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Several methods and catalysts have been investigated for eco-friendly ammonia (NH3) production under mild conditions in the past few decades. NH3 is important chemical fertilizer and now expecting as H2 carrier, and mainly synthesized by Haber-Bosch process under severe conditions (400 ℃, 20MPa). In contrast, nitrogenases, biocatalyst can activate N2 and H2O to form NH3 under ambient conditions in nature with a low synthesis rate. Herein we first reported photobiocatalytic NH3 production by the combination of cyanobacterial Anabaena variabilis as a whole-cell biocatalyst coupled with TiO2 as a photocatalyst in the existence of glycerol as a sacrificial reagent and viologens as an electron transfer mediator. Comparing with natural system, the formation rate of NH3 from a combination with inorganic photocatalyst was much increased by ca. 20.86 times. Biocatalytic reactions revealed that only reduced MV•+ passed into whole cells and transfer electrons to nitrogenase efficiently for NH3 production. The amount of intracellular [MoFe]-nitrogenase was increased in cyanobacteria cultivated in a nitrogen-deficient Allen & Arnon medium. The complete hybrid system produced NH3 with a maximum rate of 3.3 µM·g-1·h-1. This study is the first demonstration of the sustainable technology for solar-to-NH3 conversion as an energy carrier for a future carbon-neutral energy society.

To estimate the adsorption distribution of cationic dyes on the inorganic nanosheets, the fluorescence behavior of cis-DMPyP, which is a di-cationic porphyrin, was investigated using self-fluoresce...

Recent development on alternative route to bypass the bottle-neck of water oxidation, two-electron oxidation of water catalyzed by earth-abundant metalloporphyrins to form hydrogen peroxide, has been briefly reviewed. The three pioneering reports by Fujishima (Honda-Fujishima effect), Meyer (chemical oxidation of water), and Lehn (photochemical reduction of CO2) triggered the extensive studies on artificial photosynthesis to have been forming the modern history of artificial photosynthesis. The current situation, especially for artificial photosynthesis by molecular catalysts, however, has faced with bottleneck subject of photon-flux-density problem of sun light radiation. In this review article, three milestones in the modern history of artificial photosynthesis, photon-flux-density problem as the bottleneck subject in water oxidation, crucial viewpoint of renewable energy factor (REF) in designing artificial photosynthesis even in fundamental stage of studies are explained. Several approaches to minimize the energy cost in REF for molecular catalysts such as utilization of earth-abundant elements and synthesis of molecular catalyst in water at ambient temperature were also introduced. Recent development of two-electron oxidation of water to form hydrogen peroxide, which would uncover the blind point of the bottleneck subject, would induce a game change in the methodologies of artificial photosynthesis.

Water soluble tin(IV)-porphyrins, trans-dihydroxy-5,10,15,20-tetra(N-methyl-4′-pyridiniumyl)porphyrinate tin (IV) (Sn(IV)TMPyP(OH)2) was successfully synthesized in high yield (90%) through one-pot process in water at room temperature by treating the parent free base (H2TMPyP) with Sn(II)Cl2. Re-investigation by the detailed kinetic analysis of the time dependent 1H NMR signals indicated that the tin(IV)-insertion reaction reversibly proceeded through three steps to start from free base dimer, [H2TMPyP]2, through Sn(II)TMPyP. New intermediate, an association complex between SnCl2 and H2TMPyP, which should be a precursor of Sn(II)TMPyP, was clearly observed in UV–vis and 1H NMR for the first time. Sn(II)TMPyP was also detected at around 500 nm in UV–vis spectroscopy, while it was silent against 1H NMR, which was supported by DFT calculation to indicate that Sn(II)TMPyP has a paramagnetic nature through substantial population on triplet spin states. To explore possible one-pot process for other porphyrins, such as neutral tetra-meso-substituted-tolylporphyrin (TTP), tetra-meso-substituted-mesitylporphyrin (TMP), and anionic tetra-meso-substituted-carboxyphenylporphyrin (TCPP), the reactions in water, binary-phase system of water/dichloromethane, and methanol were examined. The anionic TCPP suffered the tin(IV)-insertion at ambient temperature only in methanol with good yield (90%).

A series of four Tin(IV)porphyrins with different substituents on meso-phenyl groups, trans-dihydroxy-5,10,15,20-tetra(p-tolyl)porphyrinatetin(IV) (Sn(IV)TTP(OH)2), trans-dihydroxy-tetra(2,4,6-trimethyl)phenylporphyrinatetin(IV) (Sn(IV)TMP(OH)2), trans-dihydroxy-5,10,15,20-tetra(p-carboxyphenyl)porphyrinatetin(IV) (Sn(IV)TCPP), and trans-dihydroxy-5,10,15,20-tetra(N-methyl-4′-pyridiniumyl)porphyrinatetin(IV) (Sn(IV)TMPyP(OH)2) have been prepared and characterized focusing on their protolytic behavior of the axial ligands, hydroxy groups, both in the ground and excites states as well as their electrochemical oxidation behavior. The two axially ligating hydroxy groups on each Tin(IV)-porphyrins exhibit protonations and deprotpnations in five steps. The pKa value of each protolytic equilibrium in the ground states was spectrophotometrically determined, while fluorescence decay time profiles indicate that the protolytic processes are sufficiently slower than the intrinsic fluorescence decay rates to lead to non-protolysis in the excited states. The oxidation peak potentials were determined by cyclic voltammetric analysis. Pourbaix diagram of each protolytic species of Sn(IV)TMPyP in water indicated that the one-electron oxidation of fully deprotonated Sn(IV)TMPyP(O−)2 is not a proton-coupled process, while the doubly hydroxy coordinated species Sn(IV)TMPyP(OH)2 has a proton-coupled one. Tin(IV)-porphyrins exhibit efficient catalytic currents on the first oxidation wave in their cyclic voltammetry and the saturated catalytic currents were high enough in a wide range of pH to be promising as water oxidation catalysts. This is the first detailed study on Tin(IV)-porphyrins to examine water oxidation ability of the one-electron oxidized form against twenty kinds of species (five protolytic species for each of the four Tin(IV)-porphyrins).

5, 10, 15, 20-tetra(N-methylpyridinium-4′-yl)porphyrinate tin(IV) (SnTMPyP) was found to exhibit two-electron water oxidation to form hydrogen peroxide as a primary product initiated by electrochemical one-electron oxidation. Dioxygen was also formed by the further two-electron oxidation of hydrogen peroxide on the anode. Isotope labelling experiment using H218O and enzyme catalase that converts H2O2 into O2 revealed an incorporation of 18O into the oxidation products, indicating the two-electron oxidation of water in the electrolysis catalysed by SnTMPyP. The overpotential of forming H2O2 under the practical condition is 370 mV. The Faradaic yield of the water oxidation was almost quantitative both under the basic (pH 10.9) and the nearly neutral conditions (pH 8.5), though the reactivity was much higher under the basic condition.

Two-electron water oxidation is an energy-efficient way for solar energy conversion and one of the promising candidates to get through the bottleneck of artificial photosynthesis, photon- flux density problem. In light of renewable energy factor (REF) that is defined by Energy output/Energy input, for the realization of practical systems, the energy input for catalyst preparation have much importance. Herein, we report a facile, cost-effective and environment benign synthesis of zinc (II) 5, 10, 15, 20-tetrakis(N-methylpyridinium-4′-yl)porphyrin (ZnTMPyP) in water at room temperature. We observed coordination of water molecules to the central Zn(II) ion of ZnTMPyP and four-step protolytic equilibria among five axially ligated species. Electrochemical and controlled potential electrolysis experiments, as well as theoretical DFT calculation, showed that ZnTMPyP(OH)(O−) exhibits the two-electron water oxidation to form hydrogen peroxide as the primary product initiated by one-electron oxidation process of the catalyst with a moderate turnover frequency (96.4 s-1) and a small overpotential (∼60 mV). Isotope-labeled studies clearly showed that water molecule served as an oxygen atom source in the formation of hydrogen peroxide.

Appropriate relative permeability curves for two-phase flows through subsurface fractures remain unclear. We have conducted decane-water and nitrogen-water two-phase flow experiments and simulations on real variable-aperture fractures in rocks under confining stress. Experiments have been conducted on fractures for different combinations of rock type (granite or limestone), wettability (contact angle of water: 0° or 90°), and intrinsic fracture permeability (10−11 m2 or 10−10 m2) using different combinations of shear displacement (0 or 1 mm) and effective confining stress (1 or 40 MPa). It has been demonstrated that nonwetting phase relative permeability depends on capillary pressure, except at either a higher contact angle or higher intrinsic permeability (i.e., bigger aperture), where no influence of capillarity is expected from the Young-Laplace equation. In the absence of an influence of capillarity, relations between wetting and nonwetting phase relative permeabilities agree with that of the X-type relative permeability curves. In order to determine the relative permeability curves under the influence of capillarity, the experimental results have been analyzed by two-phase flow simulations of the aperture distributions of the fractures. It has been revealed that nonwetting phase relative permeability becomes zero, even at a small wetting phase saturation of approximately 0.3, while wetting phase relative permeability exhibits Corey-type behavior, resulting in ν-shaped relative permeability curves. Similar curves have been reported in the literature, but have not been demonstrated for real fractures. It has been revealed that the new ν-type and traditional X-type relative permeability curves are appropriate for describing two-phase flows through subsurface fractures.

Variables A Cross-sectional area of the model (L) a Local aperture of the fracture (L) ai Aperture at the ith voxel (L) CTVi CT value at the ith voxel (Hounsfield unit) f Correction factor for the cubic law equation k Permeability of the model (L) L Length of the model (L) N Total number of voxels P Pressure of the fluid (MLT) DP Pressure difference (MLT) Q Total flow rate (LT) W Local width of the fracture (L)

The X-ray CT based numerical analysis of fracture flow for core samples, recently developed by the authors, was applied to two granite core samples having either a mated artificial or a mated natural fracture at confining pressures of 5 to 50 MPa. A third-generation medical X-ray CT scanner was used to image the samples within a core holder consisting of an aluminum liner and a carbon fiber overwrap. Fracture models (i.e., aperture distributions) were obtained by the CT images, the resolution of which was coarser than the apertures, and a single-phase flow simulation was performed using a local cubic law-based fracture flow model. Numerical results were evaluated by a fracture porosity measurement and a solution displacement experiment using NaCl and NaI aqueous solutions. These numerical results coincided only qualitatively with the experimental results, primarily due to image noise from the aluminum liner of the core holder. Nevertheless, the numerical results revealed flow paths within the fractures and their changes with confining pressure, whereas the experimental results did not provide such results. Different stress-dependencies in the flow paths were observed between the two samples despite the similar stress-dependency in fracture porosity and permeability. The changes in total area of the flow paths with confining pressure coincided qualitatively with changes in breakthrough points in the solution displacement experiment. Although the data is limited, the results of the present study suggest the importance of analyzing fluid flows within naturally fractured core samples under in situ conditions in order to better understand the fracture flow characteristics in a specific field. As demonstrated herein, X-ray CT-based numerical analysis is effective for addressing this concern. Using a multi-phase flow model, as well as a core holder constructed of an engineered plastic, should provide a useful, non-destructive, and non-contaminative X-ray CT-based fracture flow analysis for core samples under in situ conditions in future studies.

Summary The present study focuses on the feasibility of a precise 3D numerical modeling coupled with X-ray computed tomography (CT), which enables simple analysis of heterogeneous fracture flows within reservoir core samples, as well as the measurement of porosity and permeability. A numerical modeling was developed and applied to two fractured granite core samples. One of the samples had an artificial single fracture (sample dimensions: 100 mm in diameter, 150 mm in length), and the other had natural multiple fractures (sample dimensions: 100 mm in diameter, 120 mm in length). A linear relationship between the CT value and the fracture aperture (fracture-aperture calibration curve) was obtained by X-ray CT scanning for a fracture-aperture calibration standard while varying the aperture from 0.1 to 0.5 mm. With the fracture-aperture calibration curve, 3D distributions of the CT value for the samples (voxel dimensions: 0.35×0.35×0.50 mm3) were converted into fracture-aperture distributions in order to obtain fracture models for these samples. The numerical porosities reproduced the experimental porosities within factors of approximately 1.3 and 1.1 for the single fracture and the multiple fractures, respectively. Using the fracture models, a single-phase flow simulation was also performed with a local cubic law-based fracture-flow model for steady-state laminar flow of a viscous and incompressible fluid. The numerically obtained permeabilities were larger than the experimentally obtained permeabilities by factors of approximately 2.2 and 2.7 for the single fracture and the multiple fractures, respectively. However, these discrepancies can be reduced to approximately 1.3—2.1 and 1.6-2.6, respectively, by simply using the correction factor for the cubic-law equation proposed by Witherspoon et al. (1980). Consequently, a precise numerical modeling coupled with X-ray CT is essentially feasible. Furthermore, the development of preferential flow paths (i.e., channeling flow) was clearly demonstrated for multiple fractures, which is much more challenging to achieve by most other methods. Further progress in modeling should enable the in-situ evaluation of heterogeneous fracture flow within reservoir core samples, as well as the clarification of the impacts of the heterogeneity on the productivity of wells and, for example, the efficiency of recovery by water-/gasflooding.

Ex-chromate workers are frequently afflicted with lung cancers, especially central-type squamous cell carcinomas (SCCs) of the lung. However, little is known about the molecular and cellular biologic characteristics of chromate-induced lung cancers. We investigated expression of cyclin D1, bcl-2, and p53 proteins in chromate-induced lung cancers by immunohistochemistry, compared with those in lung cancers from nonexposed individuals and those in individuals with pneumoconiosis. Of 19 chromate-induced lung cancers, 16 tumors were SCCs, including 11 central and 5 peripheral types. Eleven (69%) of 16 chromate SCCs showed cyclin D1 expression. In contrast, cyclin D1 expression was observed in only 3 (12%) of 26 SCCs from nonexposed individuals and 6 (16%) of 37 SCCs that developed in patients with pneumoconiosis, respectively. The frequency of cyclin D1 expression proved to be significantly higher in chromate-induced SCCs than in SCCs from nonexposed individuals and from those with pneumoconiosis (P < .001). When comparisons were extended to all histologic types of lung cancer, cyclin D1 expression was observed significantly more often in chromate-induced lung cancers than in lung cancers from nonexposed subjects and those from patients with pneumoconiosis (11 [58%] of 19 v 5 [10%] of 52, P < .001, and 7 [11%] of 63, P < .001, respectively). Frequencies of bcl-2 and p53 expression were not significantly different among lung cancers from ex-chromate workers, nonexposed individuals and those with pneumoconiosis. The current study suggests that cyclin D1 expression may be involved in the development of chromate-induced lung cancers, although its underlying mechanism remains to be determined.

It has been reported that patients with pneumoconiosis occasionally have a diffuse interstitial fibrosis (DIF) that resembles interstitial pneumonia, but little is known about the relation between pneumoconiosis-associated DIF and the risk of lung cancer. In the present study, we evaluated the incidence of DIF by chest CT and its contribution to lung cancer in 563 patients with nonasbestos pneumoconiosis. Fifty-five (10%) of the 563 patients had DIF. Pneumoconiosis with DIF had an exceedingly high concurrence of lung cancers when compared with pneumoconiosis without DIF (29 [53%] of 55 versus 78 [15%] of 508, p < 0.001). Squamous cell carcinomas (SCCs) of the lung from pneumoconiosis with DIF exclusively comprised peripheral-types, as compared with SCCs from pneumoconiosis without DIF (13 [100%] of 13 versus 33 [72%] of 46, p = 0.03). In addition, lung cancers arose frequently from the area of DIF in pneumoconiosis with DIF (20 [74%] of 27). Furthermore, our pathologic examination revealed that dysplasias from pneumoconiosis with DIF were significantly more frequently observed in peripheral bronchioli than were dysplasias from pneumoconiosis without DIF (11 [69%] of 16 versus 20 [30%] of 66, p = 0.01). p53 expression evaluated by immunohistochemistry was frequently observed in dysplasias from pneumoconiosis with DIF, although it was not significantly different compared with that in dysplasias from pneumoconiosis without DIF (5 [50%] of 10 versus 12 [38%] of 32). Taken together, these results may suggest a positive causal relationship between pneumoconiosis and peripheral-type SCCs of the lung, and further indicate a pivotal role of diffuse fibrosis for the excess incidence of lung cancers, especially peripheral-type SCCs, in DIF-type pneumoconiosis.

Abstract A three dimensional numerical modeling coupled with X-ray Computed Tomography (CT) for fracture flow was applied to fractured granite core samples. One of the samples had an artificial single fracture, and the others had natural multiple fractures. A relationship between CT value and fracture aperture (fracture aperture calibration curve) was obtained by X-ray CT scanning for a fracture aperture calibration standard with varying the aperture from 0.1 to 0.5 mm. As a result, a linear relationship was obtained between CT value and fracture aperture. With the fracture aperture calibration curve, three dimensional distributions of CT values of the samples were converted into fracture aperture distributions to obtain fracture models of the samples. Porosities of the fracture models could provide good agreement with experimentally determined porosities for all the samples. By using the fracture models, a fluid flow simulation was also performed with a local cubic law-based fracture flow model. Numerical permeabilities by the flow simulation were much higher than experimentally determined permeabilities of the samples. It was however possible to match the numerical permeabilities with the experimental permeabilities for all the samples, by using a unique modification coefficient of 0.5 for the fracture aperture in the fracture flow model. With the modified flow model, it was possible to obtain detailed information of heterogeneities in fracture flow as well as permeabilities of the samples. Although the present X-ray CT scanning was performed at room temperature and pressure, it was expected that the numerical modeling had possibility to provide insights into heterogeneous nature of fracture flow in fractured reservoirs, such as channeling, as well as porosity and permeability, when the CT scanning was performed at reservoir conditions. Further studies on this kind of numerical modeling should provide simple and easy way to address heterogeneous fracture flow in reservoirs that can have impacts on productivity of wells, efficiency of recovery by water/gas flooding, and so on. Introduction Effective developments of oil/gas fractured reservoirs need well understanding of fracture flow characteristics in those reservoirs. Field and laboratory studies have suggested that fluid flow through a rock fracture is far from that of smooth parallel plates, due to channeling flow in a heterogeneous aperture distribution by rough surfaces [1–9]. When channeling flow occurs in a single fracture of granite, the area where flowing fluid exists is expected only 5–20% at confining pressures of up to 100 MPa, with various features in the preferential flow paths [9]. Against this background, we have recently developed a discrete fracture network model simulator, GeoFlow, in which fractures can have aperture distributions with natural heterogeneities [10]. Three dimensional fluid flow simulations for fracture networks by GeoFlow have demonstrated developments of three dimensional preferential flow paths in those fracture networks, and have suggested that performance of production well can be strongly affected by the heterogeneous fracture flow. Consequently, it should be considerably important to evaluate the heterogeneity and its impact for effective developments of fractured reservoirs.

Hydraulic fracturing using heavy brine was conducted to stimulate the deeper part of the completion interval in the naturally fractured reservoir, Yufutsu Japan. The microseismic monitoring and the temperature surveys showed that the deeper part was stimulated effectively as expected. The Yufutsu oil and gas reservoir is seated at around 4 km depth in the Southern Ishikari Plain, central Hokkaido, in northern Japan is known as a basement fractured reservoir. The water frac inducing shear dilation is one of the effective stimulation methods for the fractured reservoir. However it is difficult to stimulate the bottom part of the vertically long completion interval with seawater or slick water because the gradient of the fracture closure stress (that is typically 0.6-0.7 psi/ft, equivalent mud weight 1.4-1.6 sg) is commonly larger than that of the injection fluid. The heavy brine (CaCl2/CaBr2 brine 1.8 sg) realizes a pressure gradient larger than the fracture closure stress gradient that can stimulate deeper zone effectively. The numerical prediction using "SHIFT" simulator shows consistent results with the above-mentioned considerations. SHIFT simulates shearing of fractures and related permeability changes in a dynamic process by coupling analyses of the fluid flow and the shear dilation along fractures. The target well has a long completed interval of 700 m. The deeper part of this well showed poor productivity due to a damage of lost circulation materials. The fracturing operation using the 1.8 sg CaCl2/CaBr2 brine was conducted with the objective to stimulate the damaged zones. About 200kL of heavy brine was injected. The microseismic array sensor was installed in the adjacent well to monitor the stimulation during the injection. Approximately a thousand microseismic events were observed during the injection. The location of the microseismic events showed that the deeper part was stimulated effectively. A temperature survey conducted after the stimulation revealed the new production zones appeared on the temperature profiles as anomalies which had not been seen before. The AOFC of the well increased by a factor of 1.5.

To explore the mechanism by which lung cancers excessively arise from pneumoconiosis, we determined the altered expression of p53 and Bcl-2 by immunohistochemistry (IHC) in lung cancers, dysplasias and non-cancerous pulmonary epithelia in pneumoconiotics in comparison with those from non-pneumoconiotic patients. We examined p53 expression in squamous cell carcinomas (SCCs) and dysplasias separately in the central and peripheral zones of bronchial trees, based on observations that SCCs from pneumoconiotic patients occurr more frequently in peripheral epithelia than those from non-pneumoconiotic patients (55 of 72 SCCs with pneumoconiosis vs. 33 of 72 SCCs without pneumoconiosis). Forty-one of 72 patients with pneumoconiosis-related lung cancers had altered p53 expression, which was comparable to the positivity of p53 expression in lung cancers without pneumoconiosis. p53 expression was observed significantly more frequently in bronchiolar dysplasias with pneumoconiosis than in those from non-pneumoconiotic patients (13 of 23 vs. 4 of 22), while p53 expression was found in bronchial dysplasias with pneumoconiosis as frequently as those without pneumoconiosis. Moreover, in patients with pneumoconiosis, bronchiolar dysplasias exhibited p53 expression more frequently than bronchial dysplasias (13 of 23 vs. 4 of 19). When comparison was restricted to bronchiolar dysplasias from patients without lung cancer, p53 expression had a strikingly higher frequency in the dysplasias with pneumoconiosis than in those from non-pneumoconiotic patients (8 of 15 vs. 0 of 14). Bcl-2 occasionally was expressed in squamous metaplasias and basal cell hyperplasias, in contrast to p53, for which immunostaining was negative in these lesions. Altogether, our results show that pre-cancerous and/or cancerous targets in pneumoconiosis may be distributed over a more peripheral zone than those in patients without pneumoconiosis. Int. J. Cancer 75:504–511, 1998.© 1998 Wiley-Liss, Inc.

麻痺性ポリオ症候群paralytic poliomyelitis syndromeは,その原因としてポリオウイルスが広く知られているが,他の腸管系ウイルスや,ムンプスウイルス,ヘルペスウイルスなどのウイルスによつても発症する.コクサッキーA群ウイルスによつて麻痺を呈する例は,比較的少なく,とくにA2型によると確定診断されたものは,本邦では報告がない.われわれは, 27才男性で,感冒様症状をもつて発症し,四肢の弛緩性麻痺および顔面神経,舌咽神経,迷走神経麻痺を呈し, 2カ月後には,ほぼ正常にまで回復した症例を経験した.原因にかんしては,血清学的にコクサッキーウイルスA2型に対する中和抗体価の有意の上昇を認め,さらに便,髄液中から同型ウイルスを同定し,コクサッキーウイルスA型によつて発症したものと診断した.

甲状腺腫穿刺細胞診の診断率は他の臓器に比して必ずしも高率とは言い難く, 良性・悪性の鑑別の困難なことが多い. 悪性細胞の特性をより客観的な指標でとらえるために, 甲状腺腫穿刺吸引細胞の核内Feulgen DNA量を測定し, そのヒストグラムパターンより, 良性甲状腺腫と悪性甲状腺腫の差異について比較検討した. 良性甲状腺腫の穿刺吸収細胞の核内Feulgen DNA量のヒストグラムは2c域に主分布がみられるパターンで4c域を越える細胞の出現頻度は12%を示した良性濾胞腺腫の1例を除いて全例4%以下であった. 悪性甲状腺癌の穿刺吸引細胞の核内Feulgen DNA量のヒストグラムは3c域に主分布がみられ, 広範囲に分布するパターンを示した. 4c域を越える細胞の出現頻度も39～60%と多く, 良性疾患とはまったく異なるヒストグラムパターンを示した. 核内Feulgen DNA量の測定により, 細胞診で比較的判定困難な場合でも, ヒストグラムパターンを分析することにより良性・悪性の区別が可能であることが示された.

クロム粉塵の吸入, 喫煙の継続によって生じた気管支異型上皮細胞の可逆性について, 喀痰細胞診で追求した.非喫煙者ではクロム粉塵暴露中止後、約5年の経過の後, 中等度以上の異型細胞は喀痰中に検出されなくなった.禁煙者では喫煙中止後, 約3年の経過の後, 中等度以上の異型細胞は検出されなくなった.気管支異型上皮には可逆性があり, 比較的短期間で修復されることが示された.禁煙が肺癌発生減少の大きな要因となろう.

クロム肺癌に発癌の関与する物質を検討するため, クロム酸塩製造工程別の従事期間を肺癌例と非癌例で検討した.肺癌例は6価クロムを取り扱う従事者に多かった.特に, 小細胞癌例では全従事期間のほとんど全てを水溶性の6価クロムを取り扱う工程に従事していた.クロム肺癌の発癌物質として, 水溶性の6価クロムが関与している可能性が示された.

The intensity of gallium-67 scintiscans, lymphocyte counts in bronchoalveolar lavage fluid, and pathologic changes were studied in 26 patients with untreated pulmonary sarcoidosis. Noncaseating granulomas were recognized with significantly greater frequency in stage 2 (80 percent; 8/10 cases) than in stage 1 (43 percent; 6/14 cases). Alveolitis showed little relation to the roentgenographic stage. There was a strong correlation between the intensity of gallium uptake in pulmonary parenchyma and the detection rate of granuloma; however, the detection rate of alveolitis was not statistically different from the intensity of gallium uptake. A highly significant correlation was revealed between the lymphocyte counts in bronchoalveolar lavage fluid and the intensity of alveolitis. These observations suggest that the gallium uptake reflects mainly the presence of granuloma, and the lymphocyte count in bronchoalveolar lavage fluid reflects the intensity of alveolitis in patients with pulmonary sarcoidosis.

クロムエ場従業員よりの3例の多発性肺癌-両側性-を経験した.内, 2例は両肺に生じた扁平上皮癌例であり, 1例は左肺に小細胞癌, 右肺に扁平上皮癌の同時発生例であった.扁平上皮癌両側発生例の内1例は手術を行った.1例は生前に診断を得たが病期が進行していたため死亡し、最後の例と共に剖検により子細に検索し得た.昭和56年春までにクロム工場従事者303名中, 21例の肺癌を見出し, この内, 剖検, 手術の可能な例8例であった.肺癌発生率の高頻度, また症例のような多発性肺癌を生ずることよりクロム塩類の強力な発癌性が示唆された.

The manufacturing process of the chromate industry can be classified into five steps. The main hazardous pollutants of the first step are trivalent chromate compounds, and those of the second and third steps are hexavalent chromate compounds. Analysis of the detailed working history of chromate workers with bronchogenic carcinoma, yielded the following results: the work history of chromatic lung cancer patients in the first step, which produced mainly trivalent chromate dust, was rather short. Patients with small cell carcinoma were engaged mainly in the second step (98.1% of the total working months), where they were heavily exposed to hexavalent chromate dusts. Patients with squamous cell carcinoma were engaged rather evenly in the second and fourth steps, and somewhat longer in the third step. Comparisons of the exposure periods revealed that the working history of small cell carcinoma patients was significantly shorter than that of squamous cell carcinoma patients. There were many more heavy smokers among the squamous cell carcinoma group as compared to the small cell carcinoma patients. Based on these results, it is concluded that the cell type of occupational lung cancer was mainly small cell carcinoma when the exposure to carcinogenic agents was heavy, and that the carcinogenicity of chromate was derived mainly from hexavalent chromate rather than trivalent compounds.

A 24-year-old truck driver was admitted for evaluation of an abnormal shadow in the lung found on a routine chest roentgenogram. There were no complaints referable to his chest. Past history revealed that a diagnosis of left-sided pulmonary tuberculosis had been made when he was 13 years of age. Physical examination revealed a well nourished, well developed young man. The chest cage was symmetrical. Respiratory sounds were diminished over the left upper chest anteriorly. No rales were audible. Results of blood counts and blood chemistry examinations were normal. Lung function tests revealed normal vital capacity and normal maximal voluntary ventilation, 112 percent and 105 percent of predicted values respectively, and slight decrease of FEV1/FVC of 79 percent. There were no abnormal values of DLCOSB and lung mechanics.