Etretinate enhances the susceptibility of human skin squamous cell carcinoma cells to 5-aminolaevulic acid-based photodynamic therapy

BACKGROUND

Photodynamic therapy (PDT) with 5-aminolaevulinic acid (5-ALA) is a noninvasive and effective treatment for superficial skin cancers. Etretinate, a derivate of vitamin A, with the chemical formula ethyl(2E,4E,6E,8E)-9-(4-methoxy-2,3,6-trimethylphenyl)-3,7-dimethyl-2,4,6,8-nona-tetraenoate, has been reported to have antitumour effects and to regulate the proliferation and differentiation of skin cancers.

OBJECTIVE

In order to develop more efficient PDT, we investigated whether etretinate enhanced the cytotoxic action of ALA-based PDT against human squamous cell carcinoma cell line, HSC-5.

METHOD

The in vitro cytotoxicity was measured using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Apoptotic cells were detected by double-staining with fluorescent annexin V and propidium iodide. Intracellular protoporphyrin IX (PpIX) converted from exogenous ALA was measured by a fluorescence meter.

RESULTS

HSC-5 cells pretreated with a nontoxic concentration of etretinate became more susceptible to the cytotoxic action of ALA-based PDT. Etretinate-pretreated cells underwent apoptosis in response to ALA-based PDT. Etretinate pretreatment resulted in enhanced accumulation of ALA-dependent intracellular PpIX.

CONCLUSIONS

The results suggest that etretinate enhances the susceptibility of HSC-5 cells to ALA-based PDT via the intracellular increase of ALA-dependent PpIX. Etretinate might be useful for improvement of ALA-based PDT.

Lead retention mechanisms and hydraulic conductivity studies of various bentonites for geoenvironment applications

Four bentonites from various sources were exposed to batch adsorption testing, selective sequential extraction and consolidation tests to investigate their metal retention capacity and hydraulic conductivity for geoenvironmental application such as in clay barrier materials. The Japanese bentonites (JB1-JB3) contain approximately 2-4% of carbonate and trace amount of zeolite (JB2 and JB3), whereas the US bentonite has < 1% carbonate and no zeolite. The rank of smectite content in the bentonites are USB > JB1 > JB3 > JB2. The materials ranked as JB2 approximately JB3 > JB1 > USB, according to retention capacity, while after the removal of carbonate the retention capacity order was JB1 approximately JB2 approximately JB3 > USB. SSE results indicate that carbonate plays a major role at low Pb solution concentration and precipitate as PbCO3. Once the carbonate is exhausted, the clay composition dominates the sorption process. The hydraulic conductivity of the bentonite mixtures (basalt + 10% bentonite) using water was kUSB < kJB1 < kJB3 < kJB2, consistent with the smectite content and swelling power, with USB having the highest proportion of smectite. Among the Japanese bentonites studied, JB1 is the best candidate for barrier material, comparable to the widely used USB.

Experimental heating properties of re-entrant type resonant cavity applicator for deep tumor hyperthermia

This paper discusses the heating properties of a new type hyperthermia system composed of a re-entrant type resonant cavity applicator for a deep tumor of the abdominal region. In this heating method, a human body is placed between the two inner electrodes, and is heated with electromagnetic fields stimulated in the cavity without contact between the surface of the human body and the applicator. First, the experimental heating results of an agar-muscle equivalent phantom were presented. Second, we performed an experiment with a lard-agar phantom. The center region of the agar phantom could be heated selectively without generating hot spots in the lard layers. From these results, it was found that our newly developed heating method is useful for a deep-seated tumor hyperthermia treatment.

Yeast Golgi apparatus--dynamics and sorting

The yeast Saccharomyces cerevisiae is one of the best-studied organisms to understand molecular mechanisms of membrane traffic, but as far as the organization of the Golgi apparatus is concerned, yeast is only just beginning to yield clues about how dynamic and flexible the organelle is.

Unexpected delayed rupture of the vertebral-posterior inferior cerebellar artery aneurysms following closed head injury

Subarachnoid haemorrhage secondary to closed head injury is rarely associated with traumatic aneurysms of the posterior circulation. We report two cases of ruptured vertebral-posterior inferior cerebellar artery (VA-PICA) pseudoaneurysms following closed head injuries. In each case, there was no associated penetrating injury or skull fracture. The first patient was kicked followed by disturbed consciousness. The computerized tomography (CT) scan on admission and cerebral angiography on the 11th day after the trauma revealed a massive subarachnoid haemorrhage (SAH) with pan-ventricular haemorrhage and an aneurysm of the right PICA near its origin. Further ruptures occurred on the 12th, 15th, and 66th day, and he died on the 69th day. The second patient complained of persistent headache and nausea following a fight on the previous day. A CT scan and angiography on the 1st day after the trauma showed posterior fossa SAH with fourth ventricular blood and a tiny protrusion of the left VA-PICA. On the 14th day, repeated angiography revealed a remarkable growth of the aneurysm, followed by the second rupture. The repair of the VA-PICA junction was urgently performed with successful exclusion of the aneurysm. To our knowledge, only eight cases of traumatic aneurysms located at the VA or the PICA near its origin have been reported. When intraventricular blood is found with massive subarachnoid blood or with posterior fossa SAH, this ominous complication should be considered. Traumatic VA-PICA pseudoaneurysms are curable by refined microsurgical techniques, if diagnosed in time.

Gene transfer of Fc-fusion cytokine by in vivo electroporation: application to gene therapy for viral myocarditis

Among a number of techniques for gene transfer in vivo, the direct injection of plasmid DNA into muscle is simple, inexpensive and safe. Although combining direct DNA injection with in vivo electroporation increases the efficiency of gene transfer into muscle, applications of this method have remained limited because of the relatively low expression level. To overcome this problem, we developed a plasmid vector that expresses a secretory protein as a fusion protein with the noncytolytic immunoglobulin Fc portion and used it for electroporation-mediated viral interleukin 10 (vIL-10) expression in vivo. The fusion cytokine vIL-10/mutFc was successfully expressed and the peak serum concentration of vIL-10 was almost 100-fold (195 ng/ml) higher than with a non-fusion vIL-10 expression plasmid. The expressed fusion cytokine suppressed the phytohemagglutinin-induced IFN-gamma production by human peripheral blood mononuclear cells and decreased the mortality in a mouse viral myocarditis model as effectively as vIL-10 expression. These results demonstrate that the transfer of plasmid DNA expressing a noncytolytic Fc-fusion cytokine is useful to deliver enhanced levels of cytokine without altering general biological activities. This simple and efficient system should provide a new approach to gene therapy for human diseases and prove very useful for investigating the function of newly discovered secretory protein genes.

Intracoronary separation of a nosecone: an unusual complication of directional atherectomy

A rare case of coronary separation of nosecone fixed to a 6 Fr GTO cutter catheter after failed directional coronary atherectomy (DCA) is reported. Revascularization was successful using a stent via the subintimal neolumen beside the nosecone. Heavily calcified lesions are relative contraindications to DCA.

Activation of the Ras-cAMP signal transduction pathway inhibits the proteasome-independent degradation of misfolded protein aggregates in the endoplasmic reticulum lumen

Many kinds of misfolded secretory proteins are known to be degraded in the endoplasmic reticulum (ER). Dislocation of misfolded proteins from the ER to the cytosol and subsequent degradation by the proteasome have been demonstrated. Using the yeast Saccharomyces cerevisiae, we have been studying the secretion of a heterologous protein, Rhizopus niveus aspartic proteinase-I (RNAP-I). Previously, we found that the pro sequence of RNAP-I is important for the folding and secretion, and that Deltapro, a mutated derivative of RNAP-I in which the entire region of the pro sequence is deleted, forms gross aggregates in the yeast ER. In this study, we show that the degradation of Deltapro occurs independently of the proteasome. Its degradation was not inhibited either by a potent proteasome inhibitor or in a proteasome mutant. We also show that neither the export from the ER nor the vacuolar proteinase is required for the degradation of Deltapro. These results raise the possibility that the Deltapro aggregates are degraded in the ER lumen. We have isolated a yeast mutant in which the degradation of Deltapro is delayed. We show that the mutated gene is IRA2, which encodes a GTPase-activating protein for Ras. Because Ira2 protein is a negative regulator of the Ras-cAMP pathway, this result suggests that hyperactivation of the Ras-cAMP pathway inhibits the degradation of Deltapro. Consistently, down-regulation of the Ras-cAMP pathway in the ira2 mutant suppressed the defect of the degradation of Deltapro. Thus, the Ras-cAMP signal transduction pathway seems to control the proteasome-independent degradation of the ER misfolded protein aggregates.

Successful left trisegmentectomy for polycystic liver disease accompanied by jaundice

BACKGROUND

We report a case of severe polycystic liver disease (PLD) with jaundice in a 57-year-old woman who underwent successful left trisegmentectomy.

METHOD

She was admitted for the first time in February 1992 to our hospital with a 7-year history of PLD, and became jaundiced in June 1995. Because normal liver parenchyma was confirmed mainly to the posterior segment, left trisegmentectomy was performed.

RESULTS

No postoperative complication occurred. The serum bilirubin level decreased promptly after the operation, but postoperative endoscopic retrograde cholangiography showed that the root of the posterior hepatic duct remained thin. Thus, the elimination of jaundice was presumed to have been caused by a decrease of intra-abdominal and peripheral biliary pressure, since a large volume of tissue had been removed from the peritoneal cavity. She has since remained well without any symptoms.

CONCLUSION

This procedure is useful for severe PLD, because it can be performed safely and the symptoms disappear dramatically. However, further follow-up is needed to determine the long-term effects of this procedure, because the remaining liver has shown some increase in size.

Directly linked dehydropurpurin-porphyrin dyads from Ag(I)-promoted oxidation of meso-phenylethynyl substituted zinc(II) porphyrins

Ag(I)-promoted oxidation of (5,15-diaryl-10-phenylethynyl-porphyrinato)zinc(II) complexes in CHCl3 gave directly linked 12,13-dehydropurpurin-porphyrin dyads, the structures of which were revealed by X-ray analysis.

Myocardial FDG-PET examination during fasting and glucose loading states by means of a one-day protocol

We propose a new method to measure the myocardial FDG uptake during fasting and glucose loading in one day, a myocardial FDG-PET one-day protocol, with both 2- and 3-dimensional data acquisition (2D and 3D) without background activity subtraction. To confirm it, we evaluated the effect of scatter correction in the 2D and 3D modes of a PET scanner both in phantom and patient studies. In the phantom study, we used a cardiac phantom with six divided chambers and two cylindrical phantoms placed as the activity outside the field of view. Each chamber was filled with a different concentration of F- 18 solution. Regions of interest (ROI) were placed on a polar map generated from reconstructed images and were compared to the concentration of the solution in each chamber in both 2D and 3D. In the patient study, 10 non-diabetic patients with coronary artery disease were studied. Each patient received a myocardial FDG study during fasting (F) and glucose loading (L). L images with background subtraction (Lsub(+)) and without background subtraction (Lsub(-)) were compared by polar map analysis. The ROI counts for the true activity in 2D and 3D demonstrated a linear relationship, and quite similar slopes were observed (0.72 in 2D, 0.69 in 3D). The background fraction in Lsub(-) was 3.59+/-1.83%. There were significant differences between Lsub(-) or Lsub(+) and F in both normal and ischemic myocardium. Scatter correction was successfully performed in both 2D and 3D modes. Background activity is thought to be negligible and this proposed method is simple touse in measuring the myocardial FDG uptake in one day.

Declining Minamata male birth ratio associated with increased male fetal death due to heavy methylmercury pollution

The purpose of this retrospective study was to examine the effect of methylmercury pollution on the sex ratio of offspring at birth and of fetuses at stillbirth in Minamata City, Japan, in the 1950s when severe and widespread methylmercury pollution was experienced. In 4 of 5 years from 1955 to 1959 when methylmercury pollution was most severe, lower numbers of male offspring at birth were observed in the city population. The offspring sex distributions from 1950 to 1969 by 5-year period were calculated in the overall population of Minamata City, in the most prevalent area, in fishermen (most heavily exposed occupation group) and among Minamata disease patients using data from birth certificates. We also similarly calculated the sex ratio of stillborn fetuses in the city population using Kumamoto Prefecture's vital statistics on still-birth. Decreases in male births were observed in offspring in the overall city population, in fishermen, and in maternal Minamata disease patients in the city in 1955-1959, when the methylmercury pollution was most severe. An increase in the proportion of male stillborn fetuses in the city was observed at the time. It is possible that male fetuses were more susceptible to the pollution than their female counterparts, and this could be a cause for the lower numbers of male offspring at birth.

Significance of cadmium concentrations in blood and hair as an indicator of dose 15 years after the reduction of environmental exposure to cadmium

To evaluate the significance of cadmium (Cd) concentrations in blood (B-Cd) and hair (H-Cd) as an indicator of dose, a cross-sectional study was performed on 40 residents in a Cd-polluted area, Nagasaki Prefecture, Japan, in 1996. In the study area, soil replacement of Cd-polluted rice fields ended in 1981. B-Cd and H-Cd were significantly higher in the study population than in the control subjects. B-Cd was positively correlated with urinary Cd (U-Cd) (Spearman r=0.50, P=0.06 for males and r=0.72, P=0.0001 for females), while H-Cd was weakly or moderately correlated with U-Cd. After adjustment for gender using logistic regression analysis, log(B-Cd) and log(U-Cd), but not log(H-Cd), were significantly associated with the prevalence of increased urinary beta2-microglobulin (P for trend <0.05). These findings suggest that B-Cd is a good indicator of cumulative dose many years after the reduction of environmental exposure to Cd. H-Cd may be weakly or moderately correlated with body burden.

Identification of ABCC6 pseudogenes on human chromosome 16p: implications for mutation detection in pseudoxanthoma elasticum

Pseudoxanthoma elasticum (PXE), a heritable disorder affecting the skin, eyes, and the cardiovascular system, has recently been linked to mutations in the ABCC6 gene on chromosome 16p13.1. The original mutation detection strategy employed by us consisted of the amplification of each exon of the ABCC6 gene with primer pairs placed on the flanking introns, followed by heteroduplex scanning and direct nucleotide sequencing. However, this approach suggested the presence of multiple copies of the 5'-region of the gene when total genomic DNA was used as a template. In this study, we have identified two pseudogenes containing sequences highly homologous to the 5'-end of ABCC6. First, by the use of allele-specific polymerase chain reaction (PCR), two bacterial artificial chromosome (BAC) clones containing a putative pseudogene of ABCC6, designated as ABCC6-psi 1, were isolated from the human BAC library. Sequence analysis of ABCC6-psi 1 revealed it to be a truncated copy of ABCC6, which contains the upstream region and exon 1 through intron 9 of the gene. Secondly, a homology search of a high-throughput sequence database revealed the presence of another truncated copy of ABCC6, which was designated as ABCC6-psi 2, and which was shown to harbor upstream sequences and a segment spanning exon 1 through intron 4 of ABCC6. In addition to several nucleotide differences in the flanking introns and the upstream region, both pseudogenes contain several nucleotide changes in the exonic sequences, including stop codon mutations, which complicate mutation analysis in patients with PXE. Nucleotide differences in flanking introns between these two pseudogenes and ABCC6 allowed us to design allele-specific primers that eliminated the amplification of both pseudogene sequences by PCR and provided reliable amplification of ABCC6-specific sequences only. The use of allele-specific PCR has revealed, thus far, two novel 5'-end PXE mutations, 179del9 and T364R in exons 2 and 9, respectively, and several polymorphisms within the upstream region and exons 1-9 of ABCC6. These strategies facilitate comprehensive analysis of ABCC6 for mutations in PXE.

Musashi1, an evolutionarily conserved neural RNA-binding protein, is a versatile marker of human glioma cells in determining their cellular origin, malignancy, and proliferative activity

Tumor cells often express phenotypic markers that are specific to the cells from which they originated. A neural RNA-binding protein, Musashil, is an evolutionarily well-conserved marker for neural stem cells/ progenitor cells. To examine the origin of gliomas, we examined the expression of the human Musashil homolog, MSI1, in human glioma tissues and in normal human adult and fetal brains. As we had seen previously in rodents, in the normal human brain, MSI1 was expressed in cells located in the ventricular and subventricular zones, in GFAP-negative glial cells, and in GFAP-positive astrocytes. In glioblastomas, MSI1 was expressed in GFAP-negative tumor cells forming foci that were clearly demarcated and surrounded by GFAP-positive cells. Tumor cells arranged in pseudopalisades were also strongly immunoreactive with MSI1 antibodies. The percentage of MSI1-labeled tumor cells increased in higher-grade astrocytomas and correlated with proliferative activity, as estimated by an MIB-1 staining index. Our results indicate that MSI1 is an excellent marker for neural progenitor cells including neural stem cells in normal human brains. Furthermore, the expression of MSI1 correlates well with the immature nature as well as the malignancy of tumor cells in human gliomas. Thus, we expect the analysis of MSI1 expression to contribute to the understanding of the cellular origin and biology of human gliomas.

Coupling length scales for multiscale atomistics-continuum simulations: atomistically induced stress distributions in Si/Si3N4 nanopixels

A hybrid molecular-dynamics (MD) and finite-element simulation approach is used to study stress distributions in silicon/silicon-nitride nanopixels. The hybrid approach provides atomistic description near the interface and continuum description deep into the substrate, increasing the accessible length scales and greatly reducing the computational cost. The results of the hybrid simulation are in good agreement with full multimillion-atom MD simulations: atomic structures at the lattice-mismatched interface between amorphous silicon nitride and silicon induce inhomogeneous stress patterns in the substrate that cannot be reproduced by a continuum approach alone.