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K Okinaga

Publications and source records attributed to K Okinaga.

52 records · Page 3Linked to original sources
PubMed1988

Role of pili in the pathogenesis of Pseudomonas aeruginosa burn infection.

The present study using three isogenic mutants (F+P-, F-P+, F-P-) of Pseudomonas aeruginosa indicates that the presence of pili enhances the virulence of the organisms in experimental P. aeruginosa burn infection of mice. The 50% lethal dose (LD50) value for burned mice inoculated with non-piliated (P-) mutant was at least ten times higher than those inoculated with piliated (P+) bacteria. Meanwhile the LD50 value for burned mice inoculated with non-flagellated (F-) mutant was at least 10(5) times higher than those inoculated with flagellated (F+) bacteria. At 24 hr after inoculation, the bacterial counts in burned skin of mice inoculated with P+ bacteria were ten times higher than those inoculated with P- bacteria; and at 48 hr the bacterial counts became a hundred times higher in the former mice than the latter. At 24 hr after inoculation, P+ bacteria were isolated from blood, liver (F+P+), lung (F+P+), and kidney, while P- bacteria were not present in these tissues. And at 48 hr after inoculation, P+ bacteria were isolated from all tissues, while P- bacteria were isolated from some sites only. These results suggested that pili and flagella each play an important role as virulence factors independently, and that pili-mediated enhancement of virulence of P. aeruginosa was attributed to pili-mediated enhanced colonization of the organisms at the burned skin surfaces.

Animals↗
PubMed1987

Role of pili in the adherence of Pseudomonas aeruginosa to mouse epidermal cells.

Pili have been demonstrated to be the adhesins of Pseudomonas aeruginosa for mouse epidermal cells. The mechanisms of adhesion of P. aeruginosa to mouse epidermal cells was studied by using four mutants derived from a single strain: flagellated and piliated (F+P+), flagellated and nonpiliated (F+P-), nonflagellated and piliated (F-P+), and nonflagellated and nonpiliated (F-P-) mutants. F+P+ and F-P+ bacteria efficiently adhered to mouse epidermal cells, while F+P- and F-P- bacteria hardly adhered to mouse epidermal cells. The number of F+P+ bacteria that adhered to mouse epidermal cells was almost the same as that of F-P+ bacteria. The number of F+P- bacteria that adhered to mouse epidermal cells was almost the same as that of F-P- bacteria. The adhesion of P+ (F+P+ and F-P+) bacteria was inhibited by antipilus serum, while that of P- (F+P- and F-P-) bacteria was not inhibited by antipilus serum. There were no significant differences between the number of bacteria adhering to mouse epidermal cells isolated from normal skin and those adhering to cells isolated from burned skin. Heating of the mouse epidermal cell suspension had no effect on the adhesion of P. aeruginosa. These results suggest that pili mediate the adhesion of P. aeruginosa to mouse epidermal cells and that P. aeruginosa adheres efficiently to mouse epidermal cells despite the loss of cell viability caused by burning.

Animals↗
PubMed1981

The effect of partial splenectomy on experimental pneumococcal bacteremia in an animal model.

The effect of total and partial splenectomy on the blood stream clearance of type 23B Streptococcus pneumoniae was studied in chinchillas 2 wk and 2 mo following surgery to determine the amount of splenic tissue necessary for protection against overwhelming sepsis. Significantly more pneumococci were found in the blood of totally splenectomized chinchillas than in the blood of sham-operated animals throughout the 6-hr sampling period after intravenous inoculation of pneumococci. Animals that had two-thirds of their spleen removed demonstrated a significant delay in clearance of pneumococci compared with sham-operated and hemisplenectomized animals. The rate of pneumococcal clearance was similar for the sham-operated and the hemisplenectomized group, and was significantly prolonged but similar among totally splenectomized and two-thirds splenectomized animals. Pneumococcal opsonic activity was reduced only in the sera of totally splenectomized chinchillas 2 mo after surgery. There was no positive relationship between pneumococcal clearance and change in pneumococcal opsonic activity. These results suggest that the impaired clearance of circulating pneumococci in splenectomized animals is due to the loss of splenic reticuloendothelial cells as a mechanical filter, rather than deficient serum opsonic activity. There appears to be a critical splenic mass required for optimal bacterial clearance, and hemisplenectomy may protect against overwhelming postsplenectomy sepsis.

Animals↗
PubMed1978

Surgical management of islet-cell adenoma in infancy.

Persistent neonatal hypoglycemia is a potentially serious condition which should be recognized promptly, investigated thoroughly, and treated expeditiously. Islet-cell adenoma causing hypoglycemia in infancy is very unusual. Only 23 cases have been reported in the literature. This report documents eight cases of our own and summarizes diagnostic methods, proper medical preparation, and fundamental surgical management. Prompt surgical intervention is emphasized, as this will relieve hypoglycemia and may be important in preventing irreversible central nervous system damage. We are of the opinion that any infant with unremitting hypoglycemia, a high corrected insulin/glucose ratio, and failure to respond to maximum diazoxide therapy will require partial pancreatectomy. Identification of the adenoma at the time of operation is unlikely, and blind pancreatectomy and/or reoperation is not unusual.

Adenoma↗
PubMedDate not supplied

Recurrent common bile duct stones associated with periampullary duodenal diverticula and calcium bilirubinate stones.

We reviewed operative procedures, type of stones, and coexistence of periampullary duodenal diverticula in 115 patients with common bile duct stones who underwent first surgery at our department between 1982 and 1991. Among these patients, 109 underwent choledochotomy with T-tube drainage, 4 underwent side-to-side choledocho-jejunostomy, and 2 had end-to-side choledochojejunostomy. Five patients developed recurrent common bile duct stones (RCS) after surgery. All these patients were older women who had calcium bilirubinate stones in the common duct and coexisting periampullary duodenal diverticula. No patients who underwent end-to-side choledochojejunostomy developed RCS after the initial surgery or reoperation. The results of the present study suggest that both calcium bilirubinate stones and periampullary duodenal diverticula are contributing factors in the development of RCS in patients with common bile duct stones, and that end-to-side choledocho-jejunostomy should be considered for patients with these two factors after the initial common duct exploration.

Adult↗