Absorption by the bovine retina of physiological concentration of PLP-GABA increase clearing 2-32 minutes of incubation in difference of GABA and its non metabolic preparations, which store up as much as possible in first minutes: picamilon > PLP-GABA > GABA > panthogam > biotinil-GABA. Kinetics of transport of GABA and its preparations into retina has a complex character. By the growth of concentration from 33 mM to 528 mM, it is linear for picamilion, showing diffusion, and not linear for GABA, PLP-GABA and panthogam, showing differently systems of its transport. And only GABA transport is activated by Na-ions.
The absorption of polychlorinated biphenyls, dibenzo-p-dioxins and dibenzofurans was studied in four breast-fed infants. The absorption was measured by comparing the estimated total intake and the excretion in faeces, during 48 hours, at three different time points; 1, 2 and 3 months post parta. The levels of the analysed compounds in the human milk are typical for Sweden, i.e approximately 20 ppt toxic equivalents for the dibenzo-p-dioxins and dibenzofurans and for the polychlorinated biphenyls approximately 16 ppt toxic equivalents. For most of the congeners the absorption is found to be over 95%. Higher excretion is noticed for heptachlorinated and octachlorinated dioxins.
The effect of injection technique on the absorption of subcutaneously injected short-acting insulin [125I-labeled Actrapid (MC), Novo, Copenhagen, Denmark] was investigated in insulin-dependent diabetic patients. In one side of the abdomen insulin was given with a fixed standard technique. In the other side of the abdomen the temperature of the injected insulin, the depth of injection, and the duration of injection were varied. Furthermore, we compared the absorption of U40 and U100 insulin by giving either 8 U of the two insulins or 0.1 ml of both insulins simultaneously to the patients in either side of the abdomen. With regard to the injection technique the only significant finding was a faster absorption rate with deep (12 mm) than with superficial (3 mm) injection. The absorption of U100 insulin was significantly slower than of U40 insulin, when given in the same amount (8 U) as well as in the same volume (0.1 ml).
For Inuit children, a traditional diet contains 20 mg of elemental calcium per day, well below the recommended daily intake. To identify alterations in intestinal or renal calcium absorption, 10 healthy Inuit children (5 to 17 years of age) were given a standardized calcium load (Pak test). Five had hypercalciuria (hyperabsorptive in 3 and renal leak in 2), a frequency markedly different from that for white children (p
Although determining iron intakes is essential in assessing adequacy of iron in the diet, estimating iron availability may be more useful for evaluating whether iron requirements are met. Our objectives were to describe the dietary information, analytical steps, and computer algorithms needed for iron bioavailability adjustments and to demonstrate the effects of various dietary factors on calculated iron absorption. Our study was based on 9890 women and children participating in the Russian Longitudinal Monitoring Survey. Between August 1992 and February 1993, two 24-h recalls were collected from each participant, and total, heme and nonheme iron intakes were calculated. Nonheme iron availability was adjusted for meat, fish and poultry and vitamin C consumed in the same meal and then further adjusted for tea and phytates. We found mean total iron intakes to be comparable to those of women of reproductive age in the United States and lower than those of United States children. When these intakes were adjusted for enhancers and inhibitors of absorption, the iron bioavailability in these vulnerable Russian groups was extremely low. Mean bioavailable iron as well as the 25th-75th percentile ranges of intake were below the bottom of the range of requirements, indicating that iron adequacy in this population may be considerably less than expected based on total iron intakes alone. Furthermore, rural and urban food availability had a significant effect on iron bioavailability. Future research on dietary iron adequacy should be based on estimates of available iron by collecting meal-level dietary data and using detailed information on mixed dishes and phytates.
BACKGROUND: Dry powder inhalers (DPI) have in recent years become a common mode for administration of inhaled corticosteroids for preventive therapy of asthma. Inhaled steroids delivered by DPI achieve increased lung deposition compared with pressurized metered-dose inhalers (pMDI), which is associated with increased therapeutic effect. This may be associated with increased systemic absorption. OBJECTIVE: The purpose of this study was to evaluate the prevalence of adrenal suppression in children using low-dose budesonide given by DPI, as compared with pMDI attached to a large-volume spacer device (pMDI + spacer). METHODS: In an open-labeled crossover study, 15 asthmatic children aged 5 to 15 years received 200 microg of inhaled budesonide twice daily by DPI (Turbuhaler, Astra, Draco AB, Lund, Sweden) and by pMDI + spacer, 1 month each, in a randomized order. Twenty-four-hour urine collections were performed at baseline and at the end of each of the 2 months of the study period, and urinary cortisol and creatinine were measured. RESULTS: Baseline urinary cortisol:creatinine was 0.038 +/- 0.012 microg/mg, similar in both groups. After 1 month of DPI therapy, urinary cortisol:creatinine was reduced by 27 +/- 16% to 0.028 +/- 0.012 microg/mg (P = 0.018). Urinary cortisol:creatinine after 1 month of pMDI + spacer therapy was similar to baseline 0.037 +/- 0.019 microg/mg (P = 0.78). CONCLUSIONS: Treatment of asthmatic children with budesonide 400 microg daily given via a DPI for 1 month was associated with hypothalamic-pituitary-adrenal axis suppression. This effect was not observed with the same dose of budesonide administered via pMDI + spacer. This indicates that systemic absorption might be reduced with pMDI + spacer therapy.
Comment In: Ann Allergy Asthma Immunol. 2002 Dec;89(6):537-912487216