Aneurysm of aberrant right subclavian [corrected] artery arising from diverticulum of Kommerell. Report of a case with tracheal compression

A 74-year-old woman presented with severe dyspnea without dysphagia. Computed tomographic scans and Digital subtraction angiography revealed the left aortic arch with an aberrant right subclavian artery arising from the Kommerell's diverticulum and tracheal compression. The aortic arch and the Kommerell's diverticulum were aneurysmal and were responsible for this compression. Surgical relief was accomplished by replacement of the aortic arch and reconstruction of the four brachiocephalic vessels with vascular prostheses through a median sternotomy incision extending into the right supraclavicular region.

Isolation of serotype G8, P6[1] bovine rotavirus from adult cattle with diarrhea

Two electrophoretically identical strains of group A rotavirus were isolated from diarrheic cows aged 3, 4, and 7 years on a dairy farm in Japan. They had a rare serotype combination of G8 and P6[1] and were shown by RNA-RNA hybridization to be most closely related to bovine strain NCDV-Lincoln (G6P6[1]).

Natural selection and the frequency distributions of "silent" DNA polymorphism in Drosophila

In Escherichia coli, Saccharomyces cerevisiae, and Drosophila melanogaster, codon bias may be maintained by a balance among mutation pressure, genetic drift, and natural selection favoring translationally superior codons. Under such an evolutionary model, silent mutations fall into two fitness categories: preferred mutations that increase codon bias and unpreferred changes in the opposite direction. This prediction can be tested by comparing the frequency spectra of synonymous changes segregating within populations; natural selection will elevate the frequencies of advantageous mutations relative to that of deleterious changes. The frequency distributions of preferred and unpreferred mutations differ in the predicted direction among 99 alleles of two D. pseudoobscura genes and five alleles of eight D. simulans genes. This result confirms the existence of fitness classes of silent mutations. Maximum likelihood estimates suggest that selection intensity at silent sites is, on average, very weak in both D. pseudoobscura and D. simulans (magnitude of NS approximately 1). Inference of evolutionary processes from within-species sequence variation is often hindered by the assumption of a stationary frequency distribution. This assumption can be avoided when identifying the action of selection and tested when estimating selection intensity.

Aortic root replacement for annuloaortic ectasia in Shprintzen-Goldberg syndrome: a case report

Annuloaortic ectasia due to Shprintzen-Goldberg syndrome (SGS) is reported. A 10-year-old boy was admitted to our hospital for evaluation of chest pain. On admission, he was diagnosed as SGS on the basis of his various anomalies. Two-dimensional echocardiography showed a bicuspid aortic valve and marked annular dilatation, Doppler flow studies revealed severe aortic regurgitation, and retrograde aortography showed severe aortic regurgitation with annular dilatation. Successful aortic root replacement was performed; subsequent histologic examination of the ascending aorta demonstrated cystic medial necrosis. In conclusion, SGS is a generalized connective tissue dysplasia, with clinical manifestations of cardiovascular lesions similar to those in Marfan syndrome. Aortic root replacement was successfully performed; however, recurrence of aortic aneurysms outside of the ascending aorta should be carefully observed. Surgical treatment for cardiovascular disorders may be necessary to save the life of patients with SGS.

Antigenic diversity of Akabane virus detected by monoclonal antibodies

The antigenic properties of 21 Japanese field isolates and two Australian strains of Akabane (AKA) virus (Simbu serogroup, bunyavirus) isolated from 1959 to 1990 were compared by enzyme-linked immunosorbent assay (ELISA), plaque-reduction neutralization (PRNT) and hemagglutination inhibition (HI) tests using monoclonal antibodies (Mabs) to the OBE-1 strain of AKA virus. Sixteen Mabs were established by fusing P3X63Ag8U1 mouse myeloma cells and spleen cells from BALB/c mice immunized with the OBE-1 strain. Of the 16 clones, 13 produced immunoglobulin (Ig) which precipitated glycoprotein G1 and three produced Ig which precipitated nucleoprotein (N). Twelve out of 13 Mabs had both NT and HI activities to not only the homologous OBE-1 strain but also the other isolates. By the competitive binding assay, at least five antigenic regions for G1, and two for N were defined. Some of the anti-G1 Mabs which reacted to the same antigenic region had unique reactivity while anti-N Mabs recognizing the same epitope reacted with almost the same degree to all of the isolates. Finally, nine epitopes of the G1 protein in five different antigenic regions have been identified. There was no striking correlation between isolation date and place of the isolates and their reactivity to Mabs. A most interesting result is that three isolates collected in the same place over a three week period had different reactivity patterns detected by ELISA, showing great antigenic variation of the virus. AKA virus may be a single gene pool consisting of different genotypes in the field.

Operation for type B aortic dissection using hypothermic selective cerebral perfusion

A 56-year-old man who had a huge type B dissecting aortic aneurysm extending from the distal arch to the thoracoabdominal aorta underwent replacement of the descending thoracic and thoracoabdominal aorta under hypothermic circulatory arrest with selective cerebral perfusion. The intercostal arteries at the T-8 to T-11 level were preserved with beveled distal anastomosis, and the celiac artery and the intercostal arteries at the T-5 and T-6 levels were reconstructed. The patient recovered uneventfully and is presently doing well 1 year after the operation.

Modeling of a Micro-streamer Initiation and Development of ArF Excimer Laser Discharges

The dynamics of a constricted filamentary or ‘micro-streamer’ discharge in a discharge-excited ArF excimer laser has been examined using a two-dimensional fluid model. The entire process on a micro-streamer, from its initiation and development to extinction, is shown. In the present model, a micro-streamer is triggered at protrusions which always exist on cathode surfaces, and develops in the direction of the anode assisted by the high field induced by space charge. A rise in the gas temperature in the micro-streamer in the vicinity of a cathode is seen, and which is found to play an important role in its development. The effect of preionisation electron density ne0 on the streamer development is also examined, and the streamer is found to extend significantly when ne0 becomes low. The results are explained in connection with experimental observations.

Molecular evolution between Drosophila melanogaster and D. simulans: reduced codon bias, faster rates of amino acid substitution, and larger proteins in D. melanogaster

Both natural selection and mutational biases contribute to variation in codon usage bias within Drosophila species. This study addresses the cause of codon bias differences between the sibling species, Drosophila melanogaster and D. simulans. Under a model of mutation-selection-drift, variation in mutational processes between species predicts greater base composition differences in neutrally evolving regions than in highly biased genes. Variation in selection intensity, however, predicts larger base composition differences in highly biased loci. Greater differences in the G+C content of 34 coding regions than 46 intron sequences between D. melanogaster and D. simulans suggest that D. melanogaster has undergone a reduction in selection intensity for codon bias. Computer simulations suggest at least a fivefold reduction in Nes at silent sites in this lineage. Other classes of molecular change show lineage effects between these species. Rates of amino acid substitution are higher in the D. melanogaster lineage than in D. simulans in 14 genes for which outgroup sequences are available. Surprisingly, protein sizes are larger in D. melanogaster than in D. simulans in the 34 genes compared between the two species. A substantial fraction of silent, replacement, and insertion/deletion mutations in coding regions may be weakly selected in Drosophila.

Strain differentiation and phylogenic relationships, in terms of base sequence of the ure B gene, of Helicobacter pylori

We constructed a phylogenetic tree based on the nucleotide sequence of the ure B gene of Helicobacter pylori strains, amplified by polymerase chain reaction (PCR). We analyzed the tree in terms of the relationship between the PCR-restriction fragment length polymorphism (RFLP)-genotype and the sequevar. The main frame of ure B (928 bp) was amplified by PCR from 38 strains of clinical isolates and reference species. The amplified probes were sequenced and processed into matrix and phylogenic trees. Homogeneity of the strains of "intra-case" origin and heterogeneity in "inter-cases" was parallel to clustering on the phylogenic tree. Sequevars in a cluster showed an identical RFLP-genotype in one case, indicating the clonal origin of H. pylori flora in an individual.

[Surgical treatment for active infective endocarditis]

Between April 1975 and December 1995, 33 patients with active infective endocarditis underwent surgical treatment at our hospital. The location of diseased valve was shown as ; 18 in aortic, 11 in mitral, and 4 in aortic and mitral position. Of these, 14 patients had an annular abscess or mycotic aneurysm. All patients achieved antibiotic therapy previously, and predominant indication for operation was congestive heart failure. All patients underwent valve replacement. The reconstructive procedures for 14 patients with paravalvular involvement were as follows ; direct closure : 5 cases, direct closure+tilted prosthesis technique : 5 cases, and another 4 cases were, patch closure of VSP resulting from a septal abscess, patch closure+translocation, translocation, and reconstruction of annulas with pericardial patch. There were five (15.2%) operative and hospital deaths and actuarial survival rate was 81% and 61% at 5 and 10 years after operation. Including one who died early after operation, there were 5 cases with postoperative paravalvular leakage and its main cause were persistent infection. In conclusion, it considered that the principles of treating active infective endocarditis is to decide the optimal timing for operation, debride the infected tissue, and close the defect completely.

[Acute aortic dissection complicated with acute myocardial infarction--a case report of successful operation for the case of DOA]

A 61-year-old woman who suddenly manifested chest and back pain was admitted after the diagnosis of acute type A dissection complicated with acute inferior myocardial infarction at another hospital. While being transported to our hospital by ambulance, her ECG repeatedly demonstrated ventricular fibrillation of cardiac arrest. She was in the state of dead on arrival (DOA) when arrived at our hospital. ECG demonstrated complete A-V block and cardiac arrest alternately. However, soon after right ventricular pacing was done, her blood pressure increased and she recovered consciousness. We therefore performed an emergency operation. We performed reconstruction of the ascending aorta and right coronary bypass grafting, since she had aortic dissection and conus brach avulsion. The postoperative course was uneventful.

Valve detachment after aortic valve replacement--a successfully reoperated case with the Cabrol technique

A 50-year-old Japanese male was admitted with a 1 month history of progressive shortness of breath, palpitations, and intermittent low-grade fever. On admission, a musical diastolic murmur (sea-gull murmur) was heard on the 3rd left sternal border. Blood studies showed an accelerated erythrocyte sedimentation rate, and positive C-reactive protein. Retrograde aortography revealed severe aortic regurgitation. At the operation, the aortic wall was remarkably thickened, and the aortic valve commissures between the right and left coronary cusps and between the left and non-coronary cusps had completely detached from the aortic wall. The aortic valve was replaced with a St Jude Medical valve using pledgeted sutures. Histologic studies of the aorta and aortic valve revealed no evidence of any pathologic changes. Echocardiography performed 82 days after aortic valve replacement showed severe paravalvular leakage and valve detachment. At the reoperation, the prosthetic valve was detached from the extremely edematous and fragile native aortic annulus. There was no vegetation or abscess formation. Aortic root replacement with the Cabrol technique was performed using a composite graft in which the prosthetic valve was placed 1 cm above the proximal extremity to reduce the tension on the suture line and the aortic annulus. Histologic study of the aorta after the reoperation showed non-specific inflammatory disease. The patient, who received steroid therapy, has recovered without any signs of graft detachment or pseudoaneurysm formation.

Isolation of reovirus type 2 from diarrheal feces of pigs

Reoviruses designated as OS-320 to OS-324 were isolated from a total of 5 fecal specimens from 3 with diarrhea and 2 apparently healthy pigs aged 3 months. The serotype of these isolates was determined as reovirus type 2 by cross neutralizing tests. Furthermore, the results of hemagglutination test suggested the isolates were different from the other reoviruses. A survey of neutralizing antibody against reoviruses showed type 2 virus was widely prevalent among pigs in Okayama Prefecture. This paper is the first report of the isolation of reovirus type 2 from pigs.

Lesser sac hernia through the gastrocolic ligament: CT diagnosis

We present a case of a lesser sac hernia of the ileum through a defect in the gastrocolic ligament with reemergence through a defect in the gastrohepatic ligament. Computed tomography (CT) revealed the herniated bowel surrounded by the liver, the stomach and the pancreas, and demonstrated the defect in the gastrocolic ligament between the stomach and the transverse colon.

Aortic dissection after aortic valve replacement. Report of a case with an aortocameral fistula

A 58-year-old Japanese woman who had a history of aortic valve replacement for congenital bicuspid valve, was admitted for investigation of facial edema and of pulselessness of the right leg. Physical examination disclosed the patient suffering from a superior vena cava syndrome. On auscultation, a continuous murmur was heard at the left lower sternal border. Computed tomographic scans revealed aortic dissection extending from the ascending aorta to the bifurcation. Echocardiography showed an intimal flap in the dilated ascending aorta, but not abnormal blood flow from the aorta to the right atrium was detected. Cardiac catheterization and aortography, however, allowed a correct diagnosis of aortic dissection with fistula to the right atrium and with obstruction of the right common iliac artery. The patient received emergency aortic root replacement and reconstruction of the coronary arteries and then recovered uneventfully.

[Simultaneous operation for annulo-aortic ectasia, mitral regurgitation, and tricuspid regurgitation in a patient with Marfan syndrome--report of a case]

A 57-year-old man with manifestations of Marfan syndrome was referred for detail examination of cardiac murmur to our hospital. Cardioangiography showed moderate aortic valve regurgitation (2/4), and severe mitral valve regurgitation (3/4), in addition to aneurysmal dilatation of the aortic root. Moderate tricuspid valve regurgitation (2/4) was also detected by Doppler echocardiography. Aortic root replacement with the Cabrol technique, mitral valve replacement with a St. Jude Medical valve, and repair of the tricuspid valve with the bicuspidalization technique were simultaneously performed in this patient. His postoperative recovery was uneventful. In this study, we discuss about the indications of simultaneous aortic root replacement and mitral valve replacement in a patient with Marfan syndrome.

Isolation of a serotype G6P11 bovine rotavirus showing two-way cross-neutralization with the serotype G10P11 virus

Four stains designated as OB94-1 to OB94-4 of group A bovine rotavirus (BRV) were isolated from 35 fecal samples of calves with diarrhea in sporadic outbreaks. In VP7 (G) and VP4 (P) serotyping of these isolates, OB94-1 to OB94-3 were determined as G6P5, G6P5 and G10P5, respectively, by cross neutralization (NT) test and the G- and P- serotyping polymerase chain reaction (PCR) analysis. OB94-4 showed a one-way antigenic relation with the Lincoln stain (G6P1) and a weak antigenic relationship with the KK3 strain (G10P11), and was determined as G6P11 by the PCR method. Thus, OB94-4 was shown to be a new G6 BRV with different antigenic properties from the others in the NT test.

Total aortic replacement in a patient with mega aorta syndrome--a case report

A 64-year-old woman without manifestations of Marfan syndrome was referred for the close investigation of a pulsatile abdominal mass. Computed tomographic scans and magnetic resonance images revealed aneurysmal dilatation of the entire aorta, including the ascending aorta and extending to the bifurcation of the aorta, as well as tortuousness of the thoracoabdominal and abdominal aorta. Digital subtraction angiography also showed aneurysmal dilatation of the entire aorta and trivial aortic regurgitation. However, aortic annular dilatation was not found by echocardiography or aortography. The entire aorta was replaced in two stages. First, graft replacement of the ascending aorta, except for the sinus segment, and the aortic arch was performed using an elephant trunk technique under hypothermic cardiopulmonary bypass with selective cerebral perfusion. Twelve weeks later, the remaining aorta, including the descending aorta and extending to the common iliac artery on the right side, and to the common femoral artery on the left side, was replaced with a partial cardiopulmonary bypass using femoral artery and vein cannulation. We believe that patients with mega aorta syndrome are best treated by total aortic replacement. The results in the present case indicate that the elephant trunk technique is useful for extensive aortic replacement in stages, and greatly facilitates the second stage operative procedures.

Absence of polymorphism at the ZFY locus on the human Y chromosome

DNA polymorphism in the Y chromosome, examined at a 729-base pair intron located immediately upstream of the ZFY zinc-finger exon, revealed no sequence variation in a worldwide sample of 38 human males. This finding cannot be explained by global constraint on the intron sequence, because interspecific comparisons with other nonhuman primates revealed phylogenetically informative sequence changes. The invariance likely results from either a recent selective sweep, a recent origin for modern Homo sapiens, recurrent male population bottlenecks, or historically small effective male population sizes. A coalescence model predicts an expected time to a most recent common ancestral male lineage of 270,000 years (95 percent confidence limits: 0 to 800,000 years).