Optimal Blood Glucose Regulation using Single Network Adaptive Critics

Diabetes is a serious disease during which the body's production and use of insulin is impaired, causing glucose concentration level toincrease in the bloodstream. Regulating blood glucose levels as close to normal as possible, leads to a substantial decrease in long term complications of diabetes. In this paper, an intelligent neural network on-line optimal feedback treatment strategy based on nonlinear optimal control theory is presented for the disease using subcutaneous treatment strategy. A simple mathematical model of the nonlinear dynamics of glucose and insulin interaction in the blood system is considered based on the Bergman's minimal model. A glucose infusion term representing the effect of glucose intake resulting from a meal is introduced into the model equations. The efficiency of the proposed controllers is shown taking random parameters and random initial conditions in presence of physical disturbances like food intake. A comparison study with linear quadratic regulator theory brings Out the advantages of the nonlinear control synthesis approach. Simulation results show that unlike linear optimal control, the proposed on-line continuous infusion strategy never leads to severe hypoglycemia problems.

Antipyretic and antibacterial activity of Chloranthus erectus (Buch.-Ham.) Verdcourt leaf extract: A popular folk medicine of Arunachal Pradesh

Objective : The main objective of this work was to study the antipyretic and antibacterial activity of C. erectus (Buch.-Ham.) Verdcourt leaf extract in an experimental albino rat model. Materials and Methods : The methanol extract of C. erectus leaf (MECEL) was evaluated for its antipyretic potential on normal body temperature and Brewers yeast-induced pyrexia in albino rats model. While the antibacterial activity of MECEL against five Gram (-) and three Gram () bacterial strains and antimycotic activity was investigated against four fungi using agar disk diffusion and microdilution methods. Result : Yeast suspension (10 mL/kg b.w.) elevated rectal temperature after 19 h of subcutaneous injection. Oral administration of MECEL at 100 and 200 mg/kg b.w. showed significant reduction of normal rectal body temperature and yeast-provoked elevated temperature (38.8 0.2 and 37.6 0.4, respectively, at 2-3 h) in a dose-dependent manner, and the effect was comparable to that of the standard antipyretic drug-paracetamol (150 mg/kg b.w.). MECEL at 2 mg/disk showed broad spectrum of growth inhibition activity against both groups of bacteria. However, MECEL was not effective against the yeast strains tested in this study. Conclusion : This study revealed that the methanol extract of C. erectus exhibited significant antipyretic activity in the tested models and antibacterial activity as well, and may provide the scientific rationale for its popular use as antipyretic agent in Khamptiss folk medicines.

Acute toxicity of methyl isocyanate in mammals. II. Induction of hyperglycemia, lactic acidosis, uraemia, and hypothermia in rats

When rats were administered methyl isocyanate (MIC) by inhalation or subcutaneous route it produced severe hyperglycemia, clinical lactic acidosis, highly elevated plasma urea, and reduced plasma cholinesterase activity with unaltered erythrocytc acetyl cholinesterase activity. Irrespective of the route of administration, MIC also caused severe hypothermia, which was not ameliorated by prior administration of atropine sulphate. Acute toxic effects of MIC are essentially similar by either route except for the intensity of the effects

Do the Hydrolysis Products, Methylamine and N,N'-Dimethylurea, Play any Role in the Methyl Isocyanate-Induced Haematological and Biochemical Changes in Rabbits?

The subcutaneous administration of methyl isocyanate (MIC) to female rabbits, resulted in significant increases in haemoglobin concentration, erythrocyte volume fraction and leucocyte number in blood, as well as plasma total proteins, and urea. The present study was designed to investigate whether the hydrolytic products of MIC, methylamine (MA) and N,N'-dimethylurea (DMU) play any role in eliciting these changes. Both MA and DMU administered subcutaneously in an equimolar dose to that of 1.0 LD50 MIC, 2.2 mmol kg-1, had no influence on these parameters, although there was a marginal increase in the plasma urea level shortly after the administration of DMU. This study establishes that the observed haematological and biochemical changes induced by MIC intoxication in rabbits are mostly due to MIC.

Influence of methylamine and N,N'-dimethylurea, the hydrolysis products of methyl isocyanate, on its systemic toxicity

Subcutaneous administration of the LD50 dose of methyl isocyanate (MIC) to rats induced severe hyperglycaemia, lactic acidosis and uraemia in rats. Neither methylamine (MA) nor N,N′-dimethylurea (DMU), the hydrolysis products of MIC, administered in equimolar doses had any influence on these parameters except for a marginal transient increase in plasma urea by DMU. Methyl isocyanate administration led to haemoconcentration, resulting in an increase in the plasma concentration of total proteins and a decrease in both the plasma concentration of albumin and the plasma cholinesterase activity. The hydrolysis products of MIC had no influence on any of these parameters. Thus, it seems reasonable to suggest that the systemic effects of MIC are caused by MIC per se, in spite of its high hydrolytic instability.

Role of lipid peroxidation in impairment of mitochondrial function at complex I by methyl isocyanate treatment of rats in vivo

The subcutaneous administration of methyl isocyanate (MIC) in 1.0 LD50 dose in rats caused a significant effect on hepatic mitochondrial function only at complex I region of the respiratory chain. MIC administration at 1.0 LD50 dose also resulted in significant increases in malondialdehyde and ferrous ion concentration in liver mitochondria. It is suggested that the augmented lipid peroxidation in hepatic mitochondria, catalyzed by iron, possibly mobilized from intracellular stores leads to the inhibition of enzymes of mitochondrial respiration at complex I region, in vivo, in rats receiving a lethal dose of MIC subcutaneously.

Long-Term Sustained Release of Salicylic Acid from Cross-Linked Biodegradable Polyester Induces a Reduced Foreign Body Response in Mice

There has been a continuous surge toward developing new biopolymers that exhibit better in vivo biocompatibility properties in terms of demonstrating a reduced foreign body response (FBR). One approach to mitigate the undesired FBR is to develop an implant capable of releasing anti-inflammatory molecules in a sustained manner over a long time period. Implants causing inflammation are also more susceptible to infection. In this article, the in vivo biocompatibility of a novel, biodegradable salicylic acid releasing polyester (SAP) has been investigated by subcutaneous implantation in a mouse model. The tissue response to SAP was compared with that of a widely used biodegradable polymer, poly(lactic acid-co-glycolic acid) (PLGA), as a control over three time points: 2, 4, and 16 weeks postimplantation. A long-term in vitro study illustrates a continuous, linear (zero order) release of salicylic acid with a cumulative mass percent release rate of 7.34 x 10(-4) h(-1) over similar to 1.5-17 months. On the basis of physicochemical analysis, surface erosion for SAP and bulk erosion for PLGA have been confirmed as their dominant degradation modes in vivo. On the basis of the histomorphometrical analysis of inflammatory cell densities and collagen distribution as well as quantification of proinflammatory cytokine levels (TNF-alpha and IL-1 beta), a reduced foreign body response toward SAP with respect to that generated by PLGA has been unambiguously established. The favorable in vivo tissue response to SAP, as manifest from the uniform and well-vascularized encapsulation around the implant, is consistent with the decrease in inflammatory cell density and increase in angiogenesis with time. The above observations, together with the demonstration of long-term and sustained release of salicylic acid, establish the potential use of SAP for applications in improved matrices for tissue engineering and chronic wound healing.