Biphasic change and disuse-mediated regression of canal network structure in cortical bone of growing rats

The canal network in cortical bone is an indispensable basis of bone vascularity, and its structure changes according to bone growth. Using monochromatic synchrotron radiation microCT (SRmicroCT), we evaluated the structural change of the canal network in growing rat tibiae and the response of this network to disuse. Tibiae were harvested from both hindlimbs of 9- and 14-week-old male Wistar rats subjected to unilateral sciatic neurectomy (SN) at 6 weeks of age (W9, n=8; W14, n=8) and from intact hindlimbs of 6-week-old rats (W6, n=8). Images of distal diaphyseal segments were reconstructed by SRmicroCT with a voxel size of 5.83 mum and then translated into local mineral densities using a calibrated relation between linear absorption coefficients and the concentration of K(2)HPO(4) solution. The canal network was segmented by simple thresholding at a bone mineral density of 0.82 g.cm(-3) and its structural properties were determined. In intact hindlimbs, the canal network showed a biphasic change with growth, as represented by increases followed by decreases in canal volume fraction (Ca.vol.f), the density of canals running longitudinally (Ca.num.d), and the density of canal connections (Ca.con.d): Ca.vol.f=2.2, 3.1, and 1.8%, Ca.num.d=77, 98, and 70 mm(-2), and Ca.con.d=18, 41, and 21 mm(-3) in W6, W9, and W14, respectively. In SN hindlimbs, bone growth deceleration was accompanied by a 16% smaller Ca.vol.f and a 22% smaller Ca.con.d in W9 and a 27% smaller Ca.vol.f, a 12% smaller Ca.num.d, and a 39% smaller Ca.con.d in W14 than those in intact hindlimbs. Furthermore, the canal branching structure became more treelike in SN hindlimbs. The effect of SN on the canal network appeared mainly in the periosteal sector of the anteriolateral cortex in W9 and spread throughout the cortex in W14. These findings will lead to a better understanding of microcirculation in cortical bone growth.

Prooxidant action of furanone compounds: Implication of reactive oxygen species in the metal-dependent strand breaks and the formation of 8-hydroxy-2′-deoxyguanosine in DNA

Prooxidant properties of furanone compounds including 2,5-furanone (furaneol, 4-hydroxy-2,5-dimethyl-furan-3-one), 4,5-furanone (4,5-dimethyl-3-hydroxy-2(5H)-furanone) (sotolone) and cyclotene (2-hydroxy-3-methyl-2-cyclopenten-1-one) were analyzed in relation to the metal-reducing activity. Only 2.5-furanone known as a "strawberry or pineapple furanone" inactivated aconitase the most sensitive enzyme to active oxygen in the presence of ferrous sulfate, suggesting the furaneol/iron-mediated generation of reactive oxygen species. 2,5-Furanone caused strand scission of pBR322 DNA in the presence of copper. Treatment of calf thymus DNA with 2,5-furanone plus copper produced 8-hydroxy-2'-deoxyguanosine in DNA. 2,5-Furanone showed a potent copper-reducing activity, and thus, DNA strand breaks and the formation of 8-hydroxy-2'-deoxyguanosine by 2,5-furanone can be initiated by the production of superoxide radical through the reduction of cupric ion to cuprous ion, resulting in the conversion to hydrogen peroxide and hydroxyl radical. However, an isomer and analog of 2,5-furanone, 4,5-furanone and cyclotene, respectively, did not show an inactivation of aconitase, DNA injuries including strand breakage and the formation of 8-hydroxy-2'-deoxyguanosine, and copper-reducing activity. Cytotoxic effect of 2,5-furanone with hydroxyketone structure can be explained by its prooxidant properties: furaneol/transition metal complex generates reactive oxygen species causing the inactivation of aconitase and the formation of DNA base damage by hydroxyl radical.

Predictive factors of transcatheter arterial chemoembolization for hepatocellular carcinoma

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Background/Aim: Although transcatheter arterial chemoembolization (TACE) has been widely used for the treatment of unresectable hepatocellular carcinoma (HCC), the optimal indication of the TACE has not been fully elucidated. Methods: The treatment outcomes after TACE were analyzed retrospectively to determine predictive factors of anti-cancer effect on HCC. The patient (pts) selection criteria were: 1) admission between 1992 and 2005, 2) diagnosis of fresh HCC, 3) no extrahepatic metastasis and 4) primary treatment with TACE. TACE was performed by selectively introducing a catheter into the hepatic artery and injecting gelatin sponge particles following an emulsion consisting of 2–5 ml of iodized oil (Lipiodol) and 20–50 mg doxorubicin hydrochloride. Lipiodol accumulation in tumors was regarded as an indication of necrosis. We defined complete response (CR) as disappearance or 100% necrosis of all tumors, and partial response (PR) as more than 50% reduction and/or more than 50% necrosis. Results: There were 270 pts who fulfilled the above criteria. According to Japan Integrated Staging, the number of T1, T2, T3 and T4 was 10, 59, 171 and 30, respectively. There were 52 CRs, 113 PRs, 77 who remained SD and 28 who showed PD/NE. The median survival months of CR, PR, SD and PD/NE were 50, 30, 15 and 5, respectively, and there was a significant differences between them. The logistic regression analysis revealed tumor multiplicity and vascular invasion (VI) were significantly associated with the objective response (CR or PR). The response probability of patients with solitary tumor without VI was 85%, that with multiple tumors without VI was 63%, that with solitary tumor with VI was 33% and that with multiple tumors with VI was 16%. The small tumor (<5 cm) was another favorable factor which was significantly associated with CR. Among 231 patients without VI, the CR probability of patients with a solitary tumor <5 cm or >5 cm was 46% or 40%, respectively; although that of those with multiple tumors <5cm or >5cm was 21% or 5%, respectively. Conclusion: TACE is recommended for HCC patients without VI, and is optimally indicated for those with a solitary tumor or those with multiple tumor <5 cm among them.

No significant financial relationships to disclose.

Protective effect of NADP-isocitrate dehydrogenase on the paraquat-mediated oxidative inactivation of aconitase in heart mitochondria

Protective role of NADP-isocitrate dehydrogenase in the oxidative inactivation of mitochondrial enzymes was analyzed. Administration of paraquat to the rat inactivated liver mitochondrial enzymes: the aconitase activity decreased to one quarter, and citrate synthase and fumarase to half, whereas cytosolic enzymes were not affected. Activities of heart mitochondrial and cytosolic enzymes were not at all changed in the rat treated with paraquat, but paraquat directly inactivated aconitase in the heart mitochondria isolated from the non-treated rats. The paraquat-dependent inactivation of aconitase was prevented by activating NADP-isocitrate dehydrogenase in the presence of oxidized glutathione. NADP-isocitrate dehydrogenase could regenerate glutathione in isolated heart mitochondria, indicating that paraquat-mediated inactivation depends on the glutathione-regenerating activity by enhanced NADPH supply. Lower NADP-isocitrate dehydrogenase activity in liver mitochondria cannot regenerate reduced glutathione for scavenging reactive oxygen species, resulting in the paraquat-induced oxidative inactivation of mitochondrial enzymes. However, higher activity of NADP-isocitrate dehydrogenase participates in the regeneration of reduced glutathione causing stabilization of enzymes in heart mitochondria.

Proposal of a new staging system for hepatocellular carcinoma based on the treatment strategy: An analysis of 1,084 patients

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Background: Although several prognostic models have been proposed for hepatocellular carcinoma (HCC), they are not useful for conducting treatment strategy. Methods: Between July 1992 and May 2005, consecutive 1084 patients (pts) with naïve HCC were treated in our hospital. Based on our treatment strategy, we set our own HCC stage as follows: stage 1; Child-Pugh A or B, N0M0, solitary tumor without vascular invasion (VI), stage 2; Child-Pugh A or B, N0M0, multiple tumors without VI, stage 3; Child-Pugh A or B, N0M0, solitary tumor with VI, stage 4A; Child-Pugh A or B, N0M0, multiple tumors with VI, stage 4B; Child-Pugh A or B, N1 or M1, any T, stage 4C; Child-Pugh C, any TNM. Generally, treatments for stage 4C, 4B, & 4A were observation, chemotherapy trials or aggressive local therapies in selected pts, & hepatic arterial infusion chemotherapy. For the pts with stage 1–3, the priority of treatment options was hepatectomy first, percutaneous ablation (PA) second, and transcatheter arterial chemoembolization third. PA was indicated for 3 or fewer HCC nodules without VI, of which the largest diameter were smaller than 3 cm. Treatment outcomes were retrospectively analyzed according to the above staging system. Results: The overall survival rate was 50% at 3 yrs, 33% at 5 yrs, 24% at 7 yrs & 13% at 10 yrs. The median survival in stage 1, 2, 3, 4A, 4B & 4C was 5.5 yrs (N = 444), 2.9 yrs (N = 397), 0.8 yr (N = 36), 0.5 yr (N = 109), 0.3 yr (N = 76) & 0.2 yr (N = 22), respectively. Most of the definitive local therapy (91% of 371 hepatectomies with curative intent & 99% of 191 PAs) were classified in stage 1 or 2. The prognosis was also well predicted by the other 6 staging systems (Okuda, AJCC, CLIP, JIS, Tokyo and BCLC). However, hepatectomy with curative intent & PA were distributed into a CLIP score of 0–5 & 0–3, respectively, & into a JIS score of 0–4 & 0–3, respectively. Conclusions: The present staging system was simple & predicted prognosis well. Although other scoring systems caused various heterogeneities (hepatic reserve & tumor status) in each score, our staging system consisted of homogenous hepatic reserve & simple tumor status, so it might be useful for conducting treatment plan. Validation study is warranted in other population.

No significant financial relationships to disclose.

3-D imaging and quantitative comparison of human dentitions and simulated bite marks

This study presents a technique developed for 3-D imaging and quantitative comparison of human dentitions and simulated bite marks. A sample of 42 study models and the corresponding bites, made by the same subjects in acrylic dental wax, were digitised by laser scanning. This technique allows image comparison of a 3-D dentition with a 3-D bite mark, eliminating distortion due to perspective as experienced in conventional photography. Cartesian co-ordinates of a series of landmarks were used to describe the dentitions and bite marks, and a matrix was created to compare all possible combinations of matches and non-matches using cross-validation techniques. An algorithm, which estimated the probability of a dentition matching its corresponding bite mark, was developed. A receiver operating characteristic graph illustrated the relationship between values for specificity and sensitivity. This graph also showed for this sample that 15% of non-matches could not be distinguished from the true match, translating to a 15% probability of falsely convicting an innocent person.

Characterization of stretch-activated calcium permeable cation channels in freshly isolated myocytes of the cricket (Gryllus bimaculatus) lateral oviduct

Stretch-activated channels (SACs) were investigated in myocytes isolated from the lateral oviduct in cricket Gryllus bimaculatus using the cell-attached or excised inside-out patch clamp technique. Application of both negative and positive pressure (10-100 cm H(2)O) into the patch pipettes induced the unitary channel current openings. The open probability (NPo) of the channel increased when negative pressure applied into the patch pipettes increased. The single channel conductance for this channel was approximately 20 pS with 140 mM Na(+), K(+), or Cs(+) in the patch pipettes and was approximately 13 pS with 100mM Ca(2+) or Ba(2+) in the patch pipettes. External application of Gd(3+), La(3+), Cd(2+) and Zn(2+)inhibited the channel with the IC(50) values of 14, 15, 28, and 18 microM respectively. Interestingly external application of TEA, a specific blocker of K(+) channel, also inhibited this channel with IC(50) value of 8.8mM. These results show for the first time the presence of stretch activated Ca(2+)-permeable nonselective cation channel in myocytes isolated from the cricket lateral oviduct. The physiological significance of this channel in oviposition behavior is discussed.

Characterization of single L-type Ca2+ channels in myocytes isolated from the cricket lateral oviduct

The single Ca2+ channel activity was obtained from cell-attached patch recordings with the use of pipettes filled with 100 mM Ba2+ as the charge carrier in myocytes isolated from the lateral oviduct of cricket Gryllus bimaculatus. The following results were obtained. (1) The channel had a unitary conductance of 18 pS. (2) The open time histogram of the channel could be fitted with a single exponential while the closed time histogram could be fitted with the sum of two exponentials, suggesting that there are at least one open state and two closed states for this channel. (3) The open probability of the channel increased with increasing membrane depolarization. (4) The mean current reconstructed by averaging individual current trace responses inactivated slowly and the current-voltage relationship for the peak mean current showed a bell-shaped relation. (5) The dihydropyridine (DHP) Ca2+ antagonist, nifedipine, reduced the mean current by increasing the proportion of "blank" sweeps. On the other hand, the DHP Ca2+ agonist, Bay K 8644, increased the mean current by increasing the mean open-times of the channel. These results confirm a presence of DHP-sensitive L-type Ca2+ channel in myocytes isolated from the lateral oviduct of cricket G. bimaculatus.

Quantitative analysis of amplifiable DNA in tissues exposed to various environments using competitive PCR assays

Competitive PCR assays were established for the mitochondrial DNA hypervariable region I and the human amelogenin locus. Using these assays, the copy numbers of DNA participating in PCR (amplifiable DNA) were quantified in tissues exposed to different environments. Human ribs, skin and nails were left in three exposure conditions (in the open air, in soil and in water). The amounts of amplifiable DNA in these tissues were quantified during a time period of up to two months. The amount of amplifiable DNA was well preserved in hard tissues (ribs and nails) regardless of the exposure conditions, whereas the soft tissues immersed in water showed a rapid decrease in amplifiable DNA. Strong PCR inhibition was observed in the DNA extracts obtained from buried bones. This phenomenon was clearly identified from an amplification failure of the internal standards in the competitive PCR. A preliminary examination to identify the PCR inhibitor suggested that the soil itself contributed to the inhibition. In addition, the amounts of amplifiable DNA in case samples were also investigated.

Expression of epiregulin and amphiregulin in the rat ovary

We have previously reported that the epidermal growth factor (EGF) family growth factor, epiregulin, is expressed in rat ovarian granulosa cells by induction with pregnant mare serum gonadotropin (PMSG). In this study, we report that amphiregulin, another member of the EGF family, was also induced in the rat ovary by gonadotropin treatment. Northern blot analysis revealed that PMSG treatment induced the expression of both epiregulin and amphiregulin mRNA after 24 h, but the expression then decreased 48 h after treatment. Further treatment with human chorionic gonadotropin (hCG) rapidly induced the expression of both epiregulin and amphiregulin genes and maximal levels were reached 4 h after hCG treatment. A marginal increase in amphiregulin mRNA levels was also observed 6 h after PMSG treatment. In situ hybridization revealed that epiregulin and amphiregulin mRNAs were localized in the granulosa cells of large antral follicles. These spatio-temporal expression patterns were similar to those of cyclo-oxygenase-2 (COX-2) and progesterone receptor (PR). In adult cycling rats, epiregulin and amphiregulin were strongly induced at 1800 and 2000 h on proestrus coinciding with the preovulatory LH surge. An in situ hybridization study also showed that epiregulin and amphiregulin mRNAs were detectable in the granulosa cells of preovulatory ovarian follicles at 2000 h on proestrus, where transcripts of COX-2 and PR were co-localized with those of epiregulin and amphiregulin. These observations suggested that the EGF family members, epiregulin and amphiregulin, may play a role in the ovulatory process of cycling rats as well as in the induction of ovulation in immature rats.

Volumetric evaluation of facial swelling utilizing a 3-D range camera

Quantitative analysis of facial volume is important in the assessment of facial swelling. Previous research has demonstrated that the Fiore trade mark light-structured 3-D range camera is a rapid, non-invasive, and safe imaging technology for the quantitative analysis of facial morphology. The development of the Rugle-3D trade mark volumetric measurement software programme has allowed for the development of a powerful imaging and measurement system. This study aimed to determine the accuracy and reproducibility of Fiore trade mark by measuring simulated facial swelling. A model involving 20 human subjects was devised to simulate facial swelling for image acquisition and measurement in order to assess the accuracy and reproducibility of the device. A systematic error of 1.25% and reproducibility of 3.27% was determined for the imaging system. It is concluded that Fiore trade mark is an accurate and reproducible technology that is sensitive and would be applicable to clinical studies of facial swelling.

The proportion of cells with functional X disomy is associated with the severity of mental retardation in mosaic ring X Turner syndrome females

Turner syndrome females (45,X) do not have mental retardation (MR), whereas some mosaic ring X Turner syndrome females, with 45,X/46,X,r(X), have severe MR. The MR is believed to be caused by a failure of X chromosome inactivation (XCI) of the small ring X chromosome, which leads to functional X disomy (FXD), To explore this hypothesis, we examined the proportion of FXD cells in the peripheral blood of four ring X Turner syndrome females with various levels of MR, using two newly developed XCI assays based on DNA methylation of X-linked genes. As a result, the two patients with extremely severe MR showed complete FXD patterns, whereas the remaining two patients with relatively milder MR showed partial FXD patterns. These results indicate that the proportion of FXD cells may be associated with the severity of MR in mosaic ring X Turner syndrome females, although this association should be confirmed by examining brain cells during development. One of the cases with severe MR and a complete FXD pattern neither lacked the XIST gene nor had uniparental X isodisomy, and we discuss the mechanism of the failure of XCI in this case.

L-type Ca 2+ channel and Ca 2+ -permeable nonselective cation channel as a Ca 2+ conducting pathway in myocytes isolated from the cricket lateral oviduct

The Ca2+-conducting pathway of myocytes isolated from the cricket lateral oviduct was investigated by means of the whole-cell patch clamp technique. In voltage-clamp configuration, two types of whole cell inward currents were identified. One was voltage-dependent, initially activated at -40 mV and reaching a maximum at 10 mV with the use of 140 mM Cs2+-aspartate in the patch pipette and normal saline in the bath solution. Replacement of the external Ca2+ with Ba2+ slowed the current decay. Increasing the external Ca2+ or Ba2+ concentration increased the amplitude of the inward current and the current-voltage (I-V) relationship was shifted as expected from a screening effect on negative surface charges. The inward current could be carried by Na+ in the absence of extracellular Ca2+. Current carried by Na+ (INa) was almost completely blocked by the dihydropyridine Ca2+ channel antagonist, nifedipine, suggesting that the INa is through voltage-dependent L-type Ca2+ channels. The other inward current is voltage-independent and its I-V relationship was linear between -100 mV to 0 mV with a slight inward rectification at more hyperpolarizing membrane potentials when 140 mM Cs+-aspartate and 140 mM Na+-gluconate were used in the patch pipette and in the bath solution, respectively. A similar current was observed even when the external Na+ was replaced with an equimolar amount of K+ or Cs+, or 50 mM Ca2+ or Ba2+. When the osmolarity of the bath solution was reduced by removing mannitol from the bath solution, the inward current became larger at negative potentials. The I-V relationship for the current evoked by the hypotonic solution also showed a linear relationship between -100 mV to 0 mV. Bath application of Gd3+ (10 microM) decreased the inward current activated by membrane hyperpolarization. These results clearly indicate that the majority of current activated by a membrane hyperpolarization is through a stretch-activated Ca2+-permeable nonselective cation channel (NSCC). Here, for the first time, we have identified voltage-dependent L-type Ca2+ channel and stretch-activated Ca2+-permeable NSCCs from enzymatically isolated muscle cells of the cricket using the whole-cell patch clamp recording technique.

Contrast enhancement patterns of hepatic tumours during the vascular phase using coded harmonic imaging and Levovist to differentiate hepatocellular carcinoma from other focal lesions

The purpose of the study was to assess contrast enhancement patterns of hepatic tumours during the vascular phase using contrast-enhanced ultrasound and Levovist to differentiate hepatocellular carcinoma from other hepatic tumours. 89 hepatic tumours in 82 consecutive patients were evaluated using coded harmonic ultrasound imaging. The procedure used a phase inversion harmonic technique and coded technology. We observed images for 2 min from the beginning of the administration as the vascular phase using continuous transmission and intermittent transmissions of 1 s or 2 s. The contrast agent Levovist was administered intravenously as a bolus infusion of 2.5 g. Tumour vessels with flow spreading into the tumour and/or homogeneously stained hyperechoic images were observed in 34 of the 41 hepatocellular carcinomas (sensitivity, 82.9%; specificity, 93.8%). Peripheral enhancements were characteristic of intrahepatic cholangiocarcinoma and metastatic hepatic tumours (sensitivity, 60.0% and 83.3%; specificity, 65.5% and 76.4%, respectively). Pooling at the periphery or throughout the tumour was apparent only in haemangioma (sensitivity, 76.5%; specificity, 100%). A tortuous feeding artery and spoke-like vascularization were evident only in the two focal nodular hyperplasias. Contrast-enhanced ultrasound using coded harmonic ultrasound imaging and Levovist provided detailed information about tumour vascularity and contrast enhancement patterns in hepatic tumours.