A case of thoracic esophageal cancer with an unusual type of duplicated inferior vena cava

We describe here a thoracic esophageal cancer with an unusual type of duplicated inferior vena cava. A 58-year-old man was referred to our hospital because a tumor in his lower esophagus had been identified by endoscopy and radiology. Computed tomography scans showed an unusual type of duplicated inferior vena cava characterized by both common iliac veins flowing back into the left-sided inferior vena cava, which drained into the azygos vein, whereas the right-sided one had no drainage. Esophagectomy was performed 3 weeks later after preoperative chemotherapy. Because the patient could have developed thrombosis of the left-sided inferior vena cava and severe hypotension caused by decreased venous return to the heart if the azygos vein had been severed, the azygos vein was preserved. Thus, when performing surgery for thoracic esophageal cancer, the surgeon should check for a duplicated inferior vena cava and preserve the azygos vein if necessary.     

Conformational alterations in unidirectional ion transport of a light-driven chloride pump revealed using X-ray free electron lasers

Light-driven chloride-pumping rhodopsins actively transport anions, including various halide ions, across cell membranes. Recent studies using time-resolved serial femtosecond crystallography (TR-SFX) have uncovered the structural changes and ion transfer mechanisms in light-driven cation-pumping rhodopsins. However, the mechanism by which the conformational changes pump an anion to achieve unidirectional ion transport, from the extracellular side to the cytoplasmic side, in anion-pumping rhodopsins remains enigmatic. We have collected TR-SFX data of Nonlabens marinus rhodopsin-3 (NM-R3), derived from a marine flavobacterium, at 10-µs and 1-ms time points after photoexcitation. Our structural analysis reveals the conformational alterations during ion transfer and after ion release. Movements of the retinal chromophore initially displace a conserved tryptophan to the cytoplasmic side of NM-R3, accompanied by a slight shift of the halide ion bound to the retinal. After ion release, the inward movements of helix C and helix G and the lateral displacements of the retinal block access to the extracellular side of NM-R3. Anomalous signal data have also been obtained from NM-R3 crystals containing iodide ions. The anomalous density maps provide insight into the halide binding site for ion transfer in NM-R3.

Microbial ion-pumping rhodopsins are integral membrane proteins that actively transport ions across membranes upon light stimulation (1). Bacteriorhodopsin (bR) and halorhodopsin (HR) are well-known microbial ion-pumping rhodopsins found in halophilic archaea (2, 3). bR is a light-driven outward proton pump and HR is a light-driven inward anion pump, specific for chloride ion. Microbial ion-pumping rhodopsins possess common structural features consisting of seven α-helices with an all-trans retinal covalently bound to a lysine residue as the chromophore, despite the transport of different ions (4). The retinal undergoes photoisomerization from the all-trans to 13-cis configuration, which initiates the photocycle accompanied by several intermediates to export ions (4, 5). Its light-controllable function is suitable for optogenetics applications for manipulating cells, such as neurons, by changing the ion concentration inside or outside the membrane (6, 7). In fact, microbial rhodopsins, including channelrhodopsins and HRs, are employed as optogenetic tools (8–10).Nonlabens marinus rhodopsin-3 (NM-R3) is a light-driven chloride pump recently discovered in a marine flavobacterium (11). It is a distinct chloride pump from HRs and shows low amino acid sequence homology with HRs (11). To date, HR-type chloride pumps have been found in haloarchaea, marine bacteria, and cyanobacteria, including Halobacterium salinarum, Natronomonas pharaonis, and Mastigocladopsins repens, with sequence identities of 20%, 21%, and 20% to NM-R3, respectively (3, 12–15). Interestingly, NM-R3 has higher sequence identity (36%) to Krokinobacter rhodopsin 2 (KR2), a sodium pump found in Krokinobacter eikastus (16). NM-R3 possesses a unique NTQ motif (Asn98, Thr102, Gln109) in the third helix (helix C), which corresponds to key residues (DTD motif, Asp85, Thr89, Asp96) for proton transport in bR (11, 17, 18) (SI Appendix, Table S1). Asp85 acts as the primary proton acceptor of bR from the protonated Schiff-base (PSB), with assistance from Thr89 and Asp96, which is the proton donor (5, 17, 18). HRs from haloarchaea have a highly conserved TSA (Thr, Ser, Ala) motif, while the Ala residue is replaced by Asp in HR from cyanobacteria (19). In the X-ray crystal structure of NM-R3 (SI Appendix, Fig. S1A), a chloride ion located between the PSB and Asn98 (SI Appendix, Fig. S1B) is stabilized by the positive charge of the PSB (20). The position of this chloride ion is similar to those in the H. salinarum HR and N. pharaonis HR (NpHR) structures except for Thr and Ser, which correspond to Asn98 and Thr102 in NM-R3, respectively (20–22). Several amino acid residues around the retinal, including Arg95, Trp99, Trp201, and Asp231, are highly conserved among ion-pumping rhodopsins. Previous spectroscopic studies suggested that NM-R3 displays a similar sequence of intermediates, with K-, L-, N-, and O-like species, as in other HRs (23) (Fig. 1A). Recently, intermediate structures of NM-R3 obtained by low-temperature trapping X-ray crystallography and serial femtosecond crystallography (SFX) have been reported (24, 25). However, the detailed ion-pump mechanism still remains unclear, due to the lack of dynamic structures of anion transport at atomic resolution.Open in a separate windowFig. 1.TR-visible absorption spectroscopy for microcrystals. (A) Photocycle model of NM-R3 in the 1 M NaCl buffer solution (23). (B) TR difference spectra ΔA upon the 532-nm excitation. The difference was calculated by subtracting the spectrum of NM-R3. (C) Global fitting analysis with two exponentials. The A₁ and A₂ amplitude spectra correspond to the differences of [ΔA_O – ΔA_{10 µs}] and [ΔA_{200 ms} − ΔA_O], respectively. Here, ΔA_O represents the difference spectrum of the O intermediate minus NM-R3. (D) The isomeric forms of the retinal chromophore in bacterial-type rhodopsins.Time-resolved serial femtosecond crystallography (TR-SFX) is a powerful tool for visualizing reactions and motions in proteins at the atomic level (26–28). In SFX, myriads of microcrystals are continuously injected by a sample injector into an irradiation point of X-ray free electron lasers (XFELs) at room temperature, thus providing diffraction patterns before the onset of radiation damage by the intense X-ray pulse. Combined with a visible-light pump laser for reaction initiation, TR-SFX has been applied to light-driven ion pumps to observe the structural dynamics during the ion transfer. While TR-SFX has revealed femto-to-millisecond structural dynamics in light-driven cation pumps, including bR and KR2 (29–31), TR-SFX studies of anion pumps have been limited to early-stage structures adopted at picoseconds after light illumination (32). In addition, although NM-R3 pumps a chloride ion (Cl⁻) as a physiological substrate, it can also transport bromide (Br⁻), iodide (I⁻), and other anions from the extracellular side to the cytoplasmic side (23). I⁻ or Br⁻ serves as a marker for tracking the positions of ions, due to the greater number of electrons, whereas Cl⁻ is less distinguishable in X-ray crystallography. Therefore, TR-SFX experiments using I⁻ or Br⁻ are expected to directly visualize the process of ion transport.Here, we report the conformational alterations in NM-R3 during Br⁻ or I⁻ pumping, obtained by both TR-SFX and time-resolved spectroscopy of crystals. The resulting sequence of movements in NM-R3 demonstrates how the chloride pump transports anions with a large ionic radius and prevents the backflow of anions from the cytoplasmic side.     

Proteomic analysis of mechanisms of hypoxia-induced apoptosis in trophoblastic cells

Preeclampsia is often accompanied by hypoxia of the placenta and this condition induces apoptosis in trophoblastic cells. The aim of this study was to characterize global changes of apoptosis-related proteins induced by hypoxia in trophoblastic cells so as to clarify the mechanism of hypoxia-induced apoptosis by using the PoweBlot, an antibody-based Western array. Human choriocarcinoma cell line JAR was cultured for 24 hours under aerobic and hypoxic conditions. Hypoxia induced apoptosis accompanied by increased expression of Bcl-x, Caspase-3 and -9, Hsp70, PTEN, and Bag-1. Bad, pan-JNK/SAPK-1, Bcl-2, Bid, and Caspase-8 showed decreased expression. Hypoxia-induced apoptosis was increased with the transfection of a bag-1 antisense oligonucleotide. The bag-1 antisense oligonucleotide affected the expression of Bid, Bad, Bcl-2, JNK, and phosphorylated JNK, although expression of PTEN and Bcl-X did not change. Bag-1 may inhibit apoptosis by suppressing the expression of Bid and Bad. It may also enhance apoptosis by inhibiting the expression of Bcl-2 and by modulating phosphorylation of JNK. Both mitochondrial and stress-activated apoptosis pathways played important roles in the hypoxia induced cell death of trophoblastic cells. These findings will contribute to establish new approach to detect hypoxic stress of the placenta, which leads to preeclampsia and other hypoxia-related obstetrics complications.     

Hyperpolarization-activated cyclic nucleotide-gated channels and T-type calcium channels confer automaticity of embryonic stem cell-derived cardiomyocytes

Regeneration of cardiac pacemakers is an important target of cardiac regeneration. Previously, we developed a novel embryonic stem (ES) cell differentiation system that could trace cardiovascular differentiation processes at the cellular level. In the present study, we examine expressions and functions of ion channels in ES cell-derived cardiomyocytes during their differentiation and identify ion channels that confer their automaticity. ES cell-derived Flk1(+) mesoderm cells give rise to spontaneously beating cardiomyocytes on OP9 stroma cells. Spontaneously beating colonies observed at day 9.5 of Flk1(+) cell culture (Flk-d9.5) were significantly decreased at Flk-d23.5. Expressions of ion channels in pacemaker cells hyperpolarization-activated cyclic nucleotide-gated (HCN)1 and -4 and voltage-gated calcium channel (Cav)3.1 and -3.2 were significantly decreased in purified cardiomyocytes at Flk-d23.5 compared with at Flk-d9.5, whereas expression of an atrial and ventricular ion channel, inward rectifier potassium channel (Kir)2.1, did not change. Blockade of HCNs and Cav ion channels significantly inhibited beating rates of cardiomyocyte colonies. Electrophysiological studies demonstrated that spontaneously beating cardiomyocytes at Flk-d9.5 showed almost similar features to those of the native mouse sinoatrial node except for relatively deep maximal diastolic potential and faster maximal upstroke velocity. Although approximately 60% of myocytes at Flk-d23.5 revealed almost the same properties as those at Flk-d9.5, approximately 40% of myocytes showed loss of HCN and decreased Cav3 currents and ceased spontaneous beating, with no remarkable increase of Kir2.1. Thus, HCN and Cav3 ion channels should be responsible for the maintenance of automaticity in ES cell-derived cardiomyocytes. Controlled regulation of these ion channels should be required to generate complete biological pacemakers.     

The prognostic value of E-cadherin, alpha-, beta-, and gamma-catenin in urothelial cancer of the upper urinary tract

OBJECTIVES: To determine the value of loss of the expression of E-cadherin and cadherin-associated molecules as useful markers for both prognosis and bladder recurrence in patients with upper urinary tract cancer. MATERIALS AND METHODS: In 61 paraffin-embedded nephroureterectomy specimens, the expression of E-cadherin and alpha-, beta-, and gamma-catenin was examined by immunohistochemical staining. To evaluate the prognostic significance, Kaplan-Meier survival curves were calculated and compared by the log-rank test. A multivariate test was performed to detect prognostic markers. RESULTS: Normal expression was found in 32 cases (52.5%) for E-cadherin, 41 cases (67.2%) for alpha-catenin, 42 cases (68.9%) for beta-catenin, and 31 cases (50.8%) for gamma-catenin. The expression patterns of E-cadherin and alpha-, beta- and gamma-catenin were significantly correlated with each other. Survival analysis showed a significant difference between normal and aberrant expression in each staining. Multivariate analysis revealed that tumor stage and the expression of E-cadherin were independent prognostic factors for cause-specific survival. In contrast, there was no significant correlation between the expression of E-cadherin and alpha-, beta-, and gamma-catenin and bladder recurrence. CONCLUSION: Our data suggest E-cadherin may be a good prognostic marker for patients with upper urinary tract cancer.     

Isolation of a Novel Gene Showing Reduced Expression in Metastatic Colorectal Carcinoma Cell Lines and Carcinomas

To investigate genes involved in mctastatic stages of cancer, we analyzed expression of mRN As in three cell lines derived from murine colon adenocarcinoma 26 by means of a differential display method. Each of these lines exhibits distinct metastatic characteristics. Among many bands representing different expression patterns in the display, we confirmed by northern analysis that a gene corresponding to one amplified fragment, termed grm2 (gene related to metastasis 2), was expressed more abundantly in NL4, the derivative with the lowest metastatic potential, than in cell lines NL17, an experimentally metastatic derivative, and in NL22, a spontaneously metastatic derivative. Using thegrm.2 fragment as a probe, we isolated murine cDNA clones and subsequently human cDNA clones corresponding to the GRM2 gene. The human and mouse homologues both encode proteins of 600 amino-acid residues, which show weak homologies to proteins belonging to the myosin family. When we examined the expression levels of this novel gene in human colon cancers and in corresponding metastatic foci, we found that in more than half of these tissues, expression was significantly reduced in association with malignant potential. Our resultsimply that in humans the GRM2 gene product may regulate the metastatic phenotype of some colorectal cancers.     

Treatment of acute pancreatitis with protease inhibitor, H2 receptor antagonist and somatostatin analogue

Acute pancreatitis sometimes develops to severe condition with a variety of clinical manifestations and high mortality. Autodigestion of the pancreas, secondary to the activation of digestive enzymes, plays a major role in the pathogenetic mechanism of acute pancreatitis. To improve the mortality and complication rates, appropriate treatments based on the precise prediction of disease severity are required. To this end, the early administration of protease inhibitors has commonly been employed for the therapy of acute pancreatitis in Japan. However, a number of clinical trials have failed to show the clinical effects of protease inhibitors, H2 receptor antagonist and somatostatin analogue on the treatment of acute pancreatitis. To evidence the therapeutic value of these agents for acute pancreatitis, well-organized clinical studies will be required.     

Validity and clinical applicability of the Japanese version of amyotrophic lateral sclerosis--assessment questionnaire 40 (ALSAQ-40)]

We studied validity and clinical applicability of the Japanese version of amyotrophic lateral sclerosis (ALS) assessment questionnaire 40 (ALSAQ-40). The original version contains forty questions measuring five areas (domains) of health status: Physical Mobility, ADL/Independence, Eating and Drinking, Communication and Emotional Functioning. Data were obtained from 39 ALS patients and from their physicians at 15 centers in Japan. Patients completed the ALSAQ-40 and the SF-36, and provided information on their age and their status of ventilator use. Their physicians provided information on the date of diagnosis, type of disease and clinical characteristics, and ALSFRS-R. The patients' average age was 58.5 years, and 64% were men. The mean duration since diagnosis was 39.1 months. Forty four percent were classical ALS patients and 46% were receiving a respiratory intervention. Although there was much heterogeneity, the scores for Physical Mobility and ADL/Independence were higher(indicating worse health status)than the scores for the other domains. Item-scale correlations were strong, except for the item "felt embarrassed in social situations" in the Emotional Functioning domain. All the domains had very high internal consistency: Cronbach's alphas ranged 0.95 to 0.97. With regard to the cluster structure of the forty items, the Eating and Drinking domain and the Communication clustered together. The reason might be that the former consisted of only three items and both domains measure bulbar symptoms. Domain scores correlated significantly with scores of related dimensions in the SF-36 and ALSFRS-R, and did not correlate strongly with unrelated domains. The five items of the ALSAQ-5 correlated with all five domain scores on the ALSAQ-40. These results should be interpreted with caution because we analyzed together data from ALS patients with various characteristics. In conclusion, although we may need to add and remove some items and modify the wording of others, the Japanese version of the ALSAQ-40 had high validity and is likely to be useful in evaluating of QOL in ALS patients. Whether the ALSAQ-5 can be used in place of the ALSAQ-40 is a matter for further study.     

Evaluation of psychometric properties of Japanese version of international prostate symptom score and BPH impact index

PURPOSE: To evaluate psychometric properties of the Japanese version of International Prostate Symptom Score (IPSS) and BPH Impact Index (BII). METHODS: The translated IPSS and BII questionnaires were administered to 103 patients with benign prostatic hyperplasia and 23 asymptomatic men. In 82 patients the questionnaires were repeated 2 weeks later to examine reproducibility. Further 2 weeks later 21 out of 82 patients responded to the questionnaires asking symptoms during the last week rather than during the last month. To evaluated responsiveness the questionnaires were repeated after treatment in 22 patients. Internal consistency, construct validity and criterion validity were examined by proper statistic methods. RESULTS: Reproducibility was good to excellent with weighted kappa more than 0.62 for all items. It was not significantly affected by age, symptom severity, institution type, or whether the patients were asked symptoms during the last week or during the last month. Internal consistency was also good with Cronbach's alpha more than 0.83. Principle component analysis identified 2 components in IPSS and a single component in BII, with all the items contributing to the first component. Most items had significant correlation with external criteria including maximum flow rate, residual urine volume or prostate volume. The scores of patients were clearly larger than asymptomatic men and obviously reduced after receiving therapies. CONCLUSION: Japanese translations of IPSS and BII were shown to be reliable, valid and one-dimensional instruments in the Japanese patients. They would be equivalent to the original English questionnaires.