A doctor's journey to the world of faith.
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Adult↗
Biomedical subjects
F Rahman
Publications and source records attributed to F Rahman.
Umbilical artery Doppler flow-velocity waveforms and fetal acid-base balance in Rhesus-isoimmunized pregnancies.
Pulsed Doppler blood-flow velocity waveforms in the umbilical arteries, as well as blood gases, hematocrit, and lactate concentration in umbilical venous blood, were examined in 21 patients undergoing 49 cordocentesis, 34 of which were followed by fetal blood transfusion into the umbilical vein. The aim of the study was to evaluate the correlations, if any, between the Doppler indices from the umbilical artery (pulsatility index, resistance index, systolic/diastolic ratio) and the blood gas values (pO2, pCO2, O2 content, pH) and lactate content in the umbilical vein. The only correlation confirmed in this study was in the subgroup of anemic fetuses undergoing fetal blood transfusion, where correlation existed between A/B and the initial O2 content (r = -0.41, p < 0.02). We conclude that, in Rhesus-isoimmunized pregnancies, in contrast to other pregnancies, a close correlation does not exist between the Doppler indices in the umbilical artery and the fetal blood gas values.
Acid-Base Equilibrium↗
Umbilical artery Doppler flow-velocity waveforms in Rhesus-isoimmunized fetuses before and after fetal blood sampling or transfusion.
Pulsed-Doppler examinations of blood-flow velocities in the umbilical artery were carried out before and after 15 diagnostic cordocenteses and 34 fetal blood transfusions into the umbilical vein. There were decreases in the systolic/diastolic ratio (A/B) (p < 0.01), the pulsatility index (PI) (p < 0.05), and the resistance index (RI) (p < 0.01) after cordocentesis but not after fetal blood transfusion. There were no correlations between the initial hematocrit and the umbilical artery Doppler indices in the sample nor in the fetal blood sampling group. In the fetal blood transfusion group, on the other hand, there was a negative correlation between the initial hematocrit and A/B (r = -0.44; p < 0.01) and the RI (r = -0.35; p < 0.05). The umbilical artery Doppler flow-velocity indices did not predict the fetal hematocrit.
Blood Flow Velocity↗
Early bactericidal action of pulsed exposure to rifampicin, ethambutol, isoniazid & pyrazinamide in pulmonary tuberculosis patients.
The bactericidal action of two therapeutic regimens on Mycobacterium tuberculosis was assessed by viable counts in serial sputum samples in 49 pulmonary tuberculosis patients being treated with rifampicin (R), ethambutol (Emb), isoniazid (I) and pyrazinamide (Z) together in a single dose thrice weekly (REmbIZ3) or with REmb and IZ on alternate days (REmb3IZ3alt). In both groups of patients, there was a significant reduction (P < or = 0.02) in the colony forming units (cfu) of M. tuberculosis per ml of sputum during the first two days of treatment itself. This early bactericidal action (EBA) as well as the reduction in counts during the subsequent days of treatment were similar (P > 0.2) for both REmbIZ3 and REmb3IZ3alt regimens indicating that splitting up REmbIZ into REmb on one day and IZ on the next day in short course chemotherapy (SCC) regimens may not affect the bactericidal action of the regimens.
Antitubercular Agents↗
Hypoxanthine in fetal umbilical venous blood and amniotic fluid from pregnancies complicated by rhesus isoimmunization.
Concentrations of hypoxanthine (HX) was determined in umbilical venous blood and amniotic fluid obtained at 74 instances in 36 rhesus immunized patients before the onset of labor. HX concentrations were related to gestational age, concentrations of hemoglobin and lactate, pH, and partial oxygen pressure in umbilical venous blood. Multiple regression analysis revealed hemoglobin concentration to be the only variable that had any explanatory power to HX in amniotic fluid. No one of the studied variables gave any significant contribution to a regression model to explain HX in umbilical venous blood. We conclude that HX levels in umbilical venous blood and in amniotic fluid from rhesus immunized patients were not associated with fetal blood gases before the onset of labor.
Amniocentesis↗
Erythropoietin concentrations in amniotic fluid and umbilical venous blood from Rh-immunized pregnancies.
We set out to investigate prospectively the levels of erythropoietin in amniotic fluid and umbilical venous blood, and to attempt to relate these to fetal haemoglobin and lactate concentrations and to pCO2 and PO2 in Rh immunised patients studied before the onset of labor. Fetal blood was obtained by cordocentesis, and amniotic fluid by amniocentesis from a consecutive series of 36 Rh immunized patients at the time of fetal blood sampling. There was a close correlation (tau = 0.357, P = 0.0001) between the concentrations of erythropoietin in umbilical venous blood and those in amniotic fluid. Erythropoietin in umbilical venous blood correlated inversely with hemoglobin (tau = 0.453, P = 0.0001), and directly with lactate concentrations (tau = 0.450, P = 0.0005). When all other variables were considered, multiple regression analysis demonstrated hemoglobin concentration to be the only variable to be related to the level of erythropoietin in umbilical venous blood taken before transfusion. When the same analysis was performed on the same variables, adding erythropoietin concentration in amniotic fluid as the dependent variable, only erythropoietin in umbilical venous blood was found to be related to the level of erythropoietin in amniotic fluid. We conclude that the erythropoietin concentration in umbilical venous blood from Rh-immunized patients before the onset of labor, is related to fetal anemia. We also conclude that erythropoietin concentration in amniotic fluid is related to that in fetal blood, thereby indicating that the fetus is an important source of amniotic fluid erythropoietin in non laboring patients.
Amniotic Fluid↗
Intrauterine intravascular transfusions in fetal erythroblastosis: the influence of net transfusion volume on fetal survival.
The intravascular volume load that an anemic fetus can tolerate was studied retrospectively in 124 consecutive intravascular transfusions in 35 erythroblastic fetuses. The tolerated volume load correlated well to the estimated fetal weight. Transfusion volume loads above 20 ml/kg of the estimated fetal weight resulted in a lower fetal survival. We recommend an upper transfusion limit at 20 ml/kg corresponding to approximately 20% of the feto-placental blood volume.
Blood Transfusion, Intrauterine↗
Lack of relation between fetal blood gases and fetal blood flow velocity waveform indices found in rhesus isoimmunised pregnancies.
OBJECTIVE: To investigate the relation between umbilical vein blood gas components and the vascular resistance in four fetal arteries in Rh-immunised pregnancies. DESIGN: A prospective observational study over a 4-month period. SETTING: King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia. SUBJECTS: Fifteen Rh-isoimmunised pregnant women. INTERVENTIONS: Pulsed Doppler examinations of the umbilical artery, fetal internal carotid artery, thoracic aorta and abdominal aorta before transabdominal fetal blood sampling from the umbilical vein on 38 occasions. MAIN OUTCOME MEASURES: Doppler flow velocity pulsatility index (PI), systolic/diastolic ratio (A/B) and resistance index (RI) in the four fetal arteries investigated were related to the umbilical vein blood gases and acid-base status (PO2, PCO2, O2-content, CO2-content, HCO3, base excess and lactate concentration). RESULTS: There were no correlations between the Doppler indices in any of the vessels studied and the blood gases components in the umbilical vein. The ratios between the corresponding Doppler indices in the different vessels were also independent of the blood gases and acid-base status and there were no significant differences in the Doppler indices in the same vessel between fetuses with blood gas values over the 75th centile and those with values below the 25th centile. CONCLUSION: This study does not support a reduction in peripheral vascular resistance in the fetal cerebrum in relation to fetal hypoxia in Rh-immunized pregnancies.
Blood Flow Velocity↗
Breast cancer in elderly women.
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Age Factors↗
Myocardial contractility in the anemic human fetus.
Severely anemic fetuses in Rh-isoimmunized pregnancies are often found to have hydrops and the etiology is debated. Fifteen fetal blood samplings were performed in nine fetuses for determination of the degree of anemia and of the acid-base balance. Waveform analysis was performed on the maximum blood velocity curve in the umbilical arteries and the ascending fetal aorta, obtained by means of a pulsed Doppler technique. The blood acceleration in the ascending aorta increased down to a hematocrit of 0.18 and a hemoglobin concentration of 65 g/l, which might constitute a cardiac response to the anemia aimed at maintaining the peripheral blood circulation. Below these levels there was a decrease in blood acceleration, which could be caused by impaired cardiac oxygenation. This relationship could be described as a six-power function (r = 0.87; p = 0.032). A second-power relationship was found between the umbilical artery pulsatility index and the blood acceleration in the fetal ascending aorta (r = 0.64; p = 0.0418), which suggests that the cardiac pump function can alter the blood velocity waveform in the umbilical arteries.
Journal Article↗
Salivary levels of isoniazid and rifampicin in tuberculous patients.
Concentrations of isoniazid and rifampicin were determined in time-matched samples of saliva and serum from 30 tuberculous patients (18 with pulmonary tuberculosis and 12 with intestinal tuberculosis), comprising 18 slow and 12 rapid acetylators of isoniazid, following administration of isoniazid 300 mg and rifampicin 12 mg/kg. The diffusion of isoniazid into saliva was quite rapid and the salivary concentrations were similar to those in serum, suggesting that saliva could be used in place of serum for all pharmacokinetic studies with isoniazid. The salivary concentrations of rifampicin were much lower than those in serum, the mean peak concentrations being 0.9 and 8.5 microgram/ml, respectively. Further, there was evidence of a significant delay in the diffusion of rifampicin from serum to saliva.
Adolescent↗
Fetal heart rate responses to anemia in Rh isoimmunization.
On 52 occasions 24 Rh immunized women were monitored with a nonstress test (NST) prior to fetal blood sampling. Cardiotocographic characteristics were recorded for each NST. Fetal blood was analysed for hemoglobin and hematocrit. Fetal hemoglobin and hematocrit were positively correlated to long-term variability, acceleration amplitude and negatively correlated to deceleration amplitude (linear regression analysis; p less than 0.05). Decelerations were almost without exception associated with low concentrations of hemoglobin and hematocrit. In fetuses of 32 weeks' gestation or more, a loss of variability (less than or equal to 5 bpm) was associated with severe anemia. Hemoglobin and hematocrit were significantly lower in the group with a pathological NST (n = 15) compared with the group with a normal NST (n = 37) (Mann-Whitney U test; p less than 0.05). The predictive value of a pathological test was 13/15 concerning hemoglobin and hematocrit; whereas, the predictive value of a normal test was poor. A pathological NST, especially when decelerative, is a good predictor of fetal anemia, but a normal NST is no guarantee for a normal blood status.
Anemia↗
Thrombolytic effects of tissue-type and urokinase-type plasminogen activators in rabbits with experimental pulmonary thromboembolization.
The thrombolytic effects of tissue-type of plasminogen activator (t-PA) and urokinase-type of plasminogen activator (u-PA) were studied in experimental rabbit model of pulmonary thromboemboli with or without endotoxin. After intravenous injection of thrombi, we infused recombinant t-PA or double chain u-PA (0.1 mg/kg and 0.3 mg/kg each). Both lungs were histologically examined and the number of thromboemboli/area was calculated. This number of thromboemboli/area thus obtained made the basis for comparing the thrombolytic activity of both t-PA and u-PA. Administration of t-PA at both 0.1 mg/kg and 0.3 mg/kg doses significantly decreased the number of thromboemboli/area comparing to that of u-PA at the respective doses. The treatment of rabbits with endotoxin (1 microgram/kg) increased the number of thromboemboli especially in less than 50 microns diameter of pulmonary microvessels probably due to hypercoagulable and hypofibrinolytic state of rabbits. t-PA, even after endotoxin stimulation, also significantly decreased the thromboemboli comparing to u-PA. From these observations, it is confirmed that t-PA is a much stronger and more effective thrombolytic agent in vivo on the aspects of specific thrombolytic activity and the systemic hypofibrinogenemic effect than u-PA.
Animals↗
Frequency of HLA genes and islet cell antibodies (ICA) and result of postpartum oral glucose tolerance tests (OGTT) in Saudi Arabian women with abnormal OGTT during pregnancy.
A consecutive series of 55 Saudi women with abnormal 75 g oral glucose tolerance test (OGTT) during pregnancy was reinvestigated 2-4 months after delivery. A 75 g OGTT was done and samples were also drawn for analysis of C-peptide concentration, islet cells antibodies (ICA) and HLA antigens. The results of these laboratory investigations and a number of patient characteristics were analyzed to identify risk factors for patients likely to have impaired OGTT after delivery. Twenty-five (45.5%) of the patients had an abnormal OGTT after delivery. The distribution of HLA antigen frequencies did not differ from a reference group of healthy Saudis. ICA were found in only one patient. Logistic regression analysis identified insulin treatment during pregnancy (p = 0.001) as the only factor to predict an abnormal OGTT after delivery.
Adult↗
Classification of children as slow or rapid acetylators based on concentrations of isoniazid in saliva following oral administration of body-weight and surface-area-related dosages of the drug.
The acetylator phenotype of 180 children aged 3-11 years was determined on the basis of isoniazid concentrations in saliva collected at 5 hours after oral administration of body-weight and surface-area-related dosages of the drug in a syrup form. Isoniazid 2.5 mg/kg was administered on one occasion and 75 mg/m2 surface-area on another, with an interval of 3 days between the occasions. A cross-over design was employed and the sequence was determined by random allocation. The distribution of the concentrations was bimodal with both procedures, indicating the presence of two groups namely, the slow and rapid acetylators. The criterion for a rapid acetylator was a concentration of 0.3 micrograms/ml or less by body-weight-related dosage and 0.4 micrograms/ml or less by that based on surface-area. Based on these criteria, 62% of the children were classified as slow acetylators and 38% as rapid acetylators by body-weight, and 59 and 41%, respectively by surface-area, and the findings were similar in children in the different age-groups. The agreement between the two procedures was 98%.
Acetylation↗
Electron loss and transfer for 20-110-keV iodine-rare-gas collisions.
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Journal Article↗
The protective effects of trimetazidine on normothermic ischemic myocardium in rats.
The protective effects of trimetazidine on postischemic cardiac function were studied using isolated working rat heart preparations in which global ischemia had been induced with normothermic cardioplegia. After 30 minutes of reperfusion, following a 25 minutes period of ischemia, the addition of 10(-6) M or 10(-5) M trimetazidine to the cardioplegic solution significantly increased the per cent recovery of the cardiac output: from 54.8 +/- 4.1 per cent in the control group to 81.0 +/- 3.2 per cent (p less than 0.01) and 79.6 +/- 4.0 per cent (p less than 0.01), respectively, although lower (10(-7) M) or higher (10(-4) M) doses of the drug failed to result in any change. 10(-5) M trimetazidine also produced a significantly greater recovery of both the postischemic aortic flow: from 47.8 +/- 4.9 per cent to 72.2 +/- 3.8 per cent (p less than 0.01) and coronary flow: from 80.6 +/- 2.9 per cent to 105.2 +/- 6.3 per cent (p less than 0.002). However, trimetazidine did not influence the recovery of either aortic pressure or heart rate. These results suggest that trimetazidine does give some protection to the heart during ischemia and reperfusion.
Animals↗
Albumin transfusion in non-immune fetal hydrops: Doppler ultrasound evaluation of the acute effects on blood circulation in the fetal aorta and the umbilical arteries.
A case of non-immune fetal hydrops, diagnosed as mucopolysaccharidosis VII with hypoalbuminemia, was treated in utero with albumin transfusions via cordocentesis on five occasions. Blood samples were taken for analysis of full blood count and blood gases before and after the transfusions. Pulsed Doppler ultrasound examinations of the arterial waveform were performed in the umbilical arteries and the descending fetal aorta and analyzed for the pulsatility index (PI). The hemoglobin concentration and the hematocrit decreased from 111 +/- 5 g/l and 0.335 +/- 0.008 to 95 +/- 5 g/l and 0.282 +/- 0.023 (mean +/- SD), respectively, after the transfusions. The calculated blood volume increased more than the given volume, indicating an autotransfusion causing additional plasma volume expansion. The blood gases were not significantly changed by transfusion. The PI decreased both in the umbilical arteries (p less than 0.05) and the descending fetal aorta, indicating peripheral vasodilatation. A positive correlation was found between the umbilical artery PI and the hematocrit before and after the albumin transfusion (r = 0.59; p less than 0.05). This relation could be due to covariation with other factors, e.g. peripheral vasodilatation secondary to the increased blood volume and the puncture of the umbilical vein itself. No improvement of the hydrops was seen after the albumin transfusions. The fetus died in utero during spontaneous labor after 30 gestational weeks.
Albumins↗