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As a response to the Tokyo Electric Power Company's Fukushima Daiichi nuclear power plant accident in 2011, seven TEPCO workers whose exposure doses were expected to be >250 mSv (a tentative dose limit stipulated by the Japanese central authority) attended Japan's National Institute for Radiological Sciences for additional internal dose measurements. The National Institute for Radiological Sciences examination revealed that these workers' internal doses came mainly from their intake of the radionuclide I during emergency operations. In this study, we performed numerical simulations based on individual volume-pixel (voxel) phantoms of six of the seven workers for a more sophisticated evaluation of their internal doses, taking into account the individual thyroid size and other specific parameters. The voxel phantoms were created from magnetic resonance imaging scan images. As a result, the individual thyroid volumes ranged from 6.5 to 28.2 cm and were considerably smaller than the reference value (~20 cm) adopted in the International Commission on Radiation Protection's dosimetric model for four of the six subjects. Compared to the original estimates of the thyroid absorbed dose, our preliminary evaluation revealed values that were increased by approximately 3-fold or decreased by 30% at maximum. A wide difference in the individual thyroid size would be one of the significant modifiers in the current dose estimation of subjects of the ongoing epidemiological study project. The present simulations also provided evidence that the direct thyroid measurements by the National Institute for Radiological Sciences to determine the workers' I thyroid contents were sufficiently accurate.

As a response to the Tokyo Electric Power Company’s (TEPCO’s) Fukushima Daiichi Nuclear Power Plant (FDNPP) accident in 2011, seven TEPCO workers whose exposure doses were expected to be > 250 mSv (a tentative dose limit stipulated by the Japanese central authority) attended Japan’s National Institute for Radiological Sciences (NIRS) for additional internal dose measurements. The NIRS examination revealed that these workers’ internal doses came mainly from their intake of the radioisotope iodine-131 (131I) during emergency operations. In this study we performed numerical simulations based on individual volume-pixel (voxel) phantoms of six of the seven workers for a more sophisticated evaluation of their internal doses, taking into account the individual thyroid size and other specific parameters. The voxel phantoms were created from magnetic resonance imaging (MRI) scan images. As a result, the individual thyroid volumes ranged from 6.5 to 28.2 cm3, and were considerably smaller than the reference value (~20 cm3) adopted in the International Commission on Radiation Protection’s (ICRP’s) dosimetric model for four of the six subjects. Compared to the original estimates of the thyroid absorbed dose, our preliminary evaluation revealed values that were increased by approx. threefold or decreased by 30% at maximum. A wide difference in the individual thyroid size would be one of the significant modifiers in the current dose estimation of subjects of the ongoing epidemiological study project. The present simulations also provided evidence that the direct thyroid measurements by the NIRS to determine the workers’ 131I thyroid contents were sufficiently accurate.

To evaluate the chest CT findings in an environmentally homogeneous cohort from the cruise shipThis retrospective study comprised 104 cases (mean age, 62 years ± 16 [standard deviation], range, 25-93 years) with COVID-19 confirmed with reverse-transcription polymerase change reaction findings. CT images were reviewed, and the CT severity score was calculated for each lobe and the entire lung. CT findings were compared between asymptomatic and symptomatic cases.Of 104 cases, 76 (73%) were asymptomatic, 41 (54%) of which had lung opacities on CT. Twenty-eight (27%) cases were symptomatic, 22 (79%) of which had abnormal CT findings. Symptomatic cases showed lung opacities and airway abnormalities on CT more frequently than asymptomatic cases [lung opacity; 22 (79%) vs 41 (54%), airway abnormalities; 14 (50%) vs 15 (20%)]. Asymptomatic cases showed more ground-glass opacity (GGO) over consolidation (83%), while symptomatic cases more frequently showed consolidation over GGO (41%). The CT severity score was higher in symptomatic cases than asymptomatic cases, particularly in the lower lobes [symptomatic vs asymptomatic cases; right lower lobe: 2 ± 1 (0-4) vs 1 ± 1 (0-4); left lower lobe: 2 ± 1 (0-4) vs 1 ± 1 (0-3); total score: 7 ± 5 (1-17) vs 4 ± 2 (1-11)].This study documented a high incidence of subclinical CT changes in cases with COVID-19. Compared with symptomatic cases, asymptomatic cases showed more GGO over consolidation and milder extension of disease on CT.An earlier incorrect version appeared online. This article was corrected on April 8, 2020.© RSNA, 2020.

This article introduces the first accident of internal contamination with plutonium (Pu) or americium (Am) in Japan for which treatment was carried out. An accident of internal contamination with Pu and Am occurred at a Pu research facility at Oarai-town of Ibaraki prefecture in Japan. A plastic bag containing these radionuclides ruptured when five workers were inspecting a storage container in a hood. As a consequence, these workers were internally contaminated with Pu and Am. Although contamination on the body surface was observed in all five workers, a positive nasal swab was detected in only three of them. A chelating agent, calcium diethylenetriaminepenta-acetate (CaDTPA), was administered to all of them including the two workers without a positive nasal swab. However, bioassay detected a significant amount of Pu and Am in urine after administration of DTPA in these two workers, whereas the levels of these nuclides were below minimum detectable levels in urine before the administration. Since the prevalence of adverse reactions in DTPAs is low, the present results suggest that administration of DTPA can be used for the diagnosis of internal contamination even when a nasal swab is negative or contamination around body orifices is not detected.

This study revealed a high incidence of subclinical CT changes in COVID-19 infected cases, which showed more ground-glass opacity predominance over consolidation and milder severity on CT than in s...

This article introduces the first accident of internal contamination with plutonium (Pu) or americium (Am) in Japan for which treatment was carried out. An accident of internal contamination with Pu and Am occurred at a Pu research facility at Oarai-town of Ibaraki prefecture in Japan. A plastic bag containing these radionuclides ruptured when five workers were inspecting a storage container in a hood. As a consequence, these workers were internally contaminated with Pu and Am. Although contamination on the body surface was observed in all five workers, a positive nasal swab was detected in only three of them. A chelating agent, calcium diethylenetriaminepenta-acetate (CaDTPA), was administered to all of them including the two workers without a positive nasal swab. However, bioassay detected a significant amount of Pu and Am in urine after administration of DTPA in these two workers, whereas the levels of these nuclides were below minimum detectable levels in urine before the administration. Since the prevalence of adverse reactions in DTPAs is low, the present results suggest that administration of DTPA can be used for the diagnosis of internal contamination even when a nasal swab is negative or contamination around body orifices is not detected.

The effect of inhalation of hydrogen-containing gas (1.3% hydrogen + 20.8% oxygen + 77.9% nitrogen) (HCG) on radiation-induced dermatitis and on the healing of healing-impaired skin wounds in rats was examined using a rat model of radiation-induced skin injury. An X-ray dose of 20 Gy was irradiated onto the lower part of the back through two holes in a lead shield. Irradiation was performed before or after inhalation of HCG for 2 h. Inhalation of HCG significantly reduced the severity of radiodermatitis and accelerated healing-impaired wound repair. Staining with terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) and 8-hydroxy-2(')-deoxyguanosine (8-OHdG) showed that the proportion of apoptotic keratinocytes and the level of staining in the X-irradiated skin of rats that pre-inhaled HCG were significantly lower than that of rats which did not pre-inhale HCG. Cutaneous full-thickness wounds were then created in the X-irradiated area to examine the time-course of wound healing. X-irradiation significantly increased the time required for wound healing, but the inhalation of HCG prior to the irradiation significantly decreased the delay in wound healing compared with the control and post-inhalation of HCG groups. Therefore, radiation-induced skin injury can potentially be alleviated by the pre-inhalation of HCG.

A 60-year-old man with a 7-year history of multiple pulmonary nodules presented to our hospital because the nodules were seen to have increased in size on review of films on a regular medical checkup 1 week earlier. Computed tomography (CT) revealed multiple pulmonary nodules with calcification in the lungs. The largest nodule measuring 2.5 cm in the maximum dimension was lobulated and ill-defined. The patient underwent 18F-fluorodeoxyglucose positron emission tomography/CT (18F-FDG-PET/CT) to evaluate the multiple nodules and to search for a primary lesion. 18F-FDG-PET/CT revealed increased uptake in only two nodules with a standardized uptake value of 4.61 and 2.10, respectively. The two foci with increased 18F-FDG uptake were resected and pathologically proven to be pulmonary epithelioid hemangioendothelioma (PEH). PEH can transform into malignancy with metastasis. An 18F-FDG-PET/CT finding may be an indicator to decide on PEH resection.

The objective of this study was to assess the cost-effectiveness of antithyroid drug (ATD) therapy vs. radioiodine therapy (RIT) vs. subtotal thyroidectomy (STT) by calculating expected lifelong cost and utility based on Graves' disease patients' responses to questionnaires using a decision-tree sensitivity analysis and relevant variables. The decision-tree sensitivity analysis to determine expected lifelong cost and utility in Graves' disease patients was designed on the basis of the 4 competing strategies consisting of: (1) ATD therapy plus RIT strategy, (2) ATD therapy plus STT strategy, (3) low-fixed-dose (185 MBq) RIT alone strategy, and (4) high-fixed-dose (370 MBq) RIT alone strategy. One-way sensitivity analysis was designed in the ATD therapy plus RIT strategy, for replacement with RIT in place of ATD, ranging from a 100 incidence of ATD side effects to 30%. The low-fixed-dose RIT alone strategy was least costly, and the high-fixed-dose RIT alone strategy most costly. The lifelong utility of high-fixed-dose RIT alone strategy with a 5% rate of discounting was highest (lifelong utility for 30 years : 15.2/patient), and the utility of the ATD plus RIT strategy with 100 side effects of the ATD was lowest (14.1/patient) . The cost-effectiveness ratio was lowest (\5 008/utility) in a low-fixed-dose RIT alone strategy. In conclusion, a low-fixed-dose RIT alone strategy is preferred treatments in view of cost-effectiveness ratio, and RIT should be used more widely in Japan.

Incorporating mediastinoscopy (MS) into the PET-based strategy for non-small cell lung carcinoma (NSCLC) patients might be cost-effective because MS can allow unnecessary thoracotomies to be avoided. The objective of our study was to assess the cost-effectiveness of incorporating MS into a PET strategy for NSCLC patients.To determine life expectancy (LE), quality adjusted life years (QALY), and the incremental cost-effectiveness ratio (ICER), a decision-tree sensitivity analysis was designed for histopathologically confirmed NSCLC patients with M0 disease, based on the three competing strategies of chest CT only vs. PET + CT vs. PET + CT + MS. A simulation of 1000 NSCLC patients was created using baselines of other relevant variables in regard to sensitivity, specificity, mortality, LE, utilities and cost from published data. One-way sensitivity analyses were performed to determine the influences of mediastinal metastasis prevalence on LE, QALY and ICER.The LE and QALY per patient in the CT only strategy, PET + CT strategy and PET + CT + MS strategy were 4.79 and 4.35, 5.33 and 4.93 and 5.68 and 5.33 years, respectively, with a 20% prevalence of mediastinal metastasis. The ICERs were 906.6 yen x 10(3) (7555 US dollars)/QALY/patient at a 20% mediastinal metastasis prevalence, and 2194 yen x 10(3) (18,282 US dollars)/QALY/patient at a 50% prevalence, but exceeded 5280 yen x 10(3) (44,000 US dollars)/QALY/ patient at 80%.Our study quantitatively showed the CT + PET + MS strategy in place of the PET + CT strategy in managing NSCLC patients to be cost-effective. MS should be incorporated into the PET + CT strategy for NSCLC patients except in those highly suspected of having mediastinal disease on chest CT or PET.

This is the first laboratory evaluation of a new instrument, designed to test both platelet function and thrombolytic activity from a native blood sample, in vitro. The inventor assumed that the reduction and arrest of blood flow was due to activation, aggregation and stabilized thrombus formation by shear-activated platelets, and that re-establishment of flow was due to thrombolysis. Morphologic and functional studies presented here confirm these mechanisms. In vitro tests provided incontestable evidence for the principal role of platelets in the obstruction of flow (occlusion time) and for thrombolysis as the principal mechanism underlying the restoration of blood flow (lysis time). In addition to aggregation, it is the explosive generation of thrombin by shear-activated platelets that results in the formation of an occlusive haemostatic thrombus. Anticoagulation of blood completely prevented occlusion. Platelet-rich thrombus formation (occlusion time) was dose-dependently inhibited by monoclonal antibody against platelet glycoprotein (GP) Ib (6B4 and 12E4), aurin tricarboxylic acid, monoclonal antibody against platelet GPIIb/IIIa (MA-16N7C2 and abciximab), a synthetic GPIIb/IIIa antagonist (TAK-029), thrombin inhibitor (argatroban), and anti-von Willebrand factor, but not by anti-fibrinogen. Plasminogen activator streptokinase (Varidase) and tissue-type plasminogen activator (Monteplase) dose-dependently enhanced thrombolysis (lysis time) without affecting platelet function (occlusion time). The test is specific for thrombolysis. The plasmin inhibitor tranexamic acid prevented plasminogen activator-induced thrombolysis, while inhibition of clot retraction by cytochalasin B did not affect the lysis time. This rapid and sensitive global test of platelet function and thrombolytic activity could be of great value both in research and in clinical practice.

Binding of the purified type C 7S (neurotoxin), 12S and 16S botulinum toxins to epithelial cells of ligated small intestine or colon of the guinea pig (in vivotest) and to pre-fixed gastrointestinal tissue sections (in vitrotest) was analysed. The 16S toxin bound intensely to the microvilli of epithelial cells of the small intestine in bothin vivoandin vitrotests, but did not bind to cells of the stomach or colon. The neurotoxin and 12S toxin did not bind to epithelial cells of the small intestine or to cells of the stomach or colon. Absorption of the toxins was assessed by determining the toxin titre in the sera of guinea pigs 6-8 h after the intra-intestinal administration of the toxins. When the 16S toxin [1 x 105minimum lethal dose (MLD)] was injected, 200-660 MLD ml-1was detected in the sera, whereas when the 12S toxin (2 x 105MLD) or 7S toxin (2 x 105MLD) was injected, little toxin activity was detected in the sera. Therefore, the haemagglutinin of type C 16S toxin is apparently very important in the binding and absorption of botulinum toxin in the small intestine.

Effective, therapeutic thrombolysis should not only promote dissolution of fibrin but should also regulate continued thrombin-induced fibrin formation and the accumulation of platelets on the thrombotic lesion. The aim of the present study was to assess the use of a synthetic, low molecular weight thrombin inhibitor, argatroban in association with a well defined thrombolytic agent in a reproducible animal model of thrombolysis in vivo . Thrombi were formed in rat mesenteric venules with a helium neon (He-Ne) laser in the presence of Evans blue and were stabilised for 10 minutes. Thrombi formed in this manner were shown by transmission electron microscopy to be composed mainly of platelets. Thrombolysis was induced with recombinant staphylokinase in the presence and absence of argatroban and the process was monitored using computerised image analysis. Co-infusion of argatroban at a dose of 2.0mg/kg/h with staphylokinase significantly enhanced the rate of thrombolysis. The results suggested that administration of the thrombin inhibitor together with the fibrinolytic agent moderated platelet-dependent mechanisms and led to a more rapid restoration of blood vessel patency. © 1997 Elsevier Science Ltd

The middle ear is derived from various embryonic tissues. Many experiments using teratogens have been performed, employing the difference of each tissue's sensitivity to the teratogen and the tissue's critical time of development. Triazene, a foliate metabolism antagonist, produced anomalies in fetuses that resembled those associated with thalidomide in humans, the so-called the first and second branchial syndrome. In our experiment, we administrated 3,3-dimethyl-1-phenyltriazene, an inductor of triazene, to pregnant mice at 7 to 14 days of gestation resulting in unique fetal anomalies. We examined the development of the stapes, stapedial artery, facial nerve, and oval window using an optical microscopic and three-dimensional reconstruction. Middle ear and facial nerve anomalies in mice depend on the gestation day when triazene is administrated. The stapedial artery, oval window, facial nerve (horizontal segment), stapes footplate, and styloid process are affected on the 9th to 11th administration day, the annular stapedialis on the 10th to 11th day, and the malleus and incus on the 9th to 11th day. The use of the Vox View/Mac, allowed us to create three-dimensional pictures from two-dimensional slides providing an improved understanding of the relationships between anatomical structures.

To investigate the possible role of manganese superoxide dismutase (Mn-SOD) in steroidogenesis, we studied the expression of Mn-SOD mRNA in the adrenal gland and ovaries of normal and hypophysectomized rats by in situ hybridization. Very strong expression of Mn-SOD mRNA was detected in the zona fasciculata and the zona reticularis of the rat adrenal cortex. The expression was very low in the zona glomerulosa, and was almost negative in the adrenal medulla. The mRNA levels in the adrenal cortex and the ovaries were markedly reduced 4 days after hypophysectomy. Marked adrenocortical atrophy occurred 14 to 24 days after the operation, while levels of Mn-SOD mRNA in the cortex remained low. Mitochondrial structure in the fasciculata cells of normal and hypophysectomized rats were compared by electron microscopy. Mitochondria in the fasciculata cells of normal rats were characterized by dense vesicular Cristae. Four days after hypophysectomy, the cristae became tubulo-vesicular in form and their density decreased significantly. Elongated mitochondria with tubular cristae appeared. Oval mitochondria with a few tubulo-vesicular cristae were present in these cells 14 days after the operation. Our results are consistent with the hypothesis that high Mn-SOD levels might play an important role in the regulation of steroidogenesis. The possible roles of superoxide radicals and hydrogen peroxide in the formation of vesicular cristae in the mitochondria are discussed with respect to steroidogenesis.

Transitional epithelium of mammalian urinary bladder is a functional barrier which prevents passage of urine into the submucosa. In a previous study, we found uptake by the epithelial cells of horseradish peroxidase (HRP) instilled into the mouse bladder lumen. In the present study, the ability of bladder epithelial cells to take up HRP, which was visualized by the diaminobenzidine (DAB) reaction, was compared among several mammalian species by light and electron microscopy. In mouse, rabbit and dog bladder, the superficial cells of the transitional epithelium showed positive reactions for HRP, while cells in lower epithelial layers were DAB-negative. Some of the reaction products could be seen as a number of granules not surrounded by a membrane. The intercellular space of the epithelium was DAB-negative. In rat and guinea pig bladder, however, all urothelial cells showed negative reactions for HRP indicating that no uptake of HRP had been occurred in these animals. These results indicate that the uptake of HRP by the superficial cells of the bladder epithelium differs among mammalian species, indicating some functional differences in their superficial cells.

To determine the possible involvement of reactive oxygen species in ovulation, dynamic aspects of superoxide dismutase (SOD) isozyme were studied in the ovaries of rats by in situ hybridization histochemistry. Previously, mRNA levels of ovarian manganese superoxide dismutase (Mn-SOD) were reported markedly to increase whilst enzymic activity of Mn-SOD decreased during the ovulatory process after treating immature rats with 10 and 5 Units, respectively, of pregnant mare serum gonadotrophin (PMSG) and human chorionic gonadotrophin (HCG). Levels of Cu/Zn-SOD activity and Cu/Zn-SOD mRNA were reported to remain unchanged throughout ovulation. This increase in the Mn-SOD mRNA level was shown in the present study by in situ hybridization to be localized to the theca interna cells throughout the PMSG/HCG-induced ovulatory process. The observations suggest that the turnover rate of Mn-SOD but not Cu/Zn-SOD increases specifically in the mitochondria of these cells. SOD has been postulated to play important roles in steroidogenesis. The relationship is discussed between mitochondrial functions in steroid-secreting cells and superoxide radicals and related metabolite(s).

A questionnaire survey was performed to investigate the possible presence of self-selection bias in 18F-FDG PET cancer screening (PET cancer screening). Responders to the questionnaires survey consisted of 80 healthy persons, who answered whether they undergo PET cancer screening, health consciousness, age, sex, and smoking history. The univariate and multivariate analyses on the four parameters were performed between the responders who were to undergo PET cancer screening and the responders who were not. Statistically significant difference was found in health consciousness between the above-mentioned two groups by both univariate and multivariate analysis with the odds ratio of 2.088. The study indicated that self-selection bias should exist in PET cancer screening.

The national health reimbursement in 131I internal therapy for thyroid cancer and Graves' disease has increased by introducing the DPC package payment system. The thyroid cancer administration fee for shield room should be increased because of the strict regulation for 131I internal therapy, expensive equipments, confinement of radiopharmaceutical supply, and low efficiency in admission to shield rooms. In addition, the Graves' disease administration fee for shield room should be introduced since the inpatients undergo the same administration and care as the thyroid cancer inpatients.

We observed by immunofluorescence microscopy the distribution of cytoskeletal filaments in the superficial cells (SP cells) of rat urinary bladder epithelium in a distending state. To precisely detect SP cell fluorescence, the cells were separated from the distended bladder epithelium by scraping with a glass slide after paraformaldehyde fixation. Each cell appeared characteristically polygonal and flattened. In these cells, F-actins were predominantly distributed at the lateral cell border, marking the cell boundary. They also formed fine networks in the inner cytoplasm. Cytokeratin filaments were distributed in two characteristic patterns: they marked cell boundaries as did F-actin, and they formed thick circular bundles between the nucleus and cell margin. These two types of keratin filaments were also connected by thin filaments. These cytokeratins contained at least cytokeratin 18 subunit. Numerous microtubules were distributed evenly in the cytoplasm forming fine networks, except near the cell periphery.These observations show that SP cells are supported mainly by cytokeratin networks.

Previously, we found abundant filaments consisting of actin and cytokeratin in nonciliated bronchiolar epithelial (Clara) cells by treating the cells with detergent-containing medium. In this study, the presence of the filaments and the expression of actin mRNA in Clara cells of perinatal rats were investigated by electron microscopy and in situ hybridization, respectively. Clara cells in prenatal rat were characterized by the presence of glycogen and the absence of electron-dense granules. Detergent treatment did not clarify the presence of filaments in prenatal cells. After birth, there was a rapid loss of glycogen and electron-dense secretory granules appeared in the cytoplasm of Clara cells. Filaments could be recognized by detergent treatment. By the 3rd postnatal day, some Clara cells showed features similar to the cells in adult rats. To investigate whether these filaments demonstrated by detergent treatment were synthesized during the postnatal period, the localization of actin mRNA was observed using an in situ hybridization technique. Signals showing the presence of actin mRNA were observed in many cells at every stage of development. In the prenatal period, the signals were distributed diffusely in the epithelial cells of the bronchioles, but in the postnatal period, they appeared in Clara cells selectively. These results show that the actin filaments observed in the apical caps of Clara cells are synthesized during the postnatal period when Clara cells are thought to become mature.

Purpose: The purpose of this study was to reassess whether the Honda sign (HS) and its variants on bone scans can be used to differentiate an insufficiency fracture (IF) of the sacrum from a metastasis and to evaluate extrapelvic tracer accumulation in patients suspected of having a sacral IF. Methods and Materials: We retrospectively reviewed 34 bone scans of 26 patients suspected of having a sacral IF between January 1998 and June 2003. Results: Twenty-four of the patients had a sacral IF and 1 had a sacral metastasis from prostate cancer and another from lung cancer. The bone scans of only 15 (63%) of the 24 patients with a sacral IF exhibited the HS, 8 (33%) scans exhibited variants, and 4 (4%) scans showed whole-sacrum uptake. One of the 2 patients with metastasis exhibited the HS and the other exhibited a variant. The sensitivity and positive predictive value of HS plus its variants as diagnostic criteria for sacral IF were 96% and 92%, respectively. Seventeen patients (71%) had extrasacral accumulation. The most common site was the pubic bone (50%, 12 of 24), and the second most common site was the spine (46%, 11 of 24), where the accumulation was the result of a compression fracture or degenerative joint disease of the spine. Conclusions: A "Honda sign or variation" with evidence of fractures elsewhere or no evidence of other metastatic disease should be strong evidence for a sacral insufficiency fracture. The likelihood of having a solitary metastasis to the sacrum is small.

The inpatient DPC package payment system lowers national insurance reimbursement as compared to the former fee-for-service payment system for inpatients, when an inpatient with hyperthyroidism or toxic multinodular goiter (TMNG) is admitted for 2-day radioiodine therapy. The differentials are 29,970 yen and 48,870 yen for a 2-day hospital stay for administration of 555 MBq and 925 MBq, respectively. We request the Health and Labor Ministry to newly establish the fee for 131I internal therapy for hyperthyroidism. Furthermore, the fee should be paid according to the fee-for-service payment system.

Successful administration of thrombolytic agents is associated with vessel reocclusion in a high proportion of cases. We have previously established an animal model to investigate platelet-rich thrombolytic mechanisms in vivo and demonstrated that recombinant staphylokinase (rSAK)-induced thrombolysis was enhanced by the concomitant administration of the direct thrombin inhibitor argatroban. The present study expanded the use of this model by comparing arterial and venous thrombolysis using advanced image analysis software. Mural thrombi were formed by Helium-Neon laser irradiation in mesenteric arterioles and were shown to be lysed, dose-dependently, by smaller amounts of rSAK than those required in venules. Activated protein C (APC), as well as argatroban, enhanced the rSAK-induced thrombolysis. APC or argatroban also induced thrombolysis in the absence of rSAK, and the effect was inhibited by tranexamic acid. The enhanced thrombolysis induced by APC or argatroban in the presence or absence of rSAK may be due to increased endogenous thrombolysis mediated by the inhibition of thrombin activity or delayed thrombin generation.

The change in thrombus mass during thrombolytic therapy is thought to be the difference between its growth and its degradation induced by thrombolytic agents. Platelets play a pivotal role in arterial thrombosis and bind to each other and to exposed subendothelial matrices via adhesive proteins such as von Willebrand Factor, fibrinogen, and fibronectin. The aim of the present study was to assess whether administration of antibodies against these adhesive proteins, in conjunction with plasminogen activator, could enhance the degradation of platelet-rich thrombus. Mural platelet-rich thrombi were formed in rat mesenteric venules using He-Ne laser irradiation. Recombinant staphylokinase was infused continuously and polyclonal antibodies against adhesive proteins were given by bolus injection. The thrombolytic process was analysed using computer-enhanced image analysis software. Administration of each of the antibodies enhanced staphylokinase-induced thrombolysis.

The effects of exercise and catecholamines on platelet reactivity or coagulation and fibrinolysis appear to be inconsistent. This may be partly due to the methods employed in previous studies. In the present study, we investigated the effects of acute aerobic exercise and catecholamines on the thrombotic status by a novel in vitro method, shear-induced hemostatic plug formation (hemostatometry), using nonanticoagulated (native) blood. Aerobic exercise (60% maximal O2consumption) was performed by healthy male volunteers for 20 min, and the effect on platelet reactivity and coagulation was assessed by performing hemostatometry before and immediately after exercise. Exercise significantly increased shear-induced platelet reactivity, coagulation, and catecholamine levels. The effect of catecholamines on platelet reactivity and coagulation was assessed in vitro by adding catecholamines to blood collected in the resting state. The main findings of the present study are that elevation of circulating norepinephrine at levels that are attained during exercise causes platelet hyperreactivity and a platelet-mediated enhanced coagulation. This may be a mechanism of an association of aerobic exercise with thrombotic risk.

Minota, Shoichi and Sadahiro Watanabe. Inhibitory effects of arachidonic acid on nicotinic transmission in bullfrog sympathetic neurons. J. Neurophysiol. 78: 2396–2401, 1997. Arachidonic acid (AA, 0.2–40 μM) reversibly reduced the amplitude of the fast excitatory postsynaptic potentials and the underlying currents (fast EPSCs) of bullfrog sympathetic neurons evoked by preganglionic nerve stimulation in a Ca2+-deficient solution. AA reduced the acetylcholine (ACh)-induced nicotinic currents (n IACh) evoked by brief applications of ACh to the ganglion cells in a dose-related manner. AA reduced the maximum amplitude of n IAChestimated from the dose-response relationship without causing an appreciable change in the apparent dissociation constant. Indomethacin (2 μM) and nordihydroguaiaretic acid (20 μM), blockers of cyclooxygenase and lipoxygenase pathways, respectively, had no effect on the inhibition of fast EPSC by AA. AA did not obviously affect the preganglionic nerve terminal spike configuration, synaptic delay, facilitation, quantal content of transmitter release, or the presynaptic long-term potentiation elicited by the repetitive stimulation applied to the preganglionic nerve fibers. These results suggest that AA acts on an allosteric site of the nicotinic receptor-channel complex either directly or indirectly and in turn inhibits ion permeation through these channels without affecting the release of ACh from preganglionic nerve terminals.

Expression of managanese superoxide dismutase (Mn-SOD) mRNA during the pregnant mare serum gonadotrophin (PMSG)/human chorionic gonadotrophin (HCG)-induced ovulatory process, and during the estrous cycle was examined in rat female reproductive organs. Mn-SOD mRNA levels in theca interna cells markedly increased in PMSG-primed rats and high levels of the transcripts were maintained after HCG injection. The PMSG-enhanced expression of Mn-SOD mRNA in follicular epithelial cells increased concomitantly with luteinization of these cells. The levels of Mn-SOD mRNA remained high and became equivalent in both granulosa and theca lutein cells 24 h after HCG injection. Neither luteinization nor the expression of Mn-SOD mRNA was observed in the epithelial cells of unovulated follicles. Luteal bodies had formed 3 days after HCG injection, and the same level of Mn-SOD mRNA expression continued in lutein cells, but not in stromal cells. During the estrous cycle, Mn-SOD mRNA was localized to theca interna cells on proestrus, to the epithelial cells of luteinizing follicles on estrus, and to newly formed luteal bodies on diestrus. The epithelial cells in the oviduct did not express Mn-SOD mRNA throughout the ovulatory process or the estrous cycle. Expression of Mn-SOD mRNA in the luminal epithelial cells of the uterus increased after PMSG injection, reaching a maximum after 24 h, and became relatively negative 3 days after HCG injection when corpora lutea had formed in the ovary. During the estrous cycle, uterine epithelial cells and leukocytes showed marked increases in Mn-SOD mRNA expression on estrus and on proestrus, respectively. Expression in the vaginal epithelium became apparent 3 days after HCG injection and continued for at least 12 days after HCG injection. The expression was localized to the superficial layer of the epithelium. During the estrous cycle, expression occurs in the basal layer on proestrus and estrus, transferring to the superficial layer on diestrus day 1, and expression stops on diestrus day 2. The relationship between the expression of Mn-SOD mRNA and hormone-induced metabolic changes, including steroidogenesis, is discussed.

A simple method for staining the superficial cells of mouse urinary bladder epithelium with horseradish peroxidase (HRP) is presented. HRP solution was instilled into the bladder lumen in vivo. After fixation with glutaraldehyde, the bladder was treated with Triton X-100 and then reacted with diaminobenzidine (DAB). Intense DAB reactions were detected throughout the whole of the cytoplasm of superficial cells by both light and electron microscopy. No reaction was observed in intermediate or basal epithelial cells. This simple method will be useful for the three-dimensional reconstruction of cell shape and identification of the stratification of transitional epithelial cell layers.

The role of type 1 fimbriae in promoting bladder colonization and the course of Escherichia coli cystitis were examined with type 1 fimbriated strains of clinically isolated E. coli. In the experiments of mice in vivo, intact bladder epithelium showed natural resistance to the adherence of type 1 fimbriated and non-fimbriated E. coli. However, the exfoliation of bladder superficial cells by trypsinization before the bacterial inoculation promoted the adhesion and colonization of type 1 fimbriated E. coli onto bladder epithelium. After colonization of E. coli, maximum numbers of E. coli and leukocytes were observed 3 days after inoculation. Nine days after inoculation, both of E. coli and leukocytes disappeared and the regeneration of superficial cells was observed. On the other hand, superficial cells in mice injected with phosphate-buffered saline or non-fimbriated E. coli regenerated 5 days after trypsinization. The present study demonstrated that the removal of superficial cells is essential for the adhesion and colonization of type 1 fimbriated E. coli onto bladder epithelium in vivo and a new model of E. coli cystitis in mice was established. The model which we established is valuable for histopathological, immunological, and therapeutic studies.

Megakaryocytes of dog bone marrow were utilized as target cells for identifying actin mRNA expressing cells on semi-thin and thin sections. After in situ hybridization with radioisotope-labeled probes was performed on paraffin sections, gelatin capsules containing freshly prepared epoxy resin were placed on the sections. The resin was solidified and detached from the slide glass, and semi-thin and thin sections were obtained. The signals showing actin mRNA expression were detected on megakaryocytes in these sections by light and electron microscopy.

By using fluorescent isothiocyanate-conjugated concanavalin A (FITC-Con A), cell surface events were examined under a light microscope during the early period of the conjugation process in Tetrahymena thermophila. Until the two complementary mating types (D-III and IV) were mixed, Con A-binding activities were hardly detected on the cell surface of ciliates. After mixing, however, the FITC-Con A (25 μg/ml) bound especially to the anterior cell surface at the early stage of conjugation, followed by characteristic changes of the Con A-binding pattern and, subsequently, by formation of a bright fluorescent ring around the area of contact between conjugants. Such alterations of FITC-Con A-binding pattern were found to be interrupted or eliminated by cycloheximide (2 μg/ml). These findings are related to the onset and subsequent conjugation in T. thermophila.

Using its microtubule-containing axopodia, a heliozoan Echinosphaerium nucleofilum feeds on various kinds of protozoans and small metazoans. The present study revealed that food capture and ingestion were carried out in 2 different ways or by a combination of them. The first one was by the rapid contraction of axopodia, by which the food organism was conveyed directly toward the body surface. After such a contraction, many of the microtubules which had been present inside the axopodia degraded and were replaced by C-shaped microtubules. Bundles of tubular bodies were also detected alongside the axonemal microtubules, especially following the use of glutaraldehyde fixative containing ruthenium red. The second method was by means of axopodial flow, by which a food organism attached to an axopodium was conveyed to the body surface along the axopodial surface without accompanying axopodial degradation or contraction. Subsequently the food organism was surrounded by several small pseudopodia to form a food vacuole; many filamentous structures (5–10 nm in diameter) were observed inside the pseudopodia. During the ingestion process many cytoplasmic extensions, including rosary-like filaments, were observed to protrude from the contracted axopodia and the cell body. Mottled dense granules were observed to be discharged from the axopodial surface just when the prey was captured.

The effects of biscoclaurine alkaloids on ADP-or collagen-induced platelet aggregation were examined as alkaloids are known to inhibit lipid peroxidation (1, 7) and stabilize labilized biomembranes (8, 9). Most alkaloids greatly inhibit the platelet aggregation induced by ADP or collagen. This inhibition was concentration dependent and significantly higher where there was collagen aggregation.

Chronological studies on the respiratory function and membrane components of newborn rat liver mitochondria revealed that perinatal mitochondria retained considerably well-coupled oxidative phosphorylation that functioned in sites II and III prior to site I. The ratio of protein to phospholipid contents (mg/μmol) was low in these mitochondria, in which phospholipids were characterized by their high phosphatidylethanolamine contents (43% of the total phospholipids) and low cardiolipin contents (6% of the total), as compared to those of the adult. The fatty acid composition in major phospholipid species was also different from those of the adult. These characteristics altered with development, and the carbamylphosphate synthetase contents markedly increased from 12 to 20% of the total polypeptides in 10 days postnatal time. From these results structural and functional completion of mitochondria accompaying development is discussed from a mitochondrial biogenesis viewpoint.

Previously, we perfused the lungs of several mammals (rat, mouse, guinea pig and hamster) with the detergent-containing medium and found that abundant filaments were present in apical caps of nonciliated bronchiolar epithelial (Clara) cells. These filaments were bound to the plasma membrane of the apical cap at one end and ran into the interior of the cytoplasm at the other end. In the present study, we used heavy meromyosin (HMM) and an immunohistochemical method to identify these filaments in rat Clara cell. Most filaments in apical caps bound HMM, but some filaments were not decorated with HMM. To examine the latter filaments, paraffin sections were stained immuno-histochemically utilizing the antibodies against intermediate filament proteins. Apical caps were positive for cytokeratin but were negative for other intermediate filament proteins, vimentin, desmin, neurofilament protein and glial fibrillary acidic protein. These results suggested that filaments in apical cap of nonciliated bronchiolar epithelial (Clara) cells were composed of actin and cytokeratin.

Using low temperature and colchicine, we examined how axopodia play a role in the initiation and subsequent process of cell fusion in a large heliozoan Echinosphaerium nucleofilum (strain MA). Although the fusion reaction is naturally temperature-dependent, preliminary treatment with a low temperature (2°C) induced the reaction more efficiently than in the control kept at room temperature (20°C). During the recovery process from the cold, the reaction was enhanced conspicuously in the presence of colchicine; the fusion indices were 2.05 to 5.68 after a 9 h incubation with 4 to 8 mM colchicine. When treated with 4 to 10 mM colchicine without the preliminary cold treatment, the reaction also was enhanced. This means that the reaction depended upon the colchicine concentration and resulted in partial or complete degradation of axopodia; fusion indices were 1.08 to 3.77 after a 9 h incubation with 4 to 10 mM colchicine. We discuss these results and the electron-microscopical data, in relation to the role of axopodia in the fusion reaction.