Biomedical subjects

K Iseki

Publications and source records attributed to K Iseki.

At least 91 records · Page 5Linked to original sources

PubMed1996

More effective endoscopic resection with a two-channel colonoscope for carcinoid tumors of the rectum.

PURPOSE: Complete resection of small carcinoid tumors of the rectum is difficult with conventional polypectomy, because these tumors are most often located in the submucosal layer of the rectal wall. To completely remove these tumors, we used a two-channel videocolonoscope with which both a grasping forceps and a polypectomy snare could be used simultaneously. We evaluated its clinical usefulness in comparison with one-channel colonoscopic polypectomy. METHODS: At Osaka Medical Center for Cancer and Cardiovascular Diseases, seven carcinoid tumors in seven patients were removed with a one-channel videocolonoscope from 1985 to 1992. In 1993 and 1994, ten tumors in nine patients were removed with a two-channel colonoscope. RESULTS: The rate of complete removal of carcinoid tumors with a two-channel videocolonoscope (9 of 10 tumors, 90 percent) was significantly higher (P < 0.05) than with a one-channel videocolonoscope (2 of 7 tumors, 29 percent). No complications occurred during or after endoscopic resection with a two-channel colonoscope. CONCLUSIONS: Endoscopic resection with a two-channel colonoscope is a useful and safe method for resection of small carcinoid tumors of the rectum.

Carcinoid Tumor↗

PubMed1996

Endoscopic resection of large pedunculated colorectal polyps using a detachable snare.

BACKGROUND: Colonoscopic resection of pedunculated polyps with heads 1 cm or greater in diameter is difficult because of the risk of bleeding. To minimize this complication, we used a detachable snare that allowed endoscopic ligation of the stalk of a large pedunculated polyp and evaluated its safety and effectiveness in comparison with conventional endoscopic snare polypectomy. METHODS: Patients with pedunculated polyps with heads 1 cm or greater in diameter were randomly assigned to colonoscopic polypectomy with (N = 47) or without (N = 42) a detachable snare. Arterial pumping bleeding immediately after colonoscopic polypectomy or hematochezia resulting in a 10% or greater drop in hematocrit was defined as "bleeding." RESULTS: No bleeding occurred during or after polypectomy with a detachable snare, but bleeding occurred significantly more frequently (five patients, 12%) without a snare. Moreover, the use of a detachable snare reduced the duration of hospitalization after polypectomy. CONCLUSIONS: Colonoscopic polypectomy with a detachable snare may be safer than conventional polypectomy without a detachable snare for resection of large, pedunculated polyps.

Blood Loss, Surgical↗

PubMed1996

Impact of the initial levels of laboratory variables on survival in chronic dialysis patients.

Besides the age at start of dialysis and the presence of diabetes mellitus, serum albumin has been shown to be a significant predictor of survival in prevalent dialysis patients. However, this was not evaluated in incipient dialysis patients. The initial biochemical variables were retrieved for a large dialysis population (N = 1,982) who were started on chronic dialysis in Okinawa, Japan from 1971 to 1990. Biochemical data that included blood urea nitrogen, serum creatinine, serum electrolytes (sodium, potassium, calcium, and phosphate), total cholesterol, triglyceride, total protein, serum albumin, and hematocrit obtained just before the first dialysis session were available for 1,491 (75.2%) patients. Six hundred sixty-four (43.2%) patients died by the end of 1993. Cox proportional analysis adjusted for sex, age, year of start of dialysis, presence of diabetes mellitus, and the laboratory variables was performed to examine the significance of the initial biochemical data on survival. The risk ratio was 0.577 (P = 0.0025) in serum albumin, 1.291 (P = 0.0138) in serum potassium, and 0.966 (P = 0.0202) in serum sodium. The study results support the notion that nutritional status is important for survival in chronic dialysis patients. Causes of hypoalbuminemia, hyperkalemia, and hyponatremia should be evaluated carefully at initiation of dialysis.

Adolescent↗

PubMed1996

Risk of developing end-stage renal disease in a cohort of mass screening.

The prognostic significance of abnormal findings has not been demonstrated in a setting of mass screening. To evaluate the relative risk of end-stage renal disease (ESRD) indicated by various results of community-based mass screening, we utilized the registries of both community mass screening and chronic dialysis programs. In 1983, a total of 107,192 subjects over 18 years of age (51,122 men and 56,070 women) participated in dipstick urinalysis and blood pressure measurement in Okinawa, Japan. During ten years of follow-up, we identified 193 dialysis patients (105 men and 88 women) among them. Logistic regression analysis of clinical predictors of ESRD over 10 years was done and the adjusted odds ratio and 95% confidence interval were calculated in each of the predictors with adjustment to others. In the clinical predictors such as sex, age at screening, proteinuria, hematuria, systolic and diastolic blood pressure, proteinuria was the most potent predictor of ESRD (adjusted odds ratio 14.9, 95% confidence interval 10.9 to 20.2), and the next most potent predictor was hematuria (adjusted odds ratio 2.30, 95% confidence interval 1.62 to 3.28). Being of male gender was a significant risk factor for ESRD (adjusted odds ratio 1.41, 95% confidence interval 1.04 to 1.92). Diastolic blood pressure was also a significant predictor of ESRD (adjusted odds ratio 1.39, 95% confidence interval 1.17 to 1.64), but systolic blood pressure was not. In a mass screening setting, positive urine test, high diastolic blood pressure, and male sex were identified as the significant predictors of ESRD. Effect of glycosuria and other possible predictors of ESRD remained to be determined.

Adolescent↗

PubMed1996

Predictors of stroke in patients receiving chronic hemodialysis.

To identify the risk factors of stroke in patients receiving maintenance hemodialysis, we conducted a prospective study on patients in Okinawa, Japan. Patients with end-stage renal disease who were treated with maintenance hemodialysis before the end of 1990 and were alive on January 1, 1991 (N = 1,243) were studied. Medical records and pertinent data as of January 1, 1991 were compiled. All occurrences of stroke were recorded throughout the follow-up period, and until the end of 1995. The duration of observation was 5,110.3 patient-years. A total of 90 cases of stroke were observed, including 63 (70.0%) cerebral hemorrhage, 20 (22.2%) cerebral infarction, and 7 (7.8%) subarachnoid hemorrhage. Multiple logistic analysis identified hypertension as an independent predictor of stroke, with an odds ratio of 2.38 and a 95% confidence interval from 1.26 to 4.50. The present study demonstrates that the high incidence of stroke is at least partially explained by insufficient control of hypertension. Every effort to control hypertension is warranted in chronic dialysis patients.

Adolescent↗

PubMed1996

Improving the oral bioavailability of sulpiride by a gastric-retained form in rabbits.

To improve the limited oral bioavailability of sulpiride, a gastric-retained form was developed and evaluated using gastric-emptying-controlled rabbits. The AUC value after oral administration of sulpiride as an aqueous solution was less than that after oral administration of sulpiride original powder. The dissolution was not important as a rate limiting factor for sulpiride oral absorption. Sulpiride was absorbed predominantly from the upper part of the small intestine of the rabbit. A gastric-retained tablet prepared from Carbopol 934P, with sustained-release characteristics, was found to be suitable for improving and extending the oral bioavailability of sulpiride.

Acrylic Resins↗

PubMed1996

Uptake mechanism of trientine by rat intestinal brush-border membrane vesicles.

The uptake characteristics of trientine by rat intestinal brush-border membrane vesicles were studied. The uptake characteristics of trientine were similar to those of the physiological polyamines with respect to the excessive accumulation in vesicles, the pH dependency, the temperature dependency and the ineffectiveness of K+ diffusion potential (inside negative). The initial uptake of trientine was saturable with a K(m) value of 1.13 mM, which was larger than that of spermine and spermidine. Furthermore, the uptake rate of trientine was dose-dependently inhibited by spermine and spermidine. Spermine competitively inhibited the uptake of trientine with a Ki value of 18.6 microM, and it was close to the K(m) value for spermine (30.4 microM). These data suggested that the uptake of trientine was similar to that of spermine and spermidine in rat small intestinal brush-border membrane vesicles, and these polyamines seem to inhibit the absorption of trientine from the gastrointestinal tract.

Animals↗

PubMed1996

Seasonal variation in the incidence of end-stage renal disease.

The effect of ambient temperature (AMT) on the incidence of end-stage renal disease (ESRD) was examined in Okinawa, Japan, where there is a distinct seasonal variation in monthly AMT but constant intradiurnal temperature change throughout a year. Arbitral continuous and cyclic functions were examined using Fourier analysis and calculation of the cross-correlation coefficient. The calendar month of the start of chronic dialysis was regarded as the time of onset of ESRD. A total of 1,982 patients, 824 females and 1,158 males, was registered with ESRD between 1971 and 1990. The normalized monthly number of new ESRD patients, divided by days of each month, was smallest in August, n = 4.06, and largest in January, n = 6.45, and this pattern was well reproduced by the Fourier synthesized value. The cross-correlation coefficient showed that monthly mean AMT and the normalized number of ESRD patients correlated best with 6 months lag time. Taken together, our results showed that there was strong correlation between the normalized number of ESRD patients and AMT. Uremic symptoms leading to initiate dialysis, such as congestive heart failure, may be aggravated in lower AMT. We speculated a role of an inverse relation between AMT and the sympathetic nerve function. The public health implications of these findings warrant their further investigation.

Adult↗

PubMed1996

Increased risk of cardiovascular disease with erythropoietin in chronic dialysis patients.

Recombinant human erythropoietin is widely used in chronic dialysis patients. However, the long-term effect, especially on the incidence of cardiovascular disease, has not been critically evaluated. We observed the annual incidence of stroke and acute myocardial infarction from April 1988 through March 1993 in Okinawa, Japan. Until April 1990, erythropoietin was not generally used. Therefore, we have two periods: pre-erythropoietin, April 1988 through March 1990, and post-erythropoietin, April 1990 through March 1993. Two thousand one hundred and sixteen patients (1,219 males and 897 females) were on chronic dialysis during the study period by March 31, 1993. Every case of stroke and acute myocardial infarction during the study period was registered. The odds ratio was calculated using the data of the general population in each sex and age class obtained in the same area. A total of 86 cases of stroke and 15 cases of acute myocardial infarction were registered during the study period. The annual incidence, per 1,000 patient-years, of stroke was 12.5 (1988), 10.5 (1989), 12.7 (1990), 14.0 (1991), and 17.5 (1992). The incidence of stroke was increased in the post-erythropoietin period compared to the pre-erythropoietin period, odds ratio 1.22 and 95% confidence interval (95% CI 1.06-1.41, p < 0.01). The annual incidence of acute myocardial infarction was 1.0 (1988), 1.8 (1989), 0.8 (1990), 2.9 (1991) and 4.7 (1992). The incidence of acute myocardial infarction was increased significantly in the post-erythropoietin period compared to the pre-erythropoietin period, odds ratio 1.87 (95% CI 1.66-2.10, p < 0.01). The odds ratio of stroke to the general population was 4.25 (95% CI 3.10-5.82) in the pre-erythropoietin and 4.58 (95% CI 2.14-9.80) in the post-erythropoietin period. In acute myocardial infarction, it was 2.98 (95% CI 2.84-3.12) and 3.81 (95% CI 3.18-4.56). The odds ratio of acute myocardial infarction was significantly increased (p < 0.01). The introduction of erythropoietin was associated with an increased risk of cardiovascular disease, especially acute myocardial infarction. Erythropoietin may unmask the sclerotic lesion in chronic dialysis patients.

Cardiovascular Diseases↗

PubMed1996

Epidemiologic analysis of diabetic patients on chronic dialysis.

We retrospectively surveyed all of the available medical records of 404 (191 females and 213 males) chronic dialysis patients, of whom 16 (4%) had insulin-dependent diabetes mellitus (IDDM) and 388 (96%) non-insulin-dependent diabetes mellitus (NIDDM). The patients were among 2,214 dialysis patients in Okinawa, Japan, of whom 443 were diabetic. The patients entered a large population-based dialysis registry. The mean duration from the diagnosis of diabetes mellitus (DM) to dialysis was 181.6 months in the IDDM patients and 150.4 months in the NIDDM patients. The NIDDM patients were classified into four subgroups according to their status when DM was first suspected. The duration from the diagnosis of DM until the onset of dialysis treatment was significantly shorter than in any other subgroup or in the IDDM subgroup with major vascular disease (131.9 months). Otherwise, the course of renal disease in NIDDM patients was similar to that in IDDM individuals. Most of our dialysis patients with DM had NIDDM. In most of the NIDDM patients, the diagnosis had been delayed for several years for unknown reason. However, if diagnosed early, NIDDM shows a clinical time course until dialysis similar to that of IDDM. Whether NIDDM patients contract chronic renal disease at an equal incidence to that of IDDM patients and the fraction of all diabetic patients accepted for chronic dialysis remain to be determined.

Adult↗

PubMed1996

Hypertension in dialysis patients: a cross-sectional analysis.

To clarify the current status of blood pressure control in chronic dialysis patients, we investigated a large group of patients undergoing dialysis in Okinawa, Japan. A set of cross-sectional data of 18 variables, including age, antihypertensive medication, dose of dialysis, blood chemistry findings and predialysis blood pressure, were obtained in 1,243 patients (524 females, 719 males) aged 14 to 93 years who were on hemodialysis in January 1991. Systolic and diastolic blood pressures in patients taking antihypertensive medication (160.8 +/- 0.8/84.6 +/- 0.5 mmHg, mean +/- SEM) were significantly (P < 0.0001) higher than in those were not taking antihypertensive medication (141.3 +/- 0.8/76.9 +/- 0.5). Stepwise regression and univariate analysis methods were used to determine the independent predictors of blood pressure. Antihypertensive medication was positively associated with systolic and diastolic blood pressure. However, the mortality rate of the two groups during the following four years did not differ (antihypertensive-medicated group 23.1% vs. non-medicated group 20.9%). In conclusion, hypertension does not appear to be adequately controlled in our dialysis patients, despite the widespread use of antihypertensive medications.

Adult↗

PubMed1996

An epidemiologic analysis of parathyroidectomy in chronic dialysis patients. The Okinawa Dialysis Study Group.

Parathyroidectomy (PTX) is one of the treatments of choice for secondary hyperparathyroidism in chronic dialysis patients. Due to the large increase in long-term dialysis patients, hyperparathyroidism is becoming a common clinical problem. Several studies on PTX have reported various surgical procedures, but limited information is available on the incidence and risk factors of the surgery. The Okinawa Dialysis Study (OKIDS) registry is a community-based dialysis registry. It covers the entire area of Okinawa from when the use of chronic dialysis began in 1971. By the end of 1990, a total of 1,986 chronic dialysis patients were registered and 128 of these had undergone PTX by the end of 1993. The cumulative incidence of PTX was 4.3 in DM and 15.2 in non-DM per 1,000 patient-years. About half of the PTX patients underwent the surgery within 10 years of dialysis. By logistic analysis, the risk of PTX was seen to increase significantly with the duration of dialysis, P < 0.0001. Other clinical variables such as sex, age at the start of dialysis and the presence of diabetes mellitus were not significant predictors of PTX. The probability of PTX increased linearly with the duration of dialysis (r = 0.83, p < 0.0001). After the introduction of active vitamin D in 1981, the probability of PTX was significantly decreased (p < 0.05) compared to the pre-vitamin D period ('71-'80). With prolongation of the duration of dialysis, the risk of PTX increased steadily and was estimated to be 10 percent in 10 years and 20 percent in 20 years. Other uremic factors determining a pathological transformation of parathyroid tissue from reactive to autonomous growth remained to be investigated.

Adult↗

PubMed1996

Blood pressure and risk of end-stage renal disease in a screened cohort.

We prospectively studied a total of 107,192 subjects over 18 years of age (51,122 men and 56,070 women) who participated in dipstick urinalyses and blood pressure measurements in 1983. The subjects represented approximately 13.7% of the entire Okinawan adult population of 780,000 according to the 1980 Census. Independently, data for all dialysis patients registered from April 1, 1983 to March 31, 1994 were analyzed; the total number of end-stage renal disease (ESRD) dialysis patients was 2,009 (1,126 men and 883 women) during the study period. Dialysis patients who had been in the 1983 mass screening and who later required dialysis during the study period were identified and verified by reviewing the medical records. ESRD developed in 193 (105 men and 88 women) participants from the 1983 health screening. In this mass screening setting, high diastolic blood pressure was identified as the significant predictor of ESRD with an adjusted odds ratio of 1.39 and a 95% confidence interval of 1.17 to 1.64.

Adolescent↗

PubMed1996

Relationship between sustained elevation of serum alanine aminotransferase and progression from cirrhosis to hepatocellular carcinoma: comparison in patients with hepatitis B virus- and hepatitis C virus-associated cirrhosis.

Most patients with hepatocellular carcinoma (HCC) in Japan have hepatitis B virus (HBV)-or hepatitis C virus (HCV)-associated cirrhosis. In the present study, the risk of HCC in patients with cirrhosis was analysed by the levels of serum alanine aminotransferase (ALT). One hundred and one (78%) of 129 patients with cirrhosis registered from April 1979 were followed at monthly intervals with the measurement of serum ALT. Of 101 patients, 38 tested positive for hepatitis B surface antigen (HBsAg) but negative for antibody to HCV (anti-HCV; HBV group), 47 tested negative for HBsAg but positive for anti-HCV (HCV group) and nine tested positive and seven tested negative for both. Mean serum ALT during follow-up was calculated on the basis of monthly values during the observation period that started at enrolment and ended with the detection of HCC or at the end of March 1994. By the end of March 1994, 37 (37%) patients developed HCC; 12 were in the HBV group, 21 in the HCV group and four were in the group positive for both. Mean serum ALT during the observation period was similar in patients who developed HCC and those who did not develop HCC in the HBV group. In contrast, the value was significantly higher in patients who developed HCC than in patients who did not develop HCC in the HCV group (P < 0.05).

Alanine Transaminase↗

PubMed1996

A community-based evaluation of the effect of renal transplantation on survival in patients with renal-replacement therapy.

The relative effect of renal transplantation on survival was examined in chronic dialysis patients in Okinawa, Japan. Of 3,035 patients (1,722 men and 1,313 women) who were registered by the end of 1994 and followed up until April 1, 1995, 141 (91 men and 50 women) had undergone a renal transplantation during the follow-up period. The type of donor was a cadaver in 38 (26.9%) and a living relative in 103 (73.1%). At the end of the follow-up period, 12 (8.5%) of the patients with a renal transplant had died, 35 (24.8%) had returned to dialysis treatment, and 94 (66.7%) were alive with a functioning graft. In the patients who did not receive a transplant, 1,134 (39.2%) had died and 1,760 (60.8%) were alive and on dialysis. Cox proportional hazard analysis was performed with adjustment for sex, age at first dialysis, presence of diabetes mellitus, year of first dialysis, and predialysis co-morbid conditions. The hazard ratio (95% confidence interval) in the group with a transplant was 0.33 (0.18 to 0.59) when the hazard ratio of the group without a transplant was taken as 1.00. The patient survival rate was better in the former group. Our data provide fundamental evidence supporting the effectiveness of renal replacement as treatment. Whether the life-saving merit of renal transplantation is substantial enough to actively encourage donation remains to be clarified.

Adult↗

PubMed1995

Purification method for alpha-1-acid glycoprotein with subsequent high-performance liquid chromatographic determination of monosaccharides in plasma of healthy subjects and patients with renal insufficiency.

A simple purification method for human plasma alpha-1-acid glycoprotein (AAG) using an ion-exchange and hydroxyapatite column was developed. The recovery of the method was found to be high. We also improved a determination method for N-acetylneuraminic acid and monosaccharides in the carbohydrate moiety of AAG by using an ion-exchange column and pulse-amperometric detection. By this method, a composition analysis of the carbohydrate moiety of AAG (N-acetylneuraminic acid, fucose, N-acetyl glucosamine, galactose and mannose) was possible with 1.0 ml of plasma. We compared these carbohydrate concentrations in the AAG of patients with renal insufficiency with those of healthy subjects. In the AAG of the patients, the concentrations of N-acetylglucosamine, galactose and mannose were significantly higher than those in the AAG of the healthy subjects.

Acetylglucosamine↗

PubMed1995

Comparison of the transport characteristics of ceftibuten in rat renal and intestinal brush-border membranes.

The transport characteristics of ceftibuten, a dianionic cephem antibiotic, in rat renal and intestinal brush-border membranes were compared. Ceftibuten transport was mediated by two transport systems in the renal brush-border membrane and by one transport system in the intestinal brush-border membrane. The apparent kinetic parameters for the uptake of ceftibuten by the renal brush-border membrane vesicles, respectively, were: Km1, Km2 values of 26 and 1946 microM and Vmax1, Vmax2 values of 105 and 1400 pmol/mg protein per 30 s. The apparent kinetic parameters for the uptake by the intestinal brush-border membrane vesicles were: Km of 425 microM and Vmax of 1701 pmol/mg protein per 30 s. In the renal brush-border membrane, L-Ala-L-Pro was partially competitive and competitive inhibitor for the uptake by the high and low affinity systems, respectively. However, L-Ala-L-Pro was a non-competitive inhibitor for the uptake by the intestinal brush-border membrane vesicles. L-Carnosine was a specific and competitive inhibitor for the high affinity system in the renal brush-border membrane, while it had no effect on the low affinity system of the kidney or on the transport system of the intestine. It was concluded that the transport characteristics of ceftibuten in the renal and intestinal brush-border membranes are similar in some aspects but they are not identical.

Animals↗

PubMed1995

Promotion by substance P of gastric carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine in Wistar rats.

The effects of prolonged administration of neuropeptide substance P (SP) on gastric carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and on the labeling index of gastric mucosa were investigated in Wistar rats. Rats received subcutaneous injections of 12 micrograms/kg body weight of SP every other day after 25 weeks of oral treatment with MNNG. Long-term administration of SP significantly increased the incidence of gastric cancers in week 52. However, it did not affect the histological type and depth of involvement of gastric cancers. SP also caused a significant increase in the labeling index of the antral and fundic epithelial cells in week 52. These findings indicate that SP promotes gastric carcinogenesis and suggest that this effect may be related to its stimulation of antral epithelial cell proliferation.

Animals↗