Freeze-crosslinking approach for preparing carboxymethyl cellulose nanofiber/zirconium hydrogels as fluoride adsorbents

Tough carboxymethylcellulose nanofibers (CMF)/zirconium (Zr) hydrogels were easily obtained by a freeze-crosslinking method, where Zr-containing HCl solution was added to frozen CMF sol and the mixture was allowed to thaw. The Zr content of the hydrogels increased with increasing Zr concentration in the initial HCl solution. Furthermore, the mechanical strength increased with increasing Zr content. The Young's modulus value was improved by approximately 6 times compared to the CMF hydrogel without Zr, i.e., from 4.5 kPa to 27.2 kPa. The hydrogel had a porous structure with a pore size of 133 ± 37 μm and a CMF-Zr sheet structure around the pores. The obtained CMF-Zr hydrogel exhibited high adsorptivity for fluoride. The maximum adsorption capacity (Qmax) was estimated to be 24.1 mg g-1. This simple gelation method provides useful insights for the development of easy-to-handle hydrogel-based adsorbents.

Effects of Fe Ions, Ultraviolet Irradiation, and Heating on Microscopic Structures of Black Lacquer Films

The chemical reaction between Fe and lacquer has been used to create the black color in lacquer coatings since ancient times. Here, the effects of Fe ion addition, UV irradiation, and heating on the microscopic structures of black lacquer films were investigated by using X-ray absorption near edge structure (XANES), extended X-ray absorption fine structure (EXAFS), Fourier transform-infrared spectroscopy (FT-IR), small-angle X-ray scattering (SAXS), and small angle neutron scattering (SANS). The EXAFS result indicated that heating and UV irradiation made the coordination structure of Fe3+ in the lacquer nonuniform, and that heating caused the greatest nonuniformity. The FT-IR, SAXS, and SANS results demonstrated that the microscopic structural changes in the black lacquer films were induced by both heating and UV irradiation, but the changes were different. Heating caused a substantial structural change on the nanoscale, and UV irradiation mainly caused changes in the molecular binding mode. The results provide important knowledge for analyzing archeological lacquer samples and for developing lacquer-based materials. This work also demonstrates the utility of the complementary use of XANES, EXAFS, FT-IR, SAXS, and SANS for nondestructive analysis of black lacquer in precious cultural relics.

Nanocellulose hydrogels formed via crystalline transformation from cellulose I to II and subsequent freeze cross-linking reaction

We describe nanocellulose (NC) hydrogels formed from chemically unmodified NC by cellulose crystalline transformation and subsequent freeze cross-linking reaction. The freeze cross-linked NC hydrogel with macropores (~100 μm) was prepared by freezing a mixture of NC and NaOH (0.2 mol L-1), adding citric acid to the frozen mixture, and thawing it. Using NaOH and freezing together induced the crystalline transformation of NC from cellulose I to II via freeze concentration. After the crystalline transformation, cross-linking between the NC and CA in the freeze concentration layer provided a strong NC network structure, forming NC hydrogels with high mechanical strength. The structural changes in NC caused by NaOH, freezing, and freeze cross-linking on the angstrom to micrometer scale were investigated with FT-IR, SAXS, PXRD, and SEM. The freeze cross-linked NC hydrogel easily retained powder adsorbents in its inner space by mixing the NC-NaOH sol and the powder, and the hydrogel showed high removal efficiency for heavy metals. The results highlight the versatility of chemically unmodified celluloses in developing functional materials and suggest possible practical applications. This study also provides new insights into the efficient use of chemical reactions of cellulose under freezing conditions.

3D-printed epidermal sweat microfluidic systems with integrated microcuvettes for precise spectroscopic and fluorometric biochemical assays

Systems for capture, storage and analysis of eccrine sweat can provide insights into physiological health status, quantify losses of water, electrolytes, amino acids and/or other essential species, and identify exposures to adverse environmental species or illicit drugs. Recent advances in materials and device designs serve as the basis for skin-compatible classes of microfluidic platforms and in situ colorimetric assays for precise assessments of sweat rate, sweat loss and concentrations of wide-ranging types of biomarkers in sweat. This paper presents a set of findings that enhances the performance of these systems through the use of microfluidic networks, integrated valves and microscale optical cuvettes formed by three dimensional printing in hard/soft hybrid materials systems, for accurate spectroscopic and fluorometric assays. Field studies demonstrate the capability of these microcuvette systems to evaluate the concentrations of copper, chloride, and glucose in sweat, along with the pH of sweat, with laboratory-grade accuracy and sensitivity.

Polarized Neutrons Observed Nanometer-Thick Crystalline Ice Plates in Frozen Glucose Solution

Spin-contrast-variation (SCV) small-angle neutron scattering (SANS) is a technique to determine the nanostructure of composite materials from the scattering of polarized neutrons that changes with proton polarization of samples. The SCV-SANS enabled us to determine structure of nanoice crystals that were generated in rapidly frozen sugar solutions by separating the overlapped signals from the nanoice crystals and frozen amorphous solutions. In the frozen glucose solution, we found that the nanoice crystals formed a planar structure with a radius larger than several tens of nanometers and a thickness of 2.5 ± 0.5 nm, which was close to the critical nucleation size of ice crystals in supercooled water. This result suggests that the glucose molecules were preferentially bound to a specific face of nanoice crystals and then blocked the crystal growth perpendicular to that face.

Sewage sludge ash contaminated with radiocesium: Solidification with alkaline-reacted metakaolinite (geopolymer) and Portland cement

This study contributes toward developing measures for the disposal of radiocesium-contaminated sewage sludge ash (SSA). Here, we prepared two types of solidified bodies containing 30 wt% radiocesium-bearing SSA. The material used for the two solidified bodies were alkaline-reacted metakaolinite (geopolymer) and ordinary Portland cement (OPC). Cement has been used for solidification of low-level radioactive wastes, and geopolymer is a candidate of cement alternative materials. The characteristics of these solidified bodies were investigated by various aspects including mechanical strength, transformation of SSA components during solidification, and radiocesium confinement ability by leaching test. The compressive strength of geopolymer- and OPC-solidified bodies at 30 wt% SSA content was more than 40 MPa. After static leaching test at 60 °C, ¹³⁷Cs was hardly leached out from the geopolymer-solidified bodies containing SSA at 30 wt% to ultrapure water (<0.1%), whereas more than 30% ¹³⁷Cs was leached from the OPC-solidified bodies containing SSA at 30 wt% even though only ~9% of ¹³⁷Cs in the SSA is soluble. These results strongly indicate that geopolymer is far superior to OPC for solidifying radiocesium-bearing SSA.

Magnetically Navigated Protein Transduction In Vivo using Iron Oxide-Nanogel Chaperone Hybrid

Systems for "protein transduction," intracellular delivery of functional proteins, are needed to address deliverability challenges of protein therapeutics. However, in vivo protein transduction remains challenging because of instability in serum, extracellular protease digestion and rapid excretion from the bloodstream. Here, a magnetically guided in vivo protein transduction using magnetic nanogel chaperone (MC) composed of iron oxide nanoparticles and a polysaccharide nanogel, a protein carrier inspired by "catch and release" mechanisms of molecular chaperones is demonstrated. The MC system enables efficient delivery of anti-cancer proteins, saporin and RNaseA, into cultured tumor lines and inhibits cell proliferation, mainly via apoptosis. Magnetic in vivo protein transduction via intravenous whole body administration is demonstrated in a fibrosarcoma model. By in vivo optical imaging, MC accumulated in tumor tissues under magnetic field three times more than without irradiation. With subcutaneous injection, saporin is delivered by MC to the cytoplasm in magnetically targeted tissues. In an oral cancer model, MC-delivered magnetically targeted saporin decreased tumor volume without significant body weight changes and no regrowth of tumor at 3 months after complete regression. Protein transduction with MC shows promise for cancer therapeutics and, potentially, for regenerative medicine and other biomedical applications.

Intake of New Zealand Blackcurrant Powder Affects Skin-Borne Volatile Organic Compounds in Middle-Aged and Older Adults

Skin volatile organic compounds (VOCs) can cause body odor or reveal human disease and may result from lipid peroxidation or activity by skin bacteria. We examined the effect of intake of New Zealand blackcurrant (NZBC) powder for 77 skin VOCs in middle-aged and older adults in a crossover design. Fourteen adults (nine males, age: 55 ± 5 yrs) consumed NZBC powder for 7 days (6 g·day^-1 with 138.6 mg anthocyanins). Two hours after the last intake, a passive flux sampler with trapping media was applied in the base of the neck for 1 hour. Gas chromatography-mass spectrometry was used for media analysis. Habitual anthocyanin intake was quantified using a food frequency questionnaire. Compared to control (i.e., no intake of NZBC powder), emission of six skin VOCs (i.e., 2-nonenal, acetic acid, 2-hexanone, 6-methyl-5-hepten-2-one, benzaldehyde, allyl methyl sulfide) were lower by more than 25%. Increases were observed for γ-octanolactone (+184%) and γ-decanolactone (+89%). A trend for a decrease for isovaleraldehyde, hexanal, and 2-pentanone, and an increase for heptanoic acid and γ-nonanolactone was observed. There was a significant correlation with daily habitual dietary anthocyanin intake for control values of hexanal and percentage change of γ-octanolactone. NZBC powder can change emanation of some VOCs in human skin. Analysis of skin VOCs following specific polyphenol intake may address the impact of dietary components to affect internal metabolic processes, body odor, and health.

Development of spin-contrast-variation neutron powder diffractometry for extracting the structure factor of hydrogen atoms

A spin-contrast-variation neutron powder diffractometry technique that extracts the structure factor of hydrogen atoms, i.e. the contribution of hydrogen atoms to a crystal's structure factor, has been developed. Crystals of L-glutamic acid were dispersed in a D-polystyrene matrix containing 4-methacryloyloxy-2,2,6,6,-tetramethyl-1-piperidinyloxy to polarize their proton spins dynamically. The intensities of the diffraction peaks of the sample changed according to the proton polarization, and the structure factor of the hydrogen atoms was extracted from the proton-polarization-dependent intensities. This technique is expected to enable analyses of the structures of hydrogen-containing materials that are difficult to determine with conventional powder diffractometry.

Passive sweat collection and colorimetric analysis of biomarkers relevant to kidney disorders using a soft microfluidic system

The rich range of biomarkers in sweat and the ability to collect sweat in a non-invasive manner create interest in the use of this biofluid for assessments of health and physiological status, with potential applications that range from sports and fitness to clinical medicine. This paper introduces two important advances in recently reported classes of soft, skin-interfaced microfluidic systems for sweat capture and analysis: (1) a simple, broadly applicable means for collection of sweat that bypasses requirements for physical/mental exertion or pharmacological stimulation and (2) a set of enzymatic chemistries and colorimetric readout approaches for determining the concentrations of creatinine and urea in sweat, throughout ranges that are physiologically relevant. The results allow for routine, non-pharmacological capture of sweat for patient populations, such as infants and the elderly, that cannot be expected to sweat through exercise, and they create potential opportunities in the use of sweat for kidney disease screening/monitoring. Studies on human subjects demonstrate these essential capabilities, with quantitative comparisons to standard methods. The results expand the range of options available in microfluidic sampling and sensing of sweat for disease diagnostics and health monitoring.

Root-endophytic Chaetomium cupreum chemically enhances aluminium tolerance in Miscanthus sinensis via increasing the aluminium detoxicants, chlorogenic acid and oosporein

Miscanthus sinensis Andersson is a pioneer plant species that grows naturally at mining sites. Miscanthus sinensis can detoxify aluminium (Al) by producing phytosiderophores, such as chlorogenic acid, citric acid, and malic acid, and localizing Al in cell walls. Root-endophytic Chaetomium cupreum, which produces microbial siderophores, enhances Al tolerance in M. sinensis. However, we could not determine whether the siderophores produced by C. cupreum actually enhance Al tolerance in M. sinensis, because the microbial siderophores have not yet been identified in previous research. The purpose of this study was to clarify how C. cupreum chemically increases Al tolerance in M. sinensis under acidic mining site conditions, especially considering siderophores. Using instrumental analyses, the siderophore produced by C. cupreum was identified as oosporein. Comparison of the stability constant between Al and phytosiderophores and oosporein indicated that oosporein could detoxify Al similarly to chlorogenic acid, which shows higher stability constant than citric acid and malic acid. Inoculation test of C. cupreum onto M. sinensis in acidic mine soil showed that C. cupreum promoted seedling growth, and enhanced Al tolerance via inducing chlorogenic-acid production and producing oosporein. These results suggested that C. cupreum could chemically enhance Al tolerance and might promote growth via reducing excessive Al in cell walls, the main site of Al accumulation. In addition, the chemical enhancement of Al tolerance by C. cupreum might be important for M. sinensis to adapt to acidic mining sites.

Battery-free, skin-interfaced microfluidic/electronic systems for simultaneous electrochemical, colorimetric, and volumetric analysis of sweat

Wearable sweat sensors rely either on electronics for electrochemical detection or on colorimetry for visual readout. Non-ideal form factors represent disadvantages of the former, while semiquantitative operation and narrow scope of measurable biomarkers characterize the latter. Here, we introduce a battery-free, wireless electronic sensing platform inspired by biofuel cells that integrates chronometric microfluidic platforms with embedded colorimetric assays. The resulting sensors combine advantages of electronic and microfluidic functionality in a platform that is significantly lighter, cheaper, and smaller than alternatives. A demonstration device simultaneously monitors sweat rate/loss, pH, lactate, glucose, and chloride. Systematic studies of the electronics, microfluidics, and integration schemes establish the key design considerations and performance attributes. Two-day human trials that compare concentrations of glucose and lactate in sweat and blood suggest a potential basis for noninvasive, semi-quantitative tracking of physiological status.

Soft, Skin-Interfaced Microfluidic Systems with Wireless, Battery-Free Electronics for Digital, Real-Time Tracking of Sweat Loss and Electrolyte Composition

Sweat excretion is a dynamic physiological process that varies with body position, activity level, environmental factors, and health status. Conventional means for measuring the properties of sweat yield accurate results but their requirements for sampling and analytics do not allow for use in the field. Emerging wearable devices offer significant advantages over existing approaches, but each has significant drawbacks associated with bulk and weight, inability to quantify volumetric sweat rate and loss, robustness, and/or inadequate accuracy in biochemical analysis. This paper presents a thin, miniaturized, skin-interfaced microfluidic technology that includes a reusable, battery-free electronics module for measuring sweat conductivity and rate in real-time using wireless power from and data communication to electronic devices with capabilities in near field communications (NFC), including most smartphones. The platform exploits ultrathin electrodes integrated within a collection of microchannels as interfaces to circuits that leverage NFC protocols. The resulting capabilities are complementary to those of previously reported colorimetric strategies. Systematic studies of these combined microfluidic/electronic systems, accurate correlations of measurements performed with them to those of laboratory standard instrumentation, and field tests on human subjects exercising and at rest establish the key operational features and their utility in sweat analytics.

A fluorometric skin-interfaced microfluidic device and smartphone imaging module for in situ quantitative analysis of sweat chemistry

The rich composition of solutes and metabolites in sweat and its relative ease of collection upon excretion from skin pores make this class of biofluid an attractive candidate for point of care analysis. Wearable technologies that combine electrochemical sensors with conventional or emerging semiconductor device technologies offer valuable capabilities in sweat sensing, but they are limited to assays that support amperometric, potentiometric, and colorimetric analyses. Here, we present a complementary approach that exploits fluorometric sensing modalities integrated into a soft, skin-interfaced microfluidic system which, when paired with a simple smartphone-based imaging module, allows for in situ measurement of important biomarkers in sweat. A network array of microchannels and a collection of microreservoirs pre-filled with fluorescent probes that selectively react with target analytes in sweat (e.g. probes), enable quantitative, rapid analysis. Field studies on human subjects demonstrate the ability to measure the concentrations of chloride, sodium and zinc in sweat, with accuracy that matches that of conventional laboratory techniques. The results highlight the versatility of advanced fluorescent-based imaging modalities in body-worn sweat microfluidics platforms, and they suggest some practical potential for these ideas.

Super-Absorbent Polymer Valves and Colorimetric Chemistries for Time-Sequenced Discrete Sampling and Chloride Analysis of Sweat via Skin-Mounted Soft Microfluidics

This paper introduces super absorbent polymer valves and colorimetric sensing reagents as enabling components of soft, skin-mounted microfluidic devices designed to capture, store, and chemically analyze sweat released from eccrine glands. The valving technology enables robust means for guiding the flow of sweat from an inlet location into a collection of isolated reservoirs, in a well-defined sequence. Analysis in these reservoirs involves a color responsive indicator of chloride concentration with a formulation tailored to offer stable operation with sensitivity optimized for the relevant physiological range. Evaluations on human subjects with comparisons against ex situ analysis illustrate the practical utility of these advances.

Electrocatalytic synthesis of ammonia by surface proton hopping

Highly efficient ammonia synthesis at a low temperature is desirable for future energy and material sources. We accomplished efficient electrocatalytic low-temperature ammonia synthesis with the highest yield ever reported. The maximum ammonia synthesis rate was 30 099 μmol gcat-1 h-1 over a 9.9 wt% Cs/5.0 wt% Ru/SrZrO3 catalyst, which is a very high rate. Proton hopping on the surface of the heterogeneous catalyst played an important role in the reaction, revealed by in situ IR measurements. Hopping protons activate N2 even at low temperatures, and they moderate the harsh reaction condition requirements. Application of an electric field to the catalyst resulted in a drastic decrease in the apparent activation energy from 121 kJ mol-1 to 37 kJ mol-1. N2 dissociative adsorption is markedly promoted by the application of the electric field, as evidenced by DFT calculations. The process described herein opens the door for small-scale, on-demand ammonia synthesis.

Quantum Hall effect in epitaxial graphene with permanent magnets

We have observed the well-kown quantum Hall effect (QHE) in epitaxial graphene grown on silicon carbide (SiC) by using, for the first time, only commercial NdFeB permanent magnets at low temperature. The relatively large and homogeneous magnetic field generated by the magnets, together with the high quality of the epitaxial graphene films, enables the formation of well-developed quantum Hall states at Landau level filling factors v = ±2, commonly observed with superconducting electro-magnets. Furthermore, the chirality of the QHE edge channels can be changed by a top gate. These results demonstrate that basic QHE physics are experimentally accessible in graphene for a fraction of the price of conventional setups using superconducting magnets, which greatly increases the potential of the QHE in graphene for research and applications.

Surface Protonics Promotes Catalysis

Catalytic steam reforming of methane for hydrogen production proceeds even at 473 K over 1 wt% Pd/CeO₂ catalyst in an electric field, thanks to the surface protonics. Kinetic analyses demonstrated the synergetic effect between catalytic reaction and electric field, revealing strengthened water pressure dependence of the reaction rate when applying an electric field, with one-third the apparent activation energy at the lower reaction temperature range. Operando–IR measurements revealed that proton conduction via adsorbed water on the catalyst surface occurred during electric field application. Methane was activated by proton collision at the Pd–CeO₂ interface, based on the inverse kinetic isotope effect. Proton conduction on the catalyst surface plays an important role in methane activation at low temperature. This report is the first describing promotion of the catalytic reaction by surface protonics.

Operative Results and Clinical Features of Chronic Stanford Type B Aortic Dissection: Examination of 234 Patients Over 6 Years

OBJECTIVE/BACKGROUND

Recently, the indications for thoracic endovascular aortic repair (TEVAR) have been expanding, and the applicability of TEVAR for acute type B aortic dissection (TBAD) is proposed with regard to the high mortality of open surgery for chronic TBAD. TEVAR in the acute phase may lead to remodeling of the false lumen (FL), but it is controversial whether it completely resolves the aortic expansion in the chronic phase. In this study, operative results and the relationship between FL status and the time before surgical intervention were retrospectively analyzed.

METHODS

From January 2008 to September 2013, 234 patients underwent open surgery for chronic TBAD. Most patients were on left heart bypass. By considering Japanese aortic disease treatment guidelines and the smaller physique of Japanese patients, operative indications were aneurysm >50 mm in diameter or rapid aneurysm enlargement of >5 mm in a 6 month period.

RESULTS

In 180 cases, the FL was patent. The mean interval between onset of TBAD and operation was 61 ± 54 months. There was no significant difference between patients in the patent FL group and those in the thrombosed FL group (p = .44). Mean ratio of FL diameter to maximum aortic diameter (FL/AD) was 0.64 ± 0.21. There was no correlation between FL and AD before the operation (r = .12). Descending thoracic aortic replacement (DTAR) was performed in 127 cases and thoracic ascending aortic replacement (TAAR) in 107 cases (Crawford type I, n = 9; Crawford type II, n = 65; Crawford type III and IV, n = 22, respectively; Safi type V, n = 11). The overall operative mortality was 6.8%: 3.9% (5/127) for DTAR and 10.3% (11/107) for TAAR. The three year survival was 86.7, and the freedom from re-intervention rate was 97.0%.

CONCLUSION

Enlargement of uncomplicated TBAD in the chronic phase was poorly related to FL status and the results of open repair have improved. However, further prospective study is necessary.

Photocurrent generation of a single-gate graphene p-n junction fabricated by interfacial modification

A back-gate graphene p-n junction was achieved by selective interfacial modification of a chemical vapor deposition (CVD)-grown graphene field effect transistor (FET). Silane self-assembled monolayer (SAM) patterns were used to fabricate uniform p- and n-doped regions and a sharp p-n junction in the graphene FET channel. A gate-dependent photocurrent response was observed at the graphene p-n junction, and exhibited a maximum signal between two Dirac point voltages of SAM-doped graphene regions. A spatial photocurrent map shows that the photocurrent generated at the junction region was much larger than that from graphene/electrode junctions under the same incident laser power. This single-peak characteristic photocurrent in CVD graphene is dominated by the photothermoelectric contribution, and is highly sensitive to the power of incident laser. The SAM interfacial modification method provides a feasible route for the fabrication of efficient graphene-based photodetectors.

Partial restoration of protein synthesis rates by the small molecule ISRIB prevents neurodegeneration without pancreatic toxicity

Activation of the PERK branch of the unfolded protein response (UPR) in response to protein misfolding within the endoplasmic reticulum (ER) results in the transient repression of protein synthesis, mediated by the phosphorylation of the alpha subunit of eukaryotic initiation factor 2 (eIF2α). This is part of a wider integrated physiological response to maintain proteostasis in the face of ER stress, the dysregulation of which is increasingly associated with a wide range of diseases, particularly neurodegenerative disorders. In prion-diseased mice, persistently high levels of eIF2α cause sustained translational repression leading to catastrophic reduction of critical proteins, resulting in synaptic failure and neuronal loss. We previously showed that restoration of global protein synthesis using the PERK inhibitor GSK2606414 was profoundly neuroprotective, preventing clinical disease in prion-infected mice. However, this occured at the cost of toxicity to secretory tissue, where UPR activation is essential to healthy functioning. Here we show that pharmacological modulation of eIF2α-P-mediated translational inhibition can be achieved to produce neuroprotection without pancreatic toxicity. We found that treatment with the small molecule ISRIB, which restores translation downstream of eIF2α, conferred neuroprotection in prion-diseased mice without adverse effects on the pancreas. Critically, ISRIB treatment resulted in only partial restoration of global translation rates, as compared with the complete restoration of protein synthesis seen with GSK2606414. ISRIB likely provides sufficient rates of protein synthesis for neuronal survival, while allowing some residual protective UPR function in secretory tissue. Thus, fine-tuning the extent of UPR inhibition and subsequent translational de-repression uncouples neuroprotective effects from pancreatic toxicity. The data support the pursuit of this approach to develop new treatments for a range of neurodegenerative disorders that are currently incurable.

A hybrid hydrogel biomaterial by nanogel engineering: bottom-up design with nanogel and liposome building blocks to develop a multidrug delivery system

New hybrid poly(ethylene glycol) (PEG) hydrogels crosslinked with both nanogels and nanogel-coated liposome complexes are obtained by Michael addition of the acryloyl group of a cholesterol-bearing pullulan (CHP) nanogel to the thiol group of pentaerythritol tetra(mercaptoethyl) polyoxyethylene. The nanogel-coated liposome complex is stably retained after gelation and the complexes are well dispersed in the hybrid gel. Microrheological measurements show that the strength and gelation time of the hybrid hydrogel can be controlled by changing the liposome:nanogel ratio. The hydrogel is gradually degraded by hydrolysis under physiological conditions. In this process, the nanogel is released first, followed by the nanogel-coated liposomes. Hybrid hydrogels that can incorporate various molecules into the nanogel and liposomes, and release them in a two-step controllable manner, represent a new functional scaffold capable of delivering multiple drugs, proteins or DNA.

Development of prostate cancer in a patient with primary hypogonadism: intratumoural steroidogenesis in prostate cancer tissues

Intratumoural steroidogenesis may play a significant role in the progression of prostate cancer (PC) in the context of long-term ablation of circulating testosterone (T). To clarify the mechanism accounting for the progression of PC in a 74-year-old man who had undergone bilateral orchiectomy when he was 5 years old, we performed immunohistochemical studies of androgen receptor (AR) and steroidogenic enzymes in the prostate. We also measured steroid hormone levels in the serum and prostate, as well as mRNA levels of genes mediating androgen metabolism in the prostate. Positive nuclear staining of AR was detected in malignant epithelial cells. The levels of androstenedione (Adione), T, and 5-alpha dihydrotestosterone (DHT) in the serum of the patient were similar to those in PC patients receiving neoadjuvant androgen deprivation therapy (ADT), but were higher in the patient's prostate than in PC patients not receiving ADT. The gene expression of CYP17A1 and HSD3B1 was not detected, whereas that of STS, HSD3B2, AKR1C3, SRD5A1, and SRD5A2 was detected. Moreover, cytoplasmic staining of HSD3B2, AKR1C3, SRD5A1, and SRD5A2 was detected in malignant epithelial cells. Hence, in the present case (a man with primary hypogonadism), steroidogenesis in PC tissues from adrenal androgens, especially dehydroepiandrosterone sulphate, was the mechanism accounting for progression of PC. This mechanism might help elucidate the development of castration-resistant PC.

[Thoracic surgery for patients with deep vein thrombosis]

Deep vein thrombosis (DVT) is a main cause of pulmonary thromboembolism (PTE), and therefore both diseases are categorized as a serial pathophysiology of venous thromboembolism (VTE). Treatment goals for DVT include stopping clot propagation and preventing the recurrence of thrombus, the occurrence of PTE, and the development of pulmonary hypertension, which can be a complication of multiple recurrent pulmonary emboli. Clinical guidelines stratify the risk of VTE to 4 levels and recommend the treatment options. In high or extremely high risk patients for VTE, the use of low-dose heparin is recommended. The prevention against VTE, such as elastic compression stockings and intermittent sequential pneumatic leg compression( ISPC), is the most important prophylactic treatment against perioperative PTE by reducing thrombotic risk in low or moderate high risk patients for VET. Since there is no clear evidence that screening all or even selected patients for thrombophilias improves long-term outcomes, the physician's clinical judgment, and consultation with appropriate subspecialists should guide management perioperatively. Once PTE is suspected, immediate and accurate diagnosis and appropriate treatment are mandatory.

Role of squalene synthase in prostate cancer risk and the biological aggressiveness of human prostate cancer

BACKGROUND

We previously conducted a genome-wide linkage analysis of Japanese nuclear families affected with prostate cancer and showed that the susceptibility to prostate cancer was closely linked to D8S550 at 8p23. The role of farnesyl diphosphate farnesyltransferase (FDFT1), which is located under the peak marker D8S550 at 8p23, and squalene synthase, the enzyme encoded by FDFT1, in prostate cancer was studied.

METHODS

The association among common variants of FDFT1 with prostate cancer risk, the promoter activities of FDFT1 with different genotypes and the effects of inhibition of squalene synthase were studied, and the FDFT1 transcript levels of human prostate samples were quantified.

RESULTS

The A allele of rs2645429 was significantly associated with prostate cancer risk in a Japanese familial prostate cancer population. Rs2645429 was located in the promoter region of FDFT1, and the AA genotype showed significantly increased promoter activity. The knockdown of FDFT1 mRNA expression or squalene synthase inhibition led to a significant decrease in prostate cancer cell proliferation. Additionally, human prostate cancer specimens expressed significantly higher levels of FDFT1 mRNA compared with noncancerous specimens. Finally, aggressive cancers showed higher transcript levels.

CONCLUSIONS

FDFT1 and its encoded enzyme, squalene synthase, may play an important role in prostate cancer development and its aggressive phenotypes.