A subtherapeutic international normalized ratio despite increasing doses of warfarin: could this be malabsorption?

OBJECTIVE: To describe a case of warfarin resistance apparently caused by malabsorption and to review the literature regarding warfarin resistance. CASE SUMMARY: A 28-year-old renal transplant patient with systemic lupus erythematosus was admitted for upper extremity thrombophlebitis. Resistance to oral warfarin was demonstrated. Potential causes were investigated. The trapezoidal rule was used to compare the area under the curve for intravenous versus oral dosing of warfarin. The usual bioavailability of warfarin should be 100%. In this patient, warfarin bioavailability after oral dosing was 1.5%. Three potential causes, malabsorption (FF), enzymatic degradation (FG), and first-pass extraction in the portal circulation (FH), are discussed. CONCLUSION: This case demonstrates resistance to warfarin presumably caused by malabsorption.

Characterization of yellow rice and development of instant flours by hydrothermal process.

Commercial brown and yellow milled rice submitted to inappropriate storage conditions were characterized and utilized to develop instant flours that were used in the preparation of atoles. The grains were classified as long-thin; the average size was 2.13 x 6.79 mm. The milling yields obtained in laboratory with paddy rice were 70% brown rice and 60% milled rice. Brown rice and yellow milled rice had similar amylose contents, 22.5 and 25.6% respectively. Gel consistency was soft with low gelatinization temperature (63-68 degrees C) for both samples. Field fungi, such as Helminthosporium oryzae, and storage fungi, such as Aspergillus spp, were present in paddy, yellow milled and commercial rice. The fungus Helminthosporium oryzae, Aspergillus spp, and Penicillum spp were not present in instant flours. Instant flours were prepared by soaking the grain in water, and then steaming, drying and milling it. The highest values for water absorption index were obtained from yellow milled instant rice flour. The color of yellow milled instant rice flour varied from white ("L") to pale yellow (lesser values of "b"). The lower viscosity of the instant flours indicates the breakdown of polymers and reveals that unintact starch granules were not present in instant flours. Protein and ash contents of brown and milled rice were unaffected by hydrothermal process, and the lipid content showed only little changes. Sensory analyses carried out on the atoles prepared with instant flours considered them acceptable, specially for products made from milled yellow rice.