Notes: Abstract PURPOSE: The aim of this study was to determine if local injection of bupivacaine after hemorrhoidal banding causes a decrease in pain and in the incidence of associated symptoms. METHODS: After hemorrhoidal banding, patients were randomly assigned to receive a local injection of bupivacaine with 1:200,000 epinephrine, an injection of normal saline, or no injection, just superior to each band. Pain was graded by the patient and by the study nurse within 30 minutes, and any associated symptoms were recorded. At intervals 6, 24, and 48 hours postbanding, the patient recorded pain, limitation of activities, and analgesic requirements. Associated symptoms while at home were recorded. RESULTS: Of 115 patients studied, 42 received bupivacaine injection, 42 received normal saline injection, and 31 received no injection. In patients receiving bupivacaine compared with no injection, within 30 minutes postbanding there was a significant reduction in pain graded by the patient (P=0.000002) and by the nurse (P=0.000005) and a significant reduction in incidence of nausea (P=0.01) and shaking (P=0.008). However, in the bupivacaine group compared with the other two groups, at the intervals of 6, 24, and 48 hours postbanding there was no sustained reduction in the severity of pain and no reduction in analgesic requirements or limitation of normal activities. In the week after banding, there was no difference between groups in symptoms of nausea, shaking, lightheadedness, urinary retention, or bleeding. CONCLUSIONS: Bupivacaine injection may be useful for reducing pain and associated symptoms long enough to tolerate a trip home from the outpatient department but does not show a sustained effect.

Notes: Abstract SeaMARC II sidescan (imagery and bathymetry) and seismic data reveal the morphology, sedimentary processes, and structural controls on submarine canyon development in the central Izu-Bonin forearc, south of Japan. Canyons extend up to 150 km across the forearc from the trench-slope break to the active volcanic arc. The canyons are most deeply incised (1200–1700 m) into the gentle gradients (1–2°) upslope on the outer arc high (OAH) and lose bathymetric expression on the steep (6–18°) inner trench-slope. The drainage patterns indicate that canyons are formed by both headward erosion and downcutting. Headward erosion proceeds on two scales. Initially, pervasive small-scale mass wasting creates curvilinear channels and pinnate drainage patterns. Large-scale slumping, evidenced by abundant crescent-shaped scarps along the walls and tributaries of Aoga Shima Canyon, occurs only after a channel is present, and provides a mechanism for canyon branching. The largest slump has removed 〉16 km3 of sediment from an ∼85 km2 area of seafloor bounded by scarps more than 200 m high and may be in the initial stages of forming a new canyon branch. The northern branch of Aoga Shima Canyon has eroded upslope to the flanks of the arc volcanoes allowing direct tapping of this volcaniclastic sediment source. Headward erosion of the southern branch is not as advanced but the canyon may capture sediments supplied by unconfined (non-channelized) mass flows. Oligocene forearc sedimentary processes were dominated by unconfined mass flows that created sub-parallel and continuous sedimentary sequences. Pervasive channel cut-and-fill is limited to the Neogene forearc sedimentary sequences which are characterized by migrating and unconformable seismic sequences. Extensive canyon formation permitting sediment bypassing of the forearc by canyon-confined mass flows began in the early Miocene after the basin was filled to the spill points of the OAH. Structural lows in the OAH determined the initial locus of canyon formation, and outcropping basement rocks have prevented canyon incision on the lower slope. A major jog in the canyon axis, linear tributaries, and a prominent sidescan lineament all trend NW-NNW, reflecting OAH basement influence on canyon morphology. This erosional fabric may reflect joint/fracture patterns in the sedimentary strata that follow the basement trends. Once the canyons have eroded down to more erosion-resistant levels, channel downcutting slows relative to lateral erosion of the canyon walls. This accounts for the change from a narrow canyon axis in the thickly sedimented forearc basin to a wider, more rugged canyon morphology near the OAH. About 9500 km3 of sediment has been eroded from the central, 200 km long, segment of the Izu-Bonin forearc by the formation of Aoga Shima, Myojin Sho and Sumisu Jima canyons. The volume of sediment presently residing in the adjacent trench, accretionary wedge, and lower slope terrace basin accounts for 〈25% of that eroded from the canyons alone. This implies that a large volume (〉3500 km3 per 100 km of trench, ignoring sediments input via forearc bypassing) has been subducted beneath the toe of the trench slope and the small accretionary prism. Unless this sediment has been underplated beneath the forearc, it has recycled arc material into the mantle, possibly influencing the composition of arc volcanism.

Notes: Abstract The Woodlark triple junction region, a topographically and structurally complex triangular area of Quaternary age, lies east of Simbo Ridge and southwest of the New Georgia island group, Solomon Islands, at the junction of the Pacific, Australian and Solomon Sea plates. SeaMARC II side-scan imagery and bathymetry in conjunction with seismic reflection profiles, 3.5 kHz records, and petrologic, magnetic and gravity data show that the active Woodlark spreading centre does not extend into this region. South of the triple junction region, the Woodlark spreading centre reoriented at about 2 Ma into a series of short ESE-trending segments. These segments continued to spread until about 0.5 Ma, when the lithosphere on their northern sides was transferred from the Solomon Sea plate to the Australian plate. Simultaneously the Simbo transform propagated northwards along the western side of the transferred lithosphere, forming a trench-trench-transform triple junction located NNW of Simbo island and a new leaky plate boundary segment that built Simbo Ridge. As the Pacific plate approached, the area east of northern Simbo Ridge was tilted northwards, sheared by dominantly right-lateral faults, elevated, and intruded by arc-related magmas to form Ghizo Ridge. Calc-alkalic magmas sourced beneath the Pacific plate built three large strato-volcanic edifices on the subducting Australian plate: Simbo at the northern end of Simbo Ridge, and Kana Keoki and Coleman seamounts on an extensional fracture adjoining the SE end of Ghizo Ridge. A sediment drape, supplied in part from Simbo and Kana Keoki volcanoes, mantles the east-facing slopes of northern Simbo and Ghizo Ridges and passes distally into sediment ponded in the trench adjoining the Pacific plate. As a consequence of plate convergence, parts of the sediment drape and pond are presently being deformed, and faults are dismembering Kana Keoki and Coleman seamounts. The Woodlark system differs from other modern or Tertiary ridge subduction systems, which show wide variation in character and behaviour. Existing models describing the consequences of ridge subduction are likely to be predictive in only a general way, and deduced rules for the behaviour of oceanic lithosphere in ridge subduction systems may not be generally applicable.

Notes: Abstract The Manus Basin in the eastern Bismarck Sea is a fastopening backarc basin behind the New Britain arc-trench system. Within the basin, motion between the Pacific and Bismarck plates about a pole located at 11° S, 145° E, occurs along three major leftlateral transform faults and a variety of extensional segments. We interpret SeaMARC II sidescan and other geophysical data to show that a Brunhes age plate reorganization created new extensional boundaries and a microplate between the NW-trending Willaumez, Djaul, and Weitin transforms. Two linked spreading segments formed in backarc basin crust between the Willaumez and Djaul transforms: the ESE-trending extensional transform zone (ETZ) in the west and the Manus spreading center (MSC) in the east. Positively magnetized crust on the MSC forms a wedge varying in width from 72 km at its southwest end to zero at its northeast tip, with corresponding Brunhes spreading rates varying from 92 mm/yr to zero. The MSC forms the northwestern boundary of the 100 km-scale Manus microplate and opens at 51°/m.y. about a pole near its apex at 3°02′S, 150°32′E. Opposite the MSC, bordering the arc margin of New Britain, the microplate is bound by a zone of broadly distributed strike slip motion, extension, and volcanism. Within this area, the Southern Rifts contain a series of grabens partially floored by lava flows. Left-lateral motion between the Pacific and Bismarck plates appears to drive the counterclockwise pivoting motion of the Manus microplate and the complementary wedge-like opening of the MSC and the Southern Rifts. The pivoting motion of the microplate has resulted in compressional areas along its NE and SW boundaries with the Pacific and Bismarck plates respectively. East of the microplate, between the Djaul and Weitin transforms and within the arc margin of New Ireland, another zone of broad extension referred to as the Southeast Rifts takes up opening in a pull-apart basin. There, en echelon volcanic ridges may be the precursors of spreading segments, but erupted lavas include calcalkaline volcanics. Kinematic modeling and marine geophysical observations indicate that the responses to similar amounts of extension in the eastern Manus Basin have varied as a function of the different types of pre-existing crust: arc crust tectonically stretched over a broad area whereas backarc crust underwent relatively little stretching before accommodating extension by seafloor spreading.

Notes: Abstract Four new bathymetric maps of the Tonga Trench and forearc between 14 °S and 27 °S display the important morphologic and structural features of this dynamic convergent margin. The maps document a number of important geologic features of the margin. Major normal faults and fault lineaments on the Tonga platform can be traced along and across the upper trench slope. Numerous submarine canyons incised in the landward slope of the trench mark the pathways of sediment transport from the platform to mid- and lower-slope basins. Discontinuities in the trench axis and changes in the morphology of the landward slope can be clearly documented and may be associated with the passage and subduction of the Louisville Ridge and other structures on the subducting Pacific Plate. Changes in the morphology of the forearc as convergence changes from normal in the south to highly-oblique in the north are clearly documented. The bathymetric compilations, gridded at 500- and 200-m resolutions and extending along ∼500 km of the landward trench slope and axis, provide complete coverage of the outer forearc from the latitude of the Louisville Ridge-Tonga Trench collision to the northern terminus of the Tonga Ridge. These maps should serve as a valuable reference for other sea-going programs in the region, particularly the Ocean Drilling Program (ODP) and the National Science Foundation MARGINS initiative.

Notes: Abstract The aim was to determine whether the canine stomach modulates interdigestive and digestive small intestinal myoelectric activity. In four conscious dogs with electrodes implanted chronically on the duodenum and jejunum, enteric myoelectric activity was recorded during fasting and after feeding a 200-g liver meal. The dogs then underwent total gastrectomy and esophagoduodenostomy, after which they were restudied. Gastrectomy did not alter the pattern of the enteric interdigestive myoelectric complexes; the occurrence, period, duration of phase III, and consistency of distal propagation of enteric IMCs remained unchanged. Gastrectomy also preserved both the postcibal inhibition of the enteric IMCs and the postcibal induction of the fed myoelectric pattern in the small bowel. However, the onset on the fed pattern occurred more promptly after gastrectomy than before gastrectomy. We concluded that the pattern of canine duodenal and jejunal interdigestive myoelectric activity was largely independent of the stomach. The more rapid onset of the fed pattern with feeding postgastrectomy may relate to more rapid entry of chyme into the small intestine.

Notes: Abstract A cDNA clone corresponding to a transcript that was induced by auxin in tomato seedling roots encodes a 223 amino acid protein belonging to the proteinase inhibitor II family of tomato and potato. The TR8 open reading frame has an N-terminal region with characteristics of a signal peptide and three copies of a 64 amino acid segment that is also present in multiple copies in other PI–II family members. Comparison to other serine proteinase inhibitors indicates that all three domains are trypsin-specific. Transcripts homologous to TR8 increased in abundance within 24 h of auxin treatment and continued to increase through 72 h, at which point the induction was approximately ten-fold. Auxin induction was observed in roots and hypocotyls, but not in cotyledons or epicotyls. Induction may therefore be correlated with lateral and adventitious root initiation, which occurs over a similar time frame in the same tissues. RFLPs detected with the TR8 probe were mapped to the long arm of chromosome 11.

Notes: Abstract To assess the potential of the maize transposable element Ac for gene tagging in heterologous plant species we monitored transcription, excision and transposition of the element in transgenic tobacco plants and their selfed progeny. Ac excised in the majority of primary regenerants and continued to excise in the first-generation progeny plants. In one primary regenerant Ac was transcribed but did not excise. Fourteen of eighteen kanamycin-resistant progeny from this plant showed Ac excision, suggesting that excision of Ac may have been activated during meiosis or in embryo development. This finding, together with the more general observation of continued Ac mobility in the progeny of transformed plants in which Ac had excised, suggests that Ac will be useful for gene tagging.

Notes: Abstract The frequency of lateral root initiation in tomato (Lycopersicon esculentum Mill cv. VFN8) seedling roots is increased over eightfold in response to 1.6 μM α-naphthaleneacetic acid (NAA). To identify genes that are activated during lateral root initiation, a cDNA library was made with RNA from roots treated with auxin and differentially screened with radioactive probes made from RNA isolated from treated and untreated roots. A cDNA clone, TR132, was identified that hybridized to a transcript that was induced within 4 h of auxin treatment and increased tenfold by 72 h. A gene (RSI-1) corresponding to the TR132 cDNA was cloned and characterized with regard to its nucleotide sequence, transcription start site and chromosomal map position. Approximately 1 kb of the 5′ flanking DNA was linked to the β-glucuronidase (GUS) protein coding region and tested for expression in transgenic tomato seedlings. GUS activity was observed in both lateral and adventitious root initials, including very early initials, and persisted until shortly after the lateral emerged from the parent tissue. In roots from seedlings with high activity, GUS expression was also observed in the root cap and vascular tissue. The predicted RSI-1 protein is rich in cysteine, lysine and proline, and includes an N-terminal region with characteristics of a signal peptide. The putative mature protein exhibits 79% amino acid identity to a protein encoded by a gene (GAST1) that is induced by gibberellic acid in tomato shoots.

Notes: Summary Two distinct segments of transferred DNA (T-DNA) were detected in tumor tissue incited by Agrobacterium rhizogenes strain A4 on Nicotiana glauca. RNA from these tumors was examined for the presence of T-DNA encoded transcripts. Six genetic loci involved in virulence and tumor morphology have been identified by transposon mutagenesis: rol A-D on the leftward T-DNA (TL-DNA) and tms1 and 2 on the rightward T-DNA (TR-DNA). On the basis of map position, the rol A-D loci are associated with transcripts of 650, 1,050, 850 and 1,250 nucleotides, respectively, while the tms loci are associated with transcripts of 2,500 and 1,600 nucleotides. An additional transcript of 1,050 nucleotides not associated with a detectable phenotype was identified on the TL-DNA. On the TR-DNA, at least four transcripts other than those associated with tms1 and 2 were identified.