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Biomedical subjects

H Rostami

Publications and source records attributed to H Rostami.

8 recordsLinked to original sources
PubMed1998

Texturing and polishing. The final attempt at value control.

This article reviews methods for developing surface texture and controlling the luster of ceramic restorations. The authors discuss the characteristics of embryology and age, and profile characteristics of teeth that are vital in creating natural, anatomic restorations. A technique is proposed to enhance the scattering of light and the amount of luster desired in the restoration. The authors recommend hand polishing over autoglazing as a more efficient way to obtain the desired luster. The combination of developing the proper texture and luster is important for the overall value of the restoration.

Adult↗
PubMed1994

Interindividual variability of coumarin 7-hydroxylation in a Turkish population.

One hundred healthy Turkish volunteers (70 male, 30 female) aged from 19 to 56 years were given 5 mg coumarin p.o. after an overnight fast. Urine samples were collected before and 2, 4 and 8 h after drug administration. The extent and rate of formation of 7-OH-coumarin (7OHC) was determined by the urinary excretion of the metabolite as measured with the fluorometric method. On average, 80% of 7OHC formed was excreted in 2 h. The total amount of 7OHC formed was 59.8% (21.5%) (mean and SD, n = 100, range 17-100%) of the given dose. The percentage of 7OHC excreted during the first 2 h compared with the 7OHC excretion at 8 h was a constant and stable individual characteristic for the rate of the formation of 7OHC ('2 h coumarin test'). Although four individuals had relatively slow coumarin test values (34-40%), no clear-cut polymorphism in the rate of 7OHC formation was found. However, 7OHC formation was lower in males and in cigarette smokers.

Adult↗
PubMed1980

Very low density lipoprotein metabolism in domestic pigs.

Patterns of triacylglycerol (TG) turnover in plasma and liver, and the hepatic secretion of very density lipoprotein triacylglycerol (VLDL TG) into the circulation, have been studied in young Large White female pigs, using i.v. tracer [1,3-14C]- and [2-3H]glycerol. Serial measurements were made of plasma [14C]glycerol and [14C]glucose and of liver TG and plasma VLDL TG specific activities. In other studies VLDL TG obtained from a donor pig was reinjected into recipient animals to measure the early disappearance (dilution) of VLDL TG. Multicompartmental analysis revealed a mean rate of hepatic TG turnover somewhat slower than the rate of VLDL TG turnover, suggesting that almost all of the hepatic TG turnover was due to secretion of VLDL TG, and that the intestine probably contributed an appreciable part of the newly synthesized plasma VLDL TG. The t1/2 of reinjected VLDL TG, whether prepared by the most rapid possible techniques and reinjected immediately or stored for several days, was approximately 10 min. This was much faster than the t1/2 of the falling limb of the plasma VLDL TG curve seen after injection of labelled glycerol (t1/2 approximately 2 H). Thus, in these respects, the pig resembled all other species studied rather than human subjects as described by Farquhar et al.

Animals↗
PubMed1974

Evaluation of glucose turnover, body mass and recycling with reversible and irreversible tracers.

1. Methods are presented for the calculation of rates of synthesis or loss, mean transit time and total body pool of compounds from specific-radioactivity curves, without assuming a multicompartmental model and without fitting the data by exponential expressions. The methods apply to the steady state after either single injection or continuous infusion of a labelled compound. 2. The use of irreversible and reversible tracers and the effects of recycling of carbon on the estimations of the parameters of glucose metabolism are discussed. Methods for quantitatively determining recycling of glucose carbon by the use of glucose doubly labelled with (14)C and (3)H are presented.

Carbon↗
PubMed1969

Effect of glucose feeding on net transport of plasma free fatty acids.

The effect of a single glucose feeding upon the net inflow and outflow transport of plasma free fatty acids (FFA) has been studied in 75 unanesthetized rats. The animals were fasted for 22 +/- 2 hr; then 50 rats were refed 2 ml of 50% glucose by gastric intubation. At 0, 10-15, and 30-35 min after glucose refeeding, the rats were injected with palmitate-1-(14)C complexed to rat serum. The tracer dose included (131)I-labeled albumin. Plasma FFA concentration, (131)I concentration, and FFA-(14)C were measured at five time intervals after injection of the tracer dose. From these data the irreversible disposal rate, or net outflow transport, and the net inflow transport of plasma FFA were calculated. Estimations were based upon a special case of a general solution for measuring net inflow and outflow transport of a circulating metabolite. The general solution is independent of the number of compartments, how they are interconnected, the number of nonradioactive inflows, and where the inflows enter the system. Net inflow = net outflow transport = 7.6 micro eq/min in the fasted state and 3.5 micro eq/min in the new steady state that is reached 30-40 min after glucose refeeding. A very slight imbalance between the rates of net inflow and outflow transport could account for the rapid fall in plasma FFA concentration that results from a single glucose feeding. Theoretical and practical problems associated with studying inflow and outflow transport by means of the technique using a single injection of racer are discussed.

Albumins↗
PubMed1969

Effect of glucose ingestion on the metabolism of free fatty acids in human subjects.

The rate of appearance of (14)CO(2) in expired air after the injection of a single dose of NaH(14)CO(3) has been determined in normal individuals both in the fasted and fed states. These data were combined with previously obtained results on the rate of disappearance of injected palmitate-(14)C from the bloodstream, to give a multicompartmental analysis of free fatty acid oxidation and esterification. The results confirm that glucose feeding promptly inhibits the rate of free fatty acid oxidation to CO(2). The "irreversible disposal rate," or irreversible flux of free fatty acids from the plasma, was also consistently reduced by glucose feeding. The diminution in irreversible disposal, not accounted for entirely by reduction of direct oxidation, must indicate suppression of other disposal mechanisms, including net esterification of free fatty acids. An average drop of 49% in "net esterification" when glucose was given may be compared with the 65% inhibition of rapid free fatty acid oxidation.

Bicarbonates↗