Gadolinium-DTPA enhanced magnetic resonance imaging of bone and soft tissue sarcomas in comparison with pathological findings.

We compared gadolinium diethylenetriaminepentaacetic acid (Gd-DTPA) enhanced T1-weighted images (T1-Gd) with the histopathological findings in 13 patients with bone or soft tissue sarcomas. Signal intensity of the viable tumor tissue was increased in T1-Gd in 92% of the patients. The necrotic or cystic areas in the tumor were not enhanced, rendering them distinctly. The degree of enhancement of the edematous area around the tumor was similar to or more marked than that of the tumor in 54% of the patients. Area showing inflammatory cells infiltration and edematous areas in the tumor tissue were also enhanced. Thus, the effect of preoperative chemotherapy in tumor tissues other than necrotic and cystic areas tended to be underestimated in T1-Gd. Its effect should be comprehensively evaluated based on not only T1-Gd but also T2-weighted images and findings of other imaging techniques.</p

A clinical analysis of malignant schwannoma

In this study, we reviewed the clinical features of 11 patients with malignant schwannoma who were treated in our institute. Five patients had coexistent von Recklinghausen's disease and one of them showed multifocal occurrence. Patients with the centrally located tumors had a poorer prognosis than those with the others. The overall 3-year survival rate was 36%; 40% in patients with von Recklinghausen's disease and 33% in the others. At the time of the last follow-up, 9 patients had died of the tumor, one continued to be tumor free, and one was alive with tumor. Postoperative local recurrence developed in 5 patients (45%); 4 out of 6 patients (67%) who underwent a marginal excision and one out of 3 (33%) who underwent primary amputation. There was no local recurrence in patients after a wide excision with at least 3cm of normal tissue removed surrounding the tumor in all directions. Nine patients (82%) developed pulmonary metastasis. The effect of adjuvant chemotherapy was not clear in this study. The high risk of pulmonary metastasis in this disease indicates the necessity of more effective adjuvant chemotherapy.</p

‘Protected DNA Probes’ capable of strong hybridization without removal of base protecting groups

We propose a new strategy called the ‘Protected DNA Probes (PDP) method’ in which appropriately protected bases selectively bind to the complementary bases without the removal of their base protecting groups. Previously, we reported that 4-N-acetylcytosine oligonucleotides (ac4C) exhibited a higher hybridization affinity for ssDNA than the unmodified oligonucleotides. For the PDP strategy, we created a modified adenine base and synthesized an N-acylated deoxyadenosine mimic having 6-N-acetyl-8-aza-7-deazaadenine (ac6az8c7A). It was found that PDP containing ac4C and ac6az8c7A exhibited higher affinity for the complementary ssDNA than the corresponding unmodified DNA probes and showed similar base recognition ability. Moreover, it should be noted that this PDP strategy could guarantee highly efficient synthesis of DNA probes on controlled pore glass (CPG) with high purity and thereby could eliminate the time-consuming procedures for isolating DNA probes. This strategy could also avoid undesired base-mediated elimination of DNA probes from CPG under basic conditions such as concentrated ammonia solution prescribed for removal of base protecting groups in the previous standard approach. Here, several successful applications of this strategy to single nucleotide polymorphism detection are also described in detail using PDPs immobilized on glass plates and those prepared on CPG plates, suggesting its potential usefulness

Hyperbranched 5,6-glucan as reducing sugar ball

The ring-opening polymerization of 5,6-anhydro-1,2-O-isopropylidene-α-D-glucofuranose (1) as a latent cyclic AB2-type monomer was carried out using potassium tert-butoxide (t-BuOK) or boron trifluoride diethyletherate (BF3・OEt2) as an initiator in order to synthesize a novel hyperbranched glycopolymer. The anionic and cationic polymerizations proceeded via the proton-transfer reaction mechanism to produce the hyperbranched poly(5,6-anhydro-1,2-O-isopropylidene-α-D-glucofuranose) (2). In particular, the cationic polymerization with the slow-monomer-addition strategy is a facile method leading to the hyperbranched glycopolymers with high molecular weights and highly branched structures. The weight-average molecular weight (Mw,SEC-MALLs) values of 2 measured by multi-angle laser light scattering (MALLS) varied in the range from 7,400 to 122,400, which were significantly higher than the weight-average molecular weight (Mw,SEC) values determined by size exclusion chromatography (SEC). The intrinsic viscosities ([η]) of these polymers were very low in the range of 3.3-4.6 mL g^[-1] and the Mark-Houwink-Sakurada exponents α were calculated to be 0.08-0.27. These results of the MALLS, SEC, and viscosity measurements suggested that these polymers exist in a compact spherical conformation in solution because of their highly branched structure. The synthesis of the hyperbranched 5,6-glucan (3) by hydrolysis of polymer 2 was also demonstrated. Polymer 3 is a novel water-soluble hyperbranched glycopolymer arranged with numerous reducing D-glucose units on the peripheries of the polymer, and has a higher reducing ability than D-glucose because of the glycocluster effect or the multivalent effect of the reducing D-glucose units. Therefore, polymer 3 should be called a "reducing sugar ball"

SPR Sensing of Bisphenol A Using Molecularly Imprinted Nanoparticles Immobilized on Slab Optical Waveguide with Consecutive Parallel Au and Ag Deposition Bands Coexistent with Bisphenol A-Immobilized Au Nanoparticles

A slab-type optical waveguide (s_OWG)-based microfluidic SPR measurement system for bisphenol A was developed. This s_OWG possesses consecutive parallel gold and silver deposition bands in the line of plasmon flow, allowing two individual SPR signals to be independently obtained as a result of the difference in resonant reflection spectra of these metals. As a molecular recognition element, molecularly imprinted polymer nanoparticles (MIP-Np) were employed and immobilized on the surface of each of the gold and silver deposition bands. The resonant reflection spectra were measured on the MIP-Np-immobilized consecutive parallel gold and silver deposition bands coexistent with BPA-AuNp. The Ag-based SPR spectra showed a red shift (0.7 nm) when free BPA (0.1 mM) was passed over the BPA-AuNp/immobilized MIP-Np complexes formed on the s_OWG, unlike the case for the Au deposition band, while a large excess of BPA induced a blue shift due to the competitive desorption of BPA-AuNp from the immobilized MIP-Np on the s_OWG. By using the proposed detection system, binding events of other small molecules could be monitored in conjunction with the use of MIP-Np and labeled-AuNp

Ewing's Sarcoma : Evaluation of Chemotherapy in 17 Cases

Seventeen patients with Ewing's sarcoma were divided into 3 groups according to treatment. Ten patients were treated with complete chemotherapy; 9 with VACA protocol, composed of vincristine, actinomycin-D, cyclophosphamide and doxorubicin, and the remaining 1 with T-11 protocol. Four were given incomplete VACA protocol, and another 3 received no chemotherapy. Clinical results were evaluated in the three treatment subgroups described above. All patients without systematic chemotherapy died from lung metastasis within 1 year of the initial treatment. Three of 4 patients who were given incomplete chemotherapy died after a mean survival period of 17. 7 months, and one developed cancerous pleuritis after 38 months. In the group receiving complete systematic chemotherapy, 5 of 10 patients are alive, and 2 have been disease-free for more than 3 years.　　 Distant metastasis is likely when viable cells persist at the site of the primary tumor, even if the tumor size has been considerably reduced by preoperative chemotherapy. Therefore, immediate initiation of intensive chemotherapy and maintenance for the full course of therapy can improve the prognosis of Ewing's sarcoma

Isolation of poly[d-lactate (LA)-co-3-hydroxybutyrate)]-degrading bacteria from soil and characterization of D-LA homo-oligomer degradation by the isolated strains

P[d-lactate (LA)-co-3-hydroxybutyrate (3HB)] is an artificial polyhydroxyalkanoate (PHA) containing unusual D-LA units. In this study, the P(D-LA-co-3HB)-degrading bacterial group in the soil was analyzed and the bacterial degradation of the D-LA clustering structure in the copolymer were evaluated by using chemically synthetic D-LA homo-oligomers. A total of 216 soil samples were screened on the basis of clear zone formation on agar plates containing emulsified P(64 mol% D-LA-co-3HB). The 16S rRNA analysis of the isolated bacteria resulted in the identification of eight Variovorax, three Acidovorax, and one Burkholderia strains, which are closely related to previously identified natural PHA-degrading bacteria. These bacteria nearly consumed the P(D-LA-co-3HB) emulsion in the liquid culture; however, a small amount of the D-LA fraction remained unconsumed, which should be attributable to the D-LA-clustering structure in the copolymer. Cultivation of the isolated bacteria with the D-LA homo-oligomers revealed that the oligomers with a degree of polymerization (DP) ranging from 10 to 30 were partly consumed by six Variovorax and one Acidovorax strains. In contrast, the oligomers with DP ranging from 20 to 60 were not consumed by the isolated bacteria. These results indicate that D-LA homo-oligomers with DP higher than approximately 20 are hardly degraded by the soil bacteria. Molecular dynamic simulation of the D-LA homo-oligomers indicated that the upper limit of DP is likely to be determined by the conformational structure of the oligomers in water. The information obtained in this study will be useful for the molecular design of biodegradable D-LA-containing polymers