Prominent Formation Research Articles

Promoter-targeted siRNAs Induce Gene Silencing of Simian Immunodeficiency Virus (SIV) Infection In Vitro

RNA interference is a conserved process by which sequence-specific double-stranded RNA is converted into small interfering double-stranded RNAs (siRNAs) that can induce gene silencing via two pathways: post-transcriptional gene silencing and transcriptional gene silencing (TGS). We previously reported TGS of human immunodeficiency virus-1 (HIV-1) could be induced by siRNAs targeting regions within its 5'-long-terminal repeat (5'LTR) promoter region. Here we show that promoter-targeted siRNAs can also induce silencing of simian immunodeficiency virus (SIV) replication by similar mechanisms. Suppression of productive infection was achieved in two different cell lines: a CD4, CCR5, CXCR4 expressing HeLa cell line (MAGIC-5) and in a human lymphoid cell line (CEMx174). HpaII digestion demonstrated induction of methylation at a CpG site within the SIV promoter region following siRNA-induced suppression. Both 5-azacytidine (5-AzaC) and trichostatin A (TSA), inhibitors of DNA methyltransferases (DNMTs) and histone deacetylation, respectively, partially reversed the silencing effect. Furthermore, using chromatin immunoprecipitation (ChIP) assays we found enrichment in the region of the LTR of heterochromatin markers dimethylated histone 3 lysine 9 (H3K9) and trimethylated histone 3 lysine 27 (H3K27) in the siRNA silenced cultures. Together, these results strongly suggest certain siRNAs targeting the promoter region of SIV can effect viral silencing through the induction of epigenetic changes.

Inducing huntingtin inclusion formation in primary neuronal cell culture and in vivo by high‐capacity adenoviral vectors expressing truncated and full‐length huntingtin with polyglutamine expansion

Huntington's disease (HD) is an inherited autosomal dominant neurodegenerative disease caused by the expansion of a CAG trinucleotide repeat in exon 1 of the huntingtin (htt) gene. Vector-mediated delivery of N-terminal fragments of mutant htt has been used to study htt function in vitro and to establish HD models in rats. Due to the large size of the htt cDNA vector-mediated delivery of full-length htt has not been achieved so far. High-capacity adenoviral (HC-Ad) vectors were generated expressing mutant and wild-type versions of N-terminal truncated and full-length htt either in vitro in primary neuronal cells or in the striatum of mice. In vitro these vectors were used for transduction of primary neuronal cells isolated from E17 mouse embryos. Expression of mutant htt resulted in the formation of htt inclusions, a surrogate marker of the HD pathology. Kinetics of generation and localization of htt inclusions differed between truncated and full-length htt carrying identical mutations. Following injection into the striatum vector-mediated expression of mutant truncated htt led to prominent accumulation of htt inclusions in cell nuclei, while inclusions formed upon expression of mutant full-length htt localized to the cytoplasm. These results indicate that HC-Ad vector-mediated in vitro and in vivo delivery of truncated and full-length mutant htt results in prominent inclusion formation in neuronal cells but in different cell compartments. These vectors will be useful tools for studying HD and may be used to generate large animal HD models.

Intramuscular hemangioma of masseter muscle with prominent formation of phleboliths: A case report

A 14-year-old girl was referred for evaluation and management of progressive, painful swelling of the right cheek. Swelling had been present since 3-year old and had gradually increased in size. Magnetic resonance imaging (MRI) revealed a well-circumscribed, brighter mass in the right masseter muscle with numerous rounded areas of signal hypointensity. Preoperative diagnosis was intramuscular hemangioma of the masseter muscle and surgery was performed. The tumor was completely removed except for a few, small phleboliths. Pathological examination of resected tissue led to a high suspicion of cavernous hemangioma with phlebolithiasis. Nine months postoperatively, the patient developed another painful mass in the right masseter muscle. MRI indicated recurrent hemangioma and further surgery was performed. Careful exploration resulted in completely removal of residual phleboliths accompanied with fibroadipose tissue. Part of the buccal branch of the facial nerve was excised to achieve complete resection of the lesion. Histological examination revealed distinct venous formation in phleboliths adjacent to fibroadipose tissue, demonstrating that both phleboliths and feeding vessels had been left by the previous operation. The present report reviews the literature on intramuscular hemangiomas of the masseter muscle, and discusses diagnostic methods and optimal surgical treatment.

Role of Equatorial Wave Transitions in Tropical Cyclogenesis over the Western North Pacific

This study associates tropical cyclone (TC) activity over the western North Pacific (WNP) with the equatorial wave transition from an interannual viewpoint, revealing that the tropical cyclogenesis mean location may be modulated by a longitudinal shift in the transition of Mixed Rossby-gravity (MRG) waves to off-equatorial tropical depression (TD) disturbances from year to year. To a large extent, the wave transition is attributable to the monsoon trough in response to the thermal state of the warm pool (WP) over the WNP. During the cold state years in the WP, the basic flow confluence region associated with the monsoon trough penetrates eastward, leading to an eastward shift in the location of the wave transition. Such an environment, in which wave accumulation and energy conversion occur, is favorable for tropical cyclogenesis; as a result, the averaged cyclogenesis location moves eastward. The condition is reserved during the warm years in the WP, resulting in the prominent westward-retreating mean TC formation.

Effect of hydroxyapatite-coated nanofibrous membrane on the responses of human periodontal ligament fibroblast

In this study, hydroxyapatite-coated biopolymer nanofibrous membrane was synthesized by mineralizing the electrospun polycaprolactone nanofiber. The effect of the hydroxyapatite-coated nanofibrous membrane was mainly investigated on the proliferation and differentiation of human periodontal ligament fibroblast, which is necessary for periodontal tissue regeneration. Scanning electron microscopy revealed favorable cell attachment and spreading appearance on 1 d and MTS assay showed increased cell proliferation on the hydroxyapatite-coated nanofiber membrane during 14 d. From 7 to 14 d, alkaline phosphatase activity of the hydroxyapatite-coated nanofiber was significantly increased when compared to that of control group. Hydroxyapatite-coated nanofibrous membrane showed prominent mineral formation on day 14. As a result, it was clarified that the developed hydroxyapatite-coated nanofibrous membrane had favorable effects on the proliferation and differentiation of human periodontal ligament fibroblast and might be a good candidate material for periodontal tissue regeneration.

Effect of Slow-Release 5-Fluorouracil on Capsule Formation Around Silicone Breast Implants: An Experimental Study with Mice

Capsule formation around breast implants, development of tendon adhesions after tendon repair, intestinal brits after laparatomies, hypertrophic scars in skin incisions all are the results of excessive collagen synthesis to the extracellular matrix by fibroblasts. Any intervention that leads to cessation of collagen synthesis in these clinical situations may help to prevent these untoward results of wound healing. Although 5-fluorouracil (5-FU) is used mainly as a cytotoxic drug in chemotherapy protocols, it decreases cellular metabolism and blocks protein synthesis only at lower concentrations. Findings have shown that 5-FU downregulates fibroblast proliferation and differentiation in vitro. It has been used to treat fibroproliferative disorders of the eye and skin and is thought to inhibit thymidylate synthetase, blocking DNA replication. This study used five treatment groups: (1) gelatin only, (2) silicone only, (3) silicone + gelatin, (4) silicone + gelatin containing 1 mg of 5-FU, and (5) silicone + gelatin containing 5 mg of 5-FU. The release kinetics of 5-FU from gelatin have been investigated by means of ultraviolet spectrophotometric analysis. Specimens were obtained on postoperative day 30. Gross evaluation and histopathologic examination were conducted for capsule formation and the development of inflammation. The silicone group had the most prominent capsule formation among all the groups. The gelatin group was second, and the silicone + gelatin group was third. As compared with the other groups, the 5-FU-containing groups had the least capsule formation. The 5-mg 5-FU-containing group had the most inflammation. The silicone + gelatin group was second in inflammation. Although the silicone, gelatin, and 1-mg 5-FU-containing groups had the same means, the results of the silicone group showed the most divergent data within the group. Because 5-FU loaded to a gelatin carrier for its slow release seems to prevent capsule formation around silicone blocks, it may be used to prevent capsule formation around silicone breast implants.

Increased Expression of Vascular Endothelial Growth Factor in Kidney Leads to Progressive Impairment of Glomerular Functions

Vascular endothelial growth factor (VEGF) is an important mediator in maintaining normal kidney functions. In addition, several lines of evidence suggest that upregulation of VEGF in glomeruli may be associated with or cause renal dysfunction such as diabetic nephropathy. For elucidation of the pathologic consequences of high levels of VEGF in glomeruli, transgenic (Tg) rabbits that express human VEGF(165) isoform in both kidney and liver under the control of the human alpha-1-antitrypsin promoter were generated and characterized. With the use of heterozygous Tg rabbits and their littermates aged 8 to 55 wk, renal functions and structures were investigated. Compared with control rabbits, Tg rabbits exhibited progressive proteinuria with increased GFR at the early stage and decreased GFR at the later stage. Histologic examinations revealed that Tg rabbit kidneys were characterized by considerable glomerular hypertrophy as a result of increased proliferation of both glomerular capillaries and mesangial cells accompanied by prominent podocyte hypertrophy. With increasing age starting from 20 wk, Tg rabbit kidneys showed prominent formation of microaneurysms and capillary proliferation at the vascular pole area. At a later stage (55 wk), many glomeruli showed sclerosis and tuft collapse with the formation of glomerular cysts on a background of tubular atrophy and interstitial fibrosis. This study provides the first evidence that increased expression of VEGF in glomeruli directly causes the glomerular hypertrophy that is associated with proteinuria, suggesting that VEGF exerts multiple effects on the glomerular pathophysiologic processes.

Evidence that PI3K, Rac, Rho, and Rho kinase are involved in basic fibroblast growth factor‐stimulated fibroblast–Collagen matrix contraction

Fibroblast-collagen matrix contraction has been used as a model system to study how cells organize connective tissue. Previous work showed that lysophosphatidic acid (LPA)-stimulated floating collagen matrix contraction is independent of Rho kinase while platelet-derived growth factor (PDGF)-stimulated contraction is Rho kinase-dependent. The current studies were carried out to determine the signaling mechanisms of basic fibroblast growth factor (bFGF)-stimulated fibroblast-collagen matrix contraction. Both bFGF and LPA promoted equally collagen matrix contraction well. Three different inhibitors, LY294002 for phosphatidylinositol-3-kinase (PI3K), C3 exotransferase for Rho and Y27632 for Rho kinase, suppressed the bFGF-stimulated fibroblast-collagen matrix contraction. With bFGF stimulation, fibroblasts spread with prominent stress fiber network formation and focal adhesions. In the presence of Rho kinase inhibitor, focal adhesions and stress fibers were mostly lost. We demonstrated that bFGF stimulation for fibroblast caused transient Rac and Rho activation but did not activate Cdc42. In addition, bFGF enhanced fibroblast migration in wound healing assay. The present study implicates PI3K, Rac, Rho, and Rho kinase as being involved in bFGF-stimulated collagen matrix contraction. The elucidation of bFGF-triggered signal transduction may be an important clue to understand the roles of bFGF in wound healing.

Effect of vehicles and esterification on the penetration and distribution of hypericin in the skin of hairless mice

To study the in vivo penetration and skin distribution of hypericin, the compound (0.1%) was formulated in 10 different vehicles that are commonly used in pharmaceutical compounding, and applied on the skin of hairless mice for 4h. After application of hypericin in PEG ointment, white petrolatum or unguentum emulsificans, fluomicroscopic analysis of skin sections revealed penetration to be confined to the stratum corneum. On the contrary, Beeler base, unguentum sorbatis 100 and cremor non ionicus caused penetration of hypericin in the viable epidermis. To reduce the prominent depot formation in the stratum corneum, which was observed irrespectively of the formulation applied, hypericin was esterified into its hydrolyzable acetate derivative. The influence of esterification proved to be substantial when hypericin acetate (0.15%) was incorporated in unguentum sorbatis 100, as hypericin-related fluorescence could be detected deeply within the dermis. Moreover, accumulation in the sebaceous glands was found to be prominent. These results indicate the value of further studies regarding the application of hypericin and hypericin acetate as topical photosensitizers for photodynamic therapy.

Formation of multinucleated giant cells and microglial degeneration in rats expressing a mutant Cu/Zn superoxide dismutase gene

BackgroundMicroglial neuroinflammation is thought to play a role in the pathogenesis of amyotrophic lateral sclerosis (ALS). The purpose of this study was to provide a histopathological evaluation of the microglial neuroinflammatory response in a rodent model of ALS, the SOD1G93A transgenic rat.MethodsMultiple levels of the CNS from spinal cord to cerebral cortex were studied in SOD1G93A transgenic rats during three stages of natural disease progression, including presymptomatic, early symptomatic (onset), and late symptomatic (end stage), using immuno- and lectin histochemical markers for microglia, such as OX-42, OX-6, and Griffonia simplicifolia isolectin B4.ResultsOur studies revealed abnormal aggregates of microglia forming in the spinal cord as early as the presymptomatic stage. During the symptomatic stages there was prominent formation of multinucleated giant cells through fusion of microglial cells in the spinal cord, brainstem, and red nucleus of the midbrain. Other brain regions, including substantia nigra, cranial nerve nuclei, hippocampus and cortex showed normal appearing microglia. In animals during end stage disease at 4–5 months of age virtually all microglia in the spinal cord gray matter showed extensive fragmentation of their cytoplasm (cytorrhexis), indicative of widespread microglial degeneration. Few microglia exhibiting nuclear fragmentation (karyorrhexis) indicative of apoptosis were identified at any stage.ConclusionThe current findings demonstrate the occurrence of severe abnormalities in microglia, such as cell fusions and cytorrhexis, which may be the result of expression of mutant SOD1 in these cells. The microglial changes observed are different from those that accompany normal microglial activation, and they demonstrate that aberrant activation and degeneration of microglia is part of the pathogenesis of motor neuron disease.

Contribution of secondary condensable organics to new particle formation: A case study in Houston, Texas

We report aerosol simulations using the EPA's Models‐3 Community Multiscale Air Quality model (CMAQ) and ground‐based and aircraft aerosol measurements to investigate new particle formation in Houston, Texas. The aerosol measurements reveal elevated ultrafine particles that reach the highest value in the afternoon, indicating prominent new particle formation. Simulations of the binary H2SO4‐H2O nucleation predict an order of magnitude lower concentrations for aerosols near 10 nm than the measurements. A parameterized nucleation scheme that accounts for the enhanced nucleation effect of secondary condensable organics is incorporated into the Models‐3/CMAQ. The organic nucleation scheme predicts the number concentrations in agreement with the measurements during the daytime. The diurnal variation is well reproduced in the simulations including the organic nucleation scheme. Comparison with the aircraft measurements also shows that the organic nucleation scheme produces good predictions of the altitude‐dependent number size distributions of the ultrafine particles. The results corroborate the importance of secondary condensable organics in new particle formation when sulfate and organics are abundant.

Lipid bodies: structural markers of inflammatory macrophages in innate immunity

The correlation between innate immune responses and formation of cytoplasmic lipid bodies (LBs) was investigated in vivo in inflammatory macrophages from rats infected with Trypanosoma cruzi, the intracellular parasite which causes Chagas' disease. We used an experimental model of high-dose irradiation prior to infection, which depletes the humoral and cellular immune responses except for the phagocytic activity of macrophages. Rats, irradiated or not, were infected with T. cruzi and macrophages from different origins (peritoneum, heart, uterus) were studied by transmission electron microscopy (TEM). As documented by quantitative TEM, innate immune responses induced prominent formation, structural changes and intracellular interactions of LBs. LBs significantly increased their size and changed their osmiophilia in response to both infection alone and when macrophages were challenged with irradiation-induced increased parasite load. Remarkably, a consistent LB-phagolysosome association was identified. LBs were surrounding, attached to or internalized by phagolysosomes. We demonstrated that LBs are dynamic organelles notably involved in the host response to acute T. cruzi infection, an event that may be important for pathogen control during innate immunity. Our findings highlight LBs as structural markers of the innate immune responses in phagocytic cells.

Rapid Development of Multiple Pseudoaneurysms After Arterial Homograft Placement

HomeCirculationVol. 114, No. 5Rapid Development of Multiple Pseudoaneurysms After Arterial Homograft Placement Free AccessReview ArticlePDF/EPUBAboutView PDFView EPUBSections ToolsAdd to favoritesDownload citationsTrack citationsPermissions ShareShare onFacebookTwitterLinked InMendeleyReddit Jump toFree AccessReview ArticlePDF/EPUBRapid Development of Multiple Pseudoaneurysms After Arterial Homograft Placement Michael Heise, MD, Michael Werk, MD, Inga Husmann, MD, Robert Eisele, MD and Peter Neuhaus, MD Michael HeiseMichael Heise From Charité, University Medicine, Department of General Surgery, Berlin, Germany. Search for more papers by this author , Michael WerkMichael Werk From Charité, University Medicine, Department of General Surgery, Berlin, Germany. Search for more papers by this author , Inga HusmannInga Husmann From Charité, University Medicine, Department of General Surgery, Berlin, Germany. Search for more papers by this author , Robert EiseleRobert Eisele From Charité, University Medicine, Department of General Surgery, Berlin, Germany. Search for more papers by this author and Peter NeuhausPeter Neuhaus From Charité, University Medicine, Department of General Surgery, Berlin, Germany. Search for more papers by this author Originally published1 Aug 2006https://doi.org/10.1161/CIRCULATIONAHA.105.605436Circulation. 2006;114:e80–e81A 52-year-old woman received a preserved aorto-bifemoral homograft to treat an infection of an aorto-bifemoral Dacron graft (Vascutek, Renfrewshire, Scotland) that was implanted 5 years ago. The infected graft was completely removed during the operation. Donor and recipient blood groups were matched. The donor was a 16-year-old boy who died after traumatic brain injury after a car accident. For organ preservation, University-of-Wisconsin solution (Viaspan, Bristol-Myers Squibb, Munich, Germany) was used. The arterial homograft was cryopreserved using a standardized freezing protocol. Immunosuppression was started 2 weeks after the operation and was maintained using the calcineurin inhibitor FK506 (1 mg/d).After an uncomplicated recovery and discharge from the hospital, the patient rapidly developed multiple false aneurysms during the first 3 postoperative months (Figure 1). The aneurysms were detected during routine follow-up ultrasound. Two large pseudoaneurysms emerged at the level of central anastomosis, and 2 false saccular aneurysms developed on the right leg and 4 on the left leg of the homograft (Figure 2). The distal anastomoses remained intact. Because of imminent prosthetic graft reinfection, an endovascular repair approach was used; a unibody stent graft was implanted in combination with a femorofemoral crossover graft for revascularization of the left limb (Figure 2). The patient again recovered smoothly and both grafts remained patent. The histology resembled the typical pattern of arterial homograft degeneration, showing a prominent neointima formation and degenerated media (Figure 3).1 No signs of rejection were present. Therefore, the pseudoaneurysm development was attributed to fractures of the homograft after cryopreservation and thawing.2Download figureDownload PowerPointFigure 1. Multiple saccular pseudoaneurysms developed at site of central anastomosis and at both legs of the aorto-bifemoral homograft 3 months after implantation (intra-arterial digital subtraction angiography).Download figureDownload PowerPointFigure 2. Magnetic resonance angiographies at discharge (A), at the 3-month follow-up (B), and after endovascular repair in combination with a femorofemoral crossover graft (C).Download figureDownload PowerPointFigure 3. Histology of the homograft femoral artery taken after cryopreservation (A) and at surgery after 3 months (B). The homograft wall showed a degenerated media and a prominent neointima formation. NI indicates neointima; M, media.DisclosuresNone.FootnotesCorrespondence to Michael Heise, MD, Charité, University Medicine, Department of General Surgery, Augustenburger Platz 1, 13353 Berlin, Germany. E-mail [email protected]References1 Vogt PR, Stallmach T, Niederhauser U, Schneider J, Zund G, Lachat M, Kunzli A, Turina MI. Explanted cryopreserved allografts: a morphological and immuno-histochemical comparison between arterial allografts and allograft heart valves from infants and adults. Eur J Cardiothorac Surg. 1999; 15: 639–644.CrossrefMedlineGoogle Scholar2 Pegg DE, Wusteman MC, Boylan S. Fractures in cryopreserved elastic arteries. Cryobiology. 1997; 34: 183–192.CrossrefMedlineGoogle Scholar Previous Back to top Next FiguresReferencesRelatedDetailsCited By Soquet J, Chambon J, Goffin Y and Jashari R (2014) Acute rejection of a cryopreserved arterial homograft, Cell and Tissue Banking, 10.1007/s10561-014-9489-y, 16:3, (331-333), Online publication date: 1-Sep-2015. Bia D, Zócalo Y, Armentano R, Pérez-Cámpos H, Fernández-Pin J, Panuncio A, Saldías M, Mariño A and Álvarez I (2012) Post-implant evaluation of the anastomotic mechanical and geometrical coupling between human native arteries and arterial cryografts implanted in lower-limb, Cryobiology, 10.1016/j.cryobiol.2011.09.133, 64:1, (50-59), Online publication date: 1-Feb-2012. Utsumi T, Ohtsuka M, Uchida E, Yamaguchi H, Nakajima T, Akazawa H, Takano H, Nakaya H and Komuro I (2008) Abdominal aortic pseudoaneurysm caused by prolonged methicillin-resistant Staphylococcus aureus sepsis, International Journal of Cardiology, 10.1016/j.ijcard.2007.06.043, 128:2, (294-295), Online publication date: 1-Aug-2008. August 1, 2006Vol 114, Issue 5 Advertisement Article InformationMetrics https://doi.org/10.1161/CIRCULATIONAHA.105.605436PMID: 16880334 Originally publishedAugust 1, 2006 PDF download Advertisement SubjectsAngiographyCardiovascular SurgeryComputerized Tomography (CT)

The effect of manganese(II) on the structure of DNA/HMGB1/H1 complexes: Electronic and vibrational circular dichroism studies

The interactions were studied of DNA with the nonhistone chromatin protein HMGB1 and histone H1 in the presence of manganese(II) ions at different protein to DNA and manganese to DNA phosphate ratios by using absorption and optical activity spectroscopy in the electronic [ultraviolet (UV) and electronic circular dichroism ECD)] and vibrational [infrared (IR) and vibrational circular dichroism (VCD)] regions. In the presence of Mn2+, the protein-DNA interactions differ from those without the ions and cause prominent DNA compaction and formation of large intermolecular complexes. At the same time, the presence of HMGB1 and H1 also changed the mode of interaction of Mn2+ with DNA, which now takes place mostly in the major groove of DNA involving N7(G), whereas interactions between Mn2+ and DNA phosphate groups are weakened by histone molecules. Considerable interactions were also detected of Mn2+ ions with aspartic and glutamic amino acid residues of the proteins.

Determination of the Magnetic Field Vector via the Hanle and Zeeman Effects in the Heiλ10830 Multiplet: Evidence for Nearly Vertical Magnetic Fields in a Polar Crown Prominence

The magnetic field is the key physical quantity responsible for the formation, stability, and evolution of solar prominences (ribbons of cool dense gas embedded in the hot tenuous corona). Therefore, it is important to obtain good empirical knowledge of the three-dimensional structure of prominence magnetic fields. Here we show how the magnetic field vector can be inferred via the physical interpretation of spectropolarimetric observations in the He I λ10830 multiplet. To this end, we have developed an inversion code based on the quantum theory of the Hanle and Zeeman effects and on a few modeling assumptions. We show an application to full Stokes vector observations of a polar crown prominence that, in the slit-jaw Hα image, showed nearly vertical plasma structures. Our results provide evidence for magnetic fields on the order of 30 G inclined by about 25° with respect to the local solar vertical direction. Of additional interest is that the inferred nearly vertical magnetic field vector appears to be slightly rotating around a fixed direction in space as one proceeds along the direction of the spectrograph's slit. While these results provide new light on the three-dimensional geometry of the magnetic fields that confine the plasma of polar crown prominences, they also urge us to develop improved solar prominence models and to pursue new diagnostic investigations.

Inverse correlation between the formation of mitochondria-derived vacuoles and Lewy-body-like hyaline inclusions in G93A superoxide-dismutase-transgenic mice

In G93A mice, the most popular model of amyotrophic lateral sclerosis (ALS), neuronal Lewy-body-like hyaline inclusions (LBHIs) and mitochondria-derived vacuoles are observed in addition to motor neuron loss. Although LBHIs are thought to be toxic, the significance of the mitochondria-derived vacuoles has not been fully investigated. In this study, the relationship between the formation of these vacuoles and LBHIs was clarified statistically in the lumbar segment from two phyletic lines of G93A mice (G1L, G1H), using immunohistochemical methods. Furthermore, the distributions of vacuoles and LBHIs were examined in the pons including the facial nucleus, where pathological changes occur in ALS patients and G93A mice. Numerous vacuoles 2-3 microm in diameter were detected in the neuropil of the lumbar segment from G1L mice euthanatized approximately 3.5 months prior to the onset of the disease. Most of the vacuoles disappeared, but some became larger as the disease progressed. The number of vacuoles with a diameter exceeding 5 microm began to decrease after disease onset, while that of intra-neuritic LBHIs increased rapidly. There was a strong inverse correlation between the numbers of vacuoles and LBHIs in symptomatic mice (P<0.01; G1L, r=-0.91; G1H, r=-0.93). In the facial nucleus of G1L mice, where the number of motor neurons was significantly reduced, only a few LBHIs were detected along with prominent vacuole formation. In contrast, significantly more LBHIs with little vacuole formation were evident around the facial nucleus in G1L mice. Furthermore, the SOD1 immunoreactivity in vacuoles initially increased and then decreased after disease onset. Taken together, the present findings suggest that the mitochondria-derived vacuoles might prevent the formation of LBHIs by sequestering mutated SOD1 from the cytoplasm.

Cytology of pancreatic acinar cell carcinoma

Acinar cell carcinoma (ACC) of the pancreas is extremely uncommon and its cytologic features have rarely been described. We describe the cytologic features of cases we have seen, review the literature regarding its cytologic features and discuss the pitfalls that may be encountered and the use of immunohistochemistry for its diagnosis. We searched our databases for all cases of histologically confirmed pancreatic ACC which had undergone prior fine needle aspiration (FNA) of the primary pancreatic lesion. The clinical histories, radiographic and sonographic findings, cytologic features, original cytologic diagnoses, and final histologic diagnoses were reviewed. Four cases of pancreatic ACC were found that had undergone FNA prior to histologic confirmation of the diagnoses. They were from 2 men and 2 women aged 50-75 yr. All masses were in the head of the pancreas, 2 had apparent peri-pancreatic adenopathy and 1 had an apparent liver metastasis. On review, all 4 had had diagnostic material on cytology samples. Original cytologic diagnoses included "acinar cell carcinoma," "pancreatic endocrine tumor," "favor neuroendocrine tumor, low-grade" and "non-diagnostic specimen." The cytologic features included small to moderate-sized loose groups with numerous single cells, prominent acinar formation, little anisonucleosis and prominent nucleoli. The cytologic features showed significant overlap with those of pancreatic endocrine tumors.

Interplinian explosive activity of Santorini volcano (Greece) during the past 150,000 years

The eruptive history of Santorini was dominated by twelve major Plinian eruptions. Six of these (Middle Pumice, Vourvoulos, Upper Scoriae 1, Upper Scoriae 2, Cape Riva and Minoan) occurred during the past ∼150 ky. This study focuses on the stratigraphy and geochemistry of the interplinian pyroclastic deposits between 145 ka (Middle Pumice) and 3.6 ka (Minoan). Five interplinian eruptive intervals were identified between these major eruptions and are numbered M8-M12. The Upper Scoriae 1/Upper Scoriae 2 (M10) and Upper Scoriae 2/Cape Riva (M11) intervals are divided into sub-intervals by voluminous interplinian lava formations, the Skaros and Andesites of Oia and Therasia lavas, respectively. Each interval lasted between ∼17 and ∼45 ky and contains pyroclastic deposits of numerous eruptions indicating considerable volcanic activity between the major Plinian events. Most of these interplinian eruptions produced scoria-fall and ash-fall deposits predominantly from subplinian-type eruptions. Surge deposits, resulting from phreatomagmatic activity, are predominant in the Upper Scoriae 1/Skaros sub-interval (M10a). The Andesites of Oia/Cape Riva sub-interval (M11b) is entirely composed of subplinian pumice-fall and ash deposits. Other subplinian pumice-fall deposits occur in the intervals Vourvoulos/Upper Scoriae 1 (M9) and Upper Scoriae 1/Upper Scoriae 2 (M10). The Upper Scoriae 1/Skaros sub-interval (M10a) belongs to one of the longest interplinian intervals (M10) that is characterized by the thickest eruptive units and the largest number of eruptions. A further prominent interplinian pyroclastic formation in northern Thera is the Megalo Vouno cinder cone deposit, which occurred in a time span between the Vourvoulos eruption and the formation of the Skaros lava shield. The interplinian deposits vary from 50 to 70 wt.% SiO 2 and are classified as basalt, basaltic andesite, andesite and dacite with a typical calc-alkaline affinity in accordance with the general characteristics of Santorini. They are dominated by a mafic magma component, exemplified by extensive scoria-fall deposits, which is generally absent or only a minor constituent of the silicic Plinian eruptions. Major and trace element compositional trends indicate a significant role of fractional crystallization in the evolution of the interplinian Santorini magmas, where repeated replenishment of primitive magma appears to have prevented magmatic differentiation towards highly silicic compositions that dominate the Plinian eruptions. Pauses in igneous activity, immediately prior to the Plinian and often caldera-forming eruptions, are inferred to be crucial for the generation of more evolved magma compositions erupted during Plinian events.

Mixed glioneuronal tumour of the fourth ventricle with prominent rosette formation

We describe three unusual tumours characterized by a mixture of glial and neuronal differentiation, involvement of the posterior fossa and formation of rosettes. Mixed glial-neuronal tumours of the posterior fossa are rare and poorly described neoplasms. However, several distinctive entities have appeared in the literature over recent years under a variety of different names. Our cases demonstrate the morphological features of the 'rosette-forming glioneuronal tumour of the fourth ventricle', a recently identified tumour characterised by its unique location, neurocytic pseudo-rosette formation and the presence of a low grade astrocytoma component. The long term prognosis of these tumours remains unclear. However, the clinical data available including the cases presented here, along with the histological features, suggest that these are low grade tumours with a good prognosis after surgical resection.

Bone Morphogenetic Protein Gene Therapy Using a Fibrin Scaffold for a Rabbit Spinal-Fusion Experiment

To observe the feasibility of using fibrin gel as a scaffold during rabbit spinal fusion with rat kidney cells carrying bone morphogenetic protein-2 (BMP-2) expression vector. Normal Rattusnorvegicus (rat) kidney (NRK) cells were transfected with pCMV-BMP2 vectors by using a nonviral reagent (FuGENE6), following which the transfected cells (1.5 x 10(7)) were encapsulated and evenly suspended in a fibrin scaffold, and implanted to either side of the L5-L6 intertransverse space for six test rabbits. For the control group (six rabbits), the transfected cells (1.5 x 10(7)) were added on and absorbed in a surgical gelatin sponge, and implanted in an analogous location. Radiographs of the spine of all animals were taken at six, ten, and 12 weeks subsequent to fusion surgery. Gross and histological examination of the fusion masses for all the animals were performed subsequent to animals having been sacrificed at 12 weeks. Expression of BMP-2 was verified in the pCMV-BMP2 transfected NRK cells which were used for the subsequent rabbit experiment. For all 12 rabbits, no evidence of implanted-tissue rejection was seen during the postoperative course. Neither residual scaffold nor inflammatory granulation tissue was seen in the harvested spinal segments. For the six study-group rabbits, radiographic examinations revealed that four individuals (67%) featured prominent new-bone formation (good fusion), and two (33%) revealed moderate new-bone formation (fair fusion) at the implanted sites, whereas all six control-group rabbits revealed no evidence of new-bone formation (nonfusion) at the implanted sites. For the histological examinations, all animals in the study group revealed the presence of osseous tissue at the sites corresponding to the sites of radiographically demonstrated new-bone formation, whereas for the control group, no osseous tissue was seen at the implanted sites for any animal Fibrin gel, being a biocompatible and biodegradable matrix, can encapsulate pCMV-BMP2 transfected NRK cells and adhere to the intertransverse lumbar-spine spaces of test rabbits. With the above characteristics, it plays an important role in the successful delivery of pCMV-BMP2-transfected cells for this rabbit spinal-fusion experiment. Being a natural matrix and able to be obtained readily from patients' own blood, fibrin gel seems to be a promising scaffold for future gene therapy in human trials.