Comparison and contrast of affinity chromatographic determinations of plasma glycated albumin and total glycated plasma protein.

Techniques for affinity measurement of glycated albumin and for glycated total plasma protein have been developed. The two techniques were contrasted. Both techniques are linear over a 100-fold range of sample concentrations. There appears to be a non-specific early glucose binding phase to non-albumin plasma proteins. Although this phase is detected by radioactive incorporation and thiobarbituric acid, it does not interfere with the affinity determination, which does not appear to detect the early binding species. The correlation of glycated albumin levels with glycated hemoglobin levels is much stronger than that of glycated globulin levels with glycated hemoglobin levels. Due to the large contribution of glycated albumin levels to total glycated serum protein levels, the correlation of the latter with glycated hemoglobin levels is sufficiently strong to allow the use of either technique as an adequate index of glycation.

Health care data security: one size does not fit all.

In the wake of the Internet, E-commerce, and particularly the Health Insurance Portability and Accountability Act, data security has risen to the top of health care information technology priorities. What is the correct mix of data security tools, policies, and technologies for the doctor, the hospital, the insurer, the vendor, and everyone else who does business in the health care industry?

Communication security in open health care networks.

Fulfilling the shared care paradigm, health care networks providing open systems' interoperability in health care are needed. Such communicating and co-operating health information systems, dealing with sensitive personal medical information across organisational, regional, national or even international boundaries, require appropriate security solutions. Based on the generic security model, within the European MEDSEC project an open approach for secure EDI like HL7, EDIFACT, XDT or XML has been developed. The consideration includes both securing the message in an unsecure network and the transport of the unprotected information via secure channels (SSL, TLS etc.). Regarding EDI, an open and widely usable security solution has been specified and practically implemented for the examples of secure mailing and secure file transfer (FTP) via wrapping the sensitive information expressed by the corresponding protocols. The results are currently prepared for standardisation.

Utilization management in a mixed-payment environment.

Fee-for-service and capitation payment methods create different financial incentives for healthcare providers, and the objectives of utilization management differ under each payment method. These differences can be reconciled, however, by incorporating the strengths of utilization management programs associated with both methods into an overarching program that focuses on the continuum of care. Such a program should be focused on achieving the optimal outcomes for patients by identifying the appropriate level of care, who should provide it, and when and where it should be provided. Essential to this effort is access to comprehensive clinical and financial data through an integrated information system. In addition, financial incentives need to be aligned through such means as risk pools, compensation arrangements tied to achievement of medical management goals, and clearly defined policies and procedures.

Medical smart cards: health care access in your pocket.

The wallet-sized medical smart card, embedded with a programmable computer chip, stores and transmits a cardholder's clinical, insurance coverage and biographical information. When fully deployed, smart cards will conduct many functions at the point of care, from claims submission to medical records updates in real time. Ultimately, the smart card will make the individual patient record and all clinical and economic transactions within that patient log as portable, accessible and secure as an ATM account.

Organizing specialty networks for capitation.

Two of the byproducts of the shift to managed care--risk-based contracting and surplus specialist capacity--has fostered the growth of specialty networks. To remain competitive in a selective market for specialty services, specialists must develop the clinical an business capabilities to manage risk and outcomes and must adapt practice culture to the operational demands of managed care. Also, specialists must create effective delivery networks that meet payer and patient expectations for clinical excellence, patient access and business efficiency. This article addresses matching the specialty network to the market and building the specialty network.

Success factors of risk based specialty networks.

Specialty physicians are feeling the heat from managed care because of shrinking reimbursement, selective paneling and clinical re-engineering. They have felt the need to leverage their influence by developing specialty groups and networks. While each network is unique in its external circumstances, there are several common elements to successful specialty networks, including having a clear network mission, obtaining adequate capitalization, obtaining equity, accepting only a manageable amount of risk, gaining member volume establishing and maintaining payer diversity, being high quality and efficient, developing and using information tools, supporting network efficiencies, allying with other physician organizations, exercising network panel selection and deselection, and empowering physicians with knowledge.

Making risk contracting work in specialty networks.

For the next several years, capitation of specialties will increasingly influence contracting arrangements. Specialists and their networks must position themselves to operate in this environment amid a shrinking market for their services and consolidation of delivery systems and accepting capitation can be a necessary step. The specialties that can quantify the costs of specific services within a defined range, and can manage appropriate utilization of those services within acceptable parameters through wellness, patient intervention and disease management techniques, are most likely to be successful in risk contracting. This article presents how to investigate risk contracting in specialty networks and what infrastructure is required for successful risk contracting.

Protective effects of grape seed proanthocyanidins and selected antioxidants against TPA-induced hepatic and brain lipid peroxidation and DNA fragmentation, and peritoneal macrophage activation in mice.

1. The comparative protective abilities of a grape seed proanthocyanidin extract (GSPE) (25-100 mg/kg), vitamin C (100 mg/kg), vitamin E succinate (VES) (100 mg/kg) and beta-carotene (50 mg/kg) on 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced lipid peroxidation and DNA fragmentation in the hepatic and brain tissues, as well as production of reactive oxygen species by peritoneal macrophages, were assessed. 2. Treatment of mice with GSPE (100 mg/kg), vitamin C, VES and beta-carotene decreased TPA-induced production of reactive oxygen species, as evidenced by decreases in the chemiluminescence response in peritoneal macrophages by approximately 70%, 18%, 47% and 16%, respectively, and cytochrome c reduction by approximately 65%, 15%, 37% and 19%, respectively, compared with controls. 3. GSPE, vitamin C, VES and beta-carotene decreased TPA-induced DNA fragmentation by approximately 47%, 10%, 30% and 11%, respectively, in the hepatic tissues, and 50%, 14%, 31% and 11%, respectively, in the brain tissues, at the doses that were used. Similar results were observed with respect to lipid peroxidation in hepatic mitochondria and microsomes and in brain homogenates. 4. GSPE exhibited a dose-dependent inhibition of TPA-induced lipid peroxidation and DNA fragmentation in liver and brain, as well as a dose-dependent inhibition of TPA-induced reactive oxygen species production in peritoneal macrophages. 5. GSPE and other antioxidants provided significant protection against TPA-induced oxidative damage, with GSPE providing better protection than did other antioxidants at the doses that were employed.

Oxygen free radical scavenging abilities of vitamins C and E, and a grape seed proanthocyanidin extract in vitro.

Proanthocyanidins, a group of polyphenolic bioflavonoids, have been reported to exhibit a wide range of biological, pharmacological and chemoprotective properties against oxygen free radicals. We have assessed the concentration-dependent oxygen free radical scavenging abilities of a grape seed proanthocyanidin extract (GSPE), vitamin C and vitamin E succinate (VES) as well as superoxide dismutase, catalase and mannitol against biochemically generated superoxide anion and hydroxyl radical using a chemiluminescence assay and cytochrome c reduction. A concentration-dependent inhibition was demonstrated by GSPE. At a 100 mg/l concentration, GSPE exhibited 78-81% inhibition of superoxide anion and hydroxyl radical. Under similar conditions, vitamin C inhibited these two oxygen free radicals by approximately 12-19%, while VES inhibited the two radicals by 36-44%. The combination of superoxide dismutase and catalase inhibited superoxide anion by approximately 83%, while mannitol resulted in an 87% inhibition of hydroxyl radical. The results demonstrate that GSPE is a more potent scavenger of oxygen free radicals as compared to vitamin C and VES.

Protective effects of zinc salts on TPA-induced hepatic and brain lipid peroxidation, glutathione depletion, DNA damage and peritoneal macrophage activation in mice.

1. The comparative protective abilities of zinc L-methionine, zinc DL-methionine, zinc sulfate, zinc gluconate, L-methionine, DL-methionine, and vitamin E succinate (VES) on 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced lipid peroxidation, DNA fragmentation, and glutathione depletion in the hepatic and brain tissues, and production of reactive oxygen species by peritoneal macrophages were assessed. In addition, mice were fed a zinc-deficient diet for 5 weeks, and treated with TPA and/or zinc L-methionine or zinc DL-methionine, and similar studies were conducted. 2. The zinc-deficient diet induced oxidative stress in the hepatic and brain tissues as well as in the peritoneal macrophages as evidenced by significantly enhanced lipid peroxidation. DNA fragmentation, glutathione depletion, and production of reactive oxygen species. 3. Treatment of mice with zinc L-methionine, zinc DL-methionine, and VES decreased TPA-induced reactive oxygen species production as evidenced by significant decreases in chemiluminescence in peritoneal macrophages by approximately 45%, 31%, and 47%, respectively, and cytochrome c reduction by approximately 54%, 35%, and 41%, respectively, as compared with control values. Similar results were observed with liver and brain lipid peroxidation, DNA fragmentation, and glutathione depletion. 4. Zinc salts and antioxidants provided significant protection against TPA-induced oxidative damage. Zinc L-methionine provided the best protection.

Stress, diet and alcohol-induced oxidative gastrointestinal mucosal injury in rats and protection by bismuth subsalicylate.

Oxygen free radicals are implicated in the pathogenesis of stress and food/alcohol-induced gastrointestinal injury. We have investigated the effects of restraint stress, spicy food diet, high-fat diet and 40% ethanol on the enhanced production of reactive oxygen species, including superoxide anion and hydroxyl radicals, and on DNA fragmentation, lipid peroxidation and membrane microviscosity (indices of oxidative tissue damage) in gastric and intestinal mucosa of Sprague-Dawley rats. Furthermore, the protective ability of bismuth subsalicylate (BSS; 15 mg kg(-1) was determined against the gastrointestinal mucosal injury induced by these stressors. Animals on the high-fat diet consumed 31% more food as compared to other animals. Animals on the spicy food diet consumed ca. 23% more water as compared to control animals, and the high-fat diet animals consumed 17% less water. Restraint stress provided greater injury to both gastric and intestinal mucosa as compared to other stressors. Restraint stress, spicy food diet, high-fat diet and ethanol increased superoxide anion production by 10.0-, 4.3-, 5.7- and 4.8-fold, respectively, in the gastric mucosa, and by 10.4-, 5.3-, 7.0- and 5.5-fold in the intestinal mucosa. Exposure to restraint stress, spicy food diet, high-fat diet and 40% ethanol also increased hydroxyl radical production by ca. 14.3-, 4.5-, 3.5- and 4.8-fold, respectively, in the gastric mucosa, and by 17.0-, 4.8-, 3.5- and 4.7-fold in the intestinal mucosa. Bismuth subsalicylate administration to the animals provided significant protection against superoxide anion and hydroxyl radical production. Restraint stress, spicy food diet, high-fat diet and ethanol increased lipid peroxidation by 3.6-, 2.4-, 2.6- and 2.0-fold, respectively, in the gastric mucosa, and by 4.1-, 3.5-, 3.6- and 2.7-fold in intestinal mucosa. Administration of BSS decreased restraint stress, spicy food diet, high-fat diet and ethanol-induced gastric mucosal lipid peroxidation by ca. 26%, 36%, 45% and 18%, and intestinal mucosa lipid peroxidation by 20%, 21%, 46% and 42%, respectively. Approximately 4.0-, 2.0-, 2.4- and 2.0-fold increases in DNA fragmentation were observed in the gastric mucosa of rats exposed to restraint stress, spicy food diet, high-fat diet and 40% ethanol, respectively, and similar increases in the intestinal mucosa. These same four stressors increased membrane microviscosity by 11.6-, 6.1-, 7.3- and 5.4-fold, respectively, in the gastric mucosa, and by 16.2-, 7.9-, 9.5- and 7.8-fold in the intestinal mucosa. Bismuth subsalicylate exerted significant protection against DNA damage and changes in membrane microviscosity induced by the four stressors. Excellent correlations existed between the production of reactive oxygen species and the tissue damaging effects in both gastric and intestinal mucosa. In summary, the results demonstrate that physical and chemical stressors can induce gastrointestinal oxidative stress and mucosal injury through enhanced production of reactive oxygen species, and that BSS can significantly attenuate gastrointestinal injury by scavenging these reactive oxygen species.

Protection against chemically-induced oxidative gastrointestinal tissue injury in rats by bismuth salts.

Oxygen free radicals (OFR) are implicated in the pathogenesis of stress, chemically induced gastric lesions, and gastrointestinal injury. The concentration-dependent scavenging abilities of bismuth subsalicylate (SBS), colloidal bismuth subcitrate (CBS), and selected OFR scavengers, including superoxide dismutase (SOD), catalase, mannitol, and allopurinol were examined against biochemically or chemically generated superoxide anion, hydroxyl radical, and hypochlorite radical plus hypochlorous acid based on a chemiluminescence assay. Furthermore, both gastric (GM) and intestinal mucosa (IM) were individually exposed in vitro to these free radical generating systems, and the concentration-dependent protective abilities of SBS and CBS against lipid peroxidation (LP) were compared with selected OFR scavengers. In addition, 24-hr fasted rats were orally treated with the necrotizing agents 0.6 M HCl, 0.2 M NaOH, 80% ethanol, and aspirin (200 mg/kg). The extent of tissue injury in the GM and IM was determined by assessing LP, DNA fragmentation, and membrane microviscosity. Dose- and time-dependent in vivo protective abilities of CBS (100 mg/kg) and SBS (15 mg/kg) were also assessed. Following incubations with superoxide anion and hydroxyl radical generating systems in the presence of 125 mg SBS/liter, approximately 47% and 61% inhibitions were observed in the chemiluminescence response, respectively, while 48% and 46% inhibitions were observed with 125 mg CBS/liter. SBS and CBS exerted similar abilities towards hypochlorite radical plus hypochlorous acid. Approx. 3.1- and 3.7-fold increases in LP were observed in the GM and IM of rats following oral administration of 0.6 M HCl. Pretreatment of the rats with SBS and CBS decreased 0.6 M HCl-induced LP in the GM by approx. 39% and 27%, respectively, with similar decreases in LP in the IM. SBS exhibited better protective abilities towards 0.6 M HCl and 0.2 m NaOH-induced GM and IM injury as compared to CBS. SBS and CBS provided similar protection towards 80% ethanol-induced gastric injury, while CBS exerted a superior protective ability towards aspirin-induced gastric injury. The results demonstrate that both SBS and CBS can scavenge reactive oxygen species and prevent tissue damage produced by OFR.

Measurement of protein using bicinchoninic acid.

Bicinchoninic acid, sodium salt, is a stable, water-soluble compound capable of forming an intense purple complex with cuprous ion (Cu1+) in an alkaline environment. This reagent forms the basis of an analytical method capable of monitoring cuprous ion produced in the reaction of protein with alkaline Cu2+ (biuret reaction). The color produced from this reaction is stable and increases in a proportional fashion over a broad range of increasing protein concentrations. When compared to the method of Lowry et al., the results reported here demonstrate a greater tolerance of the bicinchoninate reagent toward such commonly encountered interferences as nonionic detergents and simple buffer salts. The stability of the reagent and resulting chromophore also allows for a simplified, one-step analysis and an enhanced flexibility in protocol selection. This new method maintains the high sensitivity and low protein-to-protein variation associated with the Lowry technique.

Determination of glycosylated hemoglobin by affinity chromatography: comparison with colorimetric and ion-exchange methods, and effects of common interferences.

An affinity-chromatographic method for determination of glycosylated hemoglobin (Anal. Lett. 14: 649-661, 1981) is compared with the thiobarbituric acid colorimetric (I) (Clin. Chem. 27: 669-672, 1981) and the ion-exchange liquid-chromatographic (II) (Diabetes 29: 623-628, 1980) methods. A correlation of 0.98 was obtained for the affinity method vs II and 0.97 for affinity vs I (n = 51). The within-run CV was 1.9% for specimens from non-diabetic individuals and 1.0% for those from diabetics. The respective between-run CVs were 3.4% and 2.4%. Failure to remove "labile" glucose adducts by 5-h incubation of erythrocytes in isotonic saline (37 degrees C) contributed an average error of 13.1% for II, 5.4% for I, and 1.6% for the affinity method. Affinity chromatography gave a decrease of 0.1-0.2% glycosylated hemoglobin for each 1.0 degree C temperature increase between 18 and 27 degrees C. Varying the pH of the wash buffer used in the affinity procedure from 7.75 to 8.25 (pH 8.0 optimum) produced at net change of 0.5% in glycosylated hemoglobin with one diabetic specimen. Using the affinity method, we determined the reference interval for glycosylated hemoglobin in 124 apparently healthy individuals to be 5.3 to 7.5% (mean 6.36%, SD 0.55%). Rechromatography by II and isoelectric focusing analysis of the fractions obtained by the affinity separation revealed a substantial population of glycosylated hemoglobins not measured by II. The affinity method offers a rapid, simple, precise, and accurate alternative to methods currently in use and gives substantial freedom from many common interferences.

The cytotoxic effects of a novel IH636 grape seed proanthocyanidin extract on cultured human cancer cells.

Grape seed proanthocyanidins are natural antioxidants which possess a broad spectrum of chemoprotective properties against free radicals and oxidative stress. In this study, we have assessed the cytotoxicity of a novel IH636 grape seed proanthocyanidin extract (GSPE) against MCF-7 human breast cancer cells, A-427 human lung cancer cells, CRL-1739 human gastric adenocarcinoma cells and K562 chronic myelogenous leukemic cells at 25 and 50 mg/lit concentrations for 0-72 h using cytomorphology and MTT cytotoxicity assay. In addition, we compared the effects on normal human gastric mucosal cells and normal J774A.1 murine macrophage cells with the effects on the cancer cell lines. Concentration- and time-dependent cytotoxic effects of GSPE were observed on the MCF-7 breast cancer, A-427 lung cancer and gastric adenocarcinoma cells. Following incubation of the MCF-7 cells with 25 mg/lit of the GSPE approximately 6.5, 30 and 43% inhibitions in cell growth were observed at 24, 48 and 72 h of incubation, respectively, while incubation of the MCF-7 cells with 50 mg/lit of the GSPE resulted in 11, 35 and 47% inhibition in cell growth at these same points, respectively. Similar results were observed in the A-427 and gastric adenocarcinoma cells. GSPE exhibited no cytotoxicity toward the neoplastic K562 myelogenous leukemic cells. However, GSPE enhanced the growth and viability of the normal human gastric mucosal cells and J774A.1 murine macrophage cells. These data demonstrate that GSPE exhibited cytotoxicity towards some cancer cells, while enhancing the growth and viability of the normal cells which were examined.