Nobuo Kotajima

Inflammatory cytokines in vitreous fluid and serum of patients with diabetic vitreoretinopathy

To determine whether inflammatory cytokines are increased in proliferative diabetic retinopathy. We measured concentrations of interleukin-6, 8 (IL-6, 8) and tumor necrosis factor (TNF)-alpha by enzyme-linked immunosorbent assay (ELISA) in vitreous and serum from 47 patients with proliferative diabetic retinopathy and 21 patients with vitreous noninflammatory retinopathies. Vitreous concentration of IL-6 were 64.7+/-12.8 pg/ml in proliferative diabetic retinopathy, much greater (P<.005) than in noninflammatory retinopathy (2.8+/-4.5 pg/ml). Amounts of IL-8 in vitreous fluid also were greater in proliferative retinopathy than in noninflammatory retinopathy (34.0+/-11.5 vs. 6.1+/-2.0 pg/ml, P<.005). Concentrations of TNF-alpha in vitreous fluid were not statistically different in proliferative retinopathy from those in noninflammatory retinopathy. In sera, concentrations of IL-6 and IL-8 were not different between proliferative and noninflammatory retinopathy. However, serum TNF-alpha was much greater in proliferative retinopathy than in noninflammatory retinopathy (0.81+/-0.72 vs. 0.09+/-0.00 pg/ml, P<.001). Elevated TNF-alpha in serum then may be diagnostically useful in proliferative diabetic retinopathy. And inflammatory cytokines in vitreous may be pathogenically important in this concentration.

Circulating interleukin-6 and interleukin-6 receptors in patients with acute and recent myocardial infarction.

Interleukin-6 (IL-6), a proinflammatory cytokine, plays a key role in the pathogenesis of coronary artery disease (CAD). We investigated circulating IL-6 and its receptors in patients with CAD. We evaluated 39 Japanese patients with CAD (30 males and 9 females aged 36–79 years), measuring their plasma levels of IL-6 and IL-6 receptors α and β (IL-6Rα, IL-6Rβ). Circulating levels of IL-6, IL-6Rα and IL-6Rβ were measured by an enzyme-linked immunosorbent assay. Blood was sampled immediately after admission and again after 1, 2, 3, 6 and 9 h, then every 12 h for 5 days. Atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP) were measured on day 3 after symptom onset. Plasma levels of IL-6 and IL-6Rs were significantly increased in 28 patients with acute myocardial infarction (AMI) compared with 15 normal controls. However, neither IL-6 nor IL-6Rs showed an increase in 6 patients with angina pectoris. We observed two peaks for circulating IL-6 in AMI, the first of which showed a significant correlation with ANP as well as BNP. These results may help to explain why the amount of IL-6 produced is closely related to the severity of myocardial dysfunction in patients with CAD.

Type IV collagen as an early marker for diabetic nephropathy in non-insulin-dependent diabetes mellitus.

We measured urinary albumin (U-Alb) and type IV collagen (uIV.C) in spot urine collected from 82 patients with non-insulin-dependent diabetes mellitus (NIDDM) and 205 controls. Eighty-two NIDDM patients that had no increased excretion of either U-Alb or uIV.C were observed for 6 months. Prevalence of increased excretion of U-Alb and uIV.C at 6 months in these patients were 32.9%, and 62.2%, respectively. Increased excretion of uIV.C was detected in 27 patients without microalbuminuria. chi(2) analysis suggested that uIV.C was more sensitive than U-Alb, and that hypertension enhanced increased excretion of both U-Alb and uIV.C. uIV.C was significantly correlated (P<0.01) with U-Alb but not glycosylated hemoglobin A1C (HbA1C) in NIDDM patients. Taken together, uIV.C may be a useful marker for early diabetic nephropathy.

Decreased Vitreal Hyaluronan Levels with Aging

Purpose: To investigate age-related changes in hyaluronan levels in human eyes before and after vitrectomy surgery, we measured the hyaluronan levels in the vitreous samples obtained during vitrectomy and postoperative fluid-air exchange. Methods: We obtained the vitreous during vitrectomy from 26 eyes of 26 patients with macular hole (MH) and 52 eyes of 52 patients with diabetic retinopathy (DR). After vitrectomy, we collected fluid samples during fluid-air exchange from 6 eyes with MH and 9 eyes with DR. The hyaluronan level was measured by the sandwich binding protein assay. Results: In the vitreous of the 54 eyes (26 eyes with MH and 28 eyes with DR and no vitreous hemorrhage), hyaluronan levels significantly decreased with patient age (r = –0.66, p < 0.00000005). Hyaluronan levels in postoperative vitreous fluid were significantly lower in 6 eyes with MH (p < 0.05) and 9 eyes with DR (p < 0.01) than those obtained during vitrectomy. Conclusions: There was a significant decrease in vitreous hyaluronan with aging. High-molecular-weight hyaluronan appears not to be formed in vitreous fluid after vitrectomy.

Circulating interleukin-6 significantly correlates to thyroid hormone in acute myocardial infarction but not in chronic heart failure

To investigate relationships between thyroid states and the cardiac endocrine system, we analyzed thyrotropin (TSH), thyroid hormone, plasma levels of interleukin-6 (IL-6) and brain natriuretic peptide (BNP) in 50 patients with chronic heart failure (CHF), in 30 patients with heart failure from acute myocardial infarction (AMI), and in 15 controls. Plasma levels of IL-6 and BNP in both CHF and AMI were significantly elevated, while free triiodothyronine (FT3) was significantly decreased compared to controls. FT3/ free thyroxine (FT4) ratio was significantly decreased in CHF but not in AMI compared to controls. In CHF, diuretic treatment diminished circulating BNP but not IL-6, while diuretic treatment increased FT3/FT4 ratio. In AMI, FT3/ FT4 ratio was significantly decreased 72h compared to 12h after the onset of AMI, while BNP and IL-6 were significantly increased 72h compared to 12h after the onset of AMI. In both CHF and AMI, BNP significantly correlated with FT4. On the other hand, significant correlations between IL-6 and FT3, and between IL-6 and FT3/FT4 ratio were detected in AMI but not in CHF. This preliminary study suggests that IL-6, BNP and thyroid hormone reflect ventricular dysfunction in both acute and chronic heart failure, and that IL-6 significantly relates to circulating thyroid hormone in AMI but not in CHF.

Type IV Collagen Serum and Vitreous Fluid Levels in Patients with Diabetic Retinopathy

We compared the levels of type IV collagen (IV-C) in vitreous fluid and serum and the levels of glycosylated haemoglobin in 47 patients with proliferative diabetic retinopathy (DR) and 21 patients with non-inflammatory retinopathies. Levels of IV-C were found to be higher in the vitreous fluid in patients with DR than in patients with non-inflammatory retinopathy (53.2 ± 14.9 μg/l versus 14.7 ± 4.5 μg/l). Serum levels were likewise higher in patients with DR (349.7 ± 106.2 μg/l versus 97.7 ± 13.1 μg/l) as were glycosylated haemoglobin levels (8.3 ± 0.3% versus 5.2 ± 0.4%). In addition, levels of type IV collagen in the vitreous fluid were found to be higher in the patients who had been diabetic for ≥ 10 years than in patients who had been diabetic for < 10 years (54.8 ± 15.5 μg/l versus 16.8 ± 4.6 μg/l). We conclude that accumulation of vitreous fluid IV-C may relate to high levels of glycosylated haemoglobin and long duration of diabetes. This suggests that the concentration of IV-C in vitreous fluid, and possibly also the serum levels of IV-C, reflects the progression of DR. Further investigation is needed to verify this and to investigate whether or not measuring IV-C levels is a useful means to assess therapeutic effects and/or prognosis of diabetic microangiopathy.

Blood Rheology and the Low-Density Lipoprotein Cholesterol/High-Density Lipoprotein Cholesterol Ratio in Dyslipidaemic and Normolipidaemic Subjects

The association between blood rheology and the ratio of low-density lipoprotein cholesterol (LDL-C) to high-density lipoprotein cholesterol (HDL-C) was investigated in 142 dyslipidaemic and 253 normolipidaemic subjects. Blood rheology was examined by the microchannel method and fasting serum concentrations of LDL-C, triglyceride and HDL-C were measured. Passage time of whole blood correlated positively with LDL-C concentration, triglyceride concentration and LDL-C/HDL-C ratio, and negatively with HDL-C concentration. Passage time of whole blood was significantly higher in dyslipidaemic and normolipidaemic subjects with LDL-C/HDL-C ratio > 2.0 than in those with ratio < 1.5. Thus, dyslipidaemic subjects had impaired blood rheology, elevated LDL-C and triglyceride concentrations and elevated LDL-C/HDL-C ratio, and reduced HDL-C concentrations. Dyslipidaemic and normolipidaemic subjects with a more elevated LDL-C/HDL-C ratio had greater blood rheology impairment than those with a less elevated ratio. These data suggest that an elevated LDL-C/HDL-C ratio may be helpful in predicting impaired blood rheology.

Frequency and Clinical Implication of the R450H Mutation in the Thyrotropin Receptor Gene in the Japanese Population Detected by Smart Amplification Process 2

In Japanese pediatric patients with thyrotropin (TSH) resistance, the R450H mutation in TSH receptor gene (TSHR) is occasionally observed. We studied the frequency and clinical implication of the R450H mutation in TSHR in the general population of Japanese adults using smart amplification process 2 (SmartAmp2). We designed SmartAmp2 primer sets to detect this mutation using a drop of whole blood. We analyzed thyroid function, antithyroid antibodies, and this mutation in 429 Japanese participants who had not been found to have thyroid disease. Two cases without antithyroid antibodies were heterozygous for the R450H mutation in TSHR. Thus, the prevalence of this mutation was 0.47% in the general population and 0.63% among those without antithyroid antibodies. Their serum TSH concentrations were higher than the average TSH concentration not only in subjects without antithyroid antibodies but also in those with antithyroid antibodies. The R450H mutation in TSHR is relatively common in the Japanese population and potentially affects thyroid function. The present study demonstrates that the SmartAmp2 method is useful to detect the R450H mutation in TSHR, which is one of the common causes of TSH resistance in the Japanese population.

Clinical features associated with circulating concentration of soluble leptin receptor in patients with diabetes.

We aimed to determine if there were any clinical features that were significantly associated with the circulating concentration of soluble leptin receptor (OB-Re) in 67 Japanese subjects with diabetes mellitus. The characteristics evaluated included age, height, body weight, body mass index (BMI), systolic and diastolic blood pressure, duration of diabetes, haemoglobin A1C and blood lipid concentrations, urinary albumin excretion rate, circulating concentrations of leptin, tumour necrosis factor-α (TNF-α), TNF-α receptor 1 and genotypes of the angiotensin-converting enzyme (ACE) gene. We found statistically significant negative correlations between circulating OB-Re concentration and body weight, BMI, diastolic blood pressure, concentrations of leptin and TNF-α receptor 1. Serum OB-Re concentration was not associated with any of the other clinical characteristics that were measured, or with the different ACE genotypes. Our results suggest that OB-Re might have an important influence on the biological activity of leptin in diabetic subjects.

Congestive Heart Failure Induced by the Combination of Atrial Fibrillation and Tricuspid Regurgitation

Atrial fibrillation (AF) and tricuspid regurgitation (TR) may induce congestive heart failure (CHD). Using electrocardiography and echocardiography, we examined the clinical characteristics and haemodynamic findings in 100 patients with AF + TR + CHF, AF + TR, AF or TR. The fractional shortening in all groups with AF was significantly decreased compared with the TR group. The ejection fraction in patients with AF + TR + CHF was significantly lower than in the TR group. Twenty-four of the 72 patients with AF and TR (with or without CHF) were treated, and 13 were monitored for heart rate and severity of TR. Eight months after start of treatment the heart rate and typical symptoms and signs of heart failure had improved significantly in nine patients, but the severity of TR did not change. TR worsened in the remaining four patients but they did not develop CHF. Our results suggest that increased heart rate due to the combination of AF and TR could be responsible for CHF.