Biomedical subjects

A Maruyama

Publications and source records attributed to A Maruyama.

At least 73 records · Page 4Linked to original sources

PubMed1997

Specific interaction between erythrocytes and a glucose-carrying polymer mediated by the type-1 glucose transporter (GLUT-1) on the cell membrane.

A reducing glucose-carrying polymer, called poly [3-O-(4'-vinylbenzyl)-D-glucose] (PVG), interacted with erythrocytes carrying the type-1 glucose transporter (GLUT-1) on the cell membrane. The cooperative interaction between a number of GLUT-1s and a number of reducing 3-O-methyl-D-glucose moieties on a PVG polymer chain is responsible for the increase in the interaction with erythrocytes. In contrast to the PVG homopolymer, other sugar-carrying polymers showed lower interaction with erythrocytes. The affinity of erythrocytes and PVG was studied using FITC-labeled glycopolymers. The fluorescence intensity significantly changed, whereas a small change in fluorescence intensity was observed for other homopolymers. The specific interaction between GLUT-1 on erythrocytes and the PVG polymer carrying reducing glucose was suppressed by the inhibitors, phloretin, phloridzin, and cytochalasin B, and a monoclonal antibody to GLUT-1. Direct observation by confocal laser microscopy with the use of FITC-labeled PVG demonstrated that erythrocytes interacted with the soluble form of the PVG polymer via GLUT-1, while fluorescence labeling of the cell surface was prevented on pretreatment with the monoclonal antibody to GLUT-1.

Animals↗

PubMed1997

High level expression of XMP aminase in Escherichia coli and its application for the industrial production of 5'-guanylic acid.

To improve the efficiency of the enzymatic conversion of 5'-xanthylic acid (XMP) to 5'-guanylic acid (GMP), we attempted to increase the activity of the conversion enzyme, XMP aminase (GMP synthetase) encoded by the guaA gene in Escherichia coli. By connecting the PL promoter of lambda phage, the SD sequence of trpL of E. coli, and ATG, at a suitable position upstream of the guaA gene, we obtained plasmid pPLA66. Sequencing of the nucleotides of the upstream region of the guaA gene on pPLA66 showed that the C-terminal region of the guaB gene, which encodes IMP dehydrogenase, was conserved and a short peptide consisted of 14 amino acids was coded. E. coli MP347/pPLA66 showed an increase in the activity of approximately 370 times when compared with that of the strain MM294, and the amount of the enzyme protein represented approx. 34% of the total cellular protein. Strain MP347/pPLA66 was cultivated in a 5-liter jar fermentor using a medium which contained mainly corn steep liquor. The culture broth had high XMP aminase activity. In the conversion reaction using mixed broths consisted of 600 ml of XMP-fermentation broth of Corynebacterium ummoniagenes KY13203 and 30 ml of cultured broth of E. coli MP347/pPLA66, a surfactant, Nymeen S-215 and xylene were added to the reaction mixture to make the cell membrane permeable to nucleotides. After 23 h of the reaction, 70 mg/ml (131 mM) of GMP.Na2.7H2O was accumulated from 83 mg/ml (155 mM) of XMP.Na3.7H2O, without addition of ATP. The molar conversion yield was approx. 85%. The facts that the cell membrane was treated to allow nucleotides to permeate and that the conversion reaction proceeded well enough in spite of a small amount of E. coli cells indicate ATP was regenerated from AMP by C. ammoniagenes cells and supplied to E. coli cells. Therefore, it was considered that the coupling reaction between these two kind of strains was established.

Bacteriophage lambda↗

PubMed1997

Enzymatic production of pyrimidine nucleotides using Corynebacterium ammoniagenes cells and recombinant Escherichia coli cells: enzymatic production of CDP-choline from orotic acid and choline chloride (Part I).

Enzymatic production of cytidine diphosphate choline (CDP-choline) using orotic acid and choline chloride as substrates was investigated using a 200-ml beaker as a reaction vessel. When Cornybacterium ammoniagenes KY13505 cells were used as the enzyme source, UMP was accumulated up to 28.6 g/liter (77.6 mM) from orotic acid after 26 h of reaction. In this reaction, UDP and UTP were also accumulated, but CTP, a direct precursor of CDP-choline, was not accumulated sufficiently. Escherichia coli JF646/pMW6 cells, which overproduce CTP synthetase by selfcloning of the pyrG gene, were used together with cells of KY12505 for the enzymatic reaction using orotic acid as a substrate. CTP was produced at 8.95 g/liter (15.1 mM) after 23 h of this reaction. To produce CDP-choline, two additional enzyme activities were needed. E. coli MM294/pUCK3 and MM294/pCC41 cells, which express a choline kinase from Saccharomyces cerevisiae (CKIase; encoded by the CKI gene) and a cholinephosphate cytidylyltransferase from S. cerevisiae (CCTase; encoded by the CCT gene) respectively, were added to this CTP-producing reaction system. After 23 h of the reaction using orotic acid and choline chloride as substrates, 7.7 g/liter (15.1 mM) of CDP-choline was accumulated without addition of ATP or phosphoribosylpyrophosphate (PRPP). ATP and PRPP required in the CDP-choline forming reaction system are biosynthesized by those cells using glucose as a substrate.

Carbon-Nitrogen Ligases↗

PubMed1997

Construction of a plasmid carrying both CTP synthetase and a fused gene formed from cholinephosphate cytidylyltransferase and choline kinase genes and its application to industrial CDP-choline production: enzymatic production of CDP-choline from orotic acid (Part II).

A new method for enzymatic production of cytidine diphosphate choline (CDP-choline) from orotic acid and choline chloride was developed. To establish an industrial manufacturing process, we constructed a plasmid, pCKG55, which simultaneously expressed in Escherichia coli the three following enzymes; CTP synthetase (encoded by the pyrG gene from E. coli), cholinephosphate cytidylyltransferase (encoded by the CCT gene from Saccharomyces cerevisiae), and choline kinase (encoded by the CKI gene from S. cerevisiae). CCT and CKI genes on pCKG55 were designed to be expressed as a single CCT/CKI fused protein. This CCT/CKI fused protein retained both activities and the thermal stability of its cholinephosphate cytidylyltransferase activity was nearly the same as the native CCT enzyme. Corynebacterium ammoniagenes KY13505 and E. coli MM294/pCKG55 were cultured in 5-liter jar fermentor independently. Equal volumes of each broth were mixed in a 2-liter jar fermentor, and then the enzymatic reaction was done using 47 mM orotic acid and 60 mM choline chloride as substrates. After 23 h of the reaction at 32 degrees C, 21.5 mM (11 g/liter) of CDP-choline was accumulated.

Adenosine Triphosphate↗

PubMed1997

Poly(L-lysine)-graft-dextran copolymer is a novel stabilizer of triplex DNA (I): stabilization of poly(dA).2poly(dT) triplex.

Comb-type polylysine copolymer having grafted hydrophilic side chains was newly designed as a novel stabilizer of triplex DNAs. The comb-type copolymer elevated melting temperature of poly(dA).2poly(dT) triplex by 50 degrees C without affecting reversibility, melting and reassociation, of the triplex in buffer with physiological salt concentrations. The stabilizing effect of the copolymer was greater than spermine. Our results indicate that the molecular designing of polycation with comb-type structure is a successful strategy for creating an effective triplex stabilizer.

Biocompatible Materials↗

PubMed1997

Poly(L-lysine)-graft-dextran copolymer is a novel stabilizer of triplex DNA(II): potassium-insensitive triplex formation.

Triple helix formation involving guanine-rich oligonucleotides is inhibited by physiological concentrations of potassium (K+). Using in vitro electrophoretic mobility shift assay (EMSA), we show that PLL-g-dex copolymer significantly stabilizes triplex structure at physiological levels of K+ that greatly inhibited triplex formation with a unmodified, guanine-rich oligonucleotide.

Base Sequence↗

PubMed1996

Clinical implications of the 'no reflow' phenomenon. A predictor of complications and left ventricular remodeling in reperfused anterior wall myocardial infarction.

BACKGROUND: Recent studies demonstrated that the "no reflow" phenomenon after coronary reflow implies the presence of advanced myocardial damage. In this study, we verified the prognostic value of the detection of this phenomenon by studying complications, left ventricular morphology, and in-hospital survival after acute myocardial infarction (AMI). METHODS AND RESULTS: The study population consisted of 126 patients with a first anterior AMI. All patients received coronary reflow within 24 hours of onset of symptoms and underwent myocardial contrast echocardiography (MCE) before and shortly after coronary reflow with an intracoronary injection of sonicated microbubbles. From contrast reperfusion patterns, patients were divided into two subsets: those with MCE no reflow (47 patients, 37%) and those with MCE reflow (79 patients). There was no difference in the frequency of arrhythmia or coronary events between the two subsets. Pericardial effusion and early congestive heart failure were observed more frequently in patients with MCE no reflow than in those with MCE reflow (26% versus 4%, P < .05; 45% versus 15%, P < .05, respectively). Congestive heart failure tended to be prolonged in those with MCE no reflow, and 3 patients (7%) of this subset died of pump failure. Left ventricular end-diastolic volume progressively increased in the convalescent stage in patients with MCE no reflow (early versus late, 145 +/- 43 versus 169 +/- 60 mL, P < .001), whereas it decreased in those with MCE reflow (154 +/- 42 versus 144 +/- 44 mL, P < .01). CONCLUSIONS: The substantial size of the MCE no reflow phenomenon at coronary reflow conveys useful information about an outcome of coronary intervention and left ventricular remodeling in individual patients with anterior wall AMI, although these are suggestive results in a limited number of patients.

Adult↗

PubMed1996

Temporal changes in regional end-diastolic wall thickness early after reperfusion in acute anterior myocardial infarction: relation to myocardial viability and vascular damage.

We investigated early temporal changes in end-diastolic wall thickness (EDWT) of the infarcted myocardium in 46 patients with reperfused anterior acute myocardial infarction in relation to myocardial viability. Two-dimensional echocardiography was performed on days 1 and 2 of acute myocardial infarction, and the EDWT of the anterior segment was measured in the short-axis view. Patients were divided into three groups on the basis of day 1 to day 2 ratio of EDWT: the ratio < or = 0.85 as group A (n = 13), >0.85 but < or = 1.15 as group B (n = 23), and >1.15 as group C (n = 1 0). Left ventricular functional improvement was significantly better in group B than in groups A and C. Substantial size of "no reflow" phenomenon was observed only in groups A (n = 9, 69%) and C (n = 6, 60%). The frequency of transient ST re-elevation after reperfusion was the highest in group C (70%), and left ventricular expansion was observed at day 2 only in group A. We conclude that changes in the EDWT of the infarct segment early after reperfusion, either decreases or increases, are related to irreversibly damaged myocardium. A decrease in EDWT and concomitant ventricular expansion may be related to impaired myocardial perfusion. An increase in EDWT after reperfusion may be caused by accelerated myocardial and microvascular damage after reperfusion.

Adult↗

PubMed1996

Prediction of blood lactate accumulation from excess CO2 output during constant exercise.

To determine the predictability of blood lactate accumulation from excess CO2 output derived from bicarbonate buffering of lactic acid during constant exercise, eight normal active volunteers were studied during three stages of constant exercise on a cycle ergometer. Three work rates consisted of 100% (stage I), 120% (stage II) and 150% (stage III) of each subject's anaerobic threshold (AT), each of which was lasted for 4 min. Excess CO2 output (Ex CO2, ml) at each stage of constant exercise was estimated form the integral of difference between total VCO2 and aerobic VCO2 (from regression line for VCO2 and VO2 at exercise intensities below the AT obtained in incremental exercise test). Ex CO2 per body mass (Ex CO2-mass-1) was increased progressively with blood lactate (La) accumulation from rest to each stage of constant exercise. Mean values (+/-SD) in the measured La accumulation (delta La,measured) and predicted La accumulation (delta La,predicted) at three stages of constant exercise were 1.82 +/- 0.83 vs 3.19 +/- 1.70 for stage 1, 5.58 +/- 3.47 vs 7.09 +/- 3.28 for stage II and 12.19 +/- 2.36 vs 12.74 +/- 1.83 mmol.l-1 for stage III, respectively. There was a significant difference between delta La,measured and delta La,predicted at stage I (p < 0.05), but no significant differences between these two variables at stage II and III. The averaged difference from delta La,predicted to delta La,measured at stage III (0.55 mmol.l-1) showed a tendency to be smaller than stage I (1.38 mmol.l-1) and II (1.50 mmol.l-1). On the other hand, delta La,predicted was found to correlate very closely with delta La,measured (r = 0.954, P < 0.001, n = 20). The results of this study suggest that the changes of La accumulation could be predicted from excess CO2 output generated in constant exercises above the AT.

Adolescent↗

PubMed1996

[A randomized controlled study of post-operative adjuvant therapy in non-small cell lung cancer].

The efficacy of postoperative adjuvant chemo- and chemoimmunotherapy in non-small cell lung cancer was evaluated in a multicentric prospective randomized study. From September 1987 to June 1990, resected lung cancer patients were randomly stratified into three groups. Group A received 2 courses of chemotherapy with CDDP and VDS following operation. Group B was administered UFT daily for 1 year after 2 courses of CDDP. Group C received intrapleural administration of OK-432 after lung resection, then UFT and OK-432 once every 2 weeks for 1 year. Out of 94 cases, analyses were carried out on 87 of eligible cases. The five-year survival rate was 56.8% in stage I (43 cases), 73.3% in stage II (12 cases), 18.8% in stage IIIA (24 cases), 50% in stage IIIB (2 cases) and 33.3% in stage IV (6 cases). The five-year survival rate in group A was 32.2%, 55.2% in group B and 53.9% in group C, and no statistical difference was recognized between 3 groups. But in the cases of noncurative resection, the 5-year survival rate was significantly low in group A compared with Group B or C. Similarly, the cases with low-grade TP (<6.0 g/dl) or low response of PPD skin reaction (< 12mm) showed a significantly low 5-year survival rate only in group A. From these results, it was suspected that aggressive chemotherapy provides no benefit for postoperative lung cancer patients with advanced disease.

Adult↗

PubMed1996

[Performance study of teleradiology network systems with CRT monitors: ROC analysis of an observation study of simulated lung nodules].

PURPOSE: To evaluate the diagnostic performance of commercially available CRT monitors used in a teleradiology system by determining the rate of detection of simulated lung nodules. MATERIALS AND METHODS: Three types of CRT monitors were tested in the observation study. They had matrix sizes of 1024 x 768(16 inches, color), 1024 x 768(20 inches, color) and 1600 x 1125(24 inches, black and white). Twenty chest radiographs were obtained by Fuji computed radiography(FCR) of an anthropomorphic chest phantom with ten simulated nodules on its surface. These FCR films were digitized by a film digitizer with 125 DPI(1024 x 1024 matrix sizes)and 12 bit gray scales, and the image data were transferred from Shinshu University Hospital to other hospitals where interpretation was carried out by the radiologists. Ten radiologists of three hospitals were asked to interpret independently both the original FCR films and the images shown on the CRT monitors and to indicate the presence or absence of simulated nodules on the images by using a five-category rating scale. Receiver operating characteristics(ROC)curves were generated, and the results of interpretation on the FCR films and CRT monitors were compared. RESULTS: Performance of the all readers was slightly better with the CRT monitors than on the FCR films, although the differences were not statistically significant. There were no statistically significant differences in performance depending on the type of CRT monitor. CONCLUSION: Performance of the CRT monitors was comparable to that of FCR radiography in terms of interpreting the simulated lung nodules.

Computer Communication Networks↗

PubMed1995

Oxidized low-density lipoprotein induces the production of superoxide by neutrophils.

Exposure of guinea pig peritoneal neutrophils to ox-LDL led to the production of superoxide, which was measured by the formation of superoxide-dependent chemiluminescence. The cells exposed to unoxidized LDL, e.g. native LDL, acetyl-LDL, and self-aggregates of LDL showed no production of superoxide. The superoxide production was correlated with the levels of oxidative modification of LDL and reached a maximum between 10 and 30 min during incubation, but preincubating the cells with cytochalasin B decreased the superoxide production. These findings indicate that neutrophils rapidly take up ox-LDL by phagocytosis and generate superoxide which may cause superoxide-mediated lipid peroxidation in vivo.

Animals↗

PubMed1995

Insulin resistance is associated with high plasma ouabain-like immunoreactivity concentration in NIDDM.

The aim of the present study was to elucidate the pathophysiologic significance of circulating ouabain as a link between insulin resistance (IR) and hypertension (HT) in NIDDM. Euglycaemic (4.5 mmol/l) hyperinsulinaemic (360-580 pmol/l) clamping was performed using an artificial endocrine pancreas. Plasma ouabain-like immunoreactivity (OLI) was determined by radioimmunoassay using a highly specific antibody to ouabain. HT was defined as systolic blood pressure > 140 mm Hg and/or diastolic > 90 mm Hg or being treated with antihypertensive agents. The values (mean +/- SEM) of glucose infusion rate (GIR) and plasma OLI were compared among the four groups classified using IR and HT as factors. Group I (IR-/HT-, n = 15): GIR 7.20 +/- 0.36 mg.kg-1.min-1, OLI 130.8 +/- 20.9 pmol/l, which was not different from that in eight normal control subjects (7.69 +/- 0.40 mg.kg-1.min-1 and 142.6 +/- 32.3 pmol/l, respectively); Group II (IR-/HT+, n = 13): 5.89 +/- 0.36 mg.kg-1.min-1, 172.5 +/- 35.0 pmol/l; Group III (IR+/HT-, n = 14) 1.91 +/- 0.28 mg.kg-1.min-1, 576.6 +/- 161.5 pmol/l (p < 0.01 vs Group I and II); Group IV (IR+/HT+, n = 15) 1.79 +/- 0.22 mg.kg-1.min-1, 703.1 +/- 170.1 pmol/l (p < 0.01 vs Group I and II), respectively. Six of 57 NIDDM patients studied exhibited very high (> 1500 pmol/l) plasma OLI concentrations, showed marked insulin resistance and were all hypertensive. When analysed as a whole, plasma OLI was negatively correlated with GIR (p < 0.001), but was not correlated with arterial blood pressure.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1995

Hyperglycemia facilitates urinary excretion of C-peptide by increasing glomerular filtration rate in non-insulin-dependent diabetes mellitus.

We have evaluated the feasibility of monitoring the 24-hour urinary excretion rate of C-peptide (U-CPR) as a measure of integrated beta-cell function in patients with non-insulin-dependent diabetes mellitus (NIDDM). In 37 normoalbuminuric patients, U-CPR of 117.9 +/- 9.1 micrograms/d (mean +/- SEM) during the poorly controlled glycemic phase (fasting plasma glucose [FPG], 171 +/- 7 mg/dL; hemoglobin A1C [HbA1c], 8.8% +/- 0.4%) was significantly higher than the value of 83.3 +/- 13.7 micrograms/d (P < .001) during the well-controlled phase (FPG, 135 +/- 6 mg/dL; HbA1c, 7.0% +/- 0.2%), although the plasma insulin response to meals was lower during the former phase (53.3 +/- 6.3 microU/mL) versus the latter phase (65.7 +/- 6.6, P < .005). Endogenous creatinine clearance (Ccr) was significantly elevated during the poorly controlled phase (105.4 +/- 7.3 v 88.7 +/- 4.7 mL/min, P < .005). In 26 microalbuminuric patients, the plasma insulin response was greater during good glycemic control, but U-CPR did not differ between the two phases. Ccr was comparable at two phases in this group (92.7 +/- 7.4 v 91.1 +/- 5.9 mL/min, NS). U-CPR correlated positively with Ccr in both groups (r = .593, P < .001 in normoalbuminuria; r = .585, P < .001 in microalbuminuria). In addition, when biosynthetic human C-peptide was infused intravenously at an identical rate in two healthy subjects, resulting steady-state plasma levels of CPR were lower, and fractional U-CPR was higher during the moderately hyperglycemic phase versus the euglycemic phase.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1995

Highly increased insulin secretion in a patient with postprandial hypoglycemia: role of glucagon-like peptide-1 (7-36) amide.

The mechanism(s) of an inappropriate secretion of insulin is poorly understood. We report a case of reactive hypoglycemia associated with an unusually exaggerated insulin secretion. The patient, a 32-year-old man, developed frequent episodes of postprandial hypoglycemia after interferon treatment was begun for chronic type C hepatitis. Oral glucose challenge test confirmed the patient's extremely high plasma IRI response, i.e., more than 1000 microU/ml, and that of plasma C-peptide 56.9 ng/ml at 90 min, followed by symptomatic hypoglycemia (plasma glucose 34 mg/dl) at 240 min. The plasma proinsulin level also was high, but the molar ratio of immuno reactive insulin (IRI)/plasma C-peptide and IRI/proinsulin was within the normal range. Antibodies to insulin or insulin-receptor were negative. Plasma IRI response was apparently greater when the glucose was given orally than when given intravenously. The response of plasma glucagon-like-peptide (GLP)-1 to oral glucose was quite high (from baseline of 45.5 to 303.2 pmol/L) and showed a close parallel with the change in the plasma IRI concentration. The greatly enhanced insulin secretion leading to reactive hypoglycemia in this patient may therefore be attributed to the increased secretion of GLP-1.

Adult↗

PubMed1994

Preparation of nanoparticles bearing high density carbohydrate chains using carbohydrate-carrying polymers as emulsifier.

A novel method of preparing nanoparticles bearing high density carbohydrate chains on their surface is described. Carbohydrate-bearing nanoparticles of poly(lactic acid) or polystyrene were prepared by the solvent evaporation method using a carbohydrate-carrying polystyrene derivative which served as both an emulsifier and a surface coating. The diameter of the obtained nanoparticles ranged from 80 to 300 nm depending on the concentration of the polystyrene derivative. As the concentration of the polystyrene derivatives increased the nanoparticle diameter decreased, indicating that the polystyrene derivatives worked as an emulsifier. The obtained particles were specifically aggregated by carbohydrate-specific lectin, showing that the polystyrene derivative was retained on the particle surfaces and expressed carbohydrate residues. The density of carbohydrates on the particle surfaces was determined to be 3-5 molecules per square nanometre. The particles prepared by the present method were stably dispersed and hardly aggregated in aqueous media during storage and centrifugal treatment compared with the post-coated particles that were prepared by adsorbing polystyrene particles with the polystyrene derivative. In vitro study with isolated rat hepatocytes revealed that surface carbohydrate chains were recognized by hepatocytes.

Animals↗

PubMed1994

Relationship between insulin resistance and risk factors for cardiovascular disease in Japanese non-insulin-dependent diabetic patients.

To investigate whether a resistance to insulin-stimulated glucose uptake (IR) is associated with the risk factors (RF) for cardiovascular disease (CVD) in non-insulin-dependent diabetic (NIDDM) patients, we determined the degree of IR in 135 adult NIDDM patients who had no advanced diabetic complications. The euglycemic (80 mg/dl) hyperinsulinemic clamp (insulin infusion rate 1.12 mU/kg per min) was performed and the average glucose infusion rate (GIR) during a steady-state euglycemia was determined as a measure of IR. Hypertension was more common among NIDDM patients with an increased IR and was highest in the group of patients with CVD. CVD-RF such as hypertension, hypertriglyceridemia, low HDL-cholesterol and obesity tended to cluster in the NIDDM patients who had lower GIR values and higher fasting IRI levels. GIR values were compared between a set of groups extracted from the 135 NIDDM patients that were matched for age, sex, body mass index and HbA1c levels. The CVD-positive group had the significantly lower GIR value than the CVD-negative group (2.06 +/- 0.66 vs. 3.45 +/- 1.75, P < 0.005). The GIR value was also significantly lower in the hypertriglyceridemic group compared with the normotriglyceridemic group (2.50 +/- 1.36 vs. 4.03 +/- 1.82, P < 0.0005). However, there was no significant difference between the hypertensive and normotensive groups and between the high cholesterol or low HDL-cholesterol groups and their respective control groups. In conclusion, these results suggest that IR contributes to the clustering of CVD-RFs which may accelerate the development of CVD in the subgroup of Japanese NIDDM patients.

Adult↗

PubMed1994

Development of proliferative retinopathy in Japanese patients with IDDM: Tokyo Women's Medical College Epidemiologic Study.

We studied the development of proliferative diabetic retinopathy (PDR) in Japanese insulin-dependent diabetes mellitus (IDDM). Subjects were 373 patients who were diagnosed as IDDM between 1951 and 1984, before the age of 30 years, and had no PDR at the first visit to the Diabetes Center. Development of PDR was analyzed by Kaplan-Meier's life-table method in relation to the duration of IDDM. The cumulative incidence of PDR was 20% at 15 years of duration of IDDM, 40% at 19 years, and 70% at 29 years. Female patients (n = 233) developed PDR significantly faster than males (n = 140) (P < 0.002). In both sexes, patients with onset of IDDM at 0-8 years showed significantly slower development than patients with the onset at 9-17 (P < 0.0001) and 18-29 years (P < 0.001). Impact of femaleness on the development was the greatest in patients with age at onset of IDDM at 9-17 years (P < 0.005). Analysis according to the calendar year at onset of IDDM and diabetes duration at the first visit to the Diabetes Center did not show any significant influence on the development of PDR. In conclusion, sex and age at onset of IDDM may be associated with increased risk for the development of PDR in relation to the duration of diabetes in Japanese IDDM.

Adolescent↗