Impulsive injections of glucose and insulin analogues are very important strategies for the control of diabetes mellitus. We mainly imitate diabetes patients take insulin before eating, and eating approximately as a p...Impulsive injections of glucose and insulin analogues are very important strategies for the control of diabetes mellitus. We mainly imitate diabetes patients take insulin before eating, and eating approximately as a pulse blood glucose injection, as a result, a new mathematical model with impulsive injections of both glucose and insulin at different fixed times is formulated in this paper. Using the discrete dynamical system determined by the stroboscopic map, we show that the existence and uniqueness of a positive globally asymptotically stable periodic solution for type I diabetes. By impulsive comparison theorem, we obtain the glucose concentration level of the system is uniformly bounded above and below for type Ⅱ diabetes. Numerical analysis verifies our theoretical results.展开更多
The effect of nutrition education using self-monitoring of blood glucose on glycemic control was investigated in the present study. Of 36 males and 25 females aged 30 - 69 years under outpatient treatment at 3 hospita...The effect of nutrition education using self-monitoring of blood glucose on glycemic control was investigated in the present study. Of 36 males and 25 females aged 30 - 69 years under outpatient treatment at 3 hospitals in Niigata prefecture, Japan, 61 non-insulin-treated obese type 2 diabetes patients with HbA1c of 6.9% - 9.3% and body mass index of 25 kg/m2 or higher were randomly allocated. Thirty and 31 patients were analyzed in intervention and control groups, respectively. The intervention group performed self-monitoring of blood glucose 2 hours after supper twice a week for 6 months and underwent nutrition education on the association between meals and postprandial blood glucose once every 2 months. The primary outcome was glycated hemoglobin, with the secondary outcome of body mass index. Stages of change for eating the appropriate supper amount were investigated to verify the process of the educational effect, and satisfaction with diabetes treatment and well-being were investigated to verify the continuity of treatment. On intention-to-treat analysis, glycated hemoglobin (mean ± SD) decreased from 7.9% ± 0.6% to 7.7% ± 0.6% in the intervention group but increased from 7.9% ± 0.6% to 8.1% ± 0.6% in the control group, showing a significant difference in the change after intervention between the groups (p = 0.027). In the intervention group, body mass index decreased from 28.9 ± 3.8 to 28.4 ± 3.7 kg/m2 (p = 0.019), the stages of change to learn the appropriate amount of supper progressed (p = 0.026), and satisfaction with diabetes treatment increased (p = 0.031).展开更多
AIM: To assess the efficacy and safety of vildagliptin 50 mg bid as add-on therapy to insulin in Asian patients with type 2 diabetes mellitus(T2DM).METHODS: This was a post hoc analysis of a subgroup of Asian patients...AIM: To assess the efficacy and safety of vildagliptin 50 mg bid as add-on therapy to insulin in Asian patients with type 2 diabetes mellitus(T2DM).METHODS: This was a post hoc analysis of a subgroup of Asian patients from a multicenter,randomized,double-blind,placebo-controlled,parallel-group study in T2DM patients inadequately controlled by stable insulin therapy,with or without metformin.A total of 173 patients were randomized 1:1 to receive treatment with vildagliptin 50 mg bid(n = 87) or placebo(n = 86) for 24 wk.Changes in HbA1c and fasting plasma glucose(FPG),from baseline to study endpoint,were analyzed using an analysis of covariance model.Change from baseline to endpoint in body weight was summarized by treatment.Safety and tolerability of vildagliptin was also evaluated.RESULTS: After 24 wk,the difference in adjusted mean change in HbA1c between vildagliptin and placebo was 0.82%(8.96 mmol/mol;P < 0.001) in Asian subgroup,0.85%(9.29 mmol/mol;P < 0.001) in patients also receiving metformin,and 0.73%(7.98 mmol/mol;P < 0.001) in patients without metformin,all in favor of vildagliptin.There was no significant difference in the change in FPG between treatments.Weight was stable in both treatment groups(+0.3 kg and-0.2 kg,for vildagliptin and placebo,respectively).Overall,vildagliptin was safe and well tolerated with similarly low incidences of hypoglycemia(8.0% vs 8.1%) and no severe hypoglycemic events were experienced in either group.CONCLUSION: In Asian patients inadequately controlled with insulin(with or without concomitant metformin),insulin-vildagliptin combination treatment significantly reduced HbA1c compared with placebo,without an increase in risk of hypoglycemia or weight gain.展开更多
Fluorescein isothiocyanate-labeled insulin(FITC-insulin)has been widely used for bioanalytical applications.Due to the high cost of commercial FITC-insulin and tedious labeling procedures described in the literature,t...Fluorescein isothiocyanate-labeled insulin(FITC-insulin)has been widely used for bioanalytical applications.Due to the high cost of commercial FITC-insulin and tedious labeling procedures described in the literature,there is still a need to develop a cost effective,reliable and quick labeling method for insulin.The purpose of the present work was to develop a quick and affordable method for FITC labeling of human insulin and to determine the effect of different conjugations of FITC to human insulin on its permeability through the MDCK cell monolayer.FITC labeling of insulin gives mono-,di-or tri-conjugates depending on the reaction time and the molar ratio of FITC:insulin.Mono-conjugate with unlabeled insulin,mixture of di-and tri-conjugate,and tri-conjugate with very little amount of di-conjugate were synthesized in less than 4 h.Degree of conjugation had an effect on the permeability of insulin through the MDCK cell monolayer.Mono-conjugate had higher permeability than the unlabeled insulin due to increase in partition coefficient.However,tri-conjugate showed lower permeability than the unlabeled insulin due to the increase in molecular weight.展开更多
Timing of eating is a life strategy that requires special considerations in healthy nutritional programs. Human body tolerates less glucose as evening begins, mainly because glucose is demanded most during more active...Timing of eating is a life strategy that requires special considerations in healthy nutritional programs. Human body tolerates less glucose as evening begins, mainly because glucose is demanded most during more active times or daytime. A recommendation is being developed to avoid large night meals to help reduce risks of visceral adiposity, type-2 diabetes mellitus, hypertension, and cardiovascular issues. Optimal understanding of physiology in any given species requires optimal understanding of comparative animal-human physiology. Optimal animal physiology is understood with optimal perception of ruminant physiology with its unique complex systems biology. Thus, ruminants as irreplaceable human food producers are metabolically and economically suitable models to study cell, organ and whole body physiology. Evening vs. morning feeding of lactating cows increases eating rate, postprandial levels of rumen and peripheral metabolism, and milk and meat production. External cues and internal physiology may thus be synchronized to optimize production and health. Effective education will enable the public to be adequately cognizant of time of eating as a feasible strategy for the success of nutritional programs in optimizing health status.展开更多
In order to study the pathogenesis of hypertension associated with noninsulin dependent diabetes mellitus (NIDDM), Plasma glucose, insulin levels at fasting and following an oral glucose load were measured. Na +K +pum...In order to study the pathogenesis of hypertension associated with noninsulin dependent diabetes mellitus (NIDDM), Plasma glucose, insulin levels at fasting and following an oral glucose load were measured. Na +K +pump and Ca 2+ pump activities of red blood cell membrane were also assessed. Hypertensive patients with normal or impaired glucose tolerance (NGT, or IGT) had hyperinsulinemia. Obese hypertensive patients also had hyperinsulinemia, while nonobese hypertensive patients had no hyperinsulinemia, but exhibited a delay in insulin response to oral glucose tolerance test (OGTT). In multivariate analysis, considering the factors of age, BMI and plasma glucose level, DBP were still positively related to both 30 min insulin level and IAUC, but negatively correlated to activities of Na +K +pump and Ca 2+ pump. These results demonstrated that a link between obesity, hpertension and NIDDM is the insulin resistance and/or hyperinsulinemia.展开更多
Purpose: To investigate the factors related to the development of cataract in patientswith non-insulin dependent diabetes mellitus(NIDDM).Methods: 792 NIDDM patients received ophthalmologic examinations including visu...Purpose: To investigate the factors related to the development of cataract in patientswith non-insulin dependent diabetes mellitus(NIDDM).Methods: 792 NIDDM patients received ophthalmologic examinations including visualacuity, external status of the eyes, slit lamp microscopy and ophthalmoscopy. Glucose,urea nitrogen (BUN), creatinine (Cr), urine acid (UA), N-acetyl-β2-D-glucosaminidase(NAG), β2-microglobulin(β2-MG) and serum albumin in blood were quantitativelytested. Glucose, pH value, protein, cells, cast and ketobodies in urine were assayed.Diagnosis of cataract was based on lens opacities classification system Ⅱ. Any patientmeeting "NⅡ", "CⅡ" or "PⅡ" level was diagnosed as cataract.Results: The incidence of cataract in this group of NIDDM was 62.37 % (494/792),which significantly related to the duration of the disease course, but not to the sex of thepatient. The occurrence rate of cataract in patients suffering from NIDDM of less thanfive years duration, from five to ten years, and more than ten years was 49.67 % (228/459), 71.84 % (125/174), and 88.68 % (141/159), respectively. The occurrence ofcataract in patients diagnosed of the disease from five to ten years and more than tenyears was much higher than that of those with the course of the disease less than fiveyears( P ＜ 0.05 and P ＜ 0. 001, respectively) . Rising concentrations of blood ureanitrogen, creatinine, glycosylated hemoglobin HbA1c(G-HbA1c), N-acetyl-β2-D-glucosaminidase(NAG) and β2-microglobulin(β2-MG) indicated malfunction of thekidneys, and the rate of cataract occurrence in these patients was higher.Conclusion: This study indicates that prolongation of the duration of non-insulindependent diabetes mellitus, renal dysfunction, as well as poor blood glucose control,may accelerate the development of cataract.展开更多
Aim: To study effects of recombinant human growth hormone (rhGH) on growth hormone-insulin-like growth factor axis (GH-IGFs) of human gastric cancer cell in vivo in order to reveal part mechanism of growth effects of ...Aim: To study effects of recombinant human growth hormone (rhGH) on growth hormone-insulin-like growth factor axis (GH-IGFs) of human gastric cancer cell in vivo in order to reveal part mechanism of growth effects of rhGH on gastric cancer. Methods: Nude mice were randomly divided into control group, cisplatin (DDP) group, rhGH group and DDP + rhGH group after human gastric cancer xenograft model of node mice was successfully founded and drugs were used for 6 days. We investigated volume of tumor, inhibitory rate of tumor and cell cycle by slide gauge and flow cytometry. In addition, We also respectively investigated insulin-like growth factor-I (IGF-I) and insulin-like growth factor binding protein-3 (IGFBP-3) of blood serum of nude mice, IGF-ImRNA, insulin-like growth factor-I receptor (IGF-IR) mRNA and IGFBP-3 mRNA of xenograft of nude mice by enzyme linked immunosorbent assay (ELISA) and semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR) on the first day of completing use of drugs later. Results: Tumor grew obviously slowly and tumor inhibitory rate obviously rose in DDP group and DDP + rhGH group compared with control group and rhGH group (p p p < 0.05). Expressions of IGF-I mRNA and IGF-IR mRNA were not obviously different in all groups. But expression of IGFBP-3 mRNA obviously increased in rhGH group, DDP group and DDP + rhGH group compared with control group;meanwhile, expression of IGFBP-3 mRNA also obviously increased in DDP + rhGH group compared with control group, DDP group and rhGH group. Conclusion: Our results indicated rhGH in short-time use did not improve proliferation of human gastric cancer cells and its mechanism was possible that rhGH in short-time use raised simultaneously IGF-I and IGFBP-3 of blood serum and increased IGFBP-3 mRNA, but degraded ratio of IGF-I and IGFBP-3 of blood serum in human gastric cancer cells.展开更多
The term Diabetes Mellitus (DM) comprises a group of metabolic disorders characterized by chronic hyperglycemia resulting from defects in the secretion and/or action of insulin. The Insulin therapy constitutes the pre...The term Diabetes Mellitus (DM) comprises a group of metabolic disorders characterized by chronic hyperglycemia resulting from defects in the secretion and/or action of insulin. The Insulin therapy constitutes the preferred treatment for DM, consisting of daily subcutaneous insulin injections to control blood glucose levels. The chitosan studied for Biomedicine is a biomaterial that can be used for controlled release of drugs whose release rate can be controlled by Sodium Tripolyphosphate (TPP), which is an ionic cross linker of the chitosan. Present study, therefore, was aimed to develop and evaluate membranes of chitosan and chitosan cross linked by TPP for use in controlled release of insulin system, with the purpose of obtaining an alternative to the injectable administration of this drug. The developed membranes were characterized by the techniques of Fourier Transform Infrared spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDX), High Performance Liquid Chromatography (HPLC) and Evaluation of Cell Viability of Macrophages (MTT). With the FTIR technique the interaction between chitosan, tripolyphosphate and insulin was identified. Chemical elements present in chitosan, insulin and sodium tripolyphosphate membranes were detected by EDX technique. By SEM technique, the changes in the morphology of the membrane containing insulin, with the presence of granular particles of varying sizes, could be observed when compared to pure chitosan. With HPLC assay insulin was identified and it was shown that it gets separated from chitosan membrane even when the membrane was cross linked by the TPP, though at a reduced rate. The crosslinking agent was effective to control the rate of insulin release. The biocompatibility of the prepared membranes was confirmed by cell viability of macrophages using the MTT assay. The developed membranes, therefore, have potential for use as a biomaterial in controlled release systems for insulin.展开更多
Mathematical modelling of glucose-insulin system is very important in medicine as a necessary tool to understand the homeostatic control of human body. It can also be used to design clinical trials and in the evaluati...Mathematical modelling of glucose-insulin system is very important in medicine as a necessary tool to understand the homeostatic control of human body. It can also be used to design clinical trials and in the evaluation of the diabetes prevention. In the last three decades so much work has been done in this direction. One of the most notable models is the global six compartment-mathematical model with 22 ordinary differential equations due to John Thomas Sorensen. This paper proposes a more simplified three compartment-mathematical model with only 6 ordinary differential equations by introducing a tissue compartment comprising kidney, gut, brain and periphery. For model parameter identification, we use inverse problems technique to solve a specific optimal control problem where data are obtained by solving the global model of John Thomas Sorensen. Numerical results show that the proposed model is adaptable to data and can be used to adjust diabetes mellitus type I or type II for diabetic patients.展开更多
Diabetes therapy is normally based on discrete insulin infusion that uses long-time interval measurements. Nevertheless, in this paper, a continuous drug infusion closed-loop control system was proposed to avoid the t...Diabetes therapy is normally based on discrete insulin infusion that uses long-time interval measurements. Nevertheless, in this paper, a continuous drug infusion closed-loop control system was proposed to avoid the traditional discrete approaches by automating diabetes therapy. Based on a continuous insulin injection model, two controllers were designed to deal with this plant. The controllers designed in this paper are: proportional integral derivative (PID), and fuzzy logic controllers (FLC). Simulation results have illustrated that the fuzzy logic controller outperformed the PID controller. These results were based on serious disturbances to glucose, such as exercise, delay or noise in glucose sensor and nutrition mixed meal absorption at meal time.展开更多
基金Supported by the Universities Young Teachers Program of Henan Province(2014GGJS-093)Supported by the Program for Science and Technology Innovation Talents in Universities of Henan Province(17HASTIT011)
文摘Impulsive injections of glucose and insulin analogues are very important strategies for the control of diabetes mellitus. We mainly imitate diabetes patients take insulin before eating, and eating approximately as a pulse blood glucose injection, as a result, a new mathematical model with impulsive injections of both glucose and insulin at different fixed times is formulated in this paper. Using the discrete dynamical system determined by the stroboscopic map, we show that the existence and uniqueness of a positive globally asymptotically stable periodic solution for type I diabetes. By impulsive comparison theorem, we obtain the glucose concentration level of the system is uniformly bounded above and below for type Ⅱ diabetes. Numerical analysis verifies our theoretical results.
文摘The effect of nutrition education using self-monitoring of blood glucose on glycemic control was investigated in the present study. Of 36 males and 25 females aged 30 - 69 years under outpatient treatment at 3 hospitals in Niigata prefecture, Japan, 61 non-insulin-treated obese type 2 diabetes patients with HbA1c of 6.9% - 9.3% and body mass index of 25 kg/m2 or higher were randomly allocated. Thirty and 31 patients were analyzed in intervention and control groups, respectively. The intervention group performed self-monitoring of blood glucose 2 hours after supper twice a week for 6 months and underwent nutrition education on the association between meals and postprandial blood glucose once every 2 months. The primary outcome was glycated hemoglobin, with the secondary outcome of body mass index. Stages of change for eating the appropriate supper amount were investigated to verify the process of the educational effect, and satisfaction with diabetes treatment and well-being were investigated to verify the continuity of treatment. On intention-to-treat analysis, glycated hemoglobin (mean ± SD) decreased from 7.9% ± 0.6% to 7.7% ± 0.6% in the intervention group but increased from 7.9% ± 0.6% to 8.1% ± 0.6% in the control group, showing a significant difference in the change after intervention between the groups (p = 0.027). In the intervention group, body mass index decreased from 28.9 ± 3.8 to 28.4 ± 3.7 kg/m2 (p = 0.019), the stages of change to learn the appropriate amount of supper progressed (p = 0.026), and satisfaction with diabetes treatment increased (p = 0.031).
文摘AIM: To assess the efficacy and safety of vildagliptin 50 mg bid as add-on therapy to insulin in Asian patients with type 2 diabetes mellitus(T2DM).METHODS: This was a post hoc analysis of a subgroup of Asian patients from a multicenter,randomized,double-blind,placebo-controlled,parallel-group study in T2DM patients inadequately controlled by stable insulin therapy,with or without metformin.A total of 173 patients were randomized 1:1 to receive treatment with vildagliptin 50 mg bid(n = 87) or placebo(n = 86) for 24 wk.Changes in HbA1c and fasting plasma glucose(FPG),from baseline to study endpoint,were analyzed using an analysis of covariance model.Change from baseline to endpoint in body weight was summarized by treatment.Safety and tolerability of vildagliptin was also evaluated.RESULTS: After 24 wk,the difference in adjusted mean change in HbA1c between vildagliptin and placebo was 0.82%(8.96 mmol/mol;P < 0.001) in Asian subgroup,0.85%(9.29 mmol/mol;P < 0.001) in patients also receiving metformin,and 0.73%(7.98 mmol/mol;P < 0.001) in patients without metformin,all in favor of vildagliptin.There was no significant difference in the change in FPG between treatments.Weight was stable in both treatment groups(+0.3 kg and-0.2 kg,for vildagliptin and placebo,respectively).Overall,vildagliptin was safe and well tolerated with similarly low incidences of hypoglycemia(8.0% vs 8.1%) and no severe hypoglycemic events were experienced in either group.CONCLUSION: In Asian patients inadequately controlled with insulin(with or without concomitant metformin),insulin-vildagliptin combination treatment significantly reduced HbA1c compared with placebo,without an increase in risk of hypoglycemia or weight gain.
文摘Fluorescein isothiocyanate-labeled insulin(FITC-insulin)has been widely used for bioanalytical applications.Due to the high cost of commercial FITC-insulin and tedious labeling procedures described in the literature,there is still a need to develop a cost effective,reliable and quick labeling method for insulin.The purpose of the present work was to develop a quick and affordable method for FITC labeling of human insulin and to determine the effect of different conjugations of FITC to human insulin on its permeability through the MDCK cell monolayer.FITC labeling of insulin gives mono-,di-or tri-conjugates depending on the reaction time and the molar ratio of FITC:insulin.Mono-conjugate with unlabeled insulin,mixture of di-and tri-conjugate,and tri-conjugate with very little amount of di-conjugate were synthesized in less than 4 h.Degree of conjugation had an effect on the permeability of insulin through the MDCK cell monolayer.Mono-conjugate had higher permeability than the unlabeled insulin due to increase in partition coefficient.However,tri-conjugate showed lower permeability than the unlabeled insulin due to the increase in molecular weight.
文摘Timing of eating is a life strategy that requires special considerations in healthy nutritional programs. Human body tolerates less glucose as evening begins, mainly because glucose is demanded most during more active times or daytime. A recommendation is being developed to avoid large night meals to help reduce risks of visceral adiposity, type-2 diabetes mellitus, hypertension, and cardiovascular issues. Optimal understanding of physiology in any given species requires optimal understanding of comparative animal-human physiology. Optimal animal physiology is understood with optimal perception of ruminant physiology with its unique complex systems biology. Thus, ruminants as irreplaceable human food producers are metabolically and economically suitable models to study cell, organ and whole body physiology. Evening vs. morning feeding of lactating cows increases eating rate, postprandial levels of rumen and peripheral metabolism, and milk and meat production. External cues and internal physiology may thus be synchronized to optimize production and health. Effective education will enable the public to be adequately cognizant of time of eating as a feasible strategy for the success of nutritional programs in optimizing health status.
文摘In order to study the pathogenesis of hypertension associated with noninsulin dependent diabetes mellitus (NIDDM), Plasma glucose, insulin levels at fasting and following an oral glucose load were measured. Na +K +pump and Ca 2+ pump activities of red blood cell membrane were also assessed. Hypertensive patients with normal or impaired glucose tolerance (NGT, or IGT) had hyperinsulinemia. Obese hypertensive patients also had hyperinsulinemia, while nonobese hypertensive patients had no hyperinsulinemia, but exhibited a delay in insulin response to oral glucose tolerance test (OGTT). In multivariate analysis, considering the factors of age, BMI and plasma glucose level, DBP were still positively related to both 30 min insulin level and IAUC, but negatively correlated to activities of Na +K +pump and Ca 2+ pump. These results demonstrated that a link between obesity, hpertension and NIDDM is the insulin resistance and/or hyperinsulinemia.
文摘Purpose: To investigate the factors related to the development of cataract in patientswith non-insulin dependent diabetes mellitus(NIDDM).Methods: 792 NIDDM patients received ophthalmologic examinations including visualacuity, external status of the eyes, slit lamp microscopy and ophthalmoscopy. Glucose,urea nitrogen (BUN), creatinine (Cr), urine acid (UA), N-acetyl-β2-D-glucosaminidase(NAG), β2-microglobulin(β2-MG) and serum albumin in blood were quantitativelytested. Glucose, pH value, protein, cells, cast and ketobodies in urine were assayed.Diagnosis of cataract was based on lens opacities classification system Ⅱ. Any patientmeeting "NⅡ", "CⅡ" or "PⅡ" level was diagnosed as cataract.Results: The incidence of cataract in this group of NIDDM was 62.37 % (494/792),which significantly related to the duration of the disease course, but not to the sex of thepatient. The occurrence rate of cataract in patients suffering from NIDDM of less thanfive years duration, from five to ten years, and more than ten years was 49.67 % (228/459), 71.84 % (125/174), and 88.68 % (141/159), respectively. The occurrence ofcataract in patients diagnosed of the disease from five to ten years and more than tenyears was much higher than that of those with the course of the disease less than fiveyears( P ＜ 0.05 and P ＜ 0. 001, respectively) . Rising concentrations of blood ureanitrogen, creatinine, glycosylated hemoglobin HbA1c(G-HbA1c), N-acetyl-β2-D-glucosaminidase(NAG) and β2-microglobulin(β2-MG) indicated malfunction of thekidneys, and the rate of cataract occurrence in these patients was higher.Conclusion: This study indicates that prolongation of the duration of non-insulindependent diabetes mellitus, renal dysfunction, as well as poor blood glucose control,may accelerate the development of cataract.
文摘Aim: To study effects of recombinant human growth hormone (rhGH) on growth hormone-insulin-like growth factor axis (GH-IGFs) of human gastric cancer cell in vivo in order to reveal part mechanism of growth effects of rhGH on gastric cancer. Methods: Nude mice were randomly divided into control group, cisplatin (DDP) group, rhGH group and DDP + rhGH group after human gastric cancer xenograft model of node mice was successfully founded and drugs were used for 6 days. We investigated volume of tumor, inhibitory rate of tumor and cell cycle by slide gauge and flow cytometry. In addition, We also respectively investigated insulin-like growth factor-I (IGF-I) and insulin-like growth factor binding protein-3 (IGFBP-3) of blood serum of nude mice, IGF-ImRNA, insulin-like growth factor-I receptor (IGF-IR) mRNA and IGFBP-3 mRNA of xenograft of nude mice by enzyme linked immunosorbent assay (ELISA) and semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR) on the first day of completing use of drugs later. Results: Tumor grew obviously slowly and tumor inhibitory rate obviously rose in DDP group and DDP + rhGH group compared with control group and rhGH group (p p p < 0.05). Expressions of IGF-I mRNA and IGF-IR mRNA were not obviously different in all groups. But expression of IGFBP-3 mRNA obviously increased in rhGH group, DDP group and DDP + rhGH group compared with control group;meanwhile, expression of IGFBP-3 mRNA also obviously increased in DDP + rhGH group compared with control group, DDP group and rhGH group. Conclusion: Our results indicated rhGH in short-time use did not improve proliferation of human gastric cancer cells and its mechanism was possible that rhGH in short-time use raised simultaneously IGF-I and IGFBP-3 of blood serum and increased IGFBP-3 mRNA, but degraded ratio of IGF-I and IGFBP-3 of blood serum in human gastric cancer cells.
文摘The term Diabetes Mellitus (DM) comprises a group of metabolic disorders characterized by chronic hyperglycemia resulting from defects in the secretion and/or action of insulin. The Insulin therapy constitutes the preferred treatment for DM, consisting of daily subcutaneous insulin injections to control blood glucose levels. The chitosan studied for Biomedicine is a biomaterial that can be used for controlled release of drugs whose release rate can be controlled by Sodium Tripolyphosphate (TPP), which is an ionic cross linker of the chitosan. Present study, therefore, was aimed to develop and evaluate membranes of chitosan and chitosan cross linked by TPP for use in controlled release of insulin system, with the purpose of obtaining an alternative to the injectable administration of this drug. The developed membranes were characterized by the techniques of Fourier Transform Infrared spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDX), High Performance Liquid Chromatography (HPLC) and Evaluation of Cell Viability of Macrophages (MTT). With the FTIR technique the interaction between chitosan, tripolyphosphate and insulin was identified. Chemical elements present in chitosan, insulin and sodium tripolyphosphate membranes were detected by EDX technique. By SEM technique, the changes in the morphology of the membrane containing insulin, with the presence of granular particles of varying sizes, could be observed when compared to pure chitosan. With HPLC assay insulin was identified and it was shown that it gets separated from chitosan membrane even when the membrane was cross linked by the TPP, though at a reduced rate. The crosslinking agent was effective to control the rate of insulin release. The biocompatibility of the prepared membranes was confirmed by cell viability of macrophages using the MTT assay. The developed membranes, therefore, have potential for use as a biomaterial in controlled release systems for insulin.
文摘Mathematical modelling of glucose-insulin system is very important in medicine as a necessary tool to understand the homeostatic control of human body. It can also be used to design clinical trials and in the evaluation of the diabetes prevention. In the last three decades so much work has been done in this direction. One of the most notable models is the global six compartment-mathematical model with 22 ordinary differential equations due to John Thomas Sorensen. This paper proposes a more simplified three compartment-mathematical model with only 6 ordinary differential equations by introducing a tissue compartment comprising kidney, gut, brain and periphery. For model parameter identification, we use inverse problems technique to solve a specific optimal control problem where data are obtained by solving the global model of John Thomas Sorensen. Numerical results show that the proposed model is adaptable to data and can be used to adjust diabetes mellitus type I or type II for diabetic patients.
文摘Diabetes therapy is normally based on discrete insulin infusion that uses long-time interval measurements. Nevertheless, in this paper, a continuous drug infusion closed-loop control system was proposed to avoid the traditional discrete approaches by automating diabetes therapy. Based on a continuous insulin injection model, two controllers were designed to deal with this plant. The controllers designed in this paper are: proportional integral derivative (PID), and fuzzy logic controllers (FLC). Simulation results have illustrated that the fuzzy logic controller outperformed the PID controller. These results were based on serious disturbances to glucose, such as exercise, delay or noise in glucose sensor and nutrition mixed meal absorption at meal time.
