Ultrasonic cleaning is effective in removing carbonized clots and tissue from the insulation‐tipped diathermic knife‐2

Objectives

Since carbonized clots and tissue (debris) tend to adhere firmly to the tip of the endoscopic submucosal dissection (ESD) knife as the procedure proceeds, manual removing the firm debris is often challenging and time‐consuming. Recently, effective ultrasonic cleaning for other medical devices has been reported. The aim of the present study was to clarify whether ultrasonic cleaning is effective in removing the debris on the insulation‐tipped diathermic (IT) knife‐2.

Methods

This study was an ex‐vivo experimental randomized study. A total of 40 IT knife‐2 knives with debris on their tip surfaces were prepared and randomly assigned to two groups (Group A and Group B). The knives in Group A were cleaned using the conventional scrubbing method for 30 s (conventional cleaning method), while those in Group B were cleaned using a combined method of scrubbing for 20 s and ultrasonic cleaning for 10 s (combined ultrasonic cleaning method). The tip electrode of the knife after cleaning was photographed under a microscope (40x). The 40 images of the knives were evaluated by independent three endoscopists and two clinical engineers using the five‐step evaluation criteria ranging from cleaning score 1 (dirty) to 5 (clean).

Results

The mean cleaning score of 3.78 (range: 2.33–4.67) in Group B was significantly higher than that of 1.68 (range: 1.00–2.83) in Group A.

Conclusions

The combined ultrasonic cleaning method could remove debris adhering to the IT knife‐2 more effectively than the conventional cleaning method. Ultrasonic cleaning may be applied for real‐world ESD.

A mechanical coil insertion system for endovascular coil embolization of intracranial aneurysms

Like other fields of medicine, robotics and mechanization might be introduced into endovascular coil embolization of intracranial aneurysms for effective treatment. We have already reported that coil insertion force could be smaller and more stable when the coil delivery wire is driven mechanically at a constant speed. Another background is the difficulty in synchronizing operators' minds and hands when two operators control the microcatheter and the coil respectively. We have therefore developed a mechanical coil insertion system enabling a single operator to insert coils at a fixed speed while controlling the microcatheter. Using our new system, the operator manipulated the microcatheter with both hands and drove the coil using foot switches simultaneously. A delivery wire force sensor previously reported was used concurrently, allowing the operator to detect excessive stress on the wire. In vitro coil embolization was performed using three methods: simple mechanical advance of the coil; simple mechanical advance of the coil with microcatheter control; and driving (forward and backward) of the coil using foot switches in addition to microcatheter control. The system worked without any problems, and did not interfere with any procedures. In experimental coil embolization, delivery wire control using the foot switches as well as microcatheter manipulation helped to achieve successful insertion of coils. This system could offer the possibility of developing safer and more efficient coil embolization. Although we aim at total mechanization and automation of procedures in the future, microcatheter manipulation and synchronized delivery wire control are still indispensable using this system.

Development of soft nanocomposite materials and their applications in cell culture and tissue engineering

Novel soft nanocomposite materials with unique organic/inorganic network structures have been developed by extending the strategy of “organic/inorganic nanocomposites” to the field of soft materials. The structures described here were synthesized by in-situ free-radical polymerization of various monomers in the presence of exfoliated clay (hectorite) in aqueous media. The nanocomposite hydrogels (NC gels) and soft nanocomposites (M-NCs) obtained were flexible and transparent soft materials, regardless of the clay content, that could be prepared in various shapes and surface forms, each consisting of individually different polymer/clay network structures. Owing to these unique network structures, both NC gels and M-NCs showed extraordinary mechanical properties such as ultrahigh elongation at break and widely controlled modulus and strength, which could overcome the problems (e.g., mechanical fragility, optical turbidity, poor processing ability) associated with conventional chemically crosslinked materials. In addition, the NC gels and M-NCs exhibited a number of new characteristics related to optical anisotropy, morphology, biocompatibility, stimulus sensitivity and cell culture. In the present review, we outline the novel features of these soft nanocomposites, and demonstrate their potential as soft culture substrates useful for tissue engineering as well as soft, transparent, absorbing, and mechanically tough biomaterials for many bio-applications.

Successful transplantation of in vitro expanded human corneal endothelial precursors to corneal endothelial surface using a nanocomposite sheets

BACKGROUND

Though the transplantation of in vitro expanded human corneal endothelial precursors in animal models of endothelial damage by injecting into the anterior chamber has been reported, the practical difficulties of accomplishing such procedure in human patients have been a hurdle to clinical translation. Here we report the successful transplantation of in vitro expanded human corneal precursor cells to an animal eye using a transparent Nano-composite sheet and their engraftment.

MATERIALS & METHODS

Human Corneal endothelial cells (HCEC) were isolated from human cadaver eyes with informed consent and expanded in the lab using a sphere forming assay in a novel Thermoreversible Gelation Polymer (TGP) for 26 days. HCEC obtained by sphere forming assay were seeded in a novel Nano-composite sheet, which was made of PNIPA-NC gels by in-situ, free-radical polymerization of NIPA monomer in the presence of exfoliated clay (synthetic hectorite "Laponite XLG") uniformly dispersed in aqueous media. After a further seven days in vitro culture of HCEC in the Nano-composite sheet, cells were harvested and transplanted on cadaver-bovine eyes (n=3). The cells were injected between the corneal endothelial layer and the Nano-composite sheet that had been placed prior to the injection in close proximity to the endothelial layer. After three hours, the transplanted Nano-composite sheets were removed from the bovine eyes and subjected to microscopic examination. The corneas were subjected to Histo-pathological studies along with controls.

RESULTS

HCEC formed sphere like colonies in TGP which expressed relevant markers as confirmed by RT-PCR. Microscopic studies of the Nanosheets and histopathological studies of the cornea of the Bull's eye revealed that the HCEC got engrafted to the corneal endothelial layer of the bovine eyes with no remnant cells in the Nanosheet.

CONCLUSION

Transplantation of in vitro expanded donor human corneal endothelial cells using a transparent Nano-composite sheet was feasible in bovine eyes and the HCEC an engrafted within three hours of transplantation. Pilot human studies could be planned for utilization of this material and strategy.

Mechanism of the formation of dural arteriovenous fistula: the role of the emissary vein

Dural arteriovenous fistula (DAVF) can be separated into two types: DAVF which drains through an affected sinus (sinus type) and DAVF with direct reflux to the cortical vein (non-sinus type). The present report attempted to clarify the mechanism of formation and development of DAVF focusing on the emissary vein (EV) hypothesis.First, inflammation occurs at the penetrating point of the EV on the dura due to idiopathic or secondary causes. Local inflammatory reactions induce vessel dilatation and neovascularization, and subsequently create arteriovenous (AV) connections on the arteriole level. Although EV communicating with dural arteries might play a role as draining routes at first, they start to degrade due to compression of enlarged emissary arteries or to a hemodynamic shift to the drainage pathway of least resistance. Following the occlusion of drainage pathway through EV into the sinus or cortical veins may form, resulting in clinically detectable DAVF. The AV shunt then expands to the surrounding dura associated with recruitment of feeders from distant sites induced by expression of angiogenetic factors and a shift in the hemodynamic balance. In sinus type DAVF, the sinus is progressively compartmentalized and finally occludes due to thrombogenesis with activated coagulopathy or to hemodynamic hypertrophy of the sinus wall. This progression results in the mature, aggressive DAVF with drainage impairments. Previous mechanistic hypotheses focusing on sinus hypertension and sinus thromboses cannot explain the pathogenesis of non-sinus type of DAVF. Although the etiology of DAVF may be concerned by the thrombo-occlusive change of sinus, the unique theory presented in this report may enable an understanding of the common etiology of both types of DAVF.

Species differences in the tissue distribution of catechol and methylsulphonyl metabolites of 2,4,5,2',5'-penta- and 2,3,4,2',3',6'-hexachlorobiphenyls in rats, mice, hamsters and guinea pigs

Polychlorinated biphenyls (PCBs) are metabolized to phenolic or methylsulphonyl PCBs (MeSO(2)-CBs) in animal species. The study determined the species differences in the tissue distribution of persistent PCB metabolites in rats, mice, hamsters and guinea pigs 4 days after exposure to 2,4,5,2('),5(')-pentachlorobiphenyl (CB101) or 2,3,4,2('),3('),6(')-hexachlorobiphenyl (CB132). For CB101 metabolism, the hydroxylation in rats, mice and hamsters occurred primarily at the 3(')-position in the 2('),5(')-dichlorinated phenyl ring, whereas the hydroxylation in guinea pigs occurred preferentially at the 3-position. Metabolite profiles in tissues of hamsters were dominated by 3('),4(')-catechol-CB101, whereas metabolite profiles in rats and mice were dominated by 3(')- or 4(')-MeSO(2)-CBs. For CB132 metabolism, rats and mice produced 4(')- and 5(')-MeSO(2)-CBs at similar concentration ratios, whereas guinea pigs produced MeSO(2)-CBs at higher levels and selectively retained 5(')-MeSO(2)-CB in liver. In contrast, hamsters preferentially produced 4('),5(')-catechol-CB132 that was retained in serum. Consequently, hamsters produced catechols, whereas guinea pigs produced meta-substituted MeSO(2)-CBs, preferentially from CB132. These findings indicate that PCBs with 2,3,6-chlorine substitution are preferred substrates for the formation of catechols or MeSO(2)-CBs and the differences in metabolite profiles are related to species-dependent metabolic capacities.

Evaluation of carotid plaque composition by computed tomographic angiography and black blood magnetic resonance images

The purpose of this study was to evaluate quantitatively the composition of carotid plaque by computed tomographic (CT) angiography and qualitatively by black blood magnetic resonance images (MRI). Thirty-eight patients with high-grade carotid artery stenosis were included in this study. Ultrasonography, CT angiography and black blood MRI of the cervical carotid artery were performed, and the CT number was measured in Hounsfield units (HU). The average CT number of the 15 unstable plaques (39.5%) was 27.7+/-7.5 HU and that of the 23 stable plaques (60.5%) was 60.4+/-20.8 HU (p=0.0001). In the 23 patients with stable plaque, 21 demonstrated isointensity in T (1)- and T (2)-weighted images in the black blood MRI (p=0.0001). By using CT angiography and MRI, precise images of the pathology of the carotid arterial wall can be obtained. It is possible to evaluate the components of carotid artery plaque with high reliability by quantification of the CT number in CT angiography and performing black blood MRI as well as carotid ultrasonography.

Evaluation of carotid plaque composition by computed tomography angiography and black blood magnetic resonance image

SUMMARY

The purpose of this study was to evaluate the composition of a carotid plaque quantitatively by computed tomography (CT) angiography and qualitatively by black blood magnetic resonance imaging (MRI). Thirty-eight patients with high-grade carotid artery stenosis were included in this study. Ultrasonography, CT angiography and black blood MRI of the cervical carotid artery were performed, and the CT number was measured in Hounsfield units (HU). The average CT number of the 15 unstable plaques (39.5%) was 27.7 +/- 7.5 HU and that of the 23 stable plaques (60.5%) was 60.4 +/- 20.8 HU (p < 0.0001). In the 23 patients with stable plaque, 21 demonstrated isointensity in T1 and T2 in the black blood MRI (p < 0.0001). By using CT angiography and MRI, precise images of the pathology of the carotid arterial wall can be obtained. It is possible to evaluate the components of a carotid artery plaque with high reliability by quantification of the CT number in CT angiography and performing black blood MRI as well as in carotid ultrasonography.

Ajuba negatively regulates the Wnt signaling pathway by promoting GSK-3beta-mediated phosphorylation of beta-catenin

The Wnt signaling pathway is essential for embryonic development and carcinogenesis. Upon Wnt stimulation, beta-catenin is stabilized and associates with T-cell factor or lymphoid enhancing factor, thereby activating transcription of target genes. In the absence of Wnt stimulation, the level of beta-catenin is reduced via glycogen synthase kinase (GSK)-3beta-mediated phosphorylation and subsequent proteasome-dependent degradation. Here, we report the identification of Ajuba as a negative regulator of the Wnt signaling pathway. Ajuba is a member of LIM domain-containing proteins that contribute to cell fate determination and regulate cell proliferation and differentiation. We found that enforced expression of Ajuba destabilized beta-catenin and suppressed target gene expression. Ajuba promoted GSK-3beta-mediated phosphorylation of beta-catenin by reinforcing the association between beta-catenin and GSK-3beta. Furthermore, Wnt stimulation induced both accumulation of beta-catenin and destabilization of Ajuba. Our findings suggest that Ajuba is important for regulation of the Wnt signaling pathway.

Bioaccumulation of naturally occurring mixed halogenated dimethylbipyrroles in whale and dolphin products on the Japanese market

Mixed halogenated dimethyl bipyrroles (HDBPs), which are thought to be produced naturally, were quantified in whale and dolphin products marketed for human consumption in Japan. The major component of HDBPs was 3,3',4,4'-tetrabromo-5,5'-dichloro-1,1'-dimethyl -2,2'-bipyrrole (Br(4)Cl(2)-DBP), accounting for 85% of the total of five HDBPs detected, followed by Br(3)Cl(2)-DBP. Mean concentrations of HDBPs ranged from 0.27 microg/g lipid (n = 31) in minke whale (Balaenoptera acutorostrata) from the northwest Pacific Ocean to 11.8 microg/g lipid (n = 33) in bottlenose dolphin (Tursiops trucatus) from the southwest Japanese coastal water. At higher levels, HDBPs made up 37% of the total organohalogen body burden in Dall's porpoise (Phocoenoides dalli), whereas the contribution was less than 8.9% in minke whales. In two data subsets from Baird's beaked whale (Berardius bairdii), the products from the Pacific Ocean contained significantly higher concentrations of HDBPs than those from the Sea of Japan. Furthermore, the geographical distribution of HDBPs did not resemble those of ubiquitous anthropogenic organochlorines, such as polychlorinated biphenyl (PCBs). Higher concentration ratios of SigmaHDBP/SigmaPCB and different patterns of HDBP congeners were observed in whale products from the Asia-Pacific as compared to non-Pacific Ocean mammals reported previously. These results support the hypothesis that HDBPs and anthropogenic organochlorines have different sources and that the consumption of HDBPs by Japanese individuals could be an exposure/health risk.

Distribution and toxicity of mercury in rats after oral administration of mercury-contaminated whale red meat marketed for human consumption

Toothed-whales and dolphins have been hunted for human consumption in Japan, and their muscles (red meats) are highly contaminated with mercury (Hg). We investigated the distribution and toxicity of Hg in rats after oral administration of Hg-contaminated whale red meat marketed for human consumption in Japan. Rats were orally administered the red meat homogenate for seven consecutive days (0.5 g red meat/kg-bw/day). The red meat administered to rats contained 81microg/g of total mercury (T-Hg) and 13.4 microg/g of methyl mercury (M-Hg). This dose corresponds to the human consumption of 210 g red meat/60 kg-bw/week, exceeding by about 29 times the provisional tolerable weekly intake of M-Hg at 1.6 microg/kg-bw/week set by JECFA [JECFA, 2003. Joint FAO/WHO expert committee on food additives. 61st meeting, Rome]. Twenty-four hours after the last administration, the distribution of T-Hg in rat organs and biochemical parameters in serum were analyzed. The administration of red meat significantly elevated T-Hg concentrations in the liver, kidney, erythrocytes, cerebral cortex and medulla oblongata from the control levels but did not elevate the T-Hg concentration in serum, showing the typical distribution pattern of M-Hg, not of inorganic Hg. The administration slightly but significantly increased GTP activity and P concentration and decreased BUN concentration in serum, although no abnormalities were observed in rat body weight gain and movement during the 7 days. The occasional consumption of red meat from small cetaceans, therefore, could pose a health problem for not only pregnant women but also for the general population.

In vitro metabolism of 2,2',3,4',5,5',6-heptachlorobiphenyl (CB187) by liver microsomes from rats, hamsters and guinea pigs

The metabolism of 2,2',3,4',5,5',6-heptachlorobiphenyl (heptaCB) (CB187) was studied using liver microsomes of rats, hamsters and guinea pigs, and the effect of cytochrome P450 (CYP) inducers, phenobarbital (PB) and 3-methylcholanthrene (MC), was also investigated. In untreated animals, guinea pig liver microsomes formed three metabolites which were deduced to be 4'-hydroxy-2,2',3,5,5',6-hexachlorobiphenyl (M-1), 4'-hydroxy-2,2',3,3',5,5',6-heptaCB (M-2) and 4-OH-CB187 (M-3) from the comparison of GC/MS data with some synthetic authentic samples. The formation rate of M-1, M-2 and M-3 was 18.1, 36.6, 14.7 pmol h-1 mg protein-1, respectively. Liver microsomes of untreated rats and hamsters did not form CB187 metabolites. In guinea pigs, PB-treatment increased M-1 and M-2 significantly to 1.9- and 3.4-fold of untreated animals but did not affect the formation of M-3. In rats, PB-treatment resulted in the appearance of M-2 and M-3 with formation rates of 87.1 and 13.7 pmol h-1 mg protein-1, respectively, but M-1 was not observed. In hamsters, PB-treatment formed only M-2 at a rate of 29.4 pmol h-1 mg protein-1. On the other hand, MC-treatment of guinea pigs decreased the formation of M-1 and M-2 to less than 50% of untreated animals. MC-microsomes of rats and hamsters produced no metabolites. Preincubation of antiserum (300 microl) against guinea pig CYP2B18 with liver microsomes of PB-treated guinea pigs produced 80% inhibition of M-1 and the complete inhibition of M-2 and M-3. These results suggest that PB-inducible CYP forms, especially guinea pig CYP2B18, rat CYP2B1 and hamster CYP2B, are important in CB187 metabolism and that CB187 metabolism in guinea pigs may proceed via the formation of 3,4- or 3',4'-oxide and subsequent NIH-shift or dechlorination.

Recovery of Valpha24+ NKT cells after hematopoietic stem cell transplantation

Human Valpha24+ natural killer T (NKT) cells have an invariant T-cell receptor-alpha chain and are activated in a CD1d-restricted manner. Valpha24+ NKT cells are thought to regulate immune responses and to play important roles in the induction of allograft tolerance. In this report, we analyzed the recovery of Valpha24+ NKT cells after hematopoietic stem cell transplantation and its correlation with graft-versus-host disease (GVHD). Patients who received a dose-reduced conditioning regimen, antithymocyte globulin- or CAMPATH-1H-containing conditioning regimen were excluded. NKT cells were reconstituted within 1 month after transplantation in peripheral blood stem cell transplantation recipients, while their numbers remained low for more than 1 year in bone marrow transplantation (BMT) recipients. The number of Valpha24+ NKT cells in BMT recipients with acute GVHD was lower than that in patients without acute GVHD, and both the CD4+ and CD4- Valpha24+ NKT subsets were significantly reduced. With regard to chronic GVHD, BMT recipients with extensive GVHD had significantly fewer Valpha24+ NKT cells than other patients. Furthermore, the number of CD4+ Valpha24+ NKT cells was also significantly reduced in patients with chronic extensive GVHD. Our results raise the possibility that the number of Valpha24+ NKT cells could be related to the development of GVHD.

Contamination by mercury and cadmium in the cetacean products from Japanese market

Cetaceans hunted coastally in Japan include several species of odontocete (dolphins, porpoises and beaked whales), and fresh and frozen red meat and blubber, as well as boiled internal organs, such as liver, lung, kidney and small intestine, are still sold for human consumption. Furthermore, red meat and blubber products originating from mysticete minke whales caught in the Antarctic and Northern Pacific are also sold for human consumption. We surveyed mercury and cadmium contamination levels in boiled liver, lung, kidney and red meat products being marketed in Japanese retail outlets. We also analyzed the DNA of these products to obtain information concerning gender and species. Total mercury (T-Hg) and methyl mercury (M-Hg) contamination levels in all the cetacean products were markedly higher in odontocete species than in mysticete species, and slightly higher in females than in males. T-Hg contamination in the organs was seen in the following order: boiled liver>boiled kidney=boiled lung>red meat. In particular, T-Hg concentrations in the boiled liver were high enough to cause acute intoxication even from a single ingestion: the mean +/-SD (range) of T-Hg was 388+/-543 (0.12-1980) microg/wetg. In contrast, although M-Hg contamination in the liver was not markedly higher than that in other organs, M-Hg contamination was in the following order: boiled liver>odontocete red meat>boiled kidney>boiled lung. The contamination levels of T-Hg and M-Hg in odontocete red meat, the most popular whale product, were 8.94+/-13.3 and 5.44+/-5.72 microg/wetg, respectively. These averages exceeded the provisional permitted levels of T-Hg (0.4 microg/wetg) and M-Hg (0.3 microg/wetg) in marine foods set by the Japanese Ministry of Health, Labor and Welfare by 22 and 18 times, respectively, suggesting the possibility of chronic intoxication by T-Hg and M-Hg with frequent consumption of odontocete red meat. Cadmium contamination levels in boiled liver, kidney and lung were 8.59+/-12.0, 10.4+/-8.6 and 1.66+/-1.27 (microg/wetg), respectively.

Synthesis and characterization of oligonucleotides containing formamidopyrimidine lesions (Fapy.dA, Fapy.dG) at defined sites

The preparation of oligonucleotides containing Fapy.dA (N4-(2-Deoxy-alpha,beta-D-erythro-pentofuranosyl)-4,6-diamino- 5-formamidopyrimidine) and Fapy.dG (N6-(2-Deoxy-alpha,beta-D-erythro-pento-furanosyl)-2,6- diamino-4-hydroxy-5-formamido-pyrimidine) at defined sites was achieved by introducing the lesions as dinucleotide phosphoramidites. Oligonucleotides as composed of as many as 36-nucleotides were prepared by solid-phase synthesis and/or a combination of chemical synthesis and enzymatic ligation. Oligonucleotides containing non-hydrolyzable analogues were also prepared. Oligonucleotides containing these modified nucleotides were characterized by a variety of chemical and biochemical methods.

Stereoselective synthesis of 1'-C-carbon-subsituted 4'-thionucleosides from 4-thiofuranoid glycal

PhSeCl or NIS-initiated glycosylation to 2-5, which were prepared through lithiation of 4-thiofuranoid glycal 1, proceeded stereoselectively to give the target 1'-C-carbon-substituted 4'-thiopyrimidine nucleosides. This synthetic method enabled us to synthesize 4'-thioanalogue 13 of nucleoside antibiotic angustmycin.

Mercury contamination in the red meat of whales and dolphins marketed for human consumption in Japan

Cetacean products sold for human consumption in Japan originate from a wide range of whale, dolphin, and porpoise species caught off several areas of the Japan coast, Antarctic and North Pacific Oceans. We surveyed the total mercury (T-Hg) levels in red meat, the most popular cetacean products in Japan. We also analyzed the DNA of these to obtain information regarding species. According to the genetic analysis, the red meats originating from nine species of odontocete and six species of mystecete were sold in Japanese markets. T-Hg concentrations in all odontocete red meats (0.52-81.0 microg/wet g, n = 137) exceeded the provisional permitted level of T-Hg in marine foods set by the Japanese government (0.4 microg/wet g). The highest and second highest levels of T-Hg in the red meats were found in the false killer whale (81.0 microg/wet g) and striped dolphin (63.4 microg/wet g), respectively. These concentrations of T-Hg exceeded the permitted level of T-Hg by about 200 and 160 times, respectively, suggesting the possibility of chronic intoxication by methyl mercury due to frequent consumption of odontocete red meats. The T-Hg concentration levels were higher in odontocete species such as Baird's beaked whales and pilot whales caught off southern areas than those caught off northern areas, probably reflecting a higher Hg concentration in the seawater and/or their diet (squid and fish) in the southern area. On the other hand, T-Hg concentrations in all mystecete red meat samples except for one (0.01-0.54 microg/ wet g, n = 62) were below the permitted level of T-Hg, probably reflecting their lower trophic levels.

Human health significance of organochlorine and mercury contaminants in Japanese whale meat

The concentrations of total mercury, polychlorinated biphenyls (PCBs), and organochlorine pesticides (SigmaDDT, dieldrin, hexachlorobenzene [HCB], and SigmaHCH) were determined in 61 whale meat products (bacon, blubber, red meat, liver, intestine, and tongue) purchased from retail outlets across Japan. Mean (range) concentrations of contaminants in all samples were: total mercury 4.17 (0.01-204); SigmaPCB 1.14 (0-8.94); SigmaDDT 0.98 (0-7.46); dieldrin 0.07 (0-0.35); HCB 0.06 (0-0.22); and SigmaHCH 0.07 (0-0.19) micro g/g (wet weight). The data were used to calculate estimated daily intakes (EDIs) of contaminants at two hypothetical levels of whale meat consumption. These EDIs were compared with FAO/WHO "tolerable daily intake" (TDI) values for each chemical. EDIs calculated for higher levels of whale meat consumption were in some cases exceptionally high and for many products exceeded FAO/ WHO-TDIs for total mercury, PCBs, and dieldrin, with exceedance factor values (EDI/TDI) for total mercury, PCBs, and dieldrin reaching maxima of 175, 5.36, and 2.1, respectively. For sensitive consumers and those with high-level consumption (e.g., whaling communities), exposure to mercury and to a lesser extent PCBs from certain whale blubber and bacon and striped dolphin liver products could lead to chronic health effects. The Japanese community should therefore exercise a precautionary approach to the consumption of such foods in excess, particularly by high-risk members of the population.

MR detection of iliac bone marrow involvement by malignant lymphoma with various MR sequences including diffusion-weighted echo-planar imaging

OBJECTIVE

To assess the diagnostic accuracy of MR imaging for detecting bone marrow infiltration by malignant lymphoma.

PATIENTS AND DESIGN

Fifty-three patients with malignant lymphoma underwent MR imaging and bone marrow biopsy. In 80 iliac crests of the 53 patients (13 positive specimens in 9 patients and 67 negative specimens in 44 patients), biopsy results and the signal intensity characteristics were compared. MR sequences included T1-weighted SE, T2-weighted FSE with fat suppression, FSE STIR, and diffusion-weighted EPI with fat suppression at 1.5 T.

RESULTS AND CONCLUSIONS

To detect lymphoma infiltration, T1-weighted SE had the highest sensitivity (92%) and diffusion-weighted EPI with fat suppression and FSE STIR had the highest specificity (92.5% and 92%, respectively). A combination of T1-weighted SE and FSE STIR yielded the highest sensitivity and specificity (85% and 97%, respectively). A combination of T1-weighted SE and FSE STIR sequences seems to be the current choice of imaging protocol for detecting bone marrow infiltration by malignant lymphoma.

Comparison of fit and fill between anatomic stem and straight tapered stem using virtual implantation on the ORTHODOC workstation

The objective of this article was to determine the influence of stem design on fit and fill using the preoperative planning workstation of the ROBODOC system. Anatomic ABG and straight Osteolock femoral components were virtually implanted into 50 femora (25 from patients with developmental dysplasia of the hip (DDH), 25 morphologically normal) on the workstation display. Fit and fill, and length of the proximal posterolateral femoral cortex removed by milling (LPFCR), were measured on the cross-sectional images. Lateral curvature (alpha angle) and anteversion of the femur were evaluated. The ABG components showed significantly better fit than the Osteolock components at the levels proximal to the lesser trochanter. The Osteolock components showed significantly greater LPFCR than the ABG components, especially in the patients with DDH. The patients with DDH showed significantly greater alpha angle and femoral anteversion than those with morphologically normal femora. With the Osteolock components, the alpha angle correlated significantly with femoral anteversion and LPFCR. Use of an anatomic proximal body of the stem helped to improve the proximal canal fit. Greater LPFCR was required when a straight stem was implanted in patients with a relatively high alpha angle.

Metabolite of 2,2',4',5-tetrabromobiphenyl, 3-methylsulphonyl-2,2',4',5-tetrabromobiphenyl, a potent inducer of CYP2B1/2 in rat

1. 3-Methylsulphonyl- and 4-methylsulphonyl-2,2',4',5-tetrabromobiphenyls (3-MeSO(2)- and 4-MeSO(2)-TetraBrBs) were detected in the liver, lung, kidney, adipose tissue and faeces of the 2,2',4',5-tetrabromobiphenyl (TetraBrB)-dosed rat. 2. The administration of 0.05-2.0 micromol kg(-1) doses of 3-MeSO(2)-TetraBrB produced corrresponding increases in the hepatic concentration of the methyl sulphone metabolite, corresponding increases in the content of total cytochrome P450, and corresponding increases in the activities of 7-benzyloxy-, 7-ethoxy- and 7-pentoxyresorufin O-dealkylases. The inducing effects of the 3-MeSO(2)-TetraBrB (0.2 micromol kg(-1)), both on the content of total P450 and on the activities of the three alkoxyresorufin O-dealkylases, were higher than that of the parent TetraBrB (342 micromol kg(-1)). 3. The major phenobarbital (PB)-inducible forms of P450, CYP2B1, CYP2B2, CYP3A2 and CYP2C6, were substantially induced by 3-MeSO(2)-TetraBrB, but CYP1A1 and CYP1A2 were not. On the other hand, the activities of drug-metabolizing enzymes and the four PB-inducible forms of P450 were unchanged by 4-MeSO(2)-TetraBrB treatment. 4. The induction profiles of these enzymes and P450 forms in rat treated with 3-MeSO(2)-TetraBrB were similar to those treated with PB. 5. The inducing ability of 3-MeSO(2)-TetraBrB (0.5 micromol kg(-1)) both on the activities of the three alkoxyresorufin O-dealkylases and on the contents of four PB-inducible forms of P450 was roughly equal to that of PB (431 micromol kg(-1) twice at a 24-h interval) or 3-MeSO(2)-2,2',4',5-tetrachlorobiphenyl (1 micromol kg(-1)). It is noteworthy that the effects of 3-MeSO(2)-TetraBrB on the drug-metabolizing enzymes CYP2B1 and CYP2B2 were several thousand-fold higher than those of parent TetraBrB, while the effect of its isomeric 4-MeSO(2)-TetraBrB were not. 6. The extent of hepatic accumulation of the 3-MeSO(2) metabolite after the administration of TetraBrB (342 micromol kg(-1)) was almost the same as that after the administration of 3-MeSO(2)-TetraBrB (0.1-0.2 micromol kg(-1)). The relationship between the hepatic concentration of the 3-MeSO(2) metabolite and the extent of enzyme induction after the administration of TetraBrB or 3-MeSO(2)-TetraBrB suggests that 3-MeSO(2)-TetraBrB plays an important role in the induction of microsomal drug-metabolizing enzymes by TetraBrB.

Full weight-bearing after cementless total hip arthroplasty

In a prospective study of cementless total hip arthroplasty, 19 hips in 17 patients (Group A) were allowed full weight-bearing immediately after the operation while 18 hips in 16 patients (Group B) were first allowed weight-bearing after 6 weeks. Patients were matched for sex, age at surgery, height, weight, and follow-up period and there were no significant differences in hip scores between the two groups. Rehabilitation to gain walking ability with a cane lasted 5.8 days for Group A and 44.8 days for Group B (P = 0.0001). The hospital stay after surgery was 30.1 days for Group A and 46.7 days for Group B (P = 0.006). All patients showed bone ingrowth radiographically. There were no complications in either group.

Influence of polyethylene and femoral head surface quality on wear: a retrieval study

Thirty-two polyethylene sockets and 22 femoral heads were retrieved because of aseptic loosening more than 9 years after total hip arthroplasty. The volumetric wear rates of the retrieved polyethylene sockets were significantly greater in those coupled with an alumina head (P < 0.05). The retrieved alumina heads showed significantly better surface roughness and roundness than heads of Co-Cr and of stainless steel (P < 0.05). However, no significant difference was found in polyethylene quality demonstrated as fusion defects among the three different groups. The present study suggests that maintaining better surface roughness and roundness of the femoral heads does not always result in an in vivo reduction of polyethylene wear.

Analysis of survivorship after total hip arthroplasty using a ceramic head

To determine the clinical efficacy of an alumina ceramic head, 119 cemented total hip arthroplasties in 97 patients using an alumina head coupled with ethylene oxide gas sterilized polyethylene were reviewed. Eighty-two patients (101 hips) with greater than 10 years followup were evaluated clinically and radiographically (range, 10-17.6 years), and 97 patients (119 hips) were evaluated for survivorship analysis (range, 0.6-17.6 years). The average functional hip scores according to Merle d'Aubigné and Postel improved from 8.6 preoperatively to 15.0 at the final followup, and 57 patients (64 hips) had no pain. The average polyethylene wear rate was 0.15 mm/year (range, 0.04-0.34 mm/year). Patients with polyethylene wear greater than 3 mm showed significantly higher rates of acetabular loosening. Fifteen-year survival rates (with 95% confidence intervals) with radiographic evidence of aseptic loosening as the end point were 46.8% +/- 13.4% in acetabular components and 91.9% +/- 6.6% in femoral components. Fifteen-year survival rates of hip arthroplasties with revision because of aseptic loosening as the end point were 75.3% +/- 10.2% and 97.9% +/- 3.0%, respectively. Results of the current study suggest that using an alumina head instead of a metal head may not be beneficial when coupled with ethylene oxide gas sterilized polyethylene.

Phase transformation of a zirconia ceramic head after total hip arthroplasty

We report two cases of surface deterioration of a zirconia ceramic femoral head associated with phase transformation after total hip arthroplasty. One head was retrieved at revision due to recurrent dislocation after six years and the other because of failure of the locking mechanism of the polyethylene liner after three years. The monoclinic content of the zirconia ceramics rose from 1% to about 30% on the surface of the heads. SEM revealed numerous craters indicating extraction of the zirconia ceramics at the surface. Surface roughness increased from an initial value of 0.006 microm up to 0.12 microm. This is the first report to show that phase transformation of zirconia ceramics causes deterioration of the surface roughness of the head in vivo after total hip arthroplasty.

Phase transformation of a zirconia ceramic head after total hip arthroplasty

We report two cases of surface deterioration of a zirconia ceramic femoral head associated with phase transformation after total hip arthroplasty. One head was retrieved at revision due to recurrent dislocation after six years and the other because of failure of the locking mechanism of the polyethylene liner after three years. The monoclinic content of the zirconia ceramics rose from 1% to about 30% on the surface of the heads. SEM revealed numerous craters indicating extraction of the zirconia ceramics at the surface. Surface roughness increased from an initial value of 0.006 3m up to 0.12 3m. This is the first report to show that phase transformation of zirconia ceramics causes deterioration of the surface roughness of the head in vivo after total hip arthroplasty.

Osteoblastic response to osteoarthrosis of the hip does not predict outcome of cementless cup fixation: 79 patients followed for 5-11 years

We evaluated the influence of osteoblastic response to osteoarthrosis of the hip on the outcome of cementless acetabular cup after 91 total hip replacements in 79 patients. Of the 91 hips, 23 were atrophic, 37 normotrophic, and 31 hypertrophic, according to Bombelli's criteria. There were no clinical or radiographic differences among the three groups at the final follow-up (average 7 (5-11) years), when stable bone growth had been achieved by all of the acetabular cups in patients with the atrophic type, 35/37 of the normotrophic type, and all the hypertrophic type. Revision of the acetabular cup was performed on 1 hip of the normotrophic type, in connection with severe polyethylene liner wear and progressive osteolysis.

Dome (modified Chiari) pelvic osteotomy: 10- to 18-year followup study

Ninety-six dome (modified Chiari) pelvic osteotomies in 87 patients with pain and disability because of osteoarthrosis secondary to hip dysplasia were reviewed. The mean age of the patients at the time of surgery was 29 years (range, 16-55 years). The mean followup was 13 years (range, 10-18 years). Forty-one hips were classified into a hip dysplasia stage, 32 hips into an early stage of osteoarthrosis, and 23 hips into an advanced stage of osteoarthrosis according to the radiographic grading of the Japanese Orthopaedic Association. The average preoperative Merle d'Aubigné and Postel hip score was 13.8, and the average score at final followup was 16.6. Excellent or good results with a score greater than 14 were achieved in 96% of the hips at final followup. Radiographically, signs of progression of osteoarthrosis were not seen in 87% of the hips. Osteoarthrosis progressed during the postoperative course in 13% of the hips. Four patients (four hips) eventually had a total hip arthroplasty at 13.8 years (range, 12.5-15.3 years) after surgery. The survival rate of dome pelvic osteotomy, using clinical failure as an end point, was 82% at 15 years. Using radiologic failure as an end point, 61 hips in 54 patients (survival rate, 78%) survived at 15 years. Using hip replacement as an end point, 92 hips in 83 patients (survival rate, 82%) survived at 15 years. Dome pelvic osteotomy is an excellent and effective operation for pain relief and functional maintenance of the hip.

Ligands for peroxisome proliferator-activated receptor gamma inhibit growth and induce apoptosis of human papillary thyroid carcinoma cells

Ligands for peroxisome proliferator-activated receptor gamma (PPARgamma) induce apoptosis and exert antiproliferative effects on several carcinoma cell lines. The present study investigates the expression of PPARgamma and the possibility that agonists for PPARgamma also inhibit the growth of human thyroid carcinoma cells. We examined this hypothesis using six cell lines, designated BHP thyroid carcinoma cells, which originated from patients with papillary thyroid carcinoma. RT-PCR analysis revealed that the thyroid carcinoma cell lines BHP2-7, 7-13, 10-3, and 18-21 express PPARgamma. More PPARgamma was expressed in carcinoma than in adjacent normal thyroid tissue in three of six samples of human papillary carcinoma of the thyroid. PPARgamma-positive thyroid carcinoma cells were treated with agonists of PPARgamma, troglitazone, BRL 49653, and 15-deoxy-12,14-prostaglandin J2. Troglitazone (10 micromol/L), BRL 49653 (10 micromol/L), and 15-deoxy-12,14-prostaglandin J2 (1 microg/mL) decreased [(3)H]thymidine incorporation and reduced cell number, respectively, in BHP carcinoma cell lines that expressed PPARgamma. Under low serum conditions, ligands for PPARgamma induced condensation of the nucleus and fragmentation of chromatin into nucleosome ladders. These findings indicate that the death of thyroid carcinoma cells is a form of apoptosis. To investigate the molecular mechanism of the apoptosis, we assessed expression of the apoptosis-regulatory genes bcl-2, bax, and c-myc. Troglitazone significantly increased the expression of c-myc messenger RNA but had no effect on the expression of bcl-2 and bax in thyroid carcinoma cells. These results suggest that, at least in part, the induction of apoptosis in human papillary thyroid carcinoma cells may be due to an increase of c-myc. Troglitazone (500 mg/kg.day) significantly inhibited tumor growth and prevented distant metastasis of BHP18-21 tumors in nude mice in vivo. Taken together, these results suggest that PPARgamma agonist inhibit cell growth of some types of human thyroid cancer.

[Species differences in the in vitro metabolism of 2,4,5,2',3',4'-hexachlorobiphenyl]

In vitro Metabolism of 2,4,5,2',3',4'-hexachlorobiphenyl (CB138) was studied using liver microsomes from rats, hamsters and guinea pigs. Guinea pig liver microsomes formed four metabolites named as M-1, M-2, M-3 and M-4 and these metabolites were all increased to about 4-5 fold of untreated microsomes by pretreatment of phenobarbital. Liver microsomes of rats and hamsters showed much less activity to metabolize CB138 than those of guinea pigs. Only phenobarbital-treated microsomes produced very small amounts of M-3 in rats and M-1, M-2 and M-3 in hamsters, but untreated and MC-treated microsomes did not. When mass spectra of the methylated derivatives of M-1, M-2, M-3 and M-4 were measured in GC/MS, the former two possess the molecular ion of 354 and the latter two had the molecular ion of 388. In addition, the mass fragmentation pattern indicated that M-1, M-2, M-3 and M-4 are 2-OH-4,5,2',3',4'-pentachlorobiphenyl, 5-OH-2,4,2',3',4'-pentachlorobiphenyl, 3-OH-CB138 and 2-OH-3,4,5,2',3',4'-hexachlorobiphenyl, respectively. Of four metabolites, the chemical structures of M-3 and M-4 were supported by the synthesized authentic compounds. From these results, it is suggested that the metabolism of CB138 in guinea pig liver proceeds mainly via 2,3-epoxide as an intermediate and a PB-inducible P450, CYP2B18, is the most important isozyme in CB138 metabolism.

Relationship between bone marrow cellularity and apparent diffusion coefficient

This study was performed to determine if there is a relationship between apparent diffusion coefficient (ADC) and cellularity of bone marrow of the posterior ilium. Four groups of various marrow cellularity underwent diffusion-weighted echo-planar imaging: 1) adults with normal hypocellularity (21 patients); 2) adults with normal normocellularity (13 patients); 3) young children with normal hypercellularity (5 patients); and 4) adults with lymphoma-related hypercellularity (3 patients). In all adults, marrow cellularity was confirmed by uni-or bilateral bone marrow biopsies. In children, the iliac marrow was presumed hypercellular because of their ages. A total of 66 ADC values of bone marrow calculated from diffusion-weighted images with b-values of 30 and 300 seconds/mm(2) was evaluated. Hypercellular marrow (normal and lymphoma-related) showed the highest mean ADC, and hypocellular the lowest ADC. Statistically significant differences were found between three groups of normal marrow: hypocellular, normocellular, and hypercellular. There is a positive correlation between ADC and cellularity of bone marrow. J. Magn. Reson. Imaging 2001;13:757-760.

[The changes of PCBs and PCDFs as well as symptoms in Yusho patients for 30 years]

Two mass-food poisonings called Yusho and Yucheng occurred in Western Japan and Taiwan in 1968 and 1979, respectively. Blood samples from 5 Yusho patients and 3 Yucheng patients were collected several times from 1982 to 1998 and from 1980 to 1995, respectively, and analyzed for PCB and PCDF congeners. Fat base concentrations of 2,3,4,7,8-penta-CDF in the Yusho patients, which were responsible for about 70% of the dioxin toxicity, are estimated to be decreased from 60 ppb in 1969 to 0.8 ppb in 1997 with the median half-life of 2.9 years in the first 15 years after the onset and 7.7 years in the next stage of 15 years. Fat base concentrations of total PCBs in the blood of Yusho patients are estimated to be decreased from 75 ppm just after the onset to 2.3 ppm after passage of 30 years. Typical Yusho symptoms of acneiform eruption, dermal pigmentation and increased eye discharge were very gradually recovered with lapse of ten years. However, enzyme and/or hormone mediated sign of high serum triglyceride, high serum thyroxin, immunoglobulin disorder and others are persistently maintained for 30 years.

Transcriptional activation of the thyroglobulin promoter directing suicide gene expression by thyroid transcription factor-1 in thyroid cancer cells

Gene therapy with thyroglobulin (TG) promoter and a prodrug/suicide gene combination may prove useful as a treatment for thyroid carcinoma. However, most poorly differentiated and anaplastic thyroid carcinomas have lost the ability to express the TG gene expression accompanied by loss of transcription factors [thyroid transcription factor-1 (TTF-1), TTF-2, or Pax-8] interacting with the TG promoter. In anticipation of developing transcriptionally targeted gene therapy of TG-nonproducing thyroid carcinomas, we investigated the effect of TTF-1 gene transfer on TG promoter activity and the cytotoxic effect obtained by the TG promoter-driven HSV-TK gene along with ganciclovir in thyroid carcinoma and nonthyroidal cells. Using a chimeric construct containing the 5'-flanking region of the rat TG gene between -826 and +39 bp and the luciferase gene, TG promoter activity was detected in a normal rat thyroid cell line (FRTL-5), but not in a dedifferentiated line of thyroid cells (FRT) expressing Pax-8 but not TTF-1, TTF-2, or TG [TTF-1(-)/TTF-2(-)/Pax-8(+)/TG(-)], or in a human papillary thyroid carcinoma cell line [BHP15-3; TTF-1(-)/TTF-2(-)/Pax-8(-)/TG(-)], a human pulmonary cell line [H441; TTF-1(+)/TTF-2(-)/Pax-8(-)/TG(-)], or a dog kidney epithelial cell line [MDCK; TTF-1(-)/TTF-2(-)/Pax-8(+)/TG(-)]. Cotransfection of the TTF-1 expression vector stimulated TG promoter activity in FRT and BHP15-3 dedifferentiated thyroid cells, but not in H441 pulmonary cells. Only weak activation was observed in MDCK kidney cells. We then constructed recombinant adenovirus vectors, AdTTF-1 and ADTGTK: AdTTF-1 contained cytomegalovirus promoter and rat TTF-1 cDNA; AdTGTK carried the TG promoter-driven HSV-TK gene. Infection with AdTGTK and combined with GCV treatment induced a cytotoxic effect in FRTL-5 cells but not in dedifferentiated thyroid or nonthyroid cells. Cotransduction of AdTTF-1 and AdTGTK permitted 90% cytotoxicity for BHP15-3 and >95% cytotoxicity for FRT, as well as for BHP7-13 and BHP18-21v thyroid cancer cell lines [both/TTF1(-)/TTF-2(-)/Pax-8(+)/TG(-)]. In contrast, little cytotoxicity was seen for H441 and MDCK cell lines even with 300 microg/ml of ganciclovir. These results suggest that cotransduction of a TG promoter-controlled suicide gene and the TTF-1 gene by adenoviral vectors confers transcriptionally targeted gene-mediated cytotoxicity in poorly differentiated thyroid carcinoma cells unable to express the TG gene.

Optimizing femoral anteversion and offset after total hip arthroplasty, using a modular femoral neck system: an experimental study

To investigate the effectiveness of a modular femoral neck system, consisting of two neutral and four types of retroverted necks for the correction of femoral anteversion and offset in total hip arthroplasty, an experimental study was carried out, using sawbones with four different angles of femoral anteversion (16 degrees, 34 degrees, 47 degrees, and 59 degrees ). With the neutral neck, reconstruction of the preoperative anteversion and offset in the normal femur was achieved. While the 15 degrees retroverted long neck was effective for the mildly or moderately anteverted femur, this retroverted neck showed insufficient correction for the severely anteverted femur. This modular neck system proved to be useful for correction of the medial component of femoral offset in femora with anteversion of less than 47 degrees. For patients with greater anteversion, a feature which is rarely seen in the clinical situation, femoral necks with a greater degree of retroversion may be useful.

Bioaccumulation of polychlorinated biphenyls (PCBs) and dichlorodiphenylethane (DDE) methyl sulfones in tissues of seal and dolphin morbillivirus epizootic victims

Polychlorinated biphenyl (PCB) and dichlorodiphenylethane (DDE) methyl sulfone (MSF) metabolites possess high affinities for binding two homologous 16,000 Da homodimeric receptor proteins in the lung (Clara cell secretory protein, CCSP) and the uterus (uteroglobin, UG), leading to selective bioaccumulation of MSFs in these tissues. As marine mammals are highly exposed to organochlorines, concentrations of PCBs, PCB MSFs, DDT, and DDE MSF were analyzed in blubber, lung, and uterus samples from harbor seal (Phoca vitulina) and striped dolphin (Stenella coeruleoalba) morbillivirus epizootic victims to investigate uterine and lung MSF accumulation. Mean uterus concentrations of PCB MSFs and DDE MSF in harbor seals were 0.61 and 0.04 microg/g lipid weight and in striped dolphins 0.05 and 0.01 microg/g lipid weight. Mean lung concentrations of PCB MSFs and DDE MSF in harbor seals were 0.96 and 0.02 microg/g lipid weight and in striped dolphins 0.16 and 0.01 microg/g lipid weight. To ascertain whether uterine and lung bioaccumulation of MSFs is possible due to the presence of CCSP and UG in seals, CCSP and UG proteins in uterine flushings and in uterine and lung and epithelial tissue from Baltic gray and ringed seals were characterized using gel electrophoresis and Western blotting techniques. UG- and CCSP-like proteins with molecular weights of 16,000 Da were resolved in all samples. This is the first demonstration of this protein in any marine mammalian species. The toxicological implications of MSF binding with UG and CCSP in marine mammals are discussed.

Bone scintigraphy for osteonecrosis of the knee in patients with non-traumatic osteonecrosis of the femoral head: comparison with magnetic resonance imaging

OBJECTIVE

To determine whether technetium bone scintigraphy (BS) is useful for screening of non-traumatic osteonecrosis of the knee (ONK), which was a major affected site, secondary to the femoral head, among multiple osteonecrosis, in patients with non-traumatic osteonecrosis of the femoral head (ONFH).

METHODS

A total of 214 knee joints in 107 patients with ONFH were evaluated by BS and a comparison made with magnetic resonance imaging (MRI). ONK was classified into five sites, including the femoral condyles (ONFC), distal femoral metaphysis (ONFM), tibial plateau (ONTP), proximal tibial metaphysis (ONTM), and patella (ONP).

RESULTS

Based on the diagnosis by MRI, ONK was detected in 103 knees of 62 patients (48%). ONFC was most common (86 knees, 40%), ONFM (15%), followed by ONTM (10%), ONP (3%), and ONTP (0.9%). Sensitivity, specificity, and accuracy of BS for ONFC detection were 63%, 71%, and 68%, respectively. When the ONFC lesions on the coronal views of MRI were large or medium sized and occupied two thirds, or the entire anteroposterior joint surface on the sagittal views, the sensitivity of BS for ONFC detection increased to 89% (34/38 knees). The sensitivity of BS for ONFM, ONTM, and ONP detection was 3%, 0%, and 0%, respectively, but these lesions showed a low likelihood of collapse.

CONCLUSION

BS is useful for screening large ONK in patients with ONFH given that 89% of patients with ONFC who had a high risk of collapse of the knee were identified.

Early MRI findings of rapidly destructive coxopathy

To diagnose rapidly destructive coxopathy (RDC) in its early stages and understand the pathomechanism of associated joint destruction, ten cases of RDC were followed by periodic MRI from onset of the disease. In the initial stage (stage 1) of RDC, when radiographs revealed slight narrowing of the joint space, a small subchondral area of low signal intensity was observed on T(1)-weighted images (T1WI) and inhomogeneous high intensity was observed on T(2)-weighted images (T2WI) in the antero-lateral portion of the femoral head. When radiographs showed obliteration of the joint space (stage 2), MRI revealed a diffuse area of low intensity on TIWI and high intensity on T2WI in the proximal femur, including the femoral neck and head, suggesting extensive bone marrow edema. The femoral head and acetabulum were aggressively destroyed (stage 3) in all cases 3 to 6 months after the diffuse abnormal pattern was observed on MRI. MRI in stage 3 cases showed low intensity areas on both T1WI and T2WI. RDC did not show the band-like pattern of low intensity on T1WI and high intensity on T2WI that typify MRI findings in cases of osteonecrosis. When joint space narrowing is observed radiographically, the diffuse abnormal pattern of low intensity on T1WI and high intensity on T2WI induced by a subchondral small lesion might be an early sign of RDC.

[Craniopharyngioma presenting a symptom of pituitary apoplexy and hyponatremia: a case report]

We report a case of a 70-year-old woman admitted to our hospital with sudden headache, drowsiness and hyponatremia. MRI on admission showed an intrasellar mass with suprasellar extension. Serum examination revealed decreased sodium and hypopituitarism, but they were normalized gradually by compensation using hydrocortisone, thyroid hormone and salt. Afterwards, masked diabetes insipidus appeared and required aqueous pitressin for the control of urine volume. A removal operation was performed uneventfully using the transsphenoidal approach and histological examination confirmed squamous-papillary type craniopharyngioma. Intratumoral hemorrhage of the craniopharyngioma is extremely rare. These cases tend to occur after over 15 years of maturation and the squamous-papillary type tend to bleed more than the adamantinomatous type. However, it is very difficult to make a differential diagnosis between craniopharyngioma with intratumoral hemorrhage and pituitary apoplexy, judging only by symptoms or interventional radiology. The definite mechanism of hyponatremia associated with a parasellar lesion is still obscure, but compression to the anterior hypothalamus or pituitary gland by an enlargement of the parasellar tumor is generally hypothesized.

The hDLG-associated protein DAP interacts with dynein light chain and neuronal nitric oxide synthase

BACKGROUND

Postsynaptic density (PSD)-95 interacts with and mediates clustering of the N-methyl-D-aspartate-receptors (NMDA-R). PSD-95 also interacts with the hDLG-associated protein DAP, which is also called Synapse-associated protein 90-associated protein (SAPAP), and Guanylate kinase-associated protein (GKAP).

RESULTS

DAP interacted directly with the dynein light chain (DLC) family of proteins. DLC was contained in the NMDA-R-PSD-95-DAP-neuronal nitric oxide synthase (nNOS) complex. Furthermore, DAP interacted with nNOS and recruited it into the Triton X-100-insoluble fraction of transfected cells.

CONCLUSION

DAP interacts directly with DLC and nNOS, and links these proteins to the NMDA-R-PSD-95 complex.

Detection of localized methylmercury contamination by use of the mussel adductor muscle in Minamata Bay and Kagoshima Bay, Japan

Based on our previous finding that the concentrations of total mercury in mussel adductor muscle approximated those of methylmercury, we compared concentrations of total mercury in the adductor muscle of the mussel Mytilus galloprovincialis, collected from four sites around Minamata City from 1993 to 1995 and four sites in Kagoshima Bay from 1997 to 1998, to assess the level of localized methylmercury contamination. Though the input of mercury from the chemical plant had stopped by around 1970, concentrations of total mercury in the mussel adductor muscle were higher at two sites (26-121 ng/g, n = 135) near the main fallout of wastewater from the chemical plant in Minamata Bay than at the other sites, i.e. two sites 1-5 km from the former sites in Minamata City (6-28 ng/g, n = 52), and all sites in Kagoshima Bay (2-30 ng/g, n = 287). The localized methylmercury contamination around the chemical plant in Minamata Bay was documented also by our sensitive analysis of mercury concentrations in seawater and sediment samples. The survey of concentrations of total mercury in the mussel adductor muscle seems to be useful for monitoring the methylmercury contamination in coastal areas.

Osteonecrosis of the patella in patients with nontraumatic osteonecrosis of the femoral head: MRI findings in 60 patients

We examined both knees in 60 patients with nontraumatic osteonecrosis of the femoral head with three-dimensional MRI. We found osteonecrosis of the patella in 9 patients (10 knees) and osteonecrosis of the femoral or tibial condyles/metaphyses in 35 patients (61 knees). In the patella, the necrosis was located in the proximal half and tended to develop in patients with other necrotic lesions in the knee.

[A case of Terson's syndrome with an interesting MRI finding]

We report a case of a 62-year-old woman admitted to our hospital in a semicomatose state. CT scan and MRI on admission revealed a dense subarachnoid hemorrhage and intracerebral hematoma in the right frontal lobe. Digital subtraction angiography showed a saccular aneurysm located in the anterior communicating artery, so radical neck clipping of the aneurysm was performed via the right pterional approach. The operation was unevential. The patient complained of bilateral visual disturbance on the next day and FLAIR image of MRI demonstrated clearly crescent shaped and mobile high intense lesions corresponding to subhyaloid vitreous hemorrhage in both eye balls. The fundoscopic examination revealed an intravitreous hemorrhage which gradually disappeared over the next 12 days. Terson's syndrome after subarachnoid hemorrhage has been linked to an entity of poor prognosis, so it is beneficial that characteristic findings in FLAIR image of MRI can lead to correct diagnosis of Terson's syndrome earlier.

Synthesis of 3'alpha-carbo-substituted 2',3'-dideoxyribonucleosides from naturally occurring nucleosides

Naturally occurring ribonucleosides, uridine and adenosine, were converted to their 3'alpha-CH2CO2Me and 3'alpha-CH2PO(OPh)2 2',3'-dideoxy analogues. The present reaction sequence starts with oxidative cleavage of the 2',3'-cis-diol system, and involves radical-mediated reconstruction of furanose ring as the key step.