Diatomaceous Earth

The use of silicon (Si) in functional foods is innovative. Because meat products are versatile, nutritious and highly accepted by the population, in this study a reduced-fat meat product (pâté) with added Si from diatomaceous earth was assayed. The design was a four-way postprandial randomized crossover-controlled trial. Eighteen adults (n = 18, mean age 58 ± 8 years, 68% women) consumed a standard meal with the following pâtés: control (C), with normal fat content; reduced-fat (RF), in which pork backfat was fully replaced by emulsions; the C with added diatomaceous earth powder as a source of Si (C-Si); and the RF pâté with the same Si source (RF-Si). Volunteers were characterized in terms of fasting lipemia, body weight, body composition, blood pressure, smoking habits, and medication. Blood samples were collected at 0, 1, 2, and 4 h after ingesting the standard meal containing each of the pâtés. Results show that, regardless of the type of patê, postprandial serum Si and triglycerides increased (p = 0.015 and p < 0.001), and insulin increased during the first hour and decreased thereafter (p < 0.001) while glucose was unchanged. In conclusion, Si from diatomaceous earth is unabsorbed and has no effect on normal postprandial metabolism in adult men and women, suggesting that this inorganic source of Si should not be used as a bioactive ingredient in functional foods.

The concept of dual drug delivery to treat relapsing tumors is a well-studied approach to improve the antitumor efficacies and to reduce the side effects of single drug chemotherapeutic treatments. One of the major issues with dual drug delivery to treat drug resistant tumors is the concentration and ratio dependent antagonistic behavior of two drugs, which may reverse the anticancer efficacies of individual chemotherapeutics and stimulate the growth of tumor cells. In this paper, we address this issue by developing diatomaceous earth embedded core shell materials, which are capable of encapsulating two chemotherapeutic drugs at constant molar ratios, in different compartments of a single drug delivery carrier. The encapsulation of each drug in different compartments of delivery carrier (core of diatoms versus shell of cyclodextrin) then controls the release rate of both drugs in situ, and maintains the optimal molar ratios required for their synergistic outcomes in vitro.

BACKGROUND: The activated clotting time (ACT) is widely used for monitoring heparin anticoagulation during cardiac surgery. Celite-based ACT values are prolonged when aprotinin is administered. MDCO-2010, a novel serine protease inhibitor, is currently being evaluated as a possible alternative to aprotinin. Therefore, we evaluated the in vitro effects of this novel agent on ACT values using 3 different point-of-care instruments with kaolin or celite as an activator. METHODS: The study was performed in 2 parts. In the first part, blood samples were obtained from 15 healthy volunteers. Samples were pipetted into small Eppendorf tubes and 2 concentrations of the MDCO-2010 (100 and 500 nM, final concentration) alone or with heparin (1.2 or 2.4 U/mL) were added. ACTs were measured using Helena (celite), Hemochron (kaolin), and Medtronic (kaolin) devices. In the second part of the study, blood samples were obtained intraoperatively, at 5 time points, from 15 patients undergoing cardiopulmonary bypass. MDCO-2010 at a final concentration of 100 or 500 nM was added and ACT testing was performed as before. Additional coagulation tests included prothrombin time, activated partial thromboplastin time, fibrinogen, antithrombin, prothrombin, and anti-Xa levels. RESULTS: Addition of MDCO-2010 concentration-dependently prolonged ACTs in volunteers' and patients' blood samples regardless of the ACT activator or device used. In volunteer samples (no heparin) and in patient samples (baseline and intensive care unit) percent changes in ACTs due to MDCO-2010 were on average 3.1 ± 1.8 times higher (95% confidence interval 2.6-3.6; P < 0.001) for the celite-based Helena device compared with either Hemochron or Medtronic devices. CONCLUSION: MDCO-2010 causes less ACT prolongation with kaolin than with celite activation.

BACKGROUND: Thromboelastography is used for assessment of hemostasis. Adherence to thromboelastography-guided algorithms and aprotinin administration each decrease bleeding and blood product usage after cardiac surgery. Aprotinin, through inhibition of kallikrein, causes prolongation of the celite-activated clotting time and the activated partial thromboplastin ratio. The aim of this study was to assess the effects of aprotinin on the thromboelastography trace. METHODS: Three activators were used in the thromboelastography: celite (which is widely established), kaolin, and tissue factor. Assessment was performed on blood from volunteers and from patients before and after cardiac surgery. RESULTS: The tissue factor-activated thromboelastography trace was unaffected by the addition of aprotinin. When celite and kaolin were used as activators in the presence of aprotinin, the reaction time (time to clot formation) of the thromboelastography trace was prolonged (P < 0.0001) and the maximum amplitude (clot strength) was decreased (P < 0.05). With celite as an activator, the addition of aprotinin decreased (P < 0.05) the thromboelastography alpha angle (rate of clot extension). The reaction time of the celite-activated trace correlated with the activated partial thromboplastin ratio (P < 0.01). The reaction time of the tissue factor-activated trace correlated with the international normalized ratio (P < 0.01). CONCLUSION: The thromboelastography trace is altered in the presence of aprotinin when celite and kaolin are used as activators but not when tissue factor is the activator.

Several adsorbent materials were tested at I mg/ml for their in vitro capacity to adsorb fumonisin B1(FB1) from aqueous solutions. Cholestyramine showed the best adsorption capacity (85% from a solution containing 200 microg/ml FB1) followed by activated carbon (62% FB1). Bentonite adsorbed only 12% of the toxin from a solution containing 13 microg/ml FB1, while celite was not effective even at the lowest tested FB1 concentration (3.2 microg/ml). Cholestyramine was tested in vivo to evaluate its capacity to reduce the bioavailability of fumonisins (FBs) in rats fed diet contaminated with toxigenic Fusarium verticillioides culture material. Rats were exposed for one week to FBs-free diet, FBs-contaminated diet containing 6 or 20 microg/g FB1 + FB2 and the same FBs-contaminated diet added of 20 mg/g cholestyramine. The increase of sphinganine/sphingosine (SA/SO) ratio in urine and kidney of treated rats was used as specific and sensitive biomarker of fumonisin exposure. The addition of cholestyramine to the FBs-contaminated diets consistently reduced the effect of FBs by reducing significantly (P < 0.05) both urinary and renal SA/SO ratios.

118. Am J Epidemiol. 1998 Aug 1;148(3):307-9. doi: 10.1093/oxfordjournals.aje.a009641. Re: "Dose-response associations of silica with nonmalignant respiratory disease and lung cancer mortality in the diatomaceous earth industry". Mirliss MJ. Comment on Am J Epidemiol. 1997 Apr 15;145(8):680-8. doi: 10.1093/aje/145.8.680.

119. Am J Epidemiol. 1998 Aug 1;148(3):307; author reply 308-9. doi: 10.1093/oxfordjournals.aje.a009640. Re: "Dose-response associations of silica with nonmalignant respiratory disease and lung cancer mortality in the diatomaceous earth industry". Gibbs GW. Comment on Am J Epidemiol. 1997 Apr 15;145(8):680-8. doi: 10.1093/aje/145.8.680.

Comment in Am J Epidemiol. 1998 Aug 1;148(3):307; author reply 308-9. doi: 10.1093/oxfordjournals.aje.a009640. Am J Epidemiol. 1998 Aug 1;148(3):307-9. doi: 10.1093/oxfordjournals.aje.a009641. The potential carcinogenicity of crystalline silica to humans remains a controversial issue. The authors conducted an historical cohort mortality study of 2,342 male workers exposed to crystalline silica, predominantly cristobalite, in a diatomaceous earth mining and processing facility in California. During the years 1942-1994, mortality excesses were detected for nonmalignant respiratory diseases (NMRD) (standardized mortality ratio = 2.01, 95% confidence interval (CI) 1.56-2.55) and lung cancer (standardized mortality ratio = 1.29, 95% CI 1.01-1.61). NMRD mortality rose sharply with cumulative exposure to respirable crystalline silica; allowing for a 15-year latency, the rate ratio for the highest exposure stratum (> or = 5.0 mg/m3-years) was 5.35 (95% CI 2.23-12.8). The rate ratio for lung cancer reached 2.15 (95% CI 1.08-4.28) in the highest exposure category. These associations were unlikely to have been confounded by smoking or asbestos exposure. The findings indicate a strong dose-response relation for crystalline silica and NMRD mortality. The lung cancer results, although less convincing, add further support to an etiologic role for crystalline silica. Aprotinin prolongs activated and nonactivated whole blood clotting time and potentiates the effect of heparin in vitro. Despotis GJ(1), Filos KS, Levine V, Alsoufiev A, Spitznagel E. Author information: (1)Department of Anesthesiology, Washington University School of Medicine, St. Louis, Missouri 63110, USA. This study was designed to evaluate the effect of aprotinin on activated versus nonactivated whole blood clotting time using two different on-site methods and to quantify these anticoagulant properties when compared to heparin in a controlled, in vitro environment. Blood specimens were obtained prior to heparin administration from 56 patients undergoing cardiac surgery. Specimens obtained from the first consecutive 20 patients were mixed with either normal saline (NS) or aprotinin (400 kallikrein inhibitin

32. Anesth Analg. 1996 Jun;82(6):1126-31. doi: 10.1097/00000539-199606000-00005. Aprotinin prolongs activated and nonactivated whole blood clotting time and potentiates the effect of heparin in vitro. Despotis GJ(1), Filos KS, Levine V, Alsoufiev A, Spitznagel E. Author information: (1)Departmen

In cardiopulmonary bypass (CPB) surgery high dose heparin is necessary to inhibit the clotting cascade which is activated through damage to the vessels (extrinsic pathway) as well as contact activation of the blood with the various artificial surfaces of the CPB machine (intrinsic pathway). In most European heart surgery centres, the fibrinolytic activation that always occurs in CPB due to contact activation is reduced by the proteinase inhibitor aprotinin. Monitoring of anticoagulation during CPB is performed with the activated whole blood clotting time (ACT). The two machines commonly used for this purpose, Hemotec and Hemochron, use different contact system activators, kaolin and celite. These activators displayed highly significant differences, in both in vitro tests (modified APTT with whole blood in a neutral coagulometer), and ACT in both machines where aprotinin and heparin were used, as well as with parallel measurements with the two machines with blood from patients undergoing CPB with high dose aprotinin therapy (P < 0.001). The Hemotec machine with kaolin as activator was not affected by aprotinin throughout surgery, while the Hemochron clotting times almost doubled as soon as aprotinin and heparin were combined. Our studies show that for the determination of ACT in CPB were high dose aprotinin therapy is used only ACT determinations with machines using kaolin as activator yield accurate results.