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Biomedical subjects

K Okui

Publications and source records attributed to K Okui.

At least 109 records · Page 6Linked to original sources
PubMed1987

[Clinical studies of BRL 28500 (clavulanic acid/ticarcillin) in the treatment of intraperitoneal infections and biliary tract infections].

Clinical studies have been conducted on BRL 28500 (a formulation containing 15 parts ticarcillin (TIPC) plus 1 part clavulanic acid (CVA]. BRL 28500 was administered at doses of 1.6 g or 3.2 g b.i.d., generally for 10 days by drip infusion to patients with intraperitoneal infections or biliary tract infections. Drug concentrations in the ascites were determined. A total of 76 cases was treated with BRL 28500. These cases included 49 intraperitoneal infections (suppurative peritonitis 29, postoperative peritonitis 20) and 18 biliary tract infections (cholecystitis 5, cholangitis 13). Nine cases were excluded from evaluation according to the committee's assessment. The clinical improvement as assessed by surgeons in charge increased with the duration of continued treatment and efficacies were assessed as 57.1% on day 5, 63.1% on day 7 and 77.8% on day 10 in intraperitoneal infections. Corresponding results in biliary tract infections were 38.9%, 40.0% and 42.9%, respectively. From these results, it is clear that the degree of improvement is related to the duration of treatment. The clinical usefulness as assessed by surgeons in charge of the study was 63.8% in intraperitoneal infections (suppurative peritonitis 75.0%, postoperative peritonitis 47.4%) and 58.8% in biliary tract infections (cholecystitis 100%, cholangitis 41.7%). The overall rate of usefulness was 62.5%. The clinical efficacy rates as assessed by the committee were 81.6% in intraperitoneal infections (suppurative peritonitis 93.1%, postoperative peritonitis 65.0%) and 66.7% in biliary tract infections (cholecystitis 100%, cholangitis 53.8%). In cases where causative organisms were isolated, the efficacies were 92.9% in suppurative peritonitis, 58.8% in postoperative peritonitis, 50.0% in cholangitis and overall, 69.2%. In cases from which TIPC-resistant organisms were isolated, the overall efficacy rate was 65.4% (suppurative peritonitis 88.9%, postoperative peritonitis 58.3% and cholangitis 40.0%). Regarding bacteriological effect as assessed by the committee, the eradication rate was 76.9% in intraperitoneal infections and 40.0% in biliary tract infections (71.0% overall). In cases from whom ticarcillin-resistant organisms were isolated the corresponding rates were 68.4% and 33.3% respectively, (63.6% overall). In 4 patients with peritonitis drug levels in the ascites were determined following administration of BRL 28500 by drip infusion. Good levels of both TIPC and CVA were detected 1 to 3.5 hours after administration.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1987

[Effects of preoperative transcatheter arterial embolization (TAE) on the liver following partial hepatectomy in rats].

The safety of pre-operative transcatheter arterial embolization (TAE), especially on the relation to hepatic regeneration following partial hepatectomy, was evaluated in rats. TAE was done through a catheter cannulated into hepatic artery under laparotomy. The remarkable elevation of S-GOT and S-GPT levels were demonstrated a day after TAE, which returned to normal on third post operative day. No influence of the difference of embolized materials was seen on the changes of transaminase levels. TAE severely decreased hepatic microsomal functional mass measured by [14C]-aminopyrine breath test (ABT) and the recovery of microsomal functional mass was shown on the 14th day after TAE. Histologically, recanalization could not be revealed in embolized arterioles even on the 21st day after TAE. But trabecular pattern of hepatic lobules was preserved after TAE. The serious inhibition of DNA synthesis of regenerating liver was demonstrated when TAE was performed within 14 days prior to partial hepatectomy (p less than 0.001-0.05). The period from TAE to partial hepatectomy had a influence on the survival rate after partial hepatectomy, and when appropriate interval was taken after TAE, the survival rate increased significantly (33%-50% in 24 hours interval and 88% in 14 days interval). In conclusion, preoperative TAE remarkably suppressed hepatic regeneration after partial hepatectomy, and appropriate time when suppressed hepatic functional mass, such as microsomal functional mass measured by ABT, returned to pre TAE value was required to perform hepatectomy in safety.

Animals↗
PubMed1986

Combined therapy of polyamine antimetabolites and antitumor drugs for human gastric cancer xenotransplanted into nude mice.

Antitumor therapies using polyamine antimetabolites combined with 1-(4-amino-2-methyl-5-pyrimidyl)methyl-3(2-chloroethyl)-3-nitrosourea (ACNU) or fluorinated pyrimidines for human gastric cancer xenotransplanted into nude mice were studied to determine inhibiting post-therapeutic regrowth of the tumor after cessation of antitumor treatments with polyamine antimetabolites alone. ACNU 20 mg/kg, fluorinated pyrimidine, 5-FU 52.8 mg/kg and 5'-deoxy-5-fluorouridine (5'-DFUR) 100 mg/kg as well as polyamine antimetabolites, alpha-difluoromethylornithine (DFMO) 1000 mg/kg and methylglyoxal-bis-guanylhydrazone (MGBG) 50 mg/kg were given intraperitoneally for 5 successive days. When DFMO and MGBG were combined with ACNU, the post-therapeutic regrowth was definitely inhibited, while combined treatments with 5-FU or 5'-DFUR did not inhibit the regrowth. Post-therapeutic DNA biosynthesis was suppressed in mice given DFMO, MGBG plus ACNU. On the contrary, in mice treated with DFMO, MGBG plus 5-FU or 5'-DFUR, suppression of DNA biosynthesis was not observed. Tumor tissue spermine levels in the DFMO, MGBG plus 5-FU or 5'-DFUR group remained unchanged, compared to those in the DFMO + MGBG group. In mice given DFMO, MGBG plus ACNU, however, spermine levels were markedly depressed; and the ACNU alone depressed also the tissue spermine levels. These different results between nitrosourea and fluorinated pyrimidines may relate to mechanisms of action of these antitumor drugs.

Animals↗
PubMed1986

Evaluation of echographic diagnosis of rectal cancer using intrarectal ultrasonic examination.

Ultrasonic examinations conducted in order to diagnose the depth of invasion and local lymph node metastases of rectal cancer. The intrarectal approach was performed preoperatively in 99 patients with rectal cancer, using either an Olympus-Aloka ultrasonic endoscopeTM (7.5 MHz) or other probes (Aloka, 7.5 MHz, 5 MHz). Through this method, intrapelvic organs were detected clearly, and hypoechoic findings due to tumors were detected in all patients. The normal rectal wall was echogenically divided into five layers, the third layer being the submucosal and the fourth layer being the proper muscle layer. In some cases, the proper muscle layer was divided into three layers in the echogram. In 79 of 88 patients, the diagnosis of depth of invasion, classified into three groups, was possible. Metastatic lymph nodes were shown as a hypoechoic round mass. In 52 of 71 patients proven to have local lymph node metastases in surgical specimens, lymph node metastases were diagnosed preoperatively. Thus, intrarectal ultrasonography provides valuable information concerning the choice of operating methods for rectal cancer.

Carcinoma↗
PubMed1986

Mechanism of spontaneous rhythmic contraction in isolated rat large artery.

The mechanism of spontaneous contraction of vascular smooth muscles in the elastic artery was studied in a ring-shaped preparation isolated from the rat aorta. The observation of small changes in vascular tension with a high gain AC amplification of tension signal provided a reliable detection of spontaneous contractions. The spontaneous rhythmic contraction (RC) occurred consistently in the preparation taken from the thoracic aorta without external stimuli. The RC (frequency, 5-20 cycle/min; amplitude, 10-100 mg) was accompanied with small oscillatory changes in the membrane potential (2-5 mV, peak to peak). A reduction in temperature (below 30 degrees C) or superfusing the preparation with Ca-free solution inhibited the generation of RC. Ca-entry blockers (verapamil and nifedipine) also inhibited the RC. The cessation of RC by these procedures reduced the vascular tension by about 40% of control baseline tension. The application of adrenergic blockers had little effect on the pattern of RC and on the vascular tension. The results suggest that the RC is generated by a synchronization of electrical and mechanical activities in relatively small groups of smooth muscle cells, which depends upon the temperature and requires the Ca-entry into the cells. The process of initiation of spontaneous RC in the rat aorta was discussed.

Animals↗
PubMed1986

[Preoperative clinical evaluations of rectal cancer using rectal echo, X-ray CT and MR-CT].

In order to evaluate the depth of invasion and to determine the stage of rectal cancer, we have recently performed intra-rectal echo, X-ray CT and MR-CT preoperatively. Conventional approaches such as barium enema X-ray and colonofiberscope are not satisfactory to determine the depth of invasion of tumor and to detect adjacent metastatic lymphnodes. Intra-rectal echo can reveal rectal wall layers fairly well, which can be divided into five layers. Using this technique, we are able to determine the depth of invasion of rectal cancer. X-ray CT can demonstrate all the intra-pelvic organs and metastatic lymphnodes surrounding rectal tumor. Invasion to the neighboring organs such as urinary bladder, prostate, seminal vesicle and uterus can also be evaluated preoperatively. MR-CT is also helpful to determine the stage of rectal cancer before operations. Though the images of MR-CT are not so sharp, multi-directional slices of X-ray photographs can be taken by MR-CT and so furthermore evaluations of rectal tumor invasion and adjacent metastatic lymphnodes are possible. In addition, IR-image of MR-CT demonstrates the tumor site dramatically. In conclusion, using these three techniques we can evaluate preoperative clinical stages of rectal cancer and the best operative method can be determined preoperatively.

Humans↗
PubMed1985

Biodegradable mitomycin C microspheres given intra-arterially for inoperable hepatic cancer. With particular reference to a comparison with continuous infusion of mitomycin C and 5-fluorouracil.

Thirty-two patients with inoperable hepatic cancer underwent intra-arterial hepatic infusion using mitomycin C (MMC) and 5-fluorouracil (5-FU) or intra-arterial hepatic chemoembolization using heated albumin microspheres containing MMC with an average diameter 45 +/- 8 micron. Nineteen of the 32 patients received the MMC microsphere treatment and another 13 received the conventional infusion treatment, lasting for 3.4 months. The administered doses of MMC microspheres were 11.7 +/- 11.1 mg as MMC in the 12 with metastatic cancer and 6.9 +/- 2.1 mg as MMC in the 7 with hepatocellular cancer (HCC). On the contrary, the 13 patients who underwent conventional infusion had average doses of MMC 34.5 +/- 17.3 mg and of 5-FU 13.4 +/- 7.7 g, over 3.4 months. An objective tumor response was obtained in 13/19 (68.4%) under MMC microsphere chemoembolization, compared to 6/13 (46.2%) under the conventional infusion. The average level of CEA in the 12 with metastatic cancer, who underwent MMC microsphere therapy, dropped from 57.7 ng/ml to 16.5 ng/ml, while that in the 10 patients on conventional infusion dropped from 24.0 ng/ml to 17.4 ng/ml; that of alpha-fetoprotein dropped in all 7 with HCC on MMC microsphere chemoembolization, compared to a fall in 1/3 on conventional infusion. With the MMC microsphere treatment, 5 patients from colorectal cancer lived for 15.6 +/- 7.6 months, 2 are alive with a long life expectancy; and 7 patients from gastric or pancreatic cancer lived for only 9.3 +/- 3.3 months. In case of conventional infusion, 6 patients from colorectal cancer survived for 8.6 +/- 3.2 months; and 4 patients from gastric or gallbladder cancer survived for 6.0 +/- 1.0 months. The MMC microsphere treatment is superior at P = 0.059 in survival duration to the conventional infusion treatment. However, much the same survival occurred in 7 on MMC microsphere chemoembolization and 3 on continuous infusion.

Adult↗
PubMed1985

Antitumor effects of two polyamine antimetabolites combined with mitomycin C on human stomach cancer cells xenotransplanted into nude mice.

The antitumor effects of alpha-difluoromethylornithine (DFMO), methylglyoxal-bis-guanylhydrazone (MGBG) and mitomycin C (MMC), administered separately or in various combinations, on human stomach cancer cells xenotransplanted into BALB/c nude mice were studied using the protocol of Battelle's Columbus Laboratories (Ovejera et al., 1978). DFMO (1,000 mg/kg in 2 divided doses) and MGBG (50 mg/kg) were given intraperitoneally (i.p.) for 7 consecutive days from the time when the tumor weighed about 100 mg. MMC (2 mg/kg) was given i.p. every other day from the same time. Animals treated with either DFMO or MGBG alone displayed tumor growth comparable to that seen in untreated controls. In mice treated with DFMO plus MGBG with or without MMC, or in mice treated only with MMC, tumor growth was significantly lower than in untreated mice. In the group which received only combined DFMO/MGBG there was a rapid regrowth of the tumor after termination of therapy. Tumor putrescine levels decreased within 4 days following the administration of DFMO; however, spermidine levels did not decline with either DFMO or MGBG treatment even after 7 days. When combined DFMO/MGBG was given, there was a significant decline in spermidine levels 7 days after the initiation of treatment. In contrast, when MMC alone was administered, putrescine and spermidine levels in the tumor did not differ from those in control mice. Spermine decreased markedly in tumor with the combined administration of DFMO/MGBG as well as with combined DFMO/MGBG/MMC, but decreased only slightly when MMC alone or MMC plus either DFMO or MGBG was administered. By the 7th treatment day, DNA biosynthesis in the tumor had dropped markedly in all groups except those receiving DFMO or MGBG alone.

Adenocarcinoma, Papillary↗
PubMed1985

Effects of intra-arterially infused biodegradable microspheres containing mitomycin C.

We prepared biodegradable microspheres containing about 5% mitomycin C (MMC) and of 45 +/- 8 microns in diameter. These preparations were infused into the rat hepatic artery as a preclinical model of intra-arterial infusion treatment for patients with inoperable hepatic tumor. The leaked MMC levels in the hepatic vein decreased below the assay limitation 2 hours after conventional MMC injection, whereas in the case of MMC microsphere the leaked drug levels were maintained at almost the same concentration for over 2 hours after infusion. The entrapped period of MMC microspheres within the hepatic artery was at least 2 weeks, and the necrobiotic foci due to antitumor effects of the condensed MMC released from the microspheres were observed in the area fed by these entrapped arterioles. This phenomenon was never observed in the case of conventional MMC and placebo microspheres. Intra-arterial infusion of MMC microspheres may be a promising clinical treatment for patients with malignant hepatic tumor.

Animals↗
PubMed1985

Long-term survivors of colorectal cancer with unresectable hepatic metastases.

Five patients with colorectal cancer and unresectable synchronous liver metastases have survived for over five years at this writing. Four of the five had multiple metastases over both lobes, as diagnosed preoperatively, and the other had multiple metastases in the right lobe not evident preoperatively. The primary foci were excised completely in four patients. For one patient with multiple metastases limited to the right lobe, the postoperative cancer chemotherapy prescribed was intravenous mitomycin C (MMC; 12 mg) and oral ftorafur (a derivative of 5-FU) for a total dose of 291 gm over 63 weeks. The remaining four patients underwent postoperative intra-arterial infusion therapy with the average total dose of 20.5 mg of MMC plus 5600 mg of 5-FU; subsequently, they received protracted chemotherapy with oral ftorafur of 354 gm as an average, with little or no side effects. In these four patients, duration of intra-arterial treatment was an average of 3.2 weeks, and the subsequent oral treatment continued for an average of 85 weeks. Recent hepatic echography and CEA determinations show these patients to be free from intrahepatic metastasis.

Administration, Oral↗
PubMed1985

Mitomycin C carrying microspheres as a novel method of drug delivery.

Biodegradable albumin microspheres containing about 5% mitomycin C (MMC) were prepared in an average diameter of 45 +/- 8 microns by heat denaturation in oil at 120 degrees C and/or cross-linking with glutaraldehyde. These MMC microspheres released, in vitro, about 20% of the contained MMC for over 3 days, and they were intra-arterially infused into albino rabbits and Wistar rats, as a preclinical model of intra-arterial infusion treatment for patients with inoperable hepatic tumor. We infused these microspheres into the femoral artery of rabbits with a VX-2 tumor implanted into the flank of the hindleg. High levels of MMC were maintained for several hours in the tumor and the entrapped MMC microspheres were detected within arterioles in the VX-2 tumors. The growth of VX-2 tumor was inhibited considerably, compared to findings in the control rabbits given conventional MMC. In the next studies, MMC microspheres were infused into the rat hepatic artery, and the levels of MMC in the hepatic vein blood were maintained at much the same concentration for over 2 hours after the infusion, in marked contrast to rapid decreases in the conventional MMC. Histologic findings revealed that MMC micro-spheres were entrapped within the hepatic arterioles for over 2 weeks and released biologically active MMC into the neighboring tissues for prolonged periods of time.

Albumins↗
PubMed1985

[Cyclic AMP- and ATP-mediated stimulation of DNA synthesis following partial hepatectomy by prostaglandin-E1 in D-galactosamine injured liver].

D-galactosamine (D-gal) damaged rats were infused with Prostaglandin E1 (PGE1) through a peripheral vein for 40 min. before and after partial hepatectomy. DNA synthesis following 68% partial hepatectomy was severely inhibited by the pretreatment of D-galactosamine. PGE1 infusion (0.5, 1.0 microgram/kg/min) enhanced the DNA synthesis inhibited by D-gal 600 mg/kg significantly (p less than 0.01). After 20 min. of PGE1 infusion cyclic AMP levels of liver tissue was increased as compared with saline infusion in D-gal (600 mg/kg)-damaged rat (p less than 0.05). Also 20 min. and 3 hour after partial hepatectomy. ATP levels of liver tissue was enhanced in PGE1 treated group (p less than 0.05). However the doses of PGE1 infused in this investigation could not increase the hepatic tissue blood flow measured by hydrogen gas clearance method. These results suggest that PGE1 enhance DNA synthesis of injured liver after partial hepatectomy by the mechanism which PGE1 stimulate cyclic AMP production and increase ATP level in hepatic tissue.

Adenosine Triphosphate↗
PubMed1985

[Whole body protein turnover, synthesis and breakdown in patients receiving total parenteral nutrition (TPN) before and after recovery from surgical stress].

This study was conducted to clarify the mechanisms underlying the loss of body nitrogen after trauma. Six patients who underwent abdominal surgery and six for control were studied. The measurement of whole body protein turnover was made on the third and tenth postoperative day during TPN with constant infusion of [15N] glycine according to Picou and Taylor-Roberts. The measurement was also made on six control patients during TPN in non-stressed state. The rates of whole body protein turnover (Q), synthesis (S) and breakdown (B) were calculated from the plateau 15N enrichment of urinary total N, which was analyzed with a mass spectrometer. The values were compared with control and the changes in the individual patients were examined by a paired t-test. Immediately after operation, Q and B were significantly elevated (p less than 0.05 and p less than 0.02, respectively), and reduced with the improvement of N-balance after recovery from stress by 0.95 +/- 0.21 and 0.61 +/- 0.13 g X protein/kg X day, respectively. The changes in Q and B were statistically significant (p less than 0.005 and p less than 0.005, respectively). Whereas, no tendency of alteration in S was found throughout the study. It is concluded that protein turnover rate increases in surgical stress, and that the increased protein catabolism rather than the alteration in synthesis could account for the postoperative nitrogen losses.

Adult↗
PubMed1985

[Multimodality therapy of colorectal cancer].

Multimodality therapy for colorectal cancer is composed of surgery, chemotherapy and irradiation; and hyperthermia joins them recently. As patients with operable colorectal cancer are a good candidate for a chemotherapeutic approach, we began postoperative adjuvant chemotherapy since 1971. On the other hand, our treatment policy towards inoperable cases is various treatments combined with the four therapies described above. The most patients with hepatic metastasis are unamenable for surgery, and they have been mainly treated with intra-arterial chemotherapy. With conventional infusion treatment, however, the infusion drugs are eliminated rapidly from the drainage vein. Thus, we prepared biodegradable albumin microspheres containing MMC (mean diameter 45 +/- 8 micron); and in 6 patients with liver metastasis, we infused MMC microspheres into the proper hepatic artery, with marked tumor regression. Hyperthermia treatment has been performed with ThermaTech 2000 (International Institute for Medical Sciences, U.S.A.), which has a complete capacitive, 3-channel, "crossfire" heating system operating by RF at 13.56 MHz. Six patients with local recurrence and/or hepatic metastasis were treated by hyperthermia combined with chemotherapy or irradiation, with a fair success in tumor response and improvement of subjective symptoms.

Aged↗
PubMed1985

[Changes of whole body protein turnover due to the severity of surgical stress].

This study was conducted to understand the mechanisms underlying the loss of body nitrogen after surgical trauma. Thirteen patients who underwent moderate to severe abdominal surgery and six for control were studied. The measurement of whole body protein turnover was made on the third and tenth postoperative day during isonitrogenous and isocaloric TPN using the constant infusion method of [15N] glycine. Nitrogen balance was improved markedly in 6 patients, who received moderate surgical procedures (group I). However the balance was still negative at the tenth postoperative day in 7 patients, who received severe surgery with some critical complications (group II). A significant increase in whole body protein breakdown on the third postoperative day in groups I and II were found (p less than 0.02, p less than 0.001, respectively). Breakdown was higher in group II than in group I (p less than 0.02). Whole body protein synthesis tended to increase on the third postoperative day in group II, but was within the normal range in group I. In conclusion, the change of whole body protein turnover was different depending upon the severity of stress. Protein synthesis unchanged in moderate stress, but tended to increase in severe stress with a greater increase of breakdown.

Adult↗