Identification and characterization of a matrix protein (PPP-10) in the periostracum of the pearl oyster, Pinctada fucata

AbstractThe periostracum is a layered structure that is formed as a mollusk shell grows. The shell is covered by the periostracum, which consists of organic matrices that prevent decalcification of the shell. In the present study, we discovered the presence of chitin in the periostracum and identified a novel matrix protein, Pinctada fucata periostracum protein named PPP-10. It was purified from the sodium dodecyl sulfate/dithiothreitol-soluble fraction of the periostracum of the Japanese pearl oyster, P. fucata. The deduced amino acid sequence was determined by a combination of amino acid sequence analysis and cDNA cloning. The open reading frame encoded a precursor protein of 112 amino acid residues including a 21-residue signal peptide. The 91 residues following the signal peptide contained abundant Cys and Tyr residues. PPP-10 was expressed on the outer side of the outer fold in the mantle, indicating that PPP-10 was present in the second or third layer of the periostracum. We also determined that the recombinant PPP-10 had chitin-binding activity and could incorporate chitin into the scaffolds of the periostracum. These results shed light on the early steps in mollusk shell formation

Overexpression of Tisochrysis lutea Akd1 identifies a key cold-induced alkenone desaturase enzyme

Alkenones are unusual long-chain neutral lipids that were first identified in oceanic sediments. Currently they are regarded as reliable palaeothermometers, since their unsaturation status changes depending on temperature. These molecules are synthesised by specific haptophyte algae and are stored in the lipid body as the main energy storage molecules. However, the molecular mechanisms that regulate the alkenone biosynthetic pathway, especially the low temperature-dependent desaturation reaction, have not been elucidated. Here, using an alkenone-producing haptophyte alga, Tisochrysis lutea, we show that the alkenone desaturation reaction is catalysed by a newly identified desaturase. We first isolated two candidate desaturase genes and found that one of these genes was drastically upregulated in response to cold stress. Gas chromatographic analysis revealed that the overexpression of this gene, named as Akd1 finally, increased the conversion of di-unsaturated C37-alkenone to tri-unsaturated molecule by alkenone desaturation, even at a high temperature when endogenous desaturation is efficiently suppressed. We anticipate that the Akd1 gene will be of great help for elucidating more detailed mechanisms of temperature response of alkenone desaturation, and identification of active species contributing alkenone production in metagenomic and/or metatranscriptomic studies in the field of oceanic biogeochemistry

Prolapse of Intussusception through the Anus as a Result of Sigmoid Colon Cancer

Adult intussusception is rare and most often associated with cancer. We report a case of intussuscepted sigmoid colon into the rectum protruding from the anus of a 47-year-old woman. The cause of the intussusception was sigmoid colon cancer. We removed the intussuscepted part of the sigmoid colon as well as the rectum and regional lymph nodes. The patient recovered uneventfully and there has been no evidence of recurrence of the cancer

Kre6 (yeast 1,6-β-transglycosylase) homolog, PhTGS, is essential for β-glucan synthesis in the haptophyte Pleurochrysis haptonemofera

Haptophytes synthesize unique β-glucans containing more β-1,6-linkages than β-1,3 linkages, as a storage polysaccharide. To understand the mechanism of the synthesis, we investigated the roles of Kre6 (yeast 1,6-β-transglycosylase) homologs, PhTGS, in the haptophyte Pleurochrysis haptonemofera. RNAi of PhTGS repressed β-glucan accumulation and simultaneously induced lipid production, suggesting that PhTGS is involved in β-glucan synthesis and that the knockdown leads to the alteration of the carbon metabolic flow. PhTGS was expressed more in light, where β-glucan was actively produced by photosynthesis, than in the dark. The crude extract of E. coli expressing PhKre6 demonstrated its activity to incorporate 14C-UDP-glucose into β-glucan of P. haptonemofera. These findings suggest that PhTGS functions in storage β-glucan synthesis specifically in light, probably by producing the β-1,6-branch

A giant adrenal pseudocyst presenting with right hypochondralgia and fever: a case report

<p>Abstract</p> <p>Introduction</p> <p>Adrenal pseudocysts are rare cystic masses that arise from the adrenal gland and which are usually non-functional and asymptomatic. Adrenal pseudocysts consist of a fibrous wall without an epithelial or endothelial lining. We report the case of a patient with a giant adrenal pseudocyst presenting with right hypochondralgia and high fever.</p> <p>Case presentation</p> <p>A 52-year-old Japanese man was admitted with right hypochondralgia and a chill. Abdominal computed tomography revealed a well-defined cystic mass measuring 19 cm which was located in the right adrenal region and the contents of which were not enhanced with contrast medium. Abdominal ultrasonography revealed a heterogeneously hypo-echoic lesion with a peripheral high-echoic rim. Serum hormonal levels were almost normal. Despite treatment with antibiotics, the high fever persisted. Based on these findings, we made a preoperative diagnosis of a right adrenal cyst with infection. However, the possibility of malignancy still remained. The patient underwent laparotomy and right adrenal cyst excision with partial hepatectomy in order to relieve the symptoms and to confirm an accurate diagnosis. Histological examination revealed an adrenal pseudocyst with infection. His condition improved soon after the operation.</p> <p>Conclusion</p> <p>We report a case of a giant adrenal pseudocyst with infection. Surgery is required for symptomatic cases in order to relieve the symptoms and in cases of uncertain diagnosis.</p

Analysis of organ movement during respiratory gated irradiation for particle radiotherapy

Introduction: One of advantage in the use of heavy charged particles for radiotherapy is the high potential for concentrating a uniform prescribed dose to the target volume while minimizing irradiation to surrounding normal tissues. The compensator and collimator statically define a shape of the beam to conform the irradiation filed at each patient. However the target around thorax and abdomen moves physiologically in association with heartbeat, respiration and peristaltic function. These motions cause the decline in the dose concentration to the target volume. Prior discussions about organ motions have mainly focused on inferior-superior movement with respiration. In contrast, the anterior-posterior change of the target depth along the beam path is very important in particle radiotherapy, because the shape end of the beam (Bragg peak) is so sharp as to be matched to the distal edge of the target. In addition, depth variations for particle radiotherapy must be presented in water equivalent path length (WEL) using CT numbers. The purpose of this study is to analyze depth variations of organs from the aspect of respiratory-gated irradiation.\nMethod: A set of sequential CT images was reconstructed from continuous X-ray projection data accumulated by dynamic scanning. At the same time of CT data acquisition, the respiratory signal of patient was measured. The timing of each CT image is related with the phase of respiration waveform. Then organ movements on these CT image are analyzed, and investigated the correlation with respiration waveform.\nResults: In case of liver around diaphragm, the target depth along beam path was remarkably changed depending on the respiratory organ movement. The magnitude of depth variations was comparable to the inferior-superior movement. For example, changes in WEL from the iso-center to the body surfaces of the front and the back were 6.2 mm and 18.9 mm, respectively. These variations were estimated to reduce to less than 2 mm by gated irradiation.In lung case, the correlation between the change in WEL of lung size and the respiratory signal appeared not to be clear. The change in WEL had two frequency components, one was respiration and other was heartbeat. In pancreas case, the position of pancreas itself didn’t move so much. However air cavities in intestine along the beam path changed, and affected the target depth in WEL.World Congress on Medical Physics and Biomedical Engineering 200

Method to estimate uncertainties of the range calculation associated with patient respiration

Purpose: To propose a method for estimating uncertainties of the range calculation in particle radiotherapy associated with organ motion along with patient respiration.Methods and Materials: A set of sequential CT images every 0.2 seconds was reconstructed from continuous x-ray projection data accumulated by the dynamic scanning mode in helical CT scanner. At the same time of CT data acquisition, respiratory signal of patient and on/off signal of X-ray on CT scanner were recorded. From these data, the timing of each CT image was related with the phase of respiration waveform. These CT images were analyzed in our treatment planning system that included the function converting from CT number to water equivalent path length (WEL). A set of CT images of the patient with liver cancer at upper right lobe was analyzed. The geometrical sizes of the liver and WELs from body surface to iso-center were measured in each CT image. Results: WEL variations of depth from body surface to iso-center were 6.2mm and 18.9mm at anterior-posterior and posterior-anterior direction, respectively. Liver size was changed to 35.2mm. However these variations were shown to be considerably reduced by gated irradiation.Conclusion: The proposed method using sequential CT images with respiration waveform was shown to be useful to evaluate the uncertainties of the range calculation associated with patient breathing. The variation of the depth along the beam path was presented in WEL rather than geometrical length.PTCOG XXXVI Meetin

Estimating Uncertainties of the Geometrical Range of particle Radiotherapy during Respiration

Purpose: To propose a method for estimating uncertainties of the range calculation in particle radiotherapyassociated with patient respiration.Methods and Materials: A set of sequential CT images at every 0.2 s was reconstructed from continuous X-rayprojection data accumulated by dynamic helical scanning. At the same time that CT data was acquired, therespiratory signal of the patient and the X-ray on/off signal on CT scanner were recorded. Each CT image wastimed according to the phase of respiration waveform. Conversion of the CT number to the water equivalent pathlength (WEL) was performed with our treatment planning system that included a conversion table. As anillustration, the CT images of a patient with liver cancer at the right upper lobe were analyzed. The geometricsize of the liver and WELs from body surface to isocenter were measured in each CT image.Results: Variations of WEL from body surface to isocenter at the anterior-posterior and posterior-anteriordirection were 6.2 mm and 18.9 mm, respectively. Liver size changed by 35.2 mm. However, these variations wereshown to be considerably reduced by gated irradiation.Conclusion: A method using sequential CT images with respiration waveform was proposed. It appeared to beuseful in evaluating the uncertainties of the range calculation associated with patient breathing