Takashi Gomi

Delta-shaped anastomosis in totally laparoscopic Billroth I gastrectomy: new technique of intraabdominal gastroduodenostomy.

Recently, laparoscopic gastrectomy has become popular for the treatment of benign gastroduodenal diseases or early gastric carcinomas. Several procedures can now be performed intraabdominally because of advances in technology and surgical techniques, but Billroth I reconstruction after laparoscopic distal gastrectomy is commonly performed extraabdominally because of the complexity of intraabdominal anastomotic procedure. We have developed a new method of intraabdominal Billroth I anastomosis using only endoscopic linear staplers. Our procedure is simple, easy, and safe. In this article, we describe the technique and present the results of our initial trials.

Characteristics of channel steps and reach morphology in headwater streams, southeast Alaska

Abstract The effect of timber harvesting and mass movement on channel steps and reach morphology was examined in 16 headwater streams of SE Alaska. Channel steps formed by woody debris and boulders are significant channel units in headwater streams. Numbers, intervals, and heights of steps did not differ among management and disturbance regimes. A negative exponential relationship between channel gradient and mean length of step intervals was observed in the fluvial reaches (

Bed load transport in managed steep-gradient headwater streams of southeastern Alaska

[1] Bed load transport was investigated in four headwater streams in southeastern Alaska subjected to different management and disturbance regimes. Bed load yield was positively correlated to peak discharge during the fall 1999 monitoring period. Fine bed load materials (1-11 mm) that were supplied from hillslope sources were equally mobilized during most storm events. Medium-sized bed materials (11-200 m) were only partially mobilized even during large storms, whereas large particles (>200 mm) were immobile and often formed interlocking channel structures. The transport distances of medium-size materials depended on amount of channel obstructions (e.g., woody debris) and sediment supply conditions; both of these factors were influenced by the occurrence of mass movement, timber harvesting, and the related recovery processes. The highest total bed load yield was observed in a channel affected by a debris flow in 1993. Total sediment yields are similar among channels with old-growth, clear cut (logged 4 years before monitoring), and young alder (affected by landslides and debris flows in 1961) riparian stands. By comparing the old-growth and young alder channels, it appears that bed load yield recovers from debris flow disturbances in about 40 years; however, recovery of channel conditions (e.g., reach types and woody debris) may take much longer. Effects of timber harvesting on bed load transport are controlled by sediment linkages between hillslopes and channels related to the occurrence of mass movement.

The role of litterfall in transferring Fukushima-derived radiocesium to a coniferous forest floor.

The deposition of Fukushima-derived radiocesium via falling litter in a coniferous forest 180 km downwind immediately following the nuclear power plant accident was investigated. The litterfall contribution to the transfer of radiocesium from the forest canopy to the forest floor was determined, and this pathway was compared with hydrological pathways. The results demonstrated that during the observation period, a total of approximately 5.5 kBq m(-2) of Fukushima-derived radiocesium was deposited on the forest floor through throughfall (53%), stemflow (2.3%) and litterfall (45%) routes. The data revealed that the contributions of hydrological pathways became less important as time passed. However, the litterfall route, which transferred approximately 31% (2.5±0.6 kBq m(-2)) of the local fallout within the observation period, continued depositing radiocesium onto the forest floor.

Successful long-term xenoperfusion of the pig liver : continuous administration of prostaglandin E1 and insulin

For clinical utilization of extracorporeal liver perfusion as an artificial liver assist device, we examined the possibility of long-term xenoperfusion of the pig liver by the continuous administration of prostaglandin E1 (PGE1) and insulin. After a 3-hr perfusion period, pig livers that were xenoperfused with human blood exhibited a drastic decrease in the perfusate volume, a progressive elevation of the hepatic artery pressure, a gradual deterioration of bile production, and a marked increase in the release of creatine kinase-BB component. The continuous administration of PGE1 (25 microg/hr) and insulin (1 U/hr) significantly improved these derangements (P<0.05) and allowed stable perfusion for up to 9 hr. This manipulation also inhibited leukocyte aggregation in the graft, the characteristic perfusate hemolysis, and acceleration of ketogenesis. Histological examination revealed that the interlobular edema and hemorrhage, characteristics of tissue injuries in xenogeneic hyperacute rejection, were markedly alleviated in the PGE1 and insulin-treated group. This study clarifies the finding that the combined administration of PGE1 and insulin is effective for long-term xenogeneic extracorporeal liver perfusion, with the graft viability well maintained.

Humoral injury in porcine livers perfused with human whole blood

BACKGROUND We investigated the influence of humoral injury during xenoperfusion of porcine livers by human blood. METHODS The porcine livers were perfused under physiological conditions for 9 hr. The perfusates consisted of porcine whole blood in group 1, human whole blood in group 2, and human whole blood with soluble complement receptor type 1 (300 microg/ml) in group 3. RESULTS Liver enzyme release and serum hemoglobin in group 2 increased significantly after 3 hr of xenoperfusion, compared with those in group 1 and group 3 (P<0.05). Severe histological damage with minimal cellular infiltration was observed in group 2 after 6 hr of xenoperfusion, but was present only at trace levels in group 1 and group 3. In group 2, von Willebrand factor, a possible target of natural antibodies, was induced on sinusoidal endothelial cells after 3 hr of xenoperfusion, correlating with diffuse deposition of human IgM and membrane attack complex. In group 3, von Willebrand factor, human IgM, and membrane attack complex staining in the intralobular region were present at trace levels. In group 3, the indocyanine green removal capacity, representing hepatocyte function, was significantly higher than in group 2 (P<0.05). CONCLUSIONS Based on these results, we suggest that humoral injury is a major cause of liver damage during liver xenoperfusion. The pattern of humoral injury in xenoperfused livers may be attributed to anatomical features of the liver and unique responses of sinusoidal endothelial cells to xenoperfusion.

Baseflow concentrations of nitrogen and phosphorus in forested headwaters in Japan

A comprehensive investigation on all dissolved nitrogen and phosphorus components at both local and regional scales in the headwaters from forested watersheds is valuable to improve our understanding of the factors controlling water quality. Here, we investigated the baseflow concentrations of dissolved nitrogen and phosphorus components, N:P ratio, and their associations with region and vegetation type in forested headwaters in fives regions of Japan. We found that inorganic nitrogen and phosphorus were the dominant components in the 26 temperate forested streams, rather than organic forms. There were significant positive correlations between the concentrations of N and P components. Furthermore, the regional patterns of the concentrations of nitrate, dissolved inorganic P (DIP), and dissolved total N (DTN) and P (DTP) were similar. Our results suggest that the regional patterns of the concentrations of N and P components should be related to the regional atmospheric deposition of both N and P nutrients. We also found that the nitrate and DTN concentrations were higher in man-made evergreen conifer (EC) than those in the natural deciduous broadleaf (DB). In contrast, the DIP and DTP concentrations in EC were lower than those in DB. The uniformly higher N:P ratio in EC- than in DB-forested streams for each region suggest that EC-forested streams could be more affected by P-limited than DB-forested streams when N inputs from atmospheric sources increased.

Potential influences of a net-spinning caddisfly (Trichoptera:Stenopsyche marmorata) on stream substratum stability in heterogeneous field environments

Abstract The influence of the net-spinning caddisfly larva Stenopsyche marmorata on streambed substratum stability was examined in 14 riffles of 5 rivers in northern Hokkaido, Japan. In each riffle, 6 representative stones were measured and 7 variables were quantified for each stone: 1) ambient flow velocity, 2) ambient depth, 3) extent of embeddedness, 4) force required to initiate shifting of the stone parallel to the flow direction, 5) biomass of S. marmorata living on and under the stone, 6) wet mass of the stone, and 7) size of the stone. Regression analyses were used to examine which of the variables best predicted the coherent strength of a particle with the stream bed (FC). Riffle-scale patterns derived from the means of 6 stones showed significant influences of biomass of S. marmorata/stone and embeddedness on FC; however, the collinearity of these 2 variables hindered evaluation of their relative importance. At the stone scale, biomass of S. marmorata/stone was positively related to FC when standardized for the degree of stone embeddedness. FC of stones inhabited by S. marmorata at the maximum range of their biomass is predicted to be 50 to 260% greater than FC of stones without S. marmorata. The effects of biological consolidation of substratum particles by S. marmorata probably are substantial, even in inherently heterogeneous natural environments.

Is MUSLE apt to small steeply reforested watershed

The reforested headwater watersheds in Japan are very important from the points of view of commercial and environmental aspects. At the present time, much and varied research is running to assess and understand the hydrologic behavior of these watersheds. The present study was conducted to evaluate the applicability of the deterministic model MUSLE in the Mie small steeply reforested watershed. The model was tested and calibrated using accurate continuous suspended sediment data collected during eight storm events in 2004. Results of the original model simulations for storm-wise sediment yield did not match the observed data, while the revised version of the model could imitate the observed values well. The results of the study approved the efficient application of the revised MUSLE in estimating storm-wise sediment yield in the study area with a high level of agreement of beyond 88%, an acceptable estimation error of some 14% and non-significant difference in mean values.

Managing young upland forests in southeast Alaska for wood products, wildlife, aquatic resources, and fishes: problem analysis and study plan.

Wipfli, Mark S.; Deal, Robert L.; Hennon, Paul E.; Johnson, Adelaide C.; De Santo, Toni L.; Hanley, Thomas A.; Schultz, Mark E.; Bryant, Mason D.; Edwards, Richard T.; Orlikowska, Ewa H.; Gomi, Takashi. 2002. Managing young upland forests in southeast Alaska for wood products, wildlife, aquatic resources, and fishes: problem analysis and study plan. Gen. Tech. Rep. PNW-GTR-558. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 64 p. Red alder (Alnus rubra Bong.) appears to influence the productivity of young-growth conifer forests and affect the major resources (timber, wildlife, and fisheries) of forested ecosystems in southeast Alaska. We propose an integrated approach to understanding how alder influences trophic links and processes in young-growth ecosystems. The presence of red alder is expected to increase understory biomass, and aquatic, riparian, and terrestrial invertebrate abundance, providing more food for herbivores, fish, and birds. We predict that most red alder trees will die standing, and woody debris will be small and mobile in streams. Nitrogen fixation by red alder in mixed stands may result in larger, more commercially valuable conifers. Inclusion of red alder in the regenerating stand may therefore mitigate some negative impacts of clearcutting, and may increase total wood production from the landscape.