Identification of cryptochrome DASH from vertebrates

A new type of cryptochrome, CRY-DASH, has been recently identified. The CRY-DASH proteins constitute the fifth subfamily of the photolyase/cryptochrome family. CRY-DASHs have been identified from Synechocystis sp. PCC 6803, Vibrio cholerae, and Arabidopsis thaliana. The Synechocystis CRY-DASH was the first cryptochrome identified from bacteria, and its biochemical features and tertiary structure have been extensively investigated. To determine how broadly the subfamily is distributed within living organisms, we searched for new CRY-DASH candidates within several databases. We found five sequences as new CRY-DASH candidates, which are derived from four marine bacteria and Neurospora crassa. We also found many CRY-DASH candidates from the EST databases, which included sequences from fish and amphibians. We cloned and sequenced the cDNAs of the zebrafish and Xenopus laevis candidates, based on the EST sequences. The proteins encoded by the two genes were purified and characterized. Both proteins contained folate and flavin cofactors, and have a weak DNA photolyase activity. A phylogenetic analysis revealed that the seven candidates actually belong to the new type of cryptochrome subfamily. This is the first report of the CRY-DASH members from vertebrates and fungi.     

Molecular cloning and expression analysis of a macrophage-colony stimulating factor receptor-like gene from rainbow trout, Oncorhynchus mykiss

The M-CSF and its receptor (M-CSFR, CSF-1R or c-fms proto-oncogene) system were initially implicated as essential in mammals for normal monocyte development as well as for pregnancy. To allow a comparison with the M-CSF and M-CSFR system of an oviparous animal, we cloned a M-CSFR-like gene from rainbow trout (Oncorhynchus mykiss). The gene was cloned from a cDNA library of head kidney. It contained an open reading frame encoding 967 amino acids with a predicted size of 109 kDa. The putative amino acid sequence of rainbow trout M-CSFR showed 54% amino acid identity to fugu (Takifugu rubripes) M-CSFR, 52% to zebrafish (Danio rerio) M-CSFR and 40% to mouse (Mus musculus) and human (Homo sapiens) M-CSFR. The M-CSFR-like gene was constitutively expressed in head kidney, kidney, intestine, spleen and blood. The gene was detected especially in the ovary of immature female rainbow trout. These results suggest that a M-CSFR-like receptor may be involved in female reproductive tracts even in an oviparous animal like fish.     

Pigmentary degeneration indwed by N-methyl-N-nitrosourea and the fate of pigment epithelial cells in the rat retina

Pigmentary degeneration of the retina was induced by a single intraperitoneal Injection of 75mgkg of N-methyl-N-nitrosourea (MNU) In female Brown-Norway colored rats at 50 days of age, which were then observed at 24, 48 and 72 h and 7, 21,35 and 150 days after the treatment. MNU-treated rats showed selective destruction of the photoreceptor cells by an apoptotic mechanlsm 24 h after the treatment, and the destruction was completed by day 7. During the photoreceptor cell degeneration, proliferation of Miller cells and infiltratlon of macrophages was prominent 72h and 21 days aRttr the treatment, respectively. Müller cell proliferation and macrophage infiltratbn corresponded to degenerative photo-receptor cell phagocytosis, and prollferating Müller cell processes responded to stabilize the damaged retina. Pigment epithelial cell detachment from the Bruch's membrane was seen 72 h after the treatment, and migration within all layers of the retina was seen at day 7 when photoreceptor Cells were lost. At 21, 35 and 150 days after the treatment, lack of photoreceptor cells and deposition of pigment epithelial cells within the retina but not in contact to vascular endothe-lial cells were characteristic. MNU-induced photoreceptor apoptosis followed by Miiller cell and macrophage reaction then pigment epithellal cells deposition withln the retina partially resembles retinitis pigmentosa in humans.     

Multispacer typing of Rickettsia prowazekii enabling epidemiological studies of epidemic typhus

Currently, there is no tool for typing Rickettsia prowazekii, the causative agent of epidemic typhus, currently considered a potential bioterrorism agent, at the strain level. To test if the multispacer typing (MST) method could differentiate strains of R. prowazekii, we amplified and sequenced the 25 most variable intergenic spacers between the R. prowazekii and R. conorii genomes in five strains and 10 body louse amplicons of R. prowazekii from various geographic origins. Two intergenic spacers, i.e., rpmE/tRNA(fMet) and serS/virB4, were variable among tested R. prowazekii isolates and allowed identification of three and two genotypes, respectively. When the genotypes obtained from the two spacers were combined, we identified four different genotypes. MST demonstrated that several R. prowazekii strains circulated in human body lice during an outbreak of epidemic typhus in Burundi. This may help to discriminate between natural and intentional outbreaks. Our study supports the usefulness of MST as a versatile method for rickettsial strain genotyping.     

Prognosis of pancreatic endocrine function in chronic pancreatitis: significance of surgical treatment

Of 100 cases of chronic pancreatitis, 20 received surgical treatment. The duration of illness before surgical treatment was less than 5 years in 75% of patients. Post-operatively, the persistent abdominal pain was relieved and serum pancreatic enzyme levels were normalized in all the patients except two who continued drinking alcohol. Exocrine and endocrine pancreatic function were unchanged or slightly improved post-operatively in most cases. In 9 of 10 patients who have been followed up post-operatively for over 4 years, pancreatic endocrine function has been maintained by diet control with no significant impairment of glucose tolerance. These results suggest that in patients with chronic pancreatitis surgical intervention is of greatest benefit in preservation of pancreatic functions when it is performed at an early stage in which these functions are relatively well maintained.     

IMMUNOHISTOCHEMICAL LOCALIZATION OF TYPE I, II, III, AND IV COLLAGENS IN THE LUNG

Type specific rabbit antibodies to bovine type I, 11, 111, and IV (basement membrane) collagens showing no cross-reaction with other types of collagen were prepared by cross-adsorption and diethylamiuoethyl-cellulose romatography. The antibodies to bovine type I and I11 collagens showed a high cross-reaction with the corresponding human collagens, but those to type I1 and IV collagens did moderate and no cross-reactions with human type I1 and IV collagens, respectively. By using these antibodies, tissue distribution of various types of collagen in normal bovine lung was examined by indirect immunofluorescence microscopy. Both type I and I11 collagens were found to distribute widely in the interstitium of bronchial tree, bronchial
lamina propria and of interlobules as well as alveolar nipples and adventitia of pulmonary arteries. Type I1 collagen was located only in bronchial cartilage. The tissues mainly stained for type 11 collagen were the alveolar interstitium (also stained faintly for type I collagen) and the intima and media of the arteries. Type IV collagen was located in a membranous fashion in alveolar septa and bronchial smooth muscles and subepithelial layers as well as capillaries and the intima and media of arteries. ACTA PATHOL. JPN. 31: 601–610, 1981.     

Complete Nucleotide Sequence and Phylogenetic Analyses of Hepatitis B Virus Isolated from Two Pileated Gibbons

Virus-like particles (VLPs, named HmTV1-17), about 40nm in diameter were found in the violet root rot fungus Helicobasidium mompa Tanaka strain No. 17, which had been isolated from an apple tree. Purified preparations of HmTV1-17 contained two species of double-stranded RNA (dsRNA), designated 17L and 17S. cDNAs were constructed from HmTV1-17 genomic dsRNAs purified using CF-11 cellulose column chromatography. The sequences of 17L and 17S cDNA comprised 5207 and 2096bp, respectively. Although 17S has no large open reading flame (ORF) on either strand, 17L has two large overlapping ORFs. The 5 located ORF1 encodes the coat protein (CP, 788 amino acids), whereas the gene product of ORF2, which is in the –1 frame relative to ORF1, shows the typical features of a RNA dependent RNA polymerase (RDRP, 845 amino acids). Phylogenetic analysis based on RDRP showed that HmTV1-17 is closely related to Sphaeropsis sapinea SsRV1, a member of the genus Totivirus from filamentous fungus S. sapinea.     

Fast and robust computation of colon centerline in CT colonography

Although several methods for generating the centerline of a colon from CT colonographic scans have been proposed, in general they are time-consuming and do not take into account that the images of the colon may be of nonoptimal quality, with collapsed regions, and stool within the colon. Furthermore, the colonic lumen or wall, which is often used as a basis for computation of a centerline, is not always precisely segmented. In this study, we have developed an algorithm for computation of a colon centerline that is fast compared to the centerline algorithms presented in the reviewed literature, and that relies little on a complete colon segments identification. The proposed algorithm first extracts local maxima in a distance map of a segmented colonic lumen. The maxima are considered to be nodes in a set of graphs, and are iteratively linked together, based on a set of connection criteria, giving a minimum distance spanning tree. The connection criteria are computed from the distance from object boundary, the Euclidean distance between nodes and the voxel values on the pathway between pairs of nodes. After the last iteration, redundant branches are removed and end segments are recovered for each remaining graph. A subset of the initial maxima is used for distinguishing between the colon and noncolonic centerline segments among the set of graphs, giving the final centerline representation. A phantom study showed that, with respect to phantom variations, the algorithm achieved nearly constant computation time (2.3-2.9 s) except for the most extreme setting (20.2 s). The algorithm successfully found all, or most of, the centerline (93% - 100%). Displacement from optimum varied with colon diameter (1.2-6.6 mm). By use of 40 CT colonographic scans, the computer-generated centerlines were compared with the centerlines generated by three radiologists. The similarity was measured based on percent coverage and average displacement. The computer-generated centerlines, when compared with human-generated centerlines, had approximately the same displacement as when the human-generated centerlines were compared among each other (3.8 mm versus 4.0 mm). The coverage of the computer-generated centerlines was slightly less than that of the human-generated centerlines (92% versus 94%). The 40 centerlines were, on average, computed in 10.5 seconds, including computation time for the distance transform, with an Intel Pentium-based 800 MHz computer, as compared with 12-17 seconds or more (excluding computation time for the distance transform needed) per centerline as reported in other studies.     

Functionality of chimeric Rev proteins of HIV/SIV

Studies on functional compatibility of various Rev proteins derived from all known human and simian immunodeficiency virus subgroups have shown that this essential gene product is not always exchangeable among the viruses. In an attempt to map the region of Rev proteins responsible for the observed nonreciprocal complementation, hybrid genomic Rev expression vectors were constructed by exchanging the first and second exons ofrev genes, and were examined for their abilities to activate reporter clones by transfection. With one exception, the second coding exon ofrev gene determined the functional specificity of Rev proteins.     

Changes of cerebral vasoactive intestinal polypeptide-and somatostatin-like immunoreactivity induced by noise and whole-body vibration in the rat

To clarify the role of vasoactive intestinal polypeptide (VIP) and somatostatin, somatropin-release inhibiting factor, (SRIF) neurons in the response to organisms to noise or whole-body vibration stress, VIP and SRIF-like immunoreactivity were determined in various regions of the rat brain following exposure for 90 min to noise (broad band, 102 dB) or whole-body vibration (20 Hz, 4.0 g). Both noise and whole-body vibration significantly increased VIP-like immunoreactivity in the amygdala. A significant reduction of VIP like immunoreactivity in the hippocampus was induced only by whole-body vibration. On the other hand SRIF-like immunoreactivity was decreased significantly in the hypothalamus and increased significantly in the amygdala by noise and whole-body vibration, respectively. The present findings would seem to indicate that the amygdalofugal VIP neural system is involved in regulating hypothalamic and pituitary hormone secretions in non-specific reactions to stress. Responses of hippocampal VIP and the amygdalofugal SRIF to whole-body vibration stress are assumed to be activated as specific reactions to the stress.