotonated oligomer/polymer was investigated by pH-dependent potentiometric and absorption spectrometric titrations.

Journal Article↗

PubMedDate not supplied

Postradiation malignant fibrous histiocytoma and osteosarcoma of a patient with high telomerase activities.

BACKGROUND: An extremely rare case of postradiation malignant fibrous histiocytoma (MFH) and osteosarcoma (OS) secondary to radiation therapy for leukemia-related osteolytic lesions is presented. In addition, the telomere biology of these tumors was investigated. CASE REPORT: A 14-year-old boy was diagnosed with acute lymphocytic leukemia. The right tibia was irradiated at a total dose of 60 Gy, and the left tibia was irradiated at a total dose of 40 Gy. The left tibia developed MFH and the right tibia developed OS. RESULTS: Telomere reduction (MFH 70.2, OS 70.0%) and high telomerase activities (MFH 12.1, OS 17.7 TPG) were observed. These results reflect an aggressive feature of postradiation sarcomas. CONCLUSION: Prognosis for patients diagnosed with postradiation sarcoma is poor due to its aggressiveness. However, even if sarcoma occurs after irradiation in more than two fields in a single patient, improvements in prognosis are anticipated with appropriate chemotherapies and wide resection.

Adolescent↗