A K Harouny

Kuwait University, Kuwait, Muhafazat al `Asimah, Kuwait

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Publications (4)11.56 Total impact

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    ABSTRACT: The effect of hyperglycaemic loads on L-leucine transport in the maternal-foetal direction has been investigated in human placenta in vitro, using perfusion of isolated placental lobules. National Culture and Tissue Collection medium diluted with Earle's buffered salt solution was used as the perfusate. (14)C-labelled L-leucine along with tritiated water as reference were injected as a 100-microl bolus into the maternal circulation and serial perfusate samples were collected over a 5-min study period. In 6 successful perfusions, the differential transport rate of leucine for 10, 25, 50, 75 and 90% of efflux in the foetal vein averaged 1.26, 1.10, 1.19, 1.10 and 1.04 times respectively that of reference in the control euglycaemic phase. In the experimental hyperglycaemic phases of 27.8 and 55.6 mM/l, leucine transport for the corresponding efflux periods averaged 1.37, 1.33, 1.28, 1.22 and 1.26 times and 1.16, 0.97, 1.08, 1.08 and 1.08 times respectively that of the reference marker. Analysis of variance (ANOVA) test showed that the difference between the three groups was not statistically significant. In the control euglycaemic phase, leucine transport fraction (TF) averaged 40.90+/-3.51% of corresponding water TF while in experimental hyperglycaemic phases, TF of the amino acid averaged 37.80+/-4.82% and 35.61+/-3.21% of water TF respectively. The difference between the control and hyperglycaemic perfusion phases was not statistically significant. Further, no statistical difference could be shown between the two hyperglycaemic perfusion series themselves. Similarly, kinetic parameters such as absorption rate, elimination rate and absorption rate:elimination rate ratio were not significantly different in the hyperglycaemic perfusion phases compared to control phase. Our studies seem to indicate that leucine transport kinetics in in vitro conditions are not altered significantly in placentas exposed to hyperglycaemic loads.
    Acta Diabetologica 04/2005; 42(1):16-22. · 4.63 Impact Factor
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    ABSTRACT: The objective was to assess the status of essential trace elements such as copper, iron, molybdenum, selenium and zinc in insulin-dependent diabetic pregnancies at term and to compare the data with a control group. Fetal-maternal ratios of the elements and copper:zinc ratio were also computed in the control and study populations. Samples from maternal vein, umbilical artery and umbilical vein of diabetic and control women were collected at the time of spontaneous delivery or cesarean section and activities of trace elements evaluated by atomic absorption spectrophotometry. Cu, Fe, Mo, Se and Zn concentrations in maternal venous blood averaged 2,156, 2,020, 13, 102 and 656 microg/l in control women (n=17) while in the diabetic group (n=14), the corresponding values for the trace elements averaged 3,135, 3,675, 15, 85 and 628 microg/l respectively. Values for copper and molybdenum were significantly higher (p<0.05) in the study group compared to control while those of zinc, iron and selenium were not significantly different (p>0.05). Iron and molybdenum values were significantly higher (p<0.05) and that of zinc significantly lower (p<0.05) in umbilical arterial samples of diabetic group compared to controls. In the case of molybdenum, copper the values were significantly higher (p<0.05) in umbilical venous samples of diabetic group compared to that of control. Significant differences in Cu:Zn ratio of maternal venous and umbilical samples and fetal-maternal ratios of some elements were noted between control and study group as well. We speculate that altered status of some essential trace elements and altered antioxidant mineral ratio observed in insulin dependent diabetic patients could have deleterious influences on the health of the mother as well as the fetus and newborn.
    Archives of Gynecology and Obstetrics 03/2005; 271(3):212-7. · 1.33 Impact Factor
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    ABSTRACT: The role of hyperglycemia on modulation of maternal-fetal transport of amino acids in humans is little understood. Hence, we have explored the effect of increased glucose load on transport kinetics of a model non-metabolizable amino acid, alpha-aminoisobutyric acid (AIB), in the human placenta in vitro. Transport kinetics of AIB in maternal-fetal direction was studied using perfusion of isolated human placental lobules. NCTC (National Culture and Tissue Collection)-135 medium, diluted with Earle's buffered salt solution was used as the perfusate and tritiated water was used as the reference marker. Effect of increased glucose load on transport kinetics of study and reference substances was studied in normal term placentae (n=5; gestational age, 38.5 +/- 0.5 weeks) in succeeding experimental phases, after a control perfusion phase with physiological glucose concentration. AIB transport fraction (TF), relative to tritiated water TF, averaged 54.8% in control euglycemic phase while in hyperglycemic concentration phases of 27.8 and 55.6 mM, the AIB TF index averaged 42.4% and 38.2%, respectively. Analysis of variance revealed that the difference was statistically significant. Similarly, absorption rate index of the amino acid was also significantly lower in the hyperglycemic perfusion phases compared to control euglycemic phase. We conclude that hyperglycemia may play a deleterious role in limiting maternal-fetal transport of A-type amino acids in the in vivo state.
    Acta Diabetologica 07/2002; 39(2):75-81. · 4.63 Impact Factor
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    ABSTRACT: To investigate the transport kinetics of a model amino acid, alpha-aminoisobutyric acid (AIB), in the maternal-fetal direction in placentae from pre-eclamptic pregnancies. Transport kinetics of the amino acid was assessed in vitro using perfusion of human placental lobules. Control placental lobules were perfused for comparison. National Culture and Tissue Collection--135 medium diluted with Earle's buffered salt solution was used as the perfusate, and tritiated water served as the internal reference marker. AIB along with reference marker was injected as a single bolus into the maternal arterial perfusate, and serial perfusate samples were collected from maternal and fetal venous circuits for a study period of 5 min. The differential transport rate of the amino acid for various efflux fractions differed significantly between control and experimental groups when compared to that of the reference marker. The transport rate (corresponding to 50% of efflux into the fetal vein), transport fraction, absorption and elimination rates of the amino acid differed significantly compared to the reference marker values in study and control groups. The results indicate that amino acid transport function is compromised in placentae of pre-eclamptic pregnancies.
    Medical Principles and Practice 01/2002; 11(2):75-81. · 0.96 Impact Factor