Polyamides are useful biomaterials owing to their biodegradability and good mechanical strength. We have obtained novel polyamides from succinylsarcosine and ethylenediamine by polycondensation in ...water using 1-ethyl-3-(3-dimethyl-aminopropyl)-carbodiimide (EDC·HCl) and 1-hydroxybenzotriazole. The molecular weight of the obtained polyamides depends on the concentration of the monomers or EDC·HCl, and reached a maximum of over 200,000. The optimal polycondensation temperature was between 10 and 20
°C. We also obtained copolymers of succinylsarcosine and succinylisoleucine by the same method. When the succinylisoleucine content increased, the obtained polyamides showed lower melting points, higher enzymatic degradability, and higher cell adhesion rates. Thermally responsive polyamides containing an elastin-derived pentapeptide, VPGVG, succinylsarcosine, and succinylisoleucine were obtained by the same method. The temperature-dependent precipitation of the polyamide occurred reversibly, and the temperature of precipitation varied from below room temperature to over 80
°C, depending on the ratios of succinylsarcosine and succinylisoleucine.
There are diverse strategies for gene therapy of diabetes mellitus. Prevention of beta-cell autoimmunity is a specific gene therapy for prevention of type 1 (insulin-dependent) diabetes in a ...preclinical stage, whereas improvement in insulin sensitivity of peripheral tissues is a specific gene therapy for type 2 (non-insulin-dependent) diabetes. Suppression of beta-cell apoptosis, recovery from insulin deficiency, and relief of diabetic complications are common therapeutic approaches to both types of diabetes. Several approaches to insulin replacement by gene therapy are currently employed: 1) stimulation of beta-cell growth, 2) induction of beta-cell differentiation and regeneration, 3) genetic engineering of non-beta cells to produce insulin, and 4) transplantation of engineered islets or beta cells. In type 1 diabetes, the therapeutic effect of beta-cell proliferation and regeneration is limited as long as the autoimmune destruction of beta cells continues. Therefore, the utilization of engineered non-beta cells free from autoimmunity and islet transplantation with immunological barriers are considered potential therapies for type 1 diabetes. Proliferation of the patients' own beta cells and differentiation of the patients' own non-beta cells to beta cells are desirable strategies for gene therapy of type 2 diabetes because immunological problems can be circumvented. At present, however, these strategies are technically difficult, and transplantation of engineered beta cells or islets with immunological barriers is also a potential gene therapy for type 2 diabetes.
To assess agreement between noninvasive blood pressure (NIBP) oscillometrically-derived values from a multiparameter monitor (Datex Ohmeda S/5 Compact) with those obtained by invasive blood pressure ...(IBP) measurement in anaesthetised horses undergoing elective surgery.
Prospective clinical study.
A total of 40 healthy adult horses.
Horses were anaesthetised with various anaesthetic protocols (based on clinical requirements). Depending on positioning, cannulation of the facial or lateral metatarsal artery was performed for IBP measurement. The cannula was connected via a transducer to the monitor. An appropriately sized NIBP cuff was placed around the tail base and connected to the same monitor. Systolic (SAP), mean (MAP) and diastolic (DAP) arterial blood pressures were continuously recorded from the invasive system, and at 3 minute intervals from the oscillometric system, throughout the surgical procedure using a Datex iCollect program. An appropriate arithmetic correction factor was applied to the oscillometric results where the cuff was not level with the heart. Assessment of the degree of agreement between invasive and noninvasive readings at each time point was performed using a modified Bland-Altman analysis.
While in many horses there was relatively close correlation between the values obtained over time, there was substantial variability in individual animals which resulted in wide Bland-Altman limits of agreement. The oscillometric device over-reads by approximately 32, 23 and 22 mmHg, and under-reads by 26, 17 and 19 mmHg for SAP, MAP and DAP, respectively, compared with the IBP values. However, using the mean difference and standard deviation, the device conforms to American College of Veterinary Internal Medicine (ACVIM) standards.
Oscillometric blood pressure measurement using the Datex Ohmeda S/5 Compact multiparameter monitor conforms to ACVIM standards when the NIBP cuff is placed on the tail. However, because of the wide variability in measurements, we cannot recommend this technique to guide therapy in anaesthetised adult horses.
Oligonucleotide 9mers containing 2′-O-(1-pyrenylmethyl)uridine U(pyr) at the center position were synthesized by using a protected U(pyr) phosphoramidite. The UV melting behaviors indicate that the ...pyrene-modified oligonucleotides can bind to both their complementary DNA and RNA in aqueous solution. When compared with the unmodified oligonucleotides, the pyrene-modified oligonucleotides showed higher affinity for DNA while exhibiting lower affinity for RNA. The pyrene-modified oligonucleotides in diluted solution exhibited fluorescence typical of pyrene monomer emission λmax 378 (band I) and 391 nm (band III). When these oligomers bound to DNA, the fluorescence intensity ratio of band III/band I was increased. With this fluorescence change, a new broad emission (λmax 450 nm) due to exciplex between the pyrene and an adjacent nucleobase appeared. In contrast, addition of RNA to the pyrene oligonucleotides resulted in enhancement of the pyrene monomer emission with decrease in the fluorescence band ratio. The extent of the emission enhancement was found to be highly dependent on the nucleobase adjacent to the U(pyr) in the pyrene oligomers. The pyrene oligonucleotide containing dC at the 3′-site of the modification showed remarkable increase (∼250 times) in fluorescence (375 nm) upon binding to complementary RNA. The present findings would open the way to the design of a highly sensitive fluorescent probe of RNA.
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