Direct visualization of the three-dimensional shape of skyrmion strings in a noncentrosymmetric magnet

Magnetic skyrmions are topologically stable swirling spin textures that appear as particle-like objects in two-dimensional (2D) systems. Here, utilizing scalar magnetic X-ray tomography under applied magnetic fields, we report the direct visualization of the three-dimensional (3D) shape of individual skyrmion strings in the room-temperature skyrmion-hosting non-centrosymmetric compound Mn_1.4Pt_0.9Pd_0.1Sn. Through the tomographic reconstruction of the 3D distribution of the [001] magnetization component on the basis of transmission images taken at various angles, we identify a skyrmion string running through the entire thickness of the sample, as well as various defect structures, such as the interrupted and Y-shaped strings. The observed point defect may represent the Bloch point serving as an emergent magnetic monopole, as proposed theoretically. Our tomographic approach with a tunable magnetic field paves the way for direct visualization of the structural dynamics of individual skyrmion strings in 3D space, which will contribute to a better understanding of the creation, annihilation and transfer of these topological objects.

The utility of FDG-PET for detecting multiple primary cancers in hypopharyngeal cancer patients

Aim: To examine the utility of 2'-[18F]-fluoro-2'-deoxy-D-glucose positron emission tomography (FDG-PET) for detecting multiple primary cancers (MPC) in patients with hypopharyngeal cancer (HPC). Patients, methods: Seventy patients with HPC underwent FDGPET to determine the staging. Routine clinical examinations were carried out, including computed tomography (CT), magnetic resonance imaging (MRI), ultrasound (US), and oesophagealgastroduodenoscopy (EGDS). The detection rate of synchronous and metachronous cancer was calculated based on FDG-PET alone or FDG-PET combined with clinical routine examination. Sensitivity, specificity, positive predictive values (PPV), negative predictive values (NPV), and accuracy were used to diagnose oesophageal cancer using FDG-PET. Results: Of the 70 patients, 12 (17.1%) had 15 synchronous tumours, and 2 of the 58 remaining patients (3.4%) had metachronous tumours. Oesophageal cancer was discovered most frequently: superficial type (n = 6), advanced type (n = 4). On a per-patient basis, 11 of 12 patients (91.6%) were diagnosed with synchronous tumours, and on a per-lesion basis, 12 of 15 lesions (80.0%) were detected by FDG-PET. The sensitivity, specificity, accuracy, PPV, and NPV of FDG-PET regarding oesophageal cancer were 70%, 100%, 95.7%, 100%, and 95.2% respectively. Three of the six superficial types were positive on FDG-PET. Both of the metachronous tumour lesions were detected by FDG-PET. Conclusion: FDG-PET is useful for estimating the MPC in HPC patients. Since 3 of 10 synchronous oesophageal cancer were missed with PET alone, a combination with EGDS should be considered to exclude synchronous oesophageal cancer.

Ceramide limits phosphatidylinositol-3-kinase C2β-controlled cell motility in ovarian cancer: potential of ceramide as a metastasis-suppressor lipid

Targeting cell motility, which is required for dissemination and metastasis, has therapeutic potential for ovarian cancer metastasis, and regulatory mechanisms of cell motility need to be uncovered for developing novel therapeutics. Invasive ovarian cancer cells spontaneously formed protrusions, such as lamellipodia, which are required for generating locomotive force in cell motility. Short interfering RNA screening identified class II phosphatidylinositol 3-kinase C2β (PI3KC2β) as the predominant isoform of PI3K involved in lamellipodia formation of ovarian cancer cells. The bioactive sphingolipid ceramide has emerged as an antitumorigenic lipid, and treatment with short-chain C6-ceramide decreased the number of ovarian cancer cells with PI3KC2β-driven lamellipodia. Pharmacological analysis demonstrated that long-chain ceramide regenerated from C6-ceramide through the salvage/recycling pathway, at least in part, mediated the action of C6-ceramide. Mechanistically, ceramide was revealed to interact with the PIK-catalytic domain of PI3KC2β and affect its compartmentalization, thereby suppressing PI3KC2β activation and its driven cell motility. Ceramide treatment also suppressed cell motility promoted by epithelial growth factor, which is a prometastatic factor. To examine the role of ceramide in ovarian cancer metastasis, ceramide liposomes were employed and confirmed to suppress cell motility in vitro. Ceramide liposomes had an inhibitory effect on peritoneal metastasis in a murine xenograft model of human ovarian cancer. Metastasis of PI3KC2β knocked-down cells was insensitive to treatment with ceramide liposomes, suggesting specific involvement of ceramide interaction with PI3KC2β in metastasis suppression. Our study identified ceramide as a bioactive lipid that limits PI3KC2β-governed cell motility, and ceramide is proposed to serve as a metastasis-suppressor lipid in ovarian cancer. These findings could be translated into developing ceramide-based therapy for metastatic diseases.

Clinical significance of miR-144-ZFX axis in disseminated tumour cells in bone marrow in gastric cancer cases

BACKGROUND

We previously reported that bone marrow (BM) was a homing site for gastric cancer (GC) cells leading to haematogenous metastases. There has been little study that microRNAs regulated pathways in malignant cells or host cells in BM, and thereby regulated the progression of GC.

METHODS

Both microRNA microarray and gene expression microarray analyses of total RNA from BM were conducted, comparing five early and five advanced GC patients. We focused on miR-144-ZFX axis as a candidate BM regulator of GC progression and validated the origin of the microRNA expression in diverse cell fractions (EpCAM(+)CD45(-), EpCAM(-)CD45(+), and CD14(+)) by magnetic-activated cell sorting (MACS).

RESULTS

Quantitative reverse-transcriptase (RT)-PCR analysis validated diminished miR-144 expression in stage IV GC patients with respect to stage I GC patients (t-test, P=0.02), with an inverse correlation to ZFX (ANOVA, P<0.01). Luciferase reporter assays in five GC cell lines indicated their direct binding and validated by western blotting. Pre-miR144 treatment and the resultant repression of ZFX in GC cell lines moderately upregulated their susceptibility to 5-fluorouracil chemotherapy. In MACS-purified BM fractions, the level of miR-144 expression was significantly diminished in disseminated tumour cell fraction (P=0.0005). Diminished miR-144 expression in 93 cases of primary GC indicated poor prognosis.

CONCLUSION

We speculate that disseminated cancer cells could survive in BM when low expression of miR-144 permits upregulation of ZFX. The regulation of the miR-144-ZFX axis in cancer cells has a key role in the indicator of the progression of GC cases.

Dentigerous cyst in primary dentition: case report of a 4-year-old girl

The purpose of this case report is to describe the treatment outcome of a 4-year-old girl with a dentigerous cyst on the primary mandibular right second premolar of her caries-free mouth. Her primary predecessor was extracted and the lesion decompressed by using a removable appliance with a resin projection. The succeeding premolar had not developed further 8 months later, however, and had to be extracted. Crown formation of the succeeding premolar might have been interrupted by the presence of the cyst. To our knowledge, this is the earliest reported asymptomatic dentigerous cyst in the mandibular premolar region with a vital primary second molar.

Fractional allelic loss as a potential biomarker of risk prediction in early-stage mucinous ovarian tumors of low malignant potential

Ovarian tumors of low malignant potential (LMP) appear to be intermediate between adenomas and ovarian carcinomas. Such tumors are often associated with a significantly better prognosis than for ovarian carcinomas. However, a subset of LMPs can progress and become lethal even in patients with early-stage disease. In order to seek sensitive diagnostic tools to monitor patients after surgical therapy, we performed a genome-wide scan for LOH in 37 early-stage mucinous LMPs using 91 polymorphic microsatellite markers at an average interval of 50 cM across all of the human chromosomes and 25 LOH markers reported to be associated with ovarian carcinoma. Fractional allelic loss (FAL) values were calculated as (loci scored with LOH)/(total informative loci) for each sample. With respect to tumor recurrence, high FAL values were more frequent in recurrent tumors than in non-recurrent tumors. Using the screening markers, FAL values for recurrent tumors were significantly higher than for non-recurrent tumors (19.8% vs 6.3%, respectively, p < 0.0001). Similar results were obtained using the hotspot markers (22.2% vs 7.1%, respectively, p < 0.0001). A significant correlation between FAL values obtained using screening markers and those based on hotspot markers was observed (R = 0.460, p = 0.003). Our findings suggest that a specific type of genetic instability (i.e., chromosomal instability, CIN) may exist in mucinous LMPs, and that this instability may indicate tumors with an aggressive biological nature. Therefore, FAL values may represent a new biomarker for risk prediction in early-stage mucinous LMP tumors.

Therapy-related myelodysplasia and acute myeloid leukemia following paclitaxel- and carboplatin-based chemotherapy in an ovarian cancer patient: a case report and literature review

Alkylating agents have strong leukemogenic potential. There are a number of recent acute myeloid leukemia (t-AML) cases related to previous paclitaxel exposure. These leukemias tend to be of aggressive subtypes with long-latency periods. Unlike previously reported cases, the present case was of the secondary acute megakaryoblastic myeloid leukemia (AML M7) subtype. Additionally, it did not harbor a translocation in chromosome 19. A 73-year-old woman was diagnosed with t-AML M7 with antecedent myelodysplasia. Leukemia followed a second induction of paclitaxel- and carboplatin-based chemotherapy for recurrent ovarian cancer. Her second induction began 25 months after completion of her first course of chemotherapy. The increased incidence of postpaclitaxel leukemia suggests a probable role for paclitaxel as a leukemogenic agent. It highlights the importance of assessing for leukemia risk factors prior to beginning paclitaxel therapy.

A case of extremely chemoresistant pure pleomorphic rhabdomyosarcoma of the uterus associated with a high serum LDH level

BACKGROUND

Pleomorphic rhabdomyosarcoma (RMS) of gynecologic origin is an exceedingly rare, highly malignant tumor. Only a few cases have been reported in the last decades.

CASE REPORT

A 60-year-old postmenopausal woman presented with a high LDH level of unknown origin. Ultimately, she was diagnosed with pleomorphic RMS. She underwent total hysterectomy, bilateral salpingo-oophorectomy, left pelvic and paraaortic lymphadenectomy and partial omentectomy. Surgery was followed by systemic chemotherapy and pelvic irradiation. Unfortunately, the patient did not respond to treatment. Her disease course correlated with the fluctuation of plasma LDH levels. Ultimately she died within 20 months of the diagnosis.

CONCLUSION

It is important to have better insight and to set a standard multimodal treatment for adult RMS. In addition, plasma LDH levels can be considered as a prognostic marker for RMS, particularly in advanced stage.

Leptin facilitates learning and memory performance and enhances hippocampal CA1 long-term potentiation and CaMK II phosphorylation in rats

Leptin, an adipocytokine encoded by an obesity gene and expressed in adipose tissue, affects feeding behavior, thermogenesis, and neuroendocrine status via leptin receptors distributed in the brain, especially in the hypothalamus. Leptin may also modulate the synaptic plasticity and behavioral performance related to learning and memory since: leptin receptors are found in the hippocampus, and both leptin and its receptor share structural and functional similarities with the interleukin-6 family of cytokines that modulate long-term potentiation (LTP) in the hippocampus. We therefore examined the effect of leptin on (1) behavioral performance in emotional and spatial learning tasks, (2) LTP at Schaffer collateral-CA1 synapses, (3) presynaptic and postsynaptic activities in hippocampal CA1 neurons, (4) the intracellular Ca(2+) concentration ([Ca(2+)](i)) in CA1 neurons, and (5) the activity of Ca(2+)/calmodulin protein kinase II (CaMK II) in the hippocampal CA1 tissue that exhibits LTP. Intravenous injection of 5 and/or 50mug/kg, but not of 500mug/kg leptin, facilitated behavioral performance in passive avoidance and Morris water-maze tasks. Bath application of 10(-12)M leptin in slice experiments enhanced LTP and increased the presynaptic transmitter release, whereas 10(-10)M leptin suppressed LTP and reduced the postsynaptic receptor sensitivity to N-methyl-d-aspartic acid. The increase in the [Ca(2+)](i) induced by 10(-10)M leptin was two times greater than that induced by 10(-12)M leptin. In addition, the facilitation (10(-12)M) and suppression (10(-10)M) of LTP by leptin was closely associated with an increase and decrease in Ca(2+)-independent activity of CaMK II. Our results show that leptin not only affects hypothalamic functions (such as feeding, thermogenesis, and neuroendocrine status), but also modulates higher nervous functions, such as the behavioral performance related to learning and memory and hippocampal synaptic plasticity.

Elevated cerebrospinal fluid lactate levels and the pathomechanism of calcification in Fahr's disease

In this study, we report the case of a 68-year-old man complaining of involuntary movement of his left shoulder and lower jaw plus dyspnea. On cranial computed tomography and magnetic resonance imaging, marked and symmetrical calcification at the basal ganglia and dentate nuclei was documented. An elevated cerebrospinal fluid (CSF) lactate level was confirmed by spinal tap examination and magnetic resonance spectroscopy. The raised CSF lactate level, clinical characteristics such as diabetes, bilateral hearing loss and symmetrical cerebral calcification strongly suggested some kinds of mitochondrial disease. However, gene analysis of peripheral blood leukocytes revealed no typical or known mutations. Under the diagnosis of Fahr's disease, we treated him with haloperidol, which completely abolished his symptoms. In Ellsworth-Howard test, he showed markedly decreased phosphaturic response to parathyroid hormone with same pattern as type 2 pseudohypoparathyroidism. This abnormal response in our patient, probably due to respiratory alkalosis reflecting chronic hyperventilation, might in part explain similar mechanism of ectopic calcification underlying these two diseases.

Follow-up assessment of the collateral circulation in patients with Kawasaki disease who underwent dipyridamole stress technetium-99m tetrofosmin scintigraphy

To assess the alteration of myocardial ischemic findings and the role of collateral vessels in patients with Kawasaki disease (KD), we used dipyridamole stress technetium-99m tetrofosmin (Tf) single photon emission computed tomography (SPECT). A comparison study of coronary angiography and dipyridamole stress (0.70 mg/kg) Tf-SPECT was repeated at least twice in 20 patients. The subjects included 7 patients with coronary stenosis, 1 with pre- and post-coronary artery bypass grafting (CABG) due to coronary stenosis, 1 with progression to coronary stenosis, and 11 with persistent coronary aneurysms. In the stenosis group, Tf-SPECT revealed that 6 of the 7 patients had some degree of ischemic findings, and 5 of these 6 did not show any change in their ischemic findings during follow-up. In 1 patient, the ischemic findings changed according to the collateral circulation changes. The patient who underwent CABG had pre-CABG ischemic changes that disappeared after CABG. In the patient whose coronary arteries progressed to stenosis, the ischemic findings progressed as the coronary stenosis progressed. In the persistent aneurysm group, there were no ischemic findings. In the future Tf-SPECT may become one of the most useful methods for monitoring the progressive changes of myocardial ischemia in KD.

Morphological imaging in the localization of neuroendocrine gastroenteropancreatic tumors found by somatostatin receptor scintigraphy

PURPOSE

To evaluate the necessity of morphological images (MI) in reading somatostatin receptor scintigraphy (SRS) in patients with suspected neuroendocrine gastroenteropancreatic (GEP) tumors.

MATERIAL AND METHODS

A Japanese multicenter clinical trial of SRS was conducted in 40 patients with suspected GEP tumors. Three experienced radiologists interpreted the images in three separate sessions in a blinded manner (1: SRS images alone, 2: MI alone, 3: SRS and MI analyzed simultaneously), and the reading results of each session were compared. In addition, the diagnostic abilities of SRS, MI and SRS alone and simultaneous SRS and MI readings were compared for patients where final diagnosis was obtained.

RESULTS

SRS detected more suspected lesions (positive or inconclusive uptake) than morphological images did (51 vs 27 lesions), but included many physiological uptakes detected as positive or inconclusive uptakes. Combined reading of SRS and morphological images helped to correctly recognize these physiological uptakes, and also helped in determining the anatomical localization of the abnormal uptakes. Combined reading of SRS and morphological images gave the highest diagnostic impact.

CONCLUSION

The sensitivity of SRS with regard to GEP is high. However the specificity is very low. Morphologic imaging is necessary for the exclusion of physiological uptake and correct anatomic location of an abnormal tracer uptake. The combined reading of SRS and morphologic imaging studies gives the highest diagnostic impact.

Relationship between intraoperative transoesophageal echocardiography findings and perfusion lung scintigraphy results on first postoperative day

BACKGROUND

Although intraoperative transoesophageal echocardiography (TOE) has been used to detect the occurrence of echogenic macro- and/or microembolic phenomena during total hip arthroplasty (THA), no direct correlation between macroembolism and the formation of pulmonary embolism (PE) has been conclusively determined in early postoperative periods after THA.

METHODS

Sixty-two patients scheduled for primary THA were enrolled in this study. Intraoperative TOE images were continuously recorded on videotape and the echogenic events were evaluated throughout surgery. Perfusion lung scintigraphy was performed on the first postoperative day (POD1).

RESULTS

Perfusion lung scintigraphy revealed the existence of PE in nine (15%) of the 62 patients who underwent THA: five (25%) of 20 patients with cemented THA and four (10%) of 42 patients with non-cemented THA. The grading score of intraoperative TOE findings, including the amount of echogenic particles in right atrium, the longest time of echogenesis and the diameter of the largest echogenic particles, did not differ between the groups with and without PE. The sensitivity, specificity, and positive and negative predictive values for the detection of echogenic macroemboli for the prediction of the development of PE on POD1 were 0.78, 0.60, 0.25 and 0.94, respectively.

CONCLUSION

Intraoperative TOE monitoring did not predict the occurrence of PE on POD1.

A polymorphism of DRD2 gene and brain atrophy in methamphetamine psychosis

Our group, Ujike et al., recently reported that the A1 allele of TaqI A polymorphism of the dopamine receptor D2 (DRD2) gene, associated with transient psychosis, significantly differs from that of patients with prolonged psychosis in methamphetamine psychosis. Therefore, we examined the association between the TaqI A polymorphism of the DRD2 gene and the brain MRI view for patients with methamphetamine psychosis. The subjects underwent brain MRI scans using the FLAIR method. Genotyping was performed by PCR-RFLP methods using genomic DNA extracted from peripheral blood by the phenol method. Ten subjects had the A1/A2 genotype, eleven subjects had the A2/A2 genotype, and no subject had the A1/A1 genotype. The domain size, including the thalamus and basal ganglia that were inside each side of the putamens, did not differ between the three groups (the A1/A2-group, the A2/A2-group, and the young healthy person group). In the comparison based on this domain, the temporal lobe tended to narrow in the A2/A2-group compared to the A1/A2-group (P = .06). The other domain (cerebrum, corpus callosum, etc.) showed no difference between the A1/A2-group and the A2/A2-group. It is suggested that in methamphetamine psychosis the TaqI A polymorphism not only regulates prolongation of psychosis symptoms but also influences the form of the temporal lobe.

The relative contributions of each subset of ocular infiltrated cells in experimental choroidal neovascularisation

AIM

Choroidal neovascularisation (CNV) is a major cause of blindness in adults. The aim of this study was to investigate the role of infiltrating cells in the development of experimental CNV.

METHODS

CNV was induced in C57BL/6 (B6) mice by laser photocoagulation (PC). After PC, the numbers of each subset of infiltrated cells were analysed by flow cytometry at multiple time points. Each subset (except for macrophages) was depleted by the specific antibodies in vivo. Thereafter, the area of CNV was compared between the control B6 mice and the specific antibody treated mice 7 days after PC. The CNV formation in neutrophil depleted CC chemokine receptor-2 (CCR2) knockout mice was also examined to minimise the effects of macrophages.

RESULTS

In the early phase of CNV formation, a large number of neutrophils and macrophages infiltrated to the eyes. Natural killer (NK) cells and T lymphocytes were barely detected while no B lymphocytes were detected. The CNV areas did not significantly change compared between the control B6 mice and the specific antibody treated mice. However, the neutrophil depleted CCR2KO mice resulted in a reduction of CNV.

CONCLUSION

Although lymphocytes and NK cells had little effect on CNV formation, neutrophils partially contributed to CNV in the absence of macrophages.

Characteristics of pancreas transplantation currently performed in japan

The Pancreas Transplantation (tx) Program under the Japanese Organ Transplant Act was started in 2000. PTx is indicated for type 1 diabetic patients on hemodialysis therapy. As of April 2003 93 patients are listed as candidates. Ten cases of PTx with enteric or bladder-drained technique were performed during the last 3 years as well as nine SPK and one PAK. Of 10 cases, nine recipients are insulin-free with HbA1c values ranging from 4.4% to 5.7%, although exogenous insulin was required in six cases temporarily, namely for a median 63 days (12 to 225 days). One case was lost due to pancreatic graft thrombosis. All 10 kidney grafts are functioning. Based on the experiences with 14 cases of pancreas tx using non-heart-beating (NHB) donors, we defined the criteria of NHB donor as: age younger than 40 years and cessation of respiratory support. One case of SPK with graft of NHB donor was done, and the recipient is off insulin. Pancreas and kidney are allocated for SPK if the recipient shares at least one HLA-DR antigen. Marginal donors were defined as higher mean donor age, median 37 (range 18 to 58 years); mean 38 +/- 12 years), and no death cause of by trauma. The revascularization of gastroduodenal artery to the pancreatic graft was performed in eight cases to minimize the risk of ischemic injury to the pancreatic graft and technical failure in cases of marginal donor.

Pancreas-kidney transplantation in Japan: impact of cyclosporine on the development of immunosuppressive therapy

The number of pancreas transplants reached 16,043 worldwide in October 2001, with 1800 performed in 2000. Since the introduction of cyclosporine (CyA) in 1979, a regimen consisting of CyA, azathioprine, and steroids has been shown to improve long-term survival of clinical transplants. In Japan, the first simultaneous pancreas-kidney transplantation was performed in 1984, using organs from a brain-dead donor. This procedure was followed by 14 pancreas transplantations from cardiac arrest donors. All cases utilized a CyA-based regimen with antilymphocyte globulin or OKT3 induction. Six of the 15 recipients required less insulin postoperatively. Under a new transplant law enforced in 1997, 10 pancreas/pancreas-kidney transplantations were performed in patients diagnosed with end-stage renal failure due to diabetes mellitus type 1. In 1 patient, the graft failed due to venous thrombosis, but the other 9 recipients achieved an increased quality of life without the need for insulin or for dialysis. Pancreas transplantation represents an effective treatment worldwide and in Japan, due to the availability of CyA or tacrolimus in combination with other agents such as antilymphocyte globulin, OKT3, or mycophenolate mofetil. This investigation presents the results of pancreas-kidney transplantation in Japan, in comparison with those worldwide, and describes a recent case in Japan.

Inhibition of neointimal hyperplasia after balloon injury by cis-element 'decoy' of early growth response gene-1 in hypercholesterolemic rabbits

Early growth response factor-1 (Egr-1) is a transcription factor that is rapidly activated after vascular injury and thus might contribute to vascular proliferation and inflammation. We hypothesized that Egr-1 might therefore be a therapeutic target against restenosis. Hypercholesterolemic rabbits were intraluminally administered synthetic DNA as a 'decoy' against Egr-1 immediately after carotid artery balloon injury. Efficient transfection was confirmed by the delivery of a fluorescence-labeled decoy. Gel mobility-shift assay showed increased Egr-1 activity after balloon injury and its prevention by Egr-1 decoy transfection in vivo. Egr-1 decoy transfection attenuated early inflammation and proliferation and later neointimal hyperplasia. In addition, Egr-1 decoy transfection reduced gene expression and protein production of Egr-1-dependent genes such as platelet-derived growth factor-B, transforming growth factor-beta1, and monocyte chemoattractant protein-1. The Egr-1 pathway has an essential role in the pathogenesis of neointimal hyperplasia after balloon injury in hypercholesterolemic rabbits. This decoy strategy is a potential practical form of therapy for human restenosis.

In vitro FK506 kidney tubular cell toxicity

Nephrotoxicity is the most prominent side effect of the new immunosuppressive drug FK506. Some of the histopathological changes associated with cyclosporine (CyA) nephrotoxicity such as tubular vacuolization and glomerular thrombosis have also been reported with FK506 therapy. In this study we used kidney tubular cells in culture to address the issue of FK506- and CyA-induced tubular damage. Exposure of tubular cells to high concentrations of FK506 or CyA (10, 50 and 100 microM) induced a time- and dose-dependent cell injury in vitro characterized by a direct cytotoxic effect on tubular cells as expressed by release of 3H-thymidine from prelabelled cells, N-acetyl-beta-D-glucosaminidase (NAG) release and cell detachment. Ultrastructural changes (vacuolization, swelling and mitochondrial enlargement) and inhibition of the growth (DNA and RNA synthesis) of cultured tubular cells were also observed at high concentrations of FK506 and CyA. These concentrations are higher than those reached in clinical situations, but close to the concentrations that may be reached by FK506 or CyA in tissues. Low concentrations of FK506 and CyA (1, 0.1 and 0.01 microM) were not cytotoxic and induced only a minimal inhibitory effect on the growth of tubular cells in vitro. At the same concentration CyA induced more cell detachment, more NAG release and a stronger inhibitory effect on cell growth than FK506 (P < 0.01). Since an evident cytotoxic effect was observed only at high concentrations, we can speculate that tubular toxicity is due to the accumulation of drug in the cells inducing cell disruption and death.

Liquid chromatographic-atmospheric pressure chemical ionization mass spectrometric analysis of opiates and metabolites in rat urine after inhalation of opium

To examine the urinary excretion of opiates and their metabolites following inhalation exposure of rats to opium, analytical procedures for the simultaneous determination of the compounds in opium, the vapor derived by the volatilization of opium and the urine of rats exposed to the opium vapor were developed using liquid chromatography-atmospheric pressure chemical ionization mass spectrometry (LC-APCI-MS). Seven compounds were determined in the opium, namely morphine, codeine, thebaine, noscapine, papaverine, meconic acid and meconin. All seven were extracted with 2.5% acetic acid solution and subjected to LC-APCI-MS analysis. The separation was performed on an ODS column in acetonitrile-50 mM ammonium formate buffer (pH 3.0) using a linear gradient program and quantitative analysis was carried out in the selected ion monitoring mode ([M+H](+)). For the analysis of the volatilization of opium, the opium (1 g) was added to a glass pipe, which was then heated at 300 degrees C for 20 min. Negative pressure (air flow-rate; 300 ml/min) was used to draw the vapor through a series of glass wool and methanol traps. The total amount of each compound in the vapor was estimated by measurement of the compounds trapped in the glass wool and methanol. Wister rats (n=3) were exposed to the vapor derived from the volatilization system and the urinary amounts (0-72 h) of the six opiates and metabolites including morphine-3-grucronide (M3G) and morphine-6-grucronide (M6G) were measured after solid-phase extraction. The calibration curves for those compounds in the rat urine were linear over the concentration range 10-500 ng/ml. The recoveries for each analyte from the rat urine sample spiked with standard solution were generally greater than 80%, and the relative standard deviation for the analytical procedure was less than 8% with the exception of meconin. After inhalation exposure of rats to opium, M3G (5.45-14.38 micro g), morphine (2.27-4.65 micro g), meconin (0.54-1.85 micro g), codeine (0.54-1.85 micro g), noscapine (0.34-0.40 micro g) and papaverine (0.01-0.04 micro g) were detected in the urine over 72 h. However, only trace levels of thebaine were observed despite it being one of the major alkaloids found in the opium. On the other hand, a relatively large amount of meconin was detected in the vapor and the urine as compared with the opium. It is suggested that the presence of meconin in biological fluids could be indicative of opium ingestion by inhalation.

Prevalence and serodiversity of the pandemic clone among the clinical strains of Vibrio parahaemolyticus isolated in southern Thailand

We collected diarrhoea specimens in two hospitals in southern Thailand in 1999 to examine whether infection by the Vibrio parahaemolyticus pandemic clone is prevalent. V. parahaemolyticus was isolated from 317 specimens. Seventy-six per cent of the isolated strains had the pandemic clone-specific characteristics (tdh+, trh-, and an unique toxRS sequence detectable by GS-PCR) and an associated characteristic (the ORF8 sequence of f237 phage). These strains belonged to the three pandemic servovars with the O3:K6 strains being dominant and three other serovars (O1:K25, O1:K41 and O4:K12). We also found O1:K25 and O1:K41 strains with the pandemic clone-specific characteristics among the strains isolated from the international travellers who left Thailand and three other Asian countries between 1998 and 1999, verifying pandemic potential of these strains. The results demonstrate prevalence of infection by the pandemic clone in southern Thailand and suggest emergence of various serovariants in this area and their implication in international spread.

Percentage of the positive area of bone metastasis is an independent predictor of disease death in advanced prostate cancer

We addressed in this study whether quantifying the extent of disease on bone scans can predict the disease death of patients with advanced prostate cancer using computer-assisted image analysis. Pretreatment radionuclide bone scans were reviewed in 56 patients with bone metastases from prostate cancer, and the percentage of the positive area on a bone scan (%PABS) was quantified automatically using a personal computer with the NIH Image program for estimation of the accurate extent of metastatic bone lesions on a bone scan. The significance of the %PABS as well as the other known prognostic factors was evaluated using univariate and multivariate Cox proportional hazards analysis. In univariate regression analysis, the %PABS (P=0.0155), serum alkaline phosphatase (P=0.0272), the tumour grade based on biopsy (P=0.044) and the number of bone lesions on bone scans (P=0.0388) were well associated with disease-specific survival. In multivariate analysis, the %PABS (P=0.0155, relative risk ratio 2.603), but not the other factors, was the independent predictor of the disease death. These results suggest that the %PABS is a novel parameter for predicting the prognosis of patients with advanced prostatic cancer.

Assessment of the ability of myocardial contrast echocardiography with harmonic power Doppler imaging to identify perfusion abnormalities in patients with Kawasaki disease at rest and during dipyridamole stress

The aim of our study was to assess the ability of myocardial contrast echocardiography (MCE) with harmonic power Doppler imaging (HPDI) to identify perfusion abnormalities in patients with Kawasaki disease at rest and during pharmacological stress imaging with dipyridamole. Results were compared with those of 99mTc-tetrofosmin single-photon emission computed tomography (SPECT) imaging as the clinical reference standard. MCE with HPDI was performed on 20 patients with a history of Kawasaki disease. Images were obtained at baseline and during dipyridamole infusion (0.56 mg x kg(-1)) in the apical two- and four-chamber views. Myocardial opacification suitable for the analysis was obtained in all patients. Nine patients with stenotic lesions had a reversible defect after dipyridamole infusion detected by both MCE with HPDI and SPECT, and 3 patients with a history of myocardial infarction had a partially or completely irreversible defect detected by both methods. Three patients with coronary aneurysm without stenotic lesion, 4 patients with regressed coronary aneurysm, and 2 patients with normal coronary artery in acute phase also had normal perfusion at rest and after pharmacological stress by both methods. A 96% concordance (kappa = 0.87) was obtained when comparing the respective segmental perfusion scores using the two methods at baseline, and an 86% concordance (kappa = 0.81) was obtained at postdipyridamole infusion. After combining baseline and postdipyridamole images, each segment was labeled as having normal perfusion, irreversible defects, or reversible defects. Using these classifications, concordance for the two methods was 92% (kappa = 0.87). MCE with HPDI is a safe and feasible method by which to detect asymptomatic ischemia due to severe stenotic lesion, and it may be an important addition to the modalities used to identify patients at risk for myocardial infarction as a complication of Kawasaki disease.