Preparing a liquid crystalline dispersion of carbon nanotubes with high aspect ratio

We successfully prepared a surfactant-assisted carbon nanotube (CNT) liquid crystal (LC) dispersion with double-walled CNTs (DWCNTs) having a high aspect ratio (≈1378). Compared to dispersions of single-walled CNTs (SWCNTs) with lower aspect ratio, the transition concentrations from isotropic phase to biphasic state, and from biphasic state to nematic phase are lowered, which is consistent with the predictions of the Onsager theory. An aligned DWCNT film was prepared from the DWCNT dispersion by a simple bar-coating method. Regardless of the higher aspect ratio, the order parameter obtained from the film is comparable to that from SWCNTs with lower aspect ratios. This finding implies that precise control of the film formation process, including a proper selection of substrate and deposition/drying steps, is crucial to maximize the CNT-LC utilization.

Evaluation of the Possibility of Dose Realignment Adaptation by Shifting the Isocenter in Proton Beam Therapy for Pancreatic Cancer

PURPOSE/OBJECTIVE(S)

In pancreatic cancer, a tumor is surrounded by the gastrointestinal (GI) tract, which is subject to changes in location, shape, and contents. Due to these inter-fractional changes, proton beam therapy (PBT) for pancreatic cancer may result in unintentionally high doses to the GI tract. Daily adaptive re-planning can solve this problem, but is not yet established with PBT due to its resource intensive characteristics. This study aims to evaluate the GI tract dose using weekly computed tomography (CTw) and the possibility of dose realignment adaptation by shifting the isocenter (IC) of the PBT plan, which does not require re-planning.

MATERIALS/METHODS

We retrospectively analyzed 6 consecutive patients with unresectable pancreatic cancer treated with real-time-image gated PBT using a fiducial marker. The planning CT was scanned at the natural expiration of respiration and a PBT plan of 60 GyE in 25 fractions (baseline plan, PLANbase) was created. The CTw images were acquired the day before start of PBT and once a week during the PBT course thereafter. The PLANbase was rigidly transferred to the CTw based on the relationship between the three-dimensional coordinates of the fiducial marker and those of the IC in the PLANbase. The PLANeval was created by recalculating the PLANbase on the CTw. We evaluated the doses to the stomach, duodenum, and intestines in the PLANeval according to the following criteria: Dmax of the stomach < 60 GyE, duodenum and intestines < 55 GyE, and D1cc of the stomach < 55 GyE, duodenum and intestines < 54 GyE. In addition, we investigated the GI tract dose realignment adaptation for the PLANeval with its IC shifted 2mm, 4mm, and 6mm in each of 6 directions (right, left, ventral, dorsal, cranial, and caudal), respectively.

RESULTS

A total of 35 PLANeval were created for the CTw. In the PLANbase of the 6 patients, the average of Dmax and D1cc of the stomach, duodenum and intestines were 50.7 GyE (range, 46.7-53.6) and 50.0 GyE (45.0-53.2), 49.2 GyE (44.3-51.7) and 48.8 GyE (43.7-51.5), and 49.2 GyE (44.8-52.0) and 48.9 GyE (44.6-51.8), respectively. In the PLANeval, the average of Dmax and D1cc of the stomach, duodenum, and intestines were 53.3GyE (43.8-61.4) and 52.8 GyE (43.2-61.1), 51.0 GyE (36.1-60.0) and 50.3 GyE (35.4-59.8), and 52.5 GyE (36.6-61.0) and 51.9 (34.4-60.9) GyE, respectively. Twenty-two of the 35 PLANeval (63 %) did not meet at least one of the GI tract dose criteria. In 11 of 22 PLANeval with higher doses to the GI tract, the IC shift resulted in GI dose reductions and all dose criteria were met. The minimum amount of the IC shift required to meet the criteria was 2 mm for 8 plans and 4 mm for 3 plans. The remaining 11 PLANeval did not meet the criteria using dose realignment adaptation by shifting the isocenter.

CONCLUSION

Adaptive replanning is necessary for PBT for pancreatic cancers due to excessive GI tract doses in more than 60% of the plans. Dose realignment adaptation by shifting the IC, which does not require re-planning, may be an option in adaptive treatment strategies.

A Risk Prediction Model for Severe Radiation Induced Lymphopenia in Patients with Pancreatic Cancer Treated with Concurrent Chemoradiotherapy

PURPOSE/OBJECTIVE(S)

In pancreatic cancer, radiation induced lymphopenia (RIL) is associated with a poor prognosis. However, normal tissue complication probability (NTCP) models predicting RIL in pancreatic cancer treated with concurrent chemoradiotherapy (CCRT) have yet to be developed. This study aims to develop a least absolute shrinkage and selection operator (LASSO)-based multivariate NTCP model to predict severe RIL in patients with pancreatic cancer during CCRT and to validate the model internally.

MATERIALS/METHODS

We retrospectively reviewed patients with localized pancreatic cancer who underwent CCRT using three-dimensional conformal radiation therapy from 2013 to 2021. The exclusion criteria were patients with distant metastasis; patients who did not complete RT due to tumor progression; patients who did not have absolute lymphocyte count (ALC) data available before or during RT. An ALC of < 0.5 K/μL during CCRT was defined as severe RIL. A NTCP model of severe RIL was developed by LASSO-based multivariate analysis. We used age, sex, Karnofsky performance status, maximum tumor size, carbohydrate antigen 19-9 level before RT, ALC before RT, volume of planning target volume (PTV), and dosimetric parameters for surrounding organs (including spleen, vertebrae, liver, bilateral kidneys, gastrointestinal tracts) as variables for LASSO. In addition, internal validation was performed by the bootstrap method. The predictive performance of the model was evaluated by the area under the curve (AUC) of the receiver operating characteristic curve and scaled Brier score.

RESULTS

Of the 131 patients included in the study, the median age was 68 years (range, 42-84), and 55% were male. The median ALC before RT was 1.37 K/µL (0.52-3.50). The median PTV volume was 315.4 ml (86.3-1079.3). The median dose of radiotherapy was 50.4 Gy (16.2-50.4), with 1.8 Gy per fraction. Combination chemotherapy was S-1 in 99 cases (75.6%) and gemcitabine in 32 cases (24.4%). Induction chemotherapy before CCRT was performed in 39 patients (29.8%). Severe RIL was observed in 84 (63.6%) patients. The LASSO showed that low baseline ALC (p = 0.0002), large PTV volume (p < 0.0001), and a large kidney V5 defined as the percentage of bilateral kidneys receiving 5 Gy or more (p = 0.0338) were selected as parameters of the prediction model for severe RIL (AUC = 0.917) and scaled Brier score was 0.511. As a result of internal validation by the bootstrap method, the average AUC was 0.918 (95% confidence interval, 0.849-0.954).

CONCLUSION

Severe RIL occurred frequently during CCRT for pancreatic cancer, and a NTCP model for severe RIL developed and validated internally in this study showed good predictive performance. External validation is needed before this NTCP model can be used as a benchmark for treatment planning to reduce the risk of severe RIL and for considering future treatment approaches.

A Microwave-Assisted, Solvent-Free Approach for the Versatile Functionalization of Carbon Nanotubes

While the functionalization of carbon nanotubes (CNTs) has attracted extensive interest for a wide range of applications, a facial and versatile strategy remains in demand. Here, we report a microwave-assisted, solvent-free approach to directly functionalize CNTs both in raw form and in arbitrary macroscopic assemblies. Rapid microwave irradiation was applied to generate active sites on the CNTs while not inducing excessive damage to the graphitic network, and a gas-phase deposition afforded controllable grafting for thorough or regioselective functionalization. Using methyl methacrylate (MMA) as a model functional group and a CNT sponge as a model assembly, homogeneous grafting was exhibited by the increased robust hydrophobicity (contact angle increase from 30 to 140°) and improved structural stability (compressive modulus increased by 135%). Therefore, when our MMA-functionalized CNTs served as a solar absorber for saline distillation, high operating stability with a superior water evaporation rate of ∼2.6 kg m^-2 h^-1 was observed. Finally, to highlight the efficacy and versatility of this functionalization approach, we fabricated asymmetrically hydrophobic CNT sponges by regioselective functionalization to serve as a moisture-driven generator, which demonstrated a stable open-circuit voltage of 0.6 mV. This versatile, solvent-free approach can complement conventional solution-based techniques in the design and fabrication of multifunctional nanocarbon-based materials.

Liquid Crystalline Behaviors of Single-Walled Carbon Nanotubes in an Aqueous Sodium Cholate Dispersion

Controlling the alignment of single-walled carbon nanotubes (SWCNTs) on the macroscopic scale is critical for practical applications because SWCNTs are extremely anisotropic materials. One efficient technique is to create an effective SWCNT dispersion, which shows a liquid crystal (LC) phase. A strong acid treatment can realize SWCNT liquid crystalline dispersions. However, strong acids pose a substantial safety risk, which renders the process unfit for mass production. Herein, an isolated SWCNT dispersion displaying an LC behavior is prepared using sodium cholate without an acid treatment, and its phase transition behaviors are systematically investigated across the isotropic to biphasic to nematic phases. As the SWCNT concentration increases, the dispersion undergoes an isotropic-to-nematic phase transition in which the spindle-shaped LC droplets, or the so-called tactoids, and the Schlieren textures can be observed in the intermediate biphasic state and the nematic phase, respectively. The arrangements of SWCNTs in the tactoids and the Schlieren structures are directly investigated by polarized optical microscopy. The clear LC behaviors of the CNT dispersion suggest that the CNT orientations can be controlled by the normal surfactant-assisted method, which is a crucial advantage for the liquid-phase processing of CNT fibers and films.

Comprehensive Characterization of Structural, Electrical, and Mechanical Properties of Carbon Nanotube Yarns Produced by Various Spinning Methods

A comprehensive characterization of various carbon nanotube (CNT) yarns provides insight for producing high-performance CNT yarns as well as a useful guide to select the proper yarn for a specific application. Herein we systematically investigate the correlations between the physical properties of six CNT yarns produced by three spinning methods, and their structures and the properties of the constituent CNTs. The electrical conductivity increases in all yarns regardless of the spinning method as the effective length of the constituent CNTs and the density of the yarns increase. On the other hand, the tensile strength shows a much stronger dependence on the packing density of the yarns than the CNT effective length, indicating the relative importance of the interfacial interaction. The contribution of each physical parameter to the yarn properties are quantitatively analyzed by partial least square regression.

N2 Gas Adsorption Sites of Single-Walled Carbon Nanotube Bundles: Identifying Interstitial Channels at Very Low Relative Pressure

Utilizing the nanoscale space created by carbon nanotubes (CNTs) is of importance for applications like energy storage devices, sensors, and functional materials. Gas adsorption is a versatile, quantitative characterization method to analyze nanoscale pore sizes and volumes. Here, we inspected N₂ adsorption to the nanospace formed by the bundles of single-walled CNTs with an average nanotube diameter of ca. 2.0 nm and its distributions of 0.7-4.1 nm. Based on comparisons among the as-grown, purified (opened), and heat-treated (closed) CNTs with similar geometric bundle structures, we found that the interstitial channels emerged from a very low relative pressure of approximately 10^-8 by removing the impurities from the CNT bundles, which is the first empirical demonstration. These findings can not only be utilized to understand the structures of CNT films, fibers, and bulks but also applied to porous materials science.

Nonuniform functional group distribution of carbon nanotubes studied by energy dispersive X-ray spectrometry imaging in SEM

Functionalization is a key technique to improving the dispersibility of carbon nanotubes (CNTs) in solvents and polymer matrices for producing versatile CNT-based materials. Therefore, a robust and efficient characterization method is required to confirm that the functionalization on the CNT surface is spatially uniform. Although several imaging techniques for transmission electron microscopes can characterize the spatial localization of elements chemically bound to an isolated CNT surface, they are unsuitable for examinations on a practical scale because of their limited scanning area. Here, we present high spatially resolved energy dispersive X-ray spectrometry (EDS) imaging of functionalized single-walled CNTs (SWCNTs) in scanning electron microscopy (SEM). Highly sensitive EDS detection and drift-free operation enables our technique to image the light elements of SWCNTs with sufficient spatial resolution (<10 nm). We describe an experimental visualization of the spatial distribution of the functionalization on individual SWCNT bundle structures and discuss the CNT de-bundling mechanism via surface modification and the uniformity of the CNT dispersion state.

A New, General Strategy for Fabricating Highly Concentrated and Viscoplastic Suspensions Based on a Structural Approach To Modulate Interparticle Interaction

We report a general strategy to fabricate highly concentrated, viscoplastic and stable suspensions by designing the particle surface structure to control the interparticle attractive forces. Unlike conventional methods, where the choice of solvent is critical in balancing interparticle interactions, suspensions showing excellent stability and viscoplastic properties were made using various solvents. We demonstrated this approach using highly sparse agglomerates of carbon nanotubes (CNTs) as the particles. Our results revealed that the essential feature of the CNT agglomerate to fabricate these suspensions was high porosity with a spacing size much smaller than the overall size, which was only possible using long single-walled carbon nanotubes (SWNTs). In this way, the agglomerate surface was characterized by fine network of CNT bundles. These suspensions exhibited solid-like behavior at rest (characterized by a high yield stress of c.a. 100 Pa) and a liquid-like behavior when subjected to a stress (characterized by a significant drop of an apparent viscosity to 1 Pa·s at a shear rate of 1000 s^-1). Furthermore, in contrast to conventionally fabricated suspensions, these "CNT pastes" exhibited exceptional stability at rest, under flow, and at extremely high concentrations during the drying process, with only a weakly observable dependence on solvent type. As a result, highly uniform micrometer-thick SWNT films were successfully fabricated by dried blade-coated films of these pastes. Finally, we developed a simple, semiempirical model and clarified the importance of the CNT agglomerate microstructure (the ratio of spacing size/particle size and porosity) on tailoring the cohesive forces between particles to fabricate stable viscoplastic suspensions.

Designing Neat and Composite Carbon Nanotube Materials by Porosimetric Characterization

We propose a porosimetry-based method to characterize pores formed by carbon nanotubes (CNTs) in the CNT agglomerates for designing neat CNT-based materials and composites. CNT agglomerates contain pores between individual CNTs and/or CNT bundles (micropore < 2 nm, mesopores 2-50 nm, and macropores > 50 nm). We investigated these pores structured by CNTs with different diameters and number of walls, clarifying the broader size distribution and the larger volume with increased diameters and number of walls. Further, we demonstrated that CNT agglomerate structures with different bulk density were distinguished depending on the pore sizes. Our method also revealed that CNT dispersibility in solvent correlated with the pore sizes of CNT agglomerates. By making use of these knowledge on tailorable pores for CNT agglomerates, we successfully found the correlation between electrical conductivity for CNT rubber composites and pore sizes of CNT agglomerates. Therefore, our method can distinguish diverse CNT agglomerate structures and guide pore sizes of CNT agglomerates to give high electrical conductivity of CNT rubber composites.

A sweet spot for highly efficient growth of vertically aligned single-walled carbon nanotube forests enabling their unique structures and properties

We investigated the correlation between growth efficiency and structural parameters of single-walled carbon nanotube (SWCNT) forests and report the existence of a SWCNT "sweet spot" in the CNT diameter and spacing domain for highly efficient synthesis. Only within this region could SWCNTs be grown efficiently. Through the investigation of the growth rates for ∼340 CNT forests spanning diameters from 1.3 to 8.0 nm and average spacing from 5 to 80 nm, this "sweet spot" was found to exist because highly efficient growth was constrained by several mechanistic boundaries that either hindered the formation or reduced the growth rate of SWCNT forests. Specifically, with increased diameter SWCNTs transitioned to multiwalled CNTs (multiwall border), small diameter SWCNTs could only be grown at low growth rates (low efficiency border), sparse SWCNTs lacked the requirements to vertically align (lateral growth border), and high density catalysts could not be prepared (high catalyst density border). As a result, the SWCNTs synthesized within this "sweet spot" possessed a unique set of characteristics vital for the development applications, such as large diameter, long, aligned, defective, and high specific surface area.

Green, scalable, binderless fabrication of a single-walled carbon nanotube nonwoven fabric based on an ancient Japanese paper process

We propose a fabrication method for carbon nanotube (CNT) nonwoven fabrics based on an ancient Japanese papermaking process where paper is made from natural plant fibers. In our method, CNT nonwoven fabrics are made by a scalable process of filtering binder-free, aqueous suspensions of CNTs. The aqueous suspension of these entangled single-walled carbon nanotube (SWNT) aggregates enabled smooth filtration through a cellulose filter with large pores (8 μm). The "wet SWNT cakes," which were composed solely of SWNT and water and obtained after filtration, were press-dried to fabricate an SWNT nonwoven fabric. This environmentally friendly process employs water and the raw CNT material alone. Moreover, the scalability of this process was demonstrated by manufacturing a large area (A3, 30 × 42 cm; thickness: 40-150 μm), self-supporting SWNT nonwoven fabric with a density of 0.4 g/cm(3), a basis weight of 0.2 g/m(2) , a porosity of 63%, and a specific surface area of 740 m(2)/g. This SWNT nonwoven fabric is anticipated to find application as functional particle-supported sheets, electrode materials, and filters.

Torsion-sensing material from aligned carbon nanotubes wound onto a rod demonstrating wide dynamic range

A rational torsion sensing material was fabricated by wrapping aligned single-walled carbon nanotube (SWCNT) thin films onto the surface of a rod with a predetermined and fixed wrapping angle without destroying the internal network of the SWCNTs within the film. When applied as a torsion sensor, torsion could be measured up to 400 rad/meter, that is, more than 4 times higher than conventional optical fiber torsion sensors, by monitoring increases in resistance due to fracturing of the aligned SWCNT thin films.

Hierarchical three-dimensional layer-by-layer assembly of carbon nanotube wafers for integrated nanoelectronic devices

We report a general approach to overcome the enormous obstacle of the integration of CNTs into devices by bonding single-walled carbon nanotubes (SWNTs) films to arbitrary substrates and transferring them into densified and lithographically processable "CNT wafers". Our approach allows hierarchical layer-by-layer assembly of SWNTs into organized three-dimensional structures, for example, bidirectional islands, crossbar arrays with and without contacts on Si, and flexible substrates. These organized SWNT structures can be integrated with low-power resistive random-access memory.

Mechanically durable and highly conductive elastomeric composites from long single-walled carbon nanotubes mimicking the chain structure of polymers

By using long single-walled carbon nanotubes (SWNTs) as a filler possessing the highest aspect ratio and small diameter, we mimicked the chain structure of polymers in the matrix and realized a highly conductive elastomeric composite (30 S/cm) with an excellent mechanical durability (4500 strain cycles until failure), far superior to any other reported conductive elastomers. This exceptional mechanical durability was explained by the ability of long and traversing SWNTs to deform in concert with the elastomer with minimum stress concentration at their interfaces. The conductivity was sufficient to operate many active electronics components, and thus this material would be useful for practical stretchable electronic devices.

Electrical Contacts to Polycrystalline B Doped Diamond Films

B doped diamond films were synthesized by microwave plasma CVD and electrical contacts were fabricated by R F sputtering. Rc was obtained for Pt, Ni, TaSi2, and Al asdeposited contacts at room temperature. Pt gave the minimum Rc and Al gave the maximum Rc of the metals investigated on films containing a carrier concentration of 5 × 1018/cm3. The minimum Rc, 8.6 × 10−4 Ω cm 2, was obtained on heavily B doped diamond films with a carrier concentration of 2.7 × 1020/cm3. After nnealing at 400 °C, the Rc of Pt contacts on B doped diamond films with a resistivity of 2×104 Ω1 cm decreased by approximately one order of magnitude.

Soluble Ultra-Short Single-Walled Carbon Nanotubes

Soluble, ultra-short (length < 60 nm), carboxylated, single-walled carbon nanotubes (SWNTs) have been prepared by a scalable process. This process, predicated on oleum's (100% H2SO4 with excess SO3) ability to intercalate between individual SWNTs inside SWNT ropes, is a procedure that simultaneously cuts and functionalizes SWNTs using a mixture of sulfuric and nitric acids. The solubility of these ultra-short SWNTs (US-SWNTs) in organic solvents, superacid and water is about 2 wt %. The availability of soluble US-SWNTs could open opportunities for forming high performance composites, blends, and copolymers without inhibiting their processibility.

Down-regulation of IL-18 receptor in cancer patients: its clinical significance

Interleukin-18 (IL-18) is a powerful inducer of interferon-gamma (IFN-gamma), a key immunoregulatory cytokine. Cellular immune responsiveness, as measured by IL-18-induced IFN-gamma production from peripheral blood mononuclear cells (PBMCs) in ELISA assay, was evaluated in 10 patients with advanced cancer and in 10 normal controls. Supernatant levels of IFN-gamma were detected at 2 hours after PBMCs culture and markedly increased thereafter in healthy volunteers. In contrast, IFN-gamma production in cancer patients was not detected during the culture period (0-72 hours). We also measured IL-18-stimulated IL-12 production in healthy volunteers and null response was observed in cancer-bearing patients. Next, we studied mRNA expressions of IL-18 receptor (IL-18R) and IFN-gamma in PBMCs in cancer patients and healthy volunteers by RT-PCR assay. Both mRNA levels of IL-18R and IFN-gamma were significantly decreased in cancer-bearing patients compared with normal controls. These results suggested that IL-18 responsiveness for IFN-gamma production in cancer-bearing patients was impaired. Using flow cytometric analysis, we studied T-cell subsets, CD3- CD56+ (NK cell), CD3+ CD45RO+ (memory T-cell), CD3+ CD95+ (Fas+ T-cell), CD3+ CD4+ (helper T-cell), CD3+ CD8+ (cytotoxic T-cell: CTL) and CD3+ V alpha24+ (NKT-cell), in cancer patients and normal controls. The NK and cytotoxic T-cells significantly decreased and NKT-cells had decreased tendency in cancer patients compared with normal controls. In contrast, memory T cells, Fas+ T-cells and helper T-cells were all significantly increased in cancer patients compared with normal controls. These results suggested that the underlying mechanism of impaired IL-18 responsiveness in PBMCs from cancer-bearing patients was, at least in part, ascribed to a drastic decrease of NK cells and CTL which constitutively and highly express IL-18R and also attributed to null production of IL-12 which up-regulates IL-18R.

Pubovaginal slings: a review of the technical variables

The pubovaginal sling, reintroduced in the late 1970s by Maguire and Blaivas, has become the gold standard for managing anatomic incontinence. Newer technology, materials, surgical techniques and even new theories on the mechanism of action are evolving to further reduce the morbidity of these procedures and improve patient satisfaction. In the following review, we will highlight some of the exciting advances we have witnessed over the last year and try to put them into perspective for the reader.

Cathepsin L activity and its inhibitor in human otitis media

OBJECTIVE

We examined cathepsin L activity, expression of cystatin A, and copper- and zinc-containing superoxide dismutase in human chronic otitis media. The relationships of our findings to clinical findings (e.g., grade of bone destruction) were also studied.

DESIGN

Retrospective basic and clinical study.

SETTING

Department of Otolaryngology and First Department of Biochemistry, Kinki University School of Medicine, Osaka, Japan.

METHOD

The human middle ear tissues evaluated in this study were surgically obtained from seven patients with cholesteatoma epithelium, three patients with granulation tissues in cholesteatoma, three patients with granulation tissues in noncholesteatoma, and three patients with intact mucous membrane of the middle ear.

MAIN OUTCOME MEASURES

Cathepsin L activities in cholesteatoma epithelium, granulation tissues in cholesteatoma, or granulation tissues in noncholesteatoma were measured using Barrett's method. Cystatin A expressions were observed by Western blot analysis. Copper- and zinc-containing superoxide dismutase in cholesteatoma was examined immunohistochemically.

RESULTS

Mean cathepsin L activity was higher in diseased tissues than in intact mucous membranes of the middle ear. Granulation tissues with high cathepsin L activity resulted in extensive bone destruction in both cholesteatomas and noncholesteatomas of the middle ear. All cases with intact mucous membrane of the middle ear exhibited no expression of cystatin A. Seven of 10 cases with diseased tissues expressed cystatin A in cholesteatoma epithelium, granulation tissues in cholesteatoma, or granulation tissues in noncholesteatoma. No relationships were found between cystatin A expression and grade of cathepsin L activity. Copper- and zinc-containing superoxide dismutase was more strongly positive in cholesteatoma epithelium regions than in granulation tissues.

CONCLUSION

These results suggest that copper- and zinc-containing superoxide dismutase in cholesteatoma epithelium prevents complications by suppressing cathepsin L activity.

Clinical approach to renal study incidental to 99mTc-MDP bone scintigraphy

In order to investigate the feasibility of the assessment of renal function with 99mTc-MDP, we compared renographical images, renogram patterns and the glomerular filtration rate (GFR) obtained by means of a modified Gates' method and 200 MBq of 99mTc-MDP with those obtained by means of 99mTc-DTPA. Because 19 of 20 patients had malignant tumors in the genitourinary tract, there was no difference between the two tracers in identifying a parenchymal defect corresponding to renal cancer. Of eight patients with hydronephrosis, four had a defect or decreased uptake with a dilated pelvis, whereas the other four had marked radioisotope retention in the renal pelvis or the whole kidney on serial images. There was also no difference between the two tracers in identifying hydronephrosis. Of 38 paired renograms 35 showed the same renogram patterns with both tracers. Of three patients with different renogram patterns, two had hydronephrosis. In 20 patients including three patients with bone metastasis, total GFR and split GFR obtained with both tracers correlated with a correlation coefficient of r = 0.920 (p < 0.001) and r = 0.944 (p < 0.001), respectively. Excluding bone metastasis from the analysis, a linear-regression analysis showed excellent agreement between the two measurements with a correlation coefficient of r = 0.960 (p < 0.001) and r = 0.963 (p < 0.001), respectively. The linear regression equations were Y = 1.009X - 0.111 and Y = 1.034X - 0.714, respectively. In conclusion, 99mTc-MDP can be used as a supplement to evaluate renal function incidental to the survey of bone metastases in patients with malignant tumor.

[Early phase II study of amrubicin (SM-5887) for superficial bladder cancer: a dose-finding study for intravesical chemotherapy]

An early phase II study (dose-finding study) of amrubicin hydrochloride for superficial bladder cancer was conducted. Amrubicin was dissolved in 30 ml of physiological saline and injected intravesically for 6 consecutive days. The drug solution was retained for 2 hours. Patients were randomly assigned to four groups, which were administered amrubicin at doses of 30, 60, 90, and 120 mg/day, respectively. Of 65 patients registered in this study, 63 were eligible and assessable for toxicities, and 55 assessable for efficacy. The response rate at each dose level was 50.0% (7PRs/14 patients) at 30 mg/day, 53.3% (8 PRs/15) at 60 mg/day, 61.5% (2 CRs + 6 PRs/13) at 90 mg/day, and 69.2% (2 CRs + 7 PRs/13) at 120 mg/day, respectively. These data suggests that the efficacy was related to the doses of amrubicin. The major toxicities were cystic irritabilities, such as micturition pain, pollakisuria and hematuria. These toxicities were related to the doses of amrubicin. Their incidence and the severity were not high compared with those reported about other anthracyclines such as doxorubicin and epirubicin. The optimal dose of amrubicin was estimated to be 90 to 120 mg/day in the intravesical treatment for superficial bladder cancer once a day for 6 consecutive days.

Baicalin, the predominant flavone glucuronide of scutellariae radix, is absorbed from the rat gastrointestinal tract as the aglycone and restored to its original form

When baicalin was orally administered to conventional rats, it was detected in their plasma for 24 h after administration, but baicalein, the aglycone of baicalin, was not detected. However, when baicalin was given to germ-free rats, only a small amount of baicalin was detected in their plasma within 2 h after the administration, its AUC0-lim (the area under the concentration-time curve from 0 to last determination time) being 12.0% of that in conventional rats. Subsequently, a considerable amount (55.1 +/- 6.2%) of baicalin was recovered from the gastrointestinal tract even 4 h after administration. When baicalein was orally administered to conventional rats, however, baicalin appeared rapidly in their plasma at an AUC0-lim value similar to that obtained after oral administration of baicalin, despite the absence of baicalein in plasma. When intestinal absorption was evaluated by the rat jejunal loop method, baicalein was absorbed readily, but only traces of baicalin were absorbed. Moreover, in conventional rats a small amount (13.4 +/- 3.1%) of baicalin and an appreciable amount (21.9 +/- 3.4%) of baicalein were recovered from the gastrointestinal tract even 4 h after oral administration of baicalin, but only a small amount (3.93 +/- 1.43%) of baicalein was detected in the intestinal tract 1 h after administration of baicalein. Baicalin was transformed to baicalein readily by the rat gastric and caecal contents. When baicalin was administered orally to conventional rats, an appreciable amount of baicalein was recovered in their gastrointestinal tracts. Moreover, baicalein was efficiently conjugated to baicalin in rat intestinal and hepatic microsomes. These results indicate that baicalin itself is poorly absorbed from the rat gut, but is hydrolysed to baicalein by intestinal bacteria and then restored to its original form from the absorbed baicalein in the body.

Calcineurin antagonists inhibit interferon-gamma production by downregulation of interleukin-18 in human mixed lymphocyte reactions

Tacrolimus (FK-506) and cyclosporin A (CsA) are calcineurin antagonists used widely as T-cell immunosuppressants; however, their relative efficacy on the production of interleukin-18 (IL-18) remains undefined. We have examined the effects of FK-506 and CsA on the cytokine generation of human peripheral blood mononuclear cells (PBMCs) in mixed lymphocyte reaction (MLR) with lipopolysaccharide (LPS). We studied the levels of interleukin-18 (IL-18), IL-12, IL-10, IL-6, IL-2 and interferon-gamma (IFN-gamma) in the supernatant in allo-MLR by ELISA assay. Supernatant levels of IFN-gamma, IL-2, IL-6, IL-10 and IL-12 were detected 12 h after MLR and markedly increased thereafter. In contrast, production of IL-18 was detected at 12 h, reached a near maximum level at 24 h and decreased at 72 h. These results suggested that IFN-gamma production depended on IL-18, IL-12 and IL-2 in the early phase of MLR and depended mainly on IL-12 and IL-2 in the late phase. Both calcineurin antagonists inhibit the generation of IL-18, which plays a large role in allogeneic cell interactions, in macrophages and they also promote an equivalent down-regulation of T helper 1 (Th1) and Th2 responses in a concentration-dependent manner. About 90% of IFN-gamma production induced by MLR was inhibited by an anti-IL-18 antibody, showing that IL-18 can trigger IFN-gamma production in MLR. These results suggest that dual signaling consisting of antigen-driven nuclear factor of activated T cells (NFAT) activation and LPS-mediated NF-kappaB activation is crucial for IL-18 production in macrophages, and that IL-18 can trigger IFN-gamma production in T-cells by MLR.

Intestinal absorption and excretion of troglitazone sulphate, a major biliary metabolite of troglitazone

1. Deconjugation by sulphate transfer and intestinal absorption of troglitazone sulphate (M1), the major metabolite of a thiazolidinedione antidiabetic drug, troglitazone, were studied in the male F344 rat using 14C-troglitazone, 4C-M1 and 35S-M1. 2. Some part of M1, produced in the liver and excreted mostly in the bile, was deconjugated in the intestine to the parent compound, troglitazone, by arylsulphate sulphotransferase originated from intestinal flora. However, deconjugation of M1 was not catalyzed by arylsulphatases. Caecal injection of M1 led to the appearance of troglitazone and M1 in plasma. 3. Biliary excretion mostly as M1, and, following absorption, as M1 and troglitazone after deconjugation, were indicated as the basis for the enterohepatic circulation of troglitazone. 4. Enterohepatic circulation may prolong the pharmacological effects of troglitazone.