A Val227Ala polymorphism in the peroxisome proliferator activated receptor alpha (PPARalpha) gene is associated with variations in serum lipid levels.
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Adult↗
Biomedical subjects
R Miyazaki
Publications and source records attributed to R Miyazaki.
Requirement of thrombopoietin-induced activation of ERK for megakaryocyte differentiation and of p38 for erythroid differentiation.
Thrombopoietin (TPO) plays a critical role not only in proliferation and differentiation of megakaryocytes but also in erythroid differentiation. We have investigated whether the different pathway of mitogen-activated protein kinase (MAPK) after TPO stimulation may discriminate megakaryocyte and erythroid differentiation. In this study, we have used human CD34+ hematopoietic progenitor cells (HPCs) from cord blood (CB) in serum-free liquid culture supplemented with TPO, to compare the respective effects of specific inhibitors of MAPK kinase (MEK) (PD98059) and p38 MAP kinase (p38) (SB203580) on megakaryocyte and erythroid development. PD98059, but not SB203580, significantly suppressed TPO-induced megakaryocyte differentiation when examined by the expression of CD41 and polyploidy assay. In the presence of SB203580, CD34+/CD36+ erythroid progenitors clearly decreased, whereas they increased when cultured with PD98059. These results indicate that activation of extracellular-signal-regulated kinase (ERK) is required for TPO-induced megakaryocyte differentiation and that p38 is required for TPO-induced erythroid differentiation.
Antigens, CD34↗
Cholesteryl ester transfer protein as a protective factor against vascular disease in hemodialysis patients.
Cholesteryl ester transfer protein (CETP) may promote reverse cholesterol transport. An elevated concentration of high-density lipoprotein cholesterol (HDL-C) is a protective factor against atherosclerosis. However, the effects of CETP itself and its interaction with HDL-C have not been investigated in hemodialysis patients, who are at high risk for atherosclerosis and generally considered to have decreased reverse cholesterol transport. We investigated the independent or synergistic influence of postprandial serum CETP and HDL-C concentrations on apparent atherosclerotic complications in 202 hemodialysis patients aged 40 to 80 years. Patients with vascular disease (n = 39) had significantly lower concentrations of CETP than those without vascular disease (n = 163). When all study subjects were divided into four groups according to CETP and HDL-C concentrations based on median values, we found significant differences in the prevalence of vascular disease (test for trend, P < 0.005): 28.8% in group I (HDL-C < 48 mg/dL; CETP < 2.2 microgram/mL); 25.0% in group II (HDL-C < 48 mg/dL; CETP >/= 2.2 microgram/mL); 17.8% in group III (HDL-C >/= 48 mg/dL; CETP < 2.2 microgram/mL); and 6.9% in group IV (HDL-C >/= 48 mg/dL; CETP >/= 2.2 microgram/mL). Multiple logistic regression analysis retained the interaction term between HDL-C (in milligrams per deciliter) and CETP (in micrograms per milliliter), but not HDL-C or CETP itself, as inversely associated with vascular disease in the entire patient group. In patients with HDL-C levels at the median value or greater, CETP had an independent odds ratio of 0.31 (95% confidence interval, 0.1 to 0.97; P < 0.05) after adjusting for age. These results suggest that CETP may serve as a protective factor against vascular disease in hemodialysis patients, especially those with normal or elevated HDL-C concentrations.
Adult↗
[A study on relation between active pulmonary tuberculosis and underlying diseases].
A study was made on the relation between active pulmonary tuberculosis and underlying diseases in 119 tuberculosis patients. Out of total 119 patients, 87 patients (73.1%) had underlying diseases. The most common underlying disease was diabetes mellitus in 34 patients (39.1%), followed by HCV (+) chronic hepatitis, sequela of cerebral infarction, hypertension and gastric ulcer. In patients who had underlying diseases, the mean age was higher, proportion of sputum smear positive cases was higher, albumin was lower, and period until sputum culture negative conversion was longer. In patients who had diabetes mellitus, proportion of cases with cavity on chest X-P was higher, and in patients who had sequela of cerebral infarction or hypertension, mean age was higher. In patients who had diabetes mellitus and whose HbA1C was > or = 9%, proportion of smear positive cases was higher, albumin was lower and period until culture negative conversion was longer than in patients who had diabetes mellitus and whose HbA1c was < 9%, suggesting that control of blood sugar in diabetes mellitus related to severity of pulmonary tuberculosis. In patients who had diabetes mellitus and whose albumin was < 3 g/dl, period until culture negative conversion was longer than in patients who had diabetes mellitus and whose albumin was > or = 3 g/dl. In patients who had underlying diseases, these diseases caused decline of tuberculous immunity and nutritional disturbance represented by lower albumin also promoted decline of tuberculous immunity. It is suggested that the underlying diseases affected the onset and progression of pulmonary tuberculosis.
Adult↗
Comparative analyses of megakaryocytes derived from cord blood and bone marrow.
Thrombocytopenia is typically observed in patients undergoing cord blood transplantation. We hypothesized that delayed recovery of the platelet count might be caused by defects in the megakaryocytic differentiation pathway of cord blood progenitors. To test this hypothesis, we compared the features of in vitro megakaryocytopoiesis between cord blood progenitors and those in bone marrow cells after isolation of CD34+ cells as progenitors. The proliferative responses of the progenitors in cord blood are higher than those in bone marrow cells in the presence of interleukin (IL)-3, stem cell factor (SCF) and thrombopoietin (TPO). However, the ability to generate mature megakaryocytes was higher in bone marrow progenitors than in cord blood in the same in vitro culture system, when examined by the expression of CD41, polyploidy and proplatelet formation. Furthermore, an earlier induction of c-mpl protein, a receptor for TPO, was observed in the progenitors from bone marrow than in those from cord blood in the presence of SCF and IL-3. Therefore, the ability to generate mature megakaryocytes in bone marrow progenitors is superior to that in cord blood, and the delayed engraftment of platelets after cord blood transplantation might be attributed to the features of cord blood megakaryocyte progenitors.
Antigens, CD34↗
A C677T mutation in the methylenetetrahydrofolate reductase gene modifies serum cysteine in dialysis patients.
Patients undergoing hemodialysis have impaired metabolism of such sulfur-containing amino acids as cysteine (Cys) and homocysteine (Hcy), which may lead to accelerated atherosclerosis. Considering that Cys is mainly synthesized from Hcy, a common C677T mutation in the methylenetetrahydrofolate reductase (MTHFR) gene may affect the serum total Cys (tCys) concentration, as well as total Hcy (tHcy) concentration, through reduced remethylation of Hcy to methionine, even in hemodialysis patients. To identify the independent determinants for the tCys concentration in dialysis patients, we determined MTHFR C/T genotypes and serum concentrations of tHcy, tCys, and vitamins as cofactors in 464 hemodialysis patients. Serum tCys concentration was positively associated with serum tHcy concentration and negatively associated with the MTHFR mutation, although the mutation correlated positively with serum tHcy concentration. Slopes of regression lines relating tHcy and tCys concentrations differed between the MTHFR genotypes, and the relationship was strengthened with a decreasing number of T alleles. Additionally, serum concentrations of folate and vitamin B(12) correlated positively with tCys concentration, whereas they correlated negatively with tHcy concentration. These findings suggest that the MTHFR mutation is an independent predictor for serum tCys concentrations in hemodialysis patients and that a tCys-decreasing effect of the mutation may arise largely from its attenuation of the positive Cys-Hcy correlation. The tCys-increasing effect of folate and vitamin B(12) appears to be linked to their enhancement of Hcy remethylation.
Adult↗
LHRH analogue and growth hormone did not improve the final height of a patient with juvenile hypothyroidism accompanied by precocious puberty.
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Body Height↗
Acute intermittent porphyria associated with transient elevation of transaminases during an acute attack.
A 44-year-old woman with acute intermittent porphyria (AIP) was admitted to Kudanzaka Hospital because of abdominal pain. A cholecystectomy was performed in another hospital without improvement. On admission, her transaminases were elevated to greater than 1,000 mU/ml. After an intravenous drip of mainly glucose, her transaminases returned to normal. Her acute attacks occurred during stress, and she died of respiratory failure after repetitive acute episodes. AIP should be included in a list of the differential diagnosis of gastrointestinal diseases, neurosis, and hysteria. This is the first case of AIP accompanied by transient marked elevation of transaminases during an acute attack.
Adult↗
Nephrotic syndrome due to focal glomerulosclerosis and undifferentiated carcinoma.
In neoplastic disorder-related nephrotic syndrome, focal glomerulosclerosis (FGS) has been reported mainly in hematological disorders like minimal change nephrotic syndrome (MCNS) in association with presumed T lymphocyte dysfunction. The association of FGS with cancer or solid tumor is rare. We report a case of nephrotic syndrome due to FGS in a patient with undifferentiated adenocarcinoma of the cystic duct. Although the underlying mechanism is unclear, the development of FGS seemed to be related to the poor histological differentiation of the cancer in the possibility of production of an active peptide.
Adenocarcinoma↗
HGF activates signal transduction from EPO receptor on human cord blood CD34+/CD45+ cells.
Hepatocyte growth factor (HGF) is a multifunctional cytokine with early hematopoiesis-stimulatory activity. Here, we focus on its erythropoiesis-stimulatory effect on highly purified human hematopoietic progenitor cells (CD34+/CD45+ cells) derived from the cord blood. In immunoblot analyses, c-met protein (a receptor of HGF) was detected in the CD34+/CD45+ cells, although the expression levels were different among samples. The c-met expression was facilitated by incubation of the cells with stem cell factor (SCF) or interleukin 3 (IL-3), even if the expression level had been low. IL-6, G-CSF, or erythropoietin (EPO) did not show such a stimulatory effect on the c-met expression of the cells. When HGF was added to the CD34+/CD45+ cells in the presence of SCF, the numbers of CD36+/CD11b- cells (very early erythroid lineage cells) and BFU-E increased. EPO-dependent tyrosine phosphorylation of Stat 5 also increased, but the EPO receptor (EPO-R) expression remained unchanged in the CD34+/CD45+ cells treated with SCF + HGF. Our present study suggests that stimulation of the HGF/c-met signal is concomitant with induction of c-met protein by SCF. The subsequent enhancement of signal transduction via the activation of Stat 5 from the EPO-R plays a crucial role in the commitment of hematopoietic stem cells into erythroid lineage cells.
Antigens, CD34↗
A common mutation of cholesteryl ester transfer protein gene in dialysis patients.
BACKGROUND: In patients on maintenance hemodialysis, a decreased concentration of high-density lipoprotein cholesterol (HDL-C) is an apparent independent risk factor for vascular disease (VD). A common missense mutation of cholesteryl ester transfer protein (CETP) gene, D442G (Asp442 to Gly), increases HDL-C levels, but the mutation may also diminish the activity of reverse cholesterol transport. METHODS: We compared the genotype distribution of the D442G polymorphism and postprandial serum lipid levels between patients with and without VD in 414 hemodialysis patients. RESULTS: Serum levels of total cholesterol and HDL-C did not differ in patients with the mutation [group M (+)] and without the mutation [group M (-)] and in patients with and without VD. However, patients with below median HDL-C levels (< 45 mg/dl) had a significantly higher prevalence of VD than those with above median HDL levels (26.0 vs. 15.2%, P < 0.01). Moreover, in this low-HDL-C subgroup, group M (+) patients had a significantly higher prevalence of VD than group M (-) patients (54.5 vs. 24.4%, P < 0.05). In the subgroup, group M (+) patients with VD had higher levels of total cholesterol and a higher atherogenic index than those without VD, whereas group M (-) patients with VD had lower levels of total cholesterol and a lower atherogenic index than those without VD. CONCLUSIONS: The D442G mutation may be a risk factor for atherosclerotic complications in dialysis patients with HDL-C levels below 45 mg/dl. Atherogenic lipid profiles may promote atherosclerosis in the patients with the mutation, but not in those with no mutation.
Adult↗
Significance of serum pepsinogens and their relationship to Helicobacter pylori infection and histological gastritis in dialysis patients.
BACKGROUND: Previous investigations reported that patients undergoing dialysis therapy had significantly higher serum pepsinogen (PG) levels than patients with normal renal function. However, in dialysis patients, the relationship between serum PG levels and Helicobacter pylori infection remains unknown. METHODS: Sixty three maintenance dialysis patients (54 haemodialysis and nine continuous ambulatory peritoneal dialysis) who required endoscopic examination were enrolled in the study. Sixty four age- and sex-matched patients with normal renal function served as controls. We performed endoscopic examination and obtained both the gastric antral and corpus mucosa for histopathological evaluation and H. pylori identification. Twenty three patients on dialysis underwent H. pylori eradication therapy. RESULTS: In dialysis patients, H. pylori-positives had significantly higher serum PG II levels than H. pylori-negatives (26.6+/-21.5 vs 14.1+/-7.1 ng/ml, P<0.05), but no significant difference was found in serum PG I between H. pylori-positives and H. pylori-negatives (228.8+/-158.5 vs 179. 4+/-113.5 ng/ml). There was no significant difference in serum PG II between dialysis patients and controls (19.9+/-16.5 vs 18.6+/-14.9 ng/ml), while serum PG I levels were significantly higher in dialysis patients than in controls (201.7+/-136.8 vs 77.6+/-85.8 ng/ml, P<0.05). Serum PG II levels, but not those of PG I, significantly correlated with the inflammation and activity scores of antrum in dialysis patients, and these scores were highly influenced by H. pylori infection. Dialysis patients in whom H. pylori was eradicated successfully showed significant reductions of serum PG II levels but not of PG I. CONCLUSIONS: In dialysis patients, high serum levels of PG II, but not PG I, are significantly related to H. pylori infection and mucosal inflammation. A significant decrease in serum PG II levels could be used as a predictor of the eradication of H. pylori infection in dialysis patients.
Aged↗
LDL apheresis as intensive lipid-lowering therapy for cholesterol embolism.
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Aged↗
A cholesteryl ester transfer protein gene mutation and vascular disease in dialysis patients.
Among patients undergoing maintenance hemodialysis, a decreased high-density lipoprotein cholesterol (HDL-C) concentration is among the most common abnormalities of lipid metabolism and apparently is an independent risk factor for vascular disease. A common missense mutation of cholesteryl ester transfer protein gene, D442G (Asp 442 to Gly), increases HDL-C levels through the reduced activity of cholesteryl ester transfer from HDL to VLDL, but the mutation also may lead to reduced activity of reverse cholesterol transport. To investigate the effect of the D442G polymorphism on atherosclerotic complications in dialysis patients, the genotype and allele frequency of the polymorphism were determined in 414 unselected dialysis patients and 220 control subjects, and postprandial serum lipid levels were measured in the dialysis patients. A similar genotype distribution was found between hemodialysis patients and healthy control subjects, and in dialysis patients with and without vascular disease. Serum levels of total cholesterol and HDL-C did not differ between patients with and without the mutation and in patients with and without vascular disease. However, patients with sub-median HDL-C levels (<45 mg/dl) had an independent odds ratio of 1.8 for vascular disease (95% confidence interval, 1.04 to 3.2; P < 0.05). In this low-HDL-C subgroup, patients with the D442G mutation had a significantly higher prevalence of vascular disease than those with no mutation (54.5% versus 24.4%; P < 0.05), and an independent odds ratio of 4.9 (95% confidence interval, 1.05 to 22.65; P < 0.05). In conclusion, the D442G mutation is an independent risk factor for atherosclerotic complications in dialysis patients with HDL-C levels below 45 mg/dl.
Adolescent↗
A clinicopathological study of lung cancer patients with occupational exposure to chrysotile asbestos fibers.
OBJECTIVE: To summarize the features of asbestos-related lung cancer. PATIENTS: Thirty-one lung cancer patients with occupational exposure to chrysotile asbestos fibers. They worked or had worked in one asbestos factory or its subcontracters. RESULT: All patients were male with mean age of 60.6 when diagnosed, and all except one were current or ex-'heavy' smokers. Histological types were fairly evenly divided into adeno-, squamous and small cell carcinoma and 24 (78%) of patients showed 'peripheral type' lung cancers. Regarding clinical stages, 20 patients (65%) were classified as III or IV (advanced stage). Tumor shadow(s) was detected on chest X-ray in 22 patients (71%), and in 5 patients with 'negative' chest X-ray, chest CT was necessary to recognize a primary tumor. Seventeen patients (55%) did not undergo periodical check-ups. CONCLUSION: Occupational asbestos exposure is interpreted as one of the important risks for lung cancer and frequent and accurate observation is necessary.
Adult↗
Effects of insulin and insulin-like growth factor-1 on intracellular magnesium of platelets.
Magnesium (Mg2+), the second most abundant intracellular cation, is a critical cofactor in numerous enzymatic reactions. After stimulation of platelets with insulin and insulin-like growth factor-1 (IGF-1), we examined changes in cytosolic free Mg2+ ([Mg2+]i) by using fluorescent probe magfura-2. Basal [Mg2+]i in platelets was 614 +/- 1 microM (mean +/- SEM, n = 60). Insulin and IGF-1 induced an immediate rise of [Mg2+]i in a dose-dependent manner. After stimulation of platelets with 100 microU/mL of insulin for 60 s, [Mg2+]i was significantly elevated to 1270 +/- 53 microM (n = 30, P < 0.05), i.e., 82 +/- 5% over resting [Mg2+]i. IGF-1 (5 micrograms/mL) also increased [Mg2+]i (1020 +/- 53 microM, 69 +/- 10% over resting [Mg2+]i, n = 30). In the medium containing choline instead of sodium or the medium without potassium, an elevation of [Mg2+]i with addition of insulin/IGF-1 was moderately suppressed. Amiloride, a Na+-H+ antiport inhibitor, did not block the insulin/IGF-1 effect. Insulin/ IGF-1 translocates Mg2+ from the extracellular space to intracellular space and these effects are affected by external sodium and potassium.
Amiloride↗
Polymorphisms of angiotensin converting enzyme and plasminogen activator inhibitor-1 genes in diabetes and macroangiopathy1.
BACKGROUND: An insertion or deletion (I/D) polymorphism in the angiotensin converting enzyme (ACE) gene and a 4/5-guanine tract polymorphism (4G/5G) in the promoter region of the plasminogen activator inhibitor-1 (PAI-1) gene are associated with the plasma activities of these substances and with coronary heart disease. In smooth muscle cells and mesangial cells, the angiotensin II synthesized by ACE increases mRNA expression and the activity of PAI-1, which promotes antifibrinolysis and the accumulation of extracellular matrix. Therefore, ACE and PAI-1 polymorphisms may have a synergistic effect on diabetic nephropathy and macroangiopathy. METHODS: Using multivariate logistic regression analyses, we investigated the independent or synergistic effects of the ACE I/D and PAI-1 4G/5G polymorphisms on the development of diabetic nephropathy and macroangiopathy in 208 patients with non-insulin dependent diabetes mellitus (NIDDM) over a 15 year period. RESULTS: Advanced diabetic nephropathy, defined as impaired renal function and diabetic retinopathy, was present in 98 patients. Manifest macrovascular diseases, confirmed by both clinical signs and physical and laboratory examinations, were present in 56 patients. There was no significant difference in the genotype distribution of ACE or PAI-1 polymorphisms between subjects with advanced nephropathy and those with normal renal function. There was no significant difference in the renal survival rate between patients with differing ACE or PAI-1 genotypes. Subjects with macroangiopathy had a higher frequency of the DD genotype than those without macroangiopathy. Subjects with both DD and 4G4G genotypes had a higher incidence of macroangiopathy than those with any other pair of genotypes. Multivariate logistic regression analysis showed that there was no association between ACE or PAI-1 polymorphisms and diabetic nephropathy. The ACE DD genotype and its interaction with the PAI-1 4G4G genotype and the presence of advanced diabetic nephropathy were positively associated with macrovascular disease. CONCLUSION: These results indicate that the ACE DD genotype and its interaction with the PAI-1 4G4G genotype are independent risk factors for macroangiopathy, but not for the progression of diabetic nephropathy in NIDDM patients, and that the genotyping of PAI-1 and ACE polymorphisms, especially in patients with advanced diabetic nephropathy, may be useful for predicting and preventing macroangiopathy-related events.
Adult↗
Apolipoprotein E4 reduces risk of diabetic nephropathy in patients with NIDDM.
Hypercholesterolemia is a major determinant of the decline of renal function in patients with diabetes. Apolipoprotein E polymorphism may influence the metabolism of lipoprotein in diabetic patients. The purpose of this study was to investigate the association between genetic polymorphisms in apolipoprotein E and the progression of diabetic nephropathy in patients with non-insulin-dependent diabetes mellitus over a 10-year period (13 to 37 years; median, 20 years). Subjects with a stable renal function without overt proteinuria had a higher cholesterol level, lower incidences of hypertension and proliferative diabetic retinopathy, and a higher frequency of the E4 allele than subjects with a decline in renal function (end-stage renal failure requiring dialysis treatment). In the diabetic patients, the apolipoprotein E4 carriers had a higher cholesterol level than did the noncarriers. The survival rate from renal disease in the apolipoprotein E4 carriers was higher than in the noncarriers among the diabetic patients. Apolipoprotein E polymorphism and hypertension were identified as independent risk factors for the progression to renal failure. Results indicate that apolipoprotein E polymorphism is associated with the progression of diabetic nephropathy. Presence of the apolipoprotein E4 allele is a protective factor, and other alleles are risk factors.
Adult↗