Effect of anhydrous betaine and hydrochloride betaine on growth performance, meat quality, postmortem glycolysis, and antioxidant capacity of broilers.

This study was conducted to investigate the effect of anhydrous betaine and hydrochloride betaine on growth performance, meat quality, relaxometry, postmortem glycolysis, and antioxidant capacity of partridge shank broiler chickens. A total of 400 one-day-old male broilers were randomly divided into 5 treatments and fed basal diets supplemented with 0 (control), 500 (L-AB) or 1,000 (H-AB) mg/kg anhydrous betaine, and 642.23 (L-HB) or 1,284.46 (H-HB) mg/kg hydrochloride betaine, respectively. Compared with the control group, anhydrous betaine supplementation significantly increased (P < 0.05) average daily gain and decreased (P < 0.05) drip loss24h in breast and thigh muscles of broilers. The H-AB group further increased (P < 0.05) breast muscle yield, pH24h, immobile water proportion (P21), the contents of crude protein and glutathione (GSH), the activities of creatine kinase (CK) and glutathione peroxidase (GPX), the mRNA expressions of glucose transporter 4 (GLUT4), protein kinase AMP-activated non-catalytic subunit gamma 3 (PRKAG3), nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase 1 (HO-1) in breast muscle, and a*45min, GLUT4 mRNA expression in thigh muscle, and decreased (P < 0.05) drip loss48h, free water proportion (P22), the contents of lactate and malondialdehyde (MDA) in breast muscle. Moreover, the H-HB group significantly increased (P < 0.05) pH24h, P21 proportion, the activities of CK, total antioxidant capacity (T-AOC), total superoxide dismutase (T-SOD), and GPX, the content of GSH, the mRNA levels of Nrf2, HO-1, GPX, and γ-glutamate-cysteine ligase catalytic subunit (γ-GCLc) in breast muscle, and the activity and mRNA expression of GPX in thigh muscle, and decreased (P < 0.05) drip loss24h, P22 proportion in breast muscle, and MDA content in breast and thigh muscles. In conclusion, anhydrous betaine showed better effects than hydrochloride betaine in improving growth performance and breast muscle yield of broilers. Moreover, anhydrous betaine (1,000 mg/kg) or equimolar hydrochloride betaine supplementation could improve meat quality by decreasing drip loss, free water proportion, and lactate content, and enhancing muscle antioxidant capacity.

Effects of dietary betaine supplementation on growth performance, meat quality, muscle fatty acid composition and antioxidant ability in slow-growing broiler chickens.

1. This study investigated the effects of dietary betaine supplementation on growth performance, meat quality, muscle fatty acid composition and antioxidant ability in slow-growing broiler chickens.2. In total, 400, one-day-old female Xueshan broiler chicks were randomly divided into five groups with eight replicates of ten chickens each for 102 d. Broilers were fed a basal diet supplemented with 0, 125, 250, 500 or 1,000 mg/kg betaine.3. Broilers fed betaine had better feed conversion efficiency and weight gain (P < 0.05) and increased meat redness and yellowness 24 h after slaughter. Supplementation linearly decreased cooking loss and drip loss from breast muscle (P < 0.05). Muscular resilience was improved and tenderness increased (P < 0.05). Intra-muscular saturated fatty acids decreased, while total monounsaturated fatty acids and polyunsaturated fatty acids increased (P < 0.05). Betaine increased activities of glutathione peroxidase (GPx) and total superoxide dismutase (SOD), glutathione (GSH) level, ratio of reduced glutathione/oxidised glutathione, and activity of scavenging hydroxyl radicals. It increased the activity of total antioxidant capacity (T-AOC) in the breast muscle (P < 0.05). Moreover, supplementation up-regulated (P < 0.05) mRNA expression levels of blood and antioxidant markers.4. In conclusion, 1000 mg/kg betaine can be recommended as a supplement for slow-growing, Xueshan chicken.

[Frequency characteristics of horizontal semicircular canals damage and the ultrastructure analysis of crista ampullaris in patients with Meniere's disease].

Objective: To investigate the frequency characteristics and the pathological characteristics of the horizontal crista ampullaris in patients with Meniere's disease,and to analyse its structural basis. Methods: Between March, 2019 and November, 2019, seventy-two patients diagnosed as Meniere's disease (27 males and 45 females, aged from 13 to 74 years, with a course of disease ranging from 4 months to 32 years)in Shandong Provincial ENT Hospital were included.Caloric test, sinusoidal harmonic acceleration test (SHA), video-head impulse test (v-HIT), Gadolinium-enhanced inner-ear 3D-FLAIR MRI and pure tone audiometry were conducted in the patients. The function of the horizontal semicircular canal in these patients were analysed as well as its relationship with the degree of endolymphatic hydrops,clinical stage and duration. Light microscopy and transmission electron microscopy were used to observe the ultrastructure of horizontal semicircular canal crista ampullaris from six patients with refractory Meniere's disease who underwent labyrinthectomy. The number of type Ⅰ and type Ⅱ vestibular hair cells, the common pathophysiological changes of horizontal semicircular canal crista ampullaris were investigated in these patients. Statistical analysis was performed using SPSS 19.0. Results: With the increase of detection frequency, the abnormal rate decreased gradually. The abnormal rate of caloric test was 69.4% (50/72), SHA 51.4% (37/72), V-HIT 36.1% (26/72), comparation of the positive rate among the three tests showed statistically significant differences(P<0.05).Neither caloric test nor SHA had correlation with the degree of hydrops(P>0.05), but v-HIT(r=0.434,P<0.01).There was correlation with clinical stage to SHA and v-HIT(r=0.338,0.462,P<0.01), except caloric test(P>0.05).No significant relation was found with caloric test, SHA, v-HIT and course of disease(P>0.05).Morphological observation found abnormal monolayer epithelialization of the horizontal semicircular canal crista ampullaris significantly decreased number of type Ⅱ hair cells compared with type Ⅰhair cells. Hair cells showed perinuclear vacuolization, cytoplasmic vacuoles, mitochondrial electron density increasement and loss of stereocilia. Conclusions: The horizontal semicircular canal damage in the patients with Meniere's disease has a frequency-dependent characteristic, mainly occurres in low frequency area. With progress of the disease, the high frequency area of ampulla will be impaired gradually, and it is related to the degree of endolymphatic hydrops and hearing level. Hair cell injury would be observed,the frequency characteristics may be more associated with the disorder of type Ⅱ hair cells.

miR-214 modulates cisplatin sensitivity of osteosarcoma cells through regulation of anaerobic glycolysis.

Osteosarcoma is the most frequent primary bone tumor originating from adolescents and young adults. Despite improvements in the chemo- or radio- therapy of osteosarcoma patients, survival rate has not increased and drug resistance becomes a major factor that limits the effectiveness. Therefore, investigation of new treatment modalities is urgently required to optimize therapeutic options. Our previous study described an oncogenic role of miR-214 through promotion of osteosarcoma cells proliferation. In this study, we report miR-214 contributes to cisplatin resistance in osteosarcoma cells. Overexpression of miR-214 decreased the cisplatin sensitivity. By establishing an osteosarcoma cisplatin resistant cell line, we find miR-214 is significantly upregulated in cisplatin resistant cells. Moreover, we show miR-214 promotes anaerobic glycolysis rates of osteosarcoma cells but suppresses mitochondrial oxidative phosphorylation. Consistently, cisplatin resistant cells exhibit upregulated glycolysis but decreased mitochondrial oxidative phosphorylation, a phenotype called "Warburg effect". Finally, we demonstrate inhibition of glycolysis by either glycolysis inhibitor or miR-214 inhibition significantly re-sensitizes cisplatin resistant osteosarcoma cells. In summary, this study illustrates a miRNA-involved chemosensitivity of osteosarcoma and will contribute to the developments of therapeutic agents for the anti-chemoresistance treatments.

Computationally inexpensive approach for pitch control of offshore wind turbine on barge floating platform.

Offshore floating wind turbine (OFWT) has gained increasing attention during the past decade because of the offshore high-quality wind power and complex load environment. The control system is a tradeoff between power tracking and fatigue load reduction in the above-rated wind speed area. In allusion to the external disturbances and uncertain system parameters of OFWT due to the proximity to load centers and strong wave coupling, this paper proposes a computationally inexpensive robust adaptive control approach with memory-based compensation for blade pitch control. The method is tested and compared with a baseline controller and a conventional individual blade pitch controller with the "NREL offshore 5 MW baseline wind turbine" being mounted on a barge platform run on FAST and Matlab/Simulink, operating in the above-rated condition. It is shown that the advanced control approach is not only robust to complex wind and wave disturbances but adaptive to varying and uncertain system parameters as well. The simulation results demonstrate that the proposed method performs better in reducing power fluctuations, fatigue loads and platform vibration as compared to the conventional individual blade pitch control.

Neurophysiological study on sensorimotor control mechanism in superior colliculus of echolocating bat.

This paper investigates the neural processes associated with bat sonar vocal production and their relationship with spatial orientation. The bat's heavy reliance on sound processing is reflected in specializations of auditory and motor neural structures. These specializations were utilized by investigating the mammalian superior colliculus (SC); a midbrain sensory motor nucleus mediating orientating behaviours in mammals, including vocal motor orientating. Behavioural and neurophysiological experiments were conducted in the insectivorous echolocating bat, Eptesicus fuscus. Chronic neural recording techniques were specifically developed to study neuronal activity. Potential application of the results on control systems is also addressed.

Nonselective cation current in rabbit ventricular myocytes.

Currents contributing repolarization in rabbit ventricular myocytes are very complex because the I(to.s) covers almost the whole repolarization phase of the action potential. The other components of repolarizing currents, such as I(Kr) and I(Ks), are small. In the present work, with whole-cell patch-clamp technique, a clear evidence was provided for the existence of a hitherto unreported, voltage-dependent, nonselective cation current (NSCC) in rabbit ventricular myocytes. Na(+), K(+), and Cs(+) can permeate through the nonselective cation channel and the NSCC can be blocked by Gd(3+). The channels are sensitive to Ca(2+), Mg(2+)-free, and insulin in bathing solution. Activation of NSCC may provide complex effects on action potential configuration depending on the basal conditions and the experimental situations. Considering the voltage dependence and rapid activation kinetics of this current, we speculate that this current can provide an important influence on all repolarization phases of the action potential as well as contribute to the resting membrane potential in rabbit ventricular myocytes. In addition, it is conceivable that, under certain pathophysiological conditions (e.g., ischemia or excessive mechanical stress), the sensitivity of the channels could be altered in such a way that the conductance opens even in the presence of physiological Ca(2+), Mg(2+), and insulin. It might be an important factor on the repolarization of the action potential. Changes in NSCC may lead to an induction or inhibition of arrhythmia.

Insulin sensitivity in physically fit and unfit children of parents with Type 2 diabetes.

AIMS: First-degree relatives of patients with Type 2 diabetes mellitus (T2DM) are often reported to be insulin resistant. We wanted to identify early metabolic abnormalities in this condition, and determine whether they are altered by regular physical training. METHODS: We measured insulin sensitivity using the euglycaemic glucose clamp technique and insulin response to oral glucose in 10 unfit (did not participate in routine physical exercise) offspring of T2DM parents and 10 unfit control subjects, and compared them with six fit (routinely swam for 3 h/day 5 days/week) offspring of T2DM parents and six fit controls with no family history of T2DM. RESULTS: Unfit offspring had a higher plasma glucose response than the other three groups. The mean area under the glucose curve was also significantly higher in unfit offspring than in the other three groups (12.6 +/- 0.6 vs. 10.4 +/- 0.4, 9.6 +/- 0.5, and 9.5 +/- 0.7 mmol/l per hour for the unfit controls, fit offspring and fit controls, respectively; P < 0.05). The corresponding insulin response of unfit offspring was significantly higher at 60 min in the oral glucose tolerance test (OGTT) that that of fit offspring or fit controls. In addition, the mean area under the insulin curve was significantly greater in unfit offspring than in either fit offspring or fit controls (868 +/- 172 vs. 294 +/- 71, 287 +/- 43 mmol/l per hour, respectively; P < 0.05). Moreover, the glucose disposal rate (GDR), measured using a euglycaemic clamp, was significantly lower in unfit and fit offspring than in unfit and fit controls (5.6 +/- 0.3 vs. 8.6 +/- 0.3 mg/kg per minute; P < 0.01 and 9.3 +/- 0.9 vs. 12.1 +/- 0.8 mg/kg per minute, respectively; P < 0.015), whereas the GDR was similar in unfit controls and fit offspring (8.6 +/- 0.4 vs. 9.3 +/- 0.9 mg/kg per minute; P > 0.05). CONCLUSION: These results support the concept that early metabolic abnormalities, as reflected by a decreased GDR (insulin sensitivity) in the offspring of T2DM patients, may be improved by increased physical fitness.

Therapeutic effect of recombinant human erythropoietin on anaemia with erythropoietin deficiency in diabetic patients.

AIMS: The aim of this study was to investigate the therapeutic effect of recombinant human erythropoietin (rHuEpo) on anaemia with erythropoietin deficiency in diabetic patients. METHODS: Twenty diabetic patients with anaemia and Epo deficiency were enrolled. All patients were treated with rHuEpo (Epokine; 4000 U/day s.c., three times a week) for 8 weeks. RESULTS: The responder group (n = 14) had significant increments in haemoglobin compared with the non-responder group (n = 6) (P < 0.05). No significant differences were found between the responder and non-responder groups in terms of duration of diabetes mellitus, serum creatinine level, 24-h urine albumin excretion rates, frequency of diabetic microangiopathy, or HbA1c. There was no difference between the two groups in terms of serum iron and total iron-binding capacity (TIBC). Serum ferritin level was significantly higher in the responder group than in the non-responder group (240.3 +/- 108.4, 25.8 +/- 3.0 micro g/l, P < 0.05), as was transferrin saturation (32.7 +/- 7.9%, 21.2 +/- 5.3%, P < 0.05). CONCLUSIONS: rHuEpo could be useful in the treatment of anaemia with erythropoietin deficiency in diabetic patients, and the degree of iron storage and functional iron deficiency might be the main cause of hyporesponsiveness to rHuEpo.

Clinical characteristics, GAD antibody (GADA) and change of C-peptide in Korean young age of onset diabetic patients.

AIMS: To investigate the association of clinical and immunological markers with diabetes classification in newly diagnosed young diabetic patients at disease onset. METHODS: Eighty-two diabetic patients recruited within 1 year of onset (mean age 23.0 +/- 7.1, M:F = 46:36) were divided into three groups, namely: a low fasting C-peptide (FC) level at baseline group (the low FC group (n = 14, FC < 0.18 nmol/l)), an intermediate FC group (n = 29, 0.18 nmol/l < or = FC < 0.37 nmol/l), and a high FC group (n = 39, 0.37 nmol/l < or = FC). Patients were reclassified at follow-up (mean follow-up period 3.7 +/- 1.4 years) in the same manner as described above into low FC group (n = 31), intermediate FC group (n = 20), and high FC group (n = 31). The clinical characteristics and prevalence of GADA were compared. RESULTS: Patients in the high FC group at baseline had a higher body mass index (BMI), a higher frequency of a family history of diabetes, a higher meal-stimulated C-peptide increment, a lower frequency of ketonuria, a lower frequency of history of diabetic ketoacidosis, and a lower frequency of insulin therapy at diagnosis than those in the low and intermediate FC groups at baseline. Insulin secretory capacity, which was represented by fasting C-peptide, was affected by BMI at diagnosis and the presence of GADA. All the patients of the low FC group on follow-up were finally classified as having Type 1 diabetes; moreover, the factors that determined the type of diabetes were lower BMI at onset, GADA positivity, insulin therapy, lower fasting C-peptide level and lower meal-stimulated C-peptide increment at initial admission. CONCLUSIONS: Our study suggests that follow-up involving C-peptide and GADA measurements in combination with clinical characteristics is useful for discriminating between the types of diabetes in these groups.

(AC)(n) polymorphism of aldose reductase gene and diabetic microvascular complications in type 2 diabetes mellitus.

Recent studies suggest that the gene encoding aldose reductase, the enzyme that converts glucose to sorbitol, may confer susceptibility to microvascular disease. The aim of this study therefore, was to investigate the relationship between the aldose reductase gene and type 2 diabetic microvascular complications such as diabetic nephropathy and retinopathy. DNA from 127 Korean patients with type 2 diabetes was typed for an (AC)(n) dinucleotide repeat polymorphic marker at the 5'-end of the aldose reductase gene using polymerase chain reaction. No significant difference in the frequency of the putative risk allele Z-2 was found in patients of nephropathy and retinopathy groups compared with the uncomplicated group (32.2, 34.1 vs. 25.1%, respectively, P>0.05). Similarly, no difference was found in the frequency of the putative protective allele Z+2 among any of the study groups. In conclusion, the results of the study in Korean type 2 diabetic patients do not support the hypothesis that polymorphism at the 5' end of the aldose reductase gene contributes to the susceptibility to diabetic microvascular complications.

Polycystic ovarian syndrome (PCOS) and insulin resistance.

OBJECTIVES: Polycystic ovary syndrome (PCOS) presents a high risk of developing type 2 diabetes mellitus. We studied a group of women with PCOS and evaluated this defect in insulin action. METHODS: The study population consisted of nine PCOS women, six obese type 2 diabetic patients, and five controls whose body mass index (BMI) was similar to that of the nine PCOS women. The 75-g oral glucose tolerance test (OGTT) and the hyperinsulinemic euglycemic glucose clamp test were performed. Clinical characteristics and the metabolic profiles, including the insulin sensitivity index (ISI), were compared. RESULTS: PCOS women showed significantly elevated insulin responses during OGTT, but their blood glucose levels were comparable with the controls. The subjects with PCOS had more insulin resistance than the other groups. There was no difference among the groups in terms of clinical characteristics and metabolic profiles, except age, luteinzing hormone (LH), testosterone, and sex hormone binding globulin (SHBG). CONCLUSION: We conclude that PCOS women have significant insulin resistance which is independent of adiposity.

Low-dose growth hormone treatment combined with diet restriction decreases insulin resistance by reducing visceral fat and increasing muscle mass in obese type 2 diabetic patients.

OBJECTIVE: To evaluate the effects of low-dose growth hormone (GH) therapy combined with diet restriction on changes in body composition and the consequent change in insulin resistance in newly-diagnosed obese type 2 diabetic patients. DESIGN: Double-blind and placebo-controlled trial of 25-kcal/kg IBW diet daily with GH (n=9; rhGH, 0.15 IU/kg body weight/week) or placebo (n=9) for 12 weeks. SUBJECTS: Eighteen newly-diagnosed obese type 2 diabetic patients (age 42--56 y, body mass index 28.1+/-2.7 kg/m(2)). MEASUREMENTS: Body composition and fat distribution parameters (by bioelectrical impedance analyzer and CT scans), serum IGF-1; serum glucose, insulin and free fatty acid (FFA) during oral glucose tolerance test (OGTT); HbA(1c); serum lipid profiles; and glucose disposal rate (GDR) by euglycemic hyperinsulinemic clamp at baseline and after treatment. RESULTS: The fraction of body weight lost as fat lost was significantly greater (0.98+/-0.39 vs 0.52+/-0.32 kg/kg, P<0.05) and visceral fat area was decreased more in the GH-treated group compared to the placebo-treated group (27.9 vs 21.6%, P<0.05). Lean body mass and muscle area were reduced in the placebo-treated group, whereas an increase in both was observed in the GH-treated group. GDR the was significantly increased in only the GH-treated group (4.67+/-1.05 vs 6.95+/-0.91 mg/kg/min, P<0.05). The GH-induced increase in GDR was positively correlated with the decrease in the ratio of visceral fat area/muscle area (r=0.588, P=0.001). Serum glucose levels and insulin- and FFA-area under the curve during OGTT and HbA(1c) were significantly decreased after GH treatment. LDL-cholesterol level was decreased in only the GH-treated group. CONCLUSION: Low-dose GH treatment combined with dietary restriction resulted not only in a decrease of visceral fat but also in an increase of muscle mass with a consequent improvement of the insulin resistance observed in obese type 2 diabetic patients.

beta-Cell dysfunction rather than insulin resistance is the main contributing factor for the development of postrenal transplantation diabetes mellitus.

BACKGROUND: Our study was undertaken to investigate the pathogenesis and possible risk factors for postrenal transplantation diabetes mellitus (PTDM). METHODS: We recruited 114 patients with normal glucose tolerance (NGT) and performed both 75-g oral glucose tolerance tests (OGTT) and short insulin tolerance tests 1 week before and 9-12 months after transplantation. RESULTS: The subjects were classified into three groups by World Health Organization criteria on the basis of OGTT after transplantation: (a) 36 (31.6%) subjects with normal glucose tolerance; (b) 51 (45.7%) subjects with impaired glucose tolerance (IGT); and (c) 27 (23.7%) subjects with postrenal transplantation diabetes mellitus. Dosages of steroid and cyclosporine were equivalent among the three groups. Before transplantation, the fasting and 2-hr plasma glucose and proinsulin/insulin (PI/I) ratios were significantly higher in the IGT and PTDM groups than in the NGT group, but the insulin sensitivity index (ISI) was not significantly different among the three groups. In addition, the area under the curve-insulin on OGTT was significantly lower in the PTDM group than in the NGT group. After transplantation, however, the ISI was increased in all groups. Furthermore, the ISI and PI/I ratios revealed significantly higher values in the PTDM group than in the NGT group after transplantation. CONCLUSIONS: These results revealed that fasting and 2-hr plasma glucose levels, as well as the proinsulin/insulin ratio before transplantation, are both possible indicators of beta-cell dysfunction and may be predictors for the development of PTDM. Furthermore, beta-cell dysfunction, rather than insulin resistance, was proven to be the main factor for the pathogenesis of PTDM.

Decrease in carotid intima media thickness after 1 year of cilostazol treatment in patients with type 2 diabetes mellitus.

A multicenter exploratory study at three university hospitals was performed to evaluate the effect of oral cilostazol on intima media thickness (IMT) in diabetic patients. A total of 141 patients was recruited in this study and randomized into a cilostazol group and a placebo (control) group. One hundred and twenty patients completed the study (i.e. 60 on cilostazol and 60 on placebo). Biochemical profiles and the IMT of the common carotid artery (CCA) determined by high-resolution B-mode ultrasonography were measured at 0, 6, and 12 months after the oral administration of 100--200 mg of cilostazol or placebo (i.e. two or four times daily for 12 months). Clinical and biochemical characteristics, the treatment modality, and microvascular diabetic complications after randomization were not significantly different between the two groups after the study. In the cilostazol treatment group, left CCA average IMT significantly decreased from 0.94+/-0.03 to 0.91+/-0.02 mm at 6 months (P<0.05), and thereafter increased to 0.92+/-0.01 mm (P>0.05) at 12 months, whereas in the control group, it increased from 0.92+/-0.03 to 0.93+/-0.01 mm at 6 months (P>0.05), and to 0.94+/-0.01 mm at 12 months (P>0.05). As for the right CCA average IMT, it decreased from 0.83+/-0.03 to 0.82+/-0.01 mm at 6 months (P<0.05), and to 0.81+/-0.01 mm at 12 months (P<0.05) in the cilostazol group, whereas it increased from 0.87+/-0.03 to 0.89+/-0.01 mm at 6 months (P<0.05), and to 0.90+/-0.01 mm at 12 months (P<0.05) in the control group (P<0.05). After correction for risk factors such as blood pressure, smoking, and lipid profiles, there were significant changes in left and right CCA average IMT for both groups (P<0.05). Left and right CCA average IMT was significantly different between the two groups (P<0.05). After making statistical corrections for blood pressure, smoking, and lipid profiles, the differences between these two groups remained significant (P<0.05). Meanwhile, there were no differences between the groups in the change of risk factors such as BMI, blood pressure, blood sugar, HbA(1c), and lipid profiles. Generally, cilostazol was well tolerated and the most common side effect in the cilostazol group was headache (12/60), mostly early in the treatment regimen. The results suggest that oral cilostazol may be helpful in the treatment of atherosclerosis in type 2 diabetic patients, although conventional cardiovascular risk factors remained unmodified.

Mutation in hepatocyte nuclear factor-1alpha is not a common cause of MODY and early-onset type 2 diabetes in Korea.

Maturity-onset diabetes of the young (MODY)-3 with a mutation in hepatocyte nuclear factor (HNF)-1alpha has been identified in most races, but the prevalence of Korean MODY and early-onset type 2 diabetes with a mutation in this gene is unknown. To determine the prevalence of MODY and early-onset type 2 diabetes with the mutation of HNF-1alpha gene in Korea, we analyzed this gene in 69 Korean early-onset type 2 diabetics and in 35 healthy persons using the single-strand conformation polymorphism (SSCP) technique and direct sequencing. We identified one mutation in exon 4 (C900A) in only one of the 69 Korean subjects with early-onset type 2 diabetes; this mutation was silent and did not change the amino acid (Pro300). Additionally, we identified four polymorphisms: S487N, AAC-->AGC, intron 2 (nt -23), intron 7: (nt +7) and intron 9 (nt -24). However, there was no significant difference in frequencies of the four polymorphisms between the type 2 diabetes and control groups. Among type 2 diabetics, codon 487 variant showed no relationship to age at onset, body mass index, fasting blood glucose, HbA1c, lipid profile, basal C-peptide and 2 hour C-peptide. We concluded that this genetic mutation in HNF-1alpha gene may not be a common contributor to MODY and early-onset type 2 diabetes susceptibility in Korea.

Identification of glucokinase mutation in subjects with post-renal transplantation diabetes mellitus.

Mutations in the glucokinase (GCK) gene are considered to be a possible cause of maturity-onset diabetes of the young. The purpose of this study was to evaluate the contribution of this gene to the development of post-renal transplantation diabetes mellitus (PTDM). Identification of the GCK mutation was attempted in 58 selected renal allograft recipients with PTDM and 45 normal controls. The exons in the GCK gene were examined using polymerase chain reaction (PCR), followed by an analysis of single-stranded DNA conformational polymorphism (SSCP). The abnormal bands were then confirmed by DNA sequencing analysis. The family members of the patients affected with GCK mutation were also examined. Two of the 58 PTDM patients (3. 4%) were found to have GCK mutations. One had the mutation on exon 5 and the other on intron 7. One control subject had the mutation on intron 9. The mutation on exon 5 was identified as a substitution of CCT (proline) for CTT (leucine) at codon 164, which has never been reported before. The family members of the PTDM patient with a mutation on exon 5 were analyzed by PCR, followed by SSCP, and two of them had the same mutation. The abnormal band seen on SSCP analysis of exon 7 was identified as the C-->T substitution at the 39th nucleotide in intron 7. Two of the family members also displayed the same bands on the SSCP. One of the 45 normal controls had a known polymorphism located at the 8th nucleotide in intron 9. We found a GCK mutation on the exon in subjects with PTDM and we speculate that this mutation may be one of the possible contributing factors of PTDM, although variations of the GCK gene are not common causes of PTDM.