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Biomedical subjects

H Konno

Publications and source records attributed to H Konno.

At least 145 records · Page 8Linked to original sources

Significance of hepatic vein reconstruction in hepatectomy.

BACKGROUND: To preserve remnant liver function, hepatectomy combined with hepatic vein (HV) reconstruction was performed in resection of the tumor located at the confluence of the HV and inferior vena cava. METHODS: Eight patients underwent HV reconstruction: the right HV in three, the middle HV in four, and the left HV in one. An external iliac vein graft was used in two patients, a superficial femoral vein graft in three, and a long saphenous vein graft in one. In one patient a patch graft was applied to the right HV; another patient underwent end-to-end anastomosis of the right HV without grafting. RESULTS: There were no operative deaths and liver function was adequate throughout the postoperative period. Complications included two cases of minor biliary fistula. The middle HV with a saphenous graft and the left HV with an external iliac graft became occluded because of size mismatch at the anastomosis. Six veins were patent at 1 month and three were still patent after 30 months. CONCLUSIONS: To prevent graft occlusion, it is important to select an autologous vein of optimal size and avoid inflammation of the liver stump. HV reconstruction appears to be a new surgical option for patients undergoing hepatectomy.

Adult↗

[Postoperative hypophosphatemia in patients with cancer of the thoracic esophagus].

Postoperative phosphate dynamics were studied in 30 patients who underwent radical surgery for thoracic esophageal cancer and who were postoperatively nourished by total parenteral nutrition. There was a significant fall in the serum phosphate level on the 2nd and 3rd postoperative days in all patients. Postoperative hypophosphatemia was due to an increase in urinary phosphate excretion which was indicated by the fall in TRP% and TmPO4/GFR. A highly significant positive correlation was observed between the increase in urinary phosphate loss and the enhanced secretion of parathyroid hormone which was possibly triggered by surgical stress, a decrease in the serum level of calcium, the action of phosphate buffer or diuretics. All the patients except for those with postoperative pulmonary complications responded to the drop in serum phosphate by renal conservation of phosphate. A slight decrease in the serum level of phosphate was also found on the 6th postoperative day in most patients who were receiving parenteral hyperalimentation. The second fall in phosphate was due to transcellular shifts of phosphate. It is concluded that patients with postoperative pulmonary complications develop severe hypophosphatemia which should be prevented by replacement therapy with phosphate in the immediate postoperative period.

Calcium↗

The complete amino acid sequence of yam (Dioscorea japonica) chitinase. A newly identified acidic class I chitinase.

The complete amino acid sequence of acidic chitinase from yam (Dioscorea japonica) aerial tubers was determined. The protein is composed of a single polypeptide chain of 250 amino acid residues and has a calculated molecular mass of 27,890 Da. There is an NH2-terminal domain, a hinge region, and a main structure, typical for class I chitinases (Shinshi, H., Neuhaus, J.-M., Ryals, J., and Meins, F., Jr. (1990) Plant Mol. Biol. 14, 357-368). We have obtained the first evidence for an acidic class I chitinase. Comparison with sequences of other class I chitinases revealed approximately 40% sequence similarity, a value lower than that for other class I chitinases (70-80%). We assume that there is a local conformational change in the molecule; cysteine residues that probably form disulfide bonds are completely conserved, with the exception of Cys-178. The difference in structure between this chitinase and other basic class I chitinases suggests that acidic and basic isoforms should be grouped into subclasses; this protein is an ethylene- or a pathogen-independent chitinase produced by a gene that is inherent in the tuber.

Amino Acid Sequence↗

Possible role of plasminogen activator inhibitor 2 in the prevention of the metastasis of gastric cancer tissues.

The concentrations of urinary type plasminogen activator (u-PA), plasminogen activator inhibitor 1 (PAI-1), and PAI-2 were measured in gastric cancer tissues and adjacent healthy mucosal tissues. Levels of u-PA, PAI-1 and PAI-2 were higher in cancer than in control tissues. PAI-1 levels were higher together with the progression of cancer however there were no differences in u-PA or PAI-2 levels. Tumors with higher PAI-1 and lower PAI-2 levels tend to metastasize to remote lymph nodes. When the numbers of involved lymph nodes were analyzed, tumors with the large number of metastatic lymph nodes showed higher PAI-1 and lower PAI-2 level. No difference was shown in u-PA levels among these groups. These tendencies were more significant in patients with progressed gastric cancer. These results suggest that tumor with higher PAI-2 levels tend to localize or have less tendency to metastasize to lymph nodes. On the other hand PAI-1 was generally higher in tumor with invasion into nearby tissue or with nodal metastasis.

Enzyme-Linked Immunosorbent Assay↗

Therapeutic effects of liposomal adriamycin in combination with tumor necrosis factor-alpha.

Liposomes as drug carriers in cancer chemotherapy have attracted considerable interest. To enhance the therapeutic effect of Adriamycin entrapped in liposomes (Lip-ADM) on human solid tumors, we investigated the therapeutic effects of Lip-ADM in combination with recombinant human tumor necrosis factor-alpha (rTNF-alpha), which is known to have specific effects on tumor vasculature. rTNF-alpha or saline solution was injected intravenously into nude mice bearing a human colon cancer strain, HC-1, at 1 hour before intravenous administration of Lip-ADM. The significant therapeutic effect of Lip-ADM in combination with rTNF-alpha was demonstrated by the evaluation with tumor growth curve and the actual tumor weights, in comparison with groups of mice treated with saline solution, rTNF-alpha alone, or with a Lip-ADM after saline. Levels of Adriamycin in tumor tissue in the Lip-ADM in combination with rTNF-alpha-treated group were higher than those in Lip-ADM with saline solution-treated group.

Animals↗

Effect of liposomal interleukin-2 on ascites-forming rat hepatoma.

Interleukin-2 was entrapped in liposomes (Lip-IL-2) and injected into rats. The intraperitoneal injection of Lip-IL-2 into rats bearing an ascites-forming rat hepatoma (AH-66) significantly increased the survival time when compared with rats administered free IL-2 or saline-containing liposomes. The number of peritoneal exudate cells (PEC) increased markedly after intraperitoneal injection of Lip-IL-2 and consisted mainly of macrophages. The level of tumor necrosis factor alpha (TNF-alpha) and the intensity of free radicals increased in the ascites at 48 hrs after Lip-IL-2 administration, whereas TNF-alpha was not detected and the intensity of free radicals did not increase after free IL-2 administration. Our findings suggested that entrapment of IL-2 into liposomes enhanced its potential for cancer therapy, presumably by activating macrophages to produce TNF-alpha and free radicals.

Animals↗

Breakdown of hepatic tight junctions during reoxygenation injury.

We investigated whether reoxygenation following anoxia increased biliary permeability and whether or not allopurinol had a protective effect. Isolated rat livers were perfused for 30 min in a one-pass system with buffer equilibrated with 100% nitrogen after stabilization, and then for 60 min with the oxygenated buffer. Hepatic tight junction permeability was assessed by quantifying the early appearance in the bile of horseradish peroxidase (HRP) injected with the perfusate. This early peak represents paracellular passage of HRP, whereas a later second peak results from transcellular passage. In the control livers, 7% of the total HRP passage (93 +/- 50 pg/g liver) was paracellular and 93% was transcellular. After 30 min of reoxygenation following anoxia, however, 516 +/- 20 pg/g liver of HRP passed paracellularly. Addition of allopurinol (5 micrograms/ml) to the perfusate from the start of perfusion reduced paracellular passage of HRP to 219 +/- 49 pg/g liver after anoxia and reperfusion (P less than 0.01). Allopurinol also reduced the cumulative lactate dehydrogenase (LDH) release during the first 30 min of reoxygenation from 2.1 +/- 0.3 x 10(4) to 1.4 +/- 0.4 x 10(4) units/g liver (P less than 0.01). Reduction of the anoxic period from 30 min to 25 min significantly reduced the change in tight junction permeability and the extent of cellular injury: Paracellular passage of HRP was 336 +/- 20 pg/g and LDH release was 0.7 +/- 0.1 x 10(4) units/g liver, both significantly lower than those at 30 min (P less than 0.01). No significant difference in hepatic ATP levels after 60 min of reoxygenation was noted among the experimental groups, but all had lower levels than the control group. The protective effect of allopurinol suggests that the mechanism of biliary reoxygenation injury involves free radical generation. Susceptibility of tight junctions suggests a pattern of injury similar to that involved in anoxic damage of the vascular endothelium.

Adenosine Triphosphate↗

[The comparison of postoperative multiple organ failure with arterial disease to that with gastrointestinal cancer].

The clinical features of 22 postoperative multiple organ failure (MOF) patients, comprised of 8 with arterial disease (A-MOF) and 14 with gastrointestinal cancer (G-MOF), were investigated. Differences in the operative time, blood loss, and mortality were not significant. The initial organ impaired was the lungs in 78.6% of G-MOF patients and the heart or kidneys in all A-MOF patients. Infection developed in over 80% of both groups. In many A-MOF patients, the pneumonia or septicemia developed secondary to organ failure, while intraabdominal infection triggered respiratory failure in many G-MOF patients. Our organisms in infected specimens and their antibiotic sensitivities was valuable for the early administration of effective antibiotics. Upper gastrointestinal tract bleeding was important in the prognosis of both groups and occurred more frequently in A-MOF than in G-MOF patients. Consumption coagulopathy in A-MOF patients and DIC induced by infection in G-MOF patients mainly caused such bleeding. Preoperative administration of heparin was effective in improving coagulopathy. Furthermore, measurement of intramural pH with tonometer in the stomach and gastric irrigation with oxygenated perfluorochemicals were effective in the prediction and prevention of gastrointestinal bleeding.

Aged↗

Effects of phenothiazine on contractions induced by prostaglandin F2 alpha and 5-hydroxytryptamine in normal and spastic canine cerebral artery.

We have investigated the effect of phenothiazine, a compound known to inhibit calmodulin, on the responses of normal and spastic cerebral arteries, using the canine "two hemorrhage" model of cerebrovascular spasm. Ring preparations from control vessels or vessels removed three or seven days after injection of blood, were contracted with either 5-hydroxytryptamine (5-HT) or prostaglandin F2 alpha (PGF2 alpha) and then exposed to increasing concentrations of phenothiazine. In normal arteries, low concentrations of phenothiazine enhanced the response to PGF2 alpha, while higher concentrations caused relaxation. Responses to 5-HT were inhibited by all concentrations of phenothiazine tested. When normal arteries were compared with arteries from animals injected with blood, in the case of 5-HT, phenothiazine was a less effective antagonist at low doses, but equieffective at higher doses. Similar experiments conducted with PGF2 alpha showed that phenothiazine was a more effective antagonist in spastic vessels. We conclude that 5-HT and PGF2 alpha have significant differences in the mechanism by which they produce contraction of cerebral vessels, that phenothiazine has secondary effects on contraction independent of inhibition of calmodulin, and, finally that the effects of phenothiazine in clinical vasospasm may be insufficient to reverse the condition, despite the observation that vessels in spasm may be more sensitive to this agent.

Animals↗

Bleeding peptic ulcer after abdominal aortic aneurysm surgery.

A retrospective study of 112 patients with abdominal aortic aneurysm (AAA) and 232 with arteriosclerosis obliterans (ASO) demonstrated that 16.7% of those with AAA and 1.6% of those with ASO had a history of gastroduodenal ulcer; 83% of these lesions with AAA were gastric ulcers. Ulcer bleeding after vascular reconstruction developed in seven patients with AAA and one with ASO. Serum fibrinogen levels and platelet counts were significantly lower in patients with AAA than in those with ASO or controls. A prospective study showed that 25 (52.1%) of 48 patients with AAA and six (20.0%) of 30 patients with ASO had endoscopically proved gastroduodenal lesions before vascular reconstruction. None of them developed postoperative bleeding after treatment of both their gastroduodenal lesions and coagulopathy. Furthermore, the significant decrease in blood flow and prostaglandin content of gastric mucosa was demonstrated in patients with AAA.

Aged↗

Inhibition of growth of rat hepatoma by local injection of liposomes containing recombinant interleukin-2. Antitumor effect of IL-2 liposome.

Human recombinant interleukin-2 (IL-2) was entrapped in liposome, consisting of egg phosphatidylcholine (PC) and cholesterol. The peri-tumor injections of IL-2 liposome inhibited significantly the growth of solid tumor and prolonged the survival time of rats with solid tumors which were induced by a subcutaneous (s.c.) inoculation of AH-66 cells. Immunohistochemical staining of peritoneal exudate cells and tumor tissues revealed a marked accumulation of activated macrophages in and around the tumor tissues induced by the local injections of IL-2 liposome.

Animals↗

The formation of gastric ulcers with a tendency to hemorrhage in association with aortic aneurysms.

It is widely accepted that patients with aortic aneurysm (AA) show a higher incidence of peptic ulcers than those without. However, the pathogenesis of peptic ulcers associated with AA remains obscure. We measured the gastric mucosal blood flow (GMBF) endoscopically and also determined the gastric mucosal prostaglandin (PG) levels of these AA patients to investigated the mechanism behind gastric ulcer formation. Moreover, we investigated the consumption coagulopathy (CC) of AA responsible for inducing the hemorrhage from ulcers. The GMBF values of 7 AA cases, taken at the antrum, angle and corpus, were significantly decreased compared with those of control cases, while the PGE2 levels of the gastric mucosa were also significantly reduced. With regard to CC, the serum levels of fibrinogen or platelets were significantly lower than those of the control group. These results indicate that the decrease in GMBF, followed by the reduction in endogenous PG, might contribute to the gastric ulcer formation in AA patients, and that CC associated with AA could be an important factor causing the hemorrhage from these ulcers. AA patients should therefore be treated with focusing attention on the possibility of an associated ulcer and ulcer bleeding.

Aged↗