Hemoglobin Deficit Research Articles

Ruptur der Arteria uterina nach Spontangeburt mit ungewöhnlichem Verlauf im Wochenbett

Haemorrhage from ruptured uterine vessels is a rare but life-threatening complication during pregnancy. The high rate of mortality associated with this condition is correlated to the rapidity of haematoma formation. The dynamics of this event become particularly evident at the time of birth when the uterus requires one-fifth of the cardiac output. This high rate of flow emphasizes the possible fatal consequences of delayed therapeutical intervention. Information available on the aetiology and pathogenesis of such events is poor, especially if an involvement of cervical vessels or extraperitoneal (incomplete) rupture of the uterus can be excluded. Diagnosis and therapy are based on the classical clinical symptoms of acute abdominal pain-and-shock symptomatology. We report on a 31-year old patient after spontaneous delivery and initially uneventful puerperium. She had to be laparotomised on the third day post partum because of pain and haemoglobin deficiency. We found a large retroperitoneal (supralevatorial) haematoma caused by ruptured lateral branches of the left arteria uterina. The uterus was preserved after haematoma removal and revision and suture of the bleeding vessels. The case reported on shows that peripartal rupture of arterial uterine vessels may turn out to be clinically relevant only after a relatively long time (> 72 hours). Only four comparable cases have been reported in the literature, the course being different from that in all the other cases. In all the documented cases arterial uterine haemorrhages resulted in short-term acute aggravation of the symptomatology with severe abdominal pain, haemodynamic collapse and simultaneous haemoglobin deficit. The case under report in the present paper was at first clinically occult and eventually developed a pathology that had not been described before. Its specific significance lies in illustrating the need for re-evaluating such initially hidden cases while paying special attention to ruptured uterine vessels.

Middle cerebral artery Doppler velocimetric deceleration angle as a predictor of fetal anemia in Rh-alloimmunized fetuses without hydrops

Objective: The purpose of this study was to evaluate the screening performance of a new middle cerebral artery Doppler velocimetric index for the prediction of fetal anemia. Study Design: Doppler velocimetry of the middle cerebral artery was performed before cordocentesis in 24 Rh-alloimmunized fetuses without hydrops on 52 occasions. The angle between the line describing the average slope during the diastolic phase of the cardiac cycle and the vertical, the middle cerebral artery standardized deceleration angle, was measured. The deceleration angle values were expressed in multiples of the median for gestational age. The screening performances of deceleration angle for the prediction of anemia (difference between expected mean hemoglobin level and measured value ≥2 g/dL) and severe anemia (hemoglobin deficit ≥5 g/dL) were determined. Results: The mean (±SD) gestational age at cordocentesis was 28.6 ± 5.7 weeks’ gestation. The risk of fetal anemia increased with decreasing deceleration angle values. The sensitivity and false-positive rate for the detection of anemia in cases with no previous transfusions (one measurement per patient) were 72.0% and 13.3%, respectively; among those with one previous transfusion the values were 90.0% and 0.0%, respectively. For severe anemia the corresponding values were 100% and 0%, respectively, among those with no previous transfusions and 100.0% and 16.7%, respectively, among those with one previous transfusion. There was no risk of severe anemia when the angle was >0.9 multiples of the median. The risk of anemia was significantly reduced with an angle greater than the median for gestational age (deceleration angle >1.0 multiples of the median; relative risk, 0.09; 95% confidence interval, 0.02-0.37). The risk was significantly increased with an angle less than the median for gestational age (deceleration angle <1.0 multiples of the median; relative risk, 30.0; 95% confidence interval, 5.9-158.4). Conclusion: The risk of fetal hydrops is remote in the absence of severe anemia. With a new Doppler velocimetric index in the middle cerebral artery the risk of severe anemia was found to be low when the deceleration angle was >0.9 multiples of the median. Anemia can also be predicted with this index. The high sensitivities and acceptable false-positive rates support the potential clinical applicability of the method to reduce the reliance on cordocentesis in Rh alloimmunization. Our findings appear to validate the utility of the deceleration angle for the prediction of fetal anemia. (Am J Obstet Gynecol 2000;183:746-51.)

Splenic artery Doppler peak systolic velocity predicts severe fetal anemia in rhesus disease

Objective: We sought to determine whether main splenic artery Doppler peak systolic velocity predicts severe anemia in the rhesus-alloimmunized fetus. Study Design: Splenic artery Doppler peak systolic velocity was obtained before cordocentesis in rhesus-alloimmunized fetuses. Normative values for mean peak systolic velocity based on gestational age were obtained cross-sectionally from a separate group of 144 normal fetuses. The peak systolic velocity values in the study group were expressed as multiples of the median for gestation, and threshold values were used as a screening test for severe anemia. The hemoglobin deficit was defined as mean hemoglobin for gestation minus measured hemoglobin. A hemoglobin deficit value of ≥5 g/dL was used to define severe anemia. We used the peak systolic velocity to screen for severe anemia in the overall study group and the subgroups with or without prior transfusions. Results: The study population consisted of 26 singleton nonhydropic fetuses in which cordocentesis and Doppler measurements were performed on a total of 55 occasions. The mean gestational age and standard deviation at cordocentesis was 29.6 ± 4.0 weeks. Severe anemia was noted in 20% of fetal cord blood specimens obtained. On the basis of a receiver operating characteristic curve, a peak systolic velocity of ≥1.4 multiples of the median had a detection rate of 100%, with a false-positive rate of 20.8% in the subgroup with no prior transfusion (relative risk, 4.8; 95% confidence interval, 2.2-10.5). For peak systolic velocity threshold of ≥1.50 multiples of the median, corresponding values in the group with one prior transfusion were 80% and 12.5%, respectively (relative risk, 2.5; 95% confidence interval, 1.2-5.3). There was no risk of severe anemia with a peak systolic velocity below the median for gestation. Conclusion: Fetal hydrops is rare, with a hemoglobin deficit of <5 g/dL. In the first such report the main splenic artery peak systolic velocity was noted to be a strong predictor of severe anemia. For the overall population, all such instances could be diagnosed while cordocentesis was performed 22.7% of the time. There is no risk of severe anemia with Doppler peak systolic velocities below the median for gestational age. The measurement is easily obtained and should be investigated as a clinical tool for minimizing the necessity for cordocentesis. (Am J Obstet Gynecol 2000;182:1222-6.)

A new splenic artery Doppler velocimetric index for prediction of severe fetal anemia associated with Rh alloimmunization

Objective: We developed a new Doppler index for the noninvasive prediction of severe fetal anemia by means of Doppler velocimetry of the main splenic artery. Study Design: Doppler velocimetry of the main splenic artery was performed in 85 healthy fetuses and in 22 nonhydropic study case patients (41 measurements) at risk for anemia from Rh sensitization. The deceleration angle between the line describing the average slope during the diastolic phase of the cycle and the vertical axis was measured and expressed in multiples of the median (MoM) for gestational age. Severe anemia was defined as a hemoglobin deficit (mean hemoglobin for gestational age minus measured hemoglobin) ≥5 g/dL. Anemia overall was defined as a hemoglobin deficit ≥2 g/dL. Results: Mean gestational age at cordocentesis was 28.6 weeks. Severe anemia was noted on 7 occasions (12.6%) and anemia was noted on 21 (51.2%) occasions. There was a significant correlation between deceleration angle and hemoglobin deficit ≥2 g/dL ( r = 0.5763, P < .0001) and also with hemoglobin deficit ≥5 g/dL ( r = 0.6418, P < .0001). At deceleration angles <0.90 MoM, a 90.5% sensitivity and a 30% false-positive rate were achieved for anemia detection. At a threshold deceleration angle of <0.60 MoM, the sensitivity for severe anemia was 100%, with an 8.8% false-positive rate. Conclusion: We report a new and sensitive Doppler velocimetric technique for predicting severe anemia. By means of splenic artery velocimetry, all cases of severe anemia could be identified before the development of hydrops, with a >91% reduction in the rate of cordocentesis. (Am J Obstet Gynecol 1999;180:49-54.)

Fetal Splenic Size in Anemia Due to Rh-alloimmunization

In Brief Objective To determine whether fetal splenic enlargement predicts anemia in Rh-alloimmunized nonhydropic singleton fetuses. Methods Splenic circumference was measured before funipuncture in 21 singleton pregnancies on 47 occasions. The spleen was imaged in an axial section of the fetal abdomen close to the level used for measurement of the abdominal circumference. The splenic length and width were measured and the circumference calculated by the formula (length and width × 1.57). One measurement per patient was used for each analysis. Splenic circumference was measured and expressed as multiples of the normal median (MoM) for gestational age. One hundred twenty-one cases were used to provide cross-sectional normative data. The expected median splenic circumference values were derived from a normal group. Fetal anemia was defined as hemoglobin deficit, ie, mean hemoglobin concentration for gestation minus the measured value. Anemia was defined as hemoglobin deficit exceeding 2 g/dL, and severe anemia as hemoglobin deficit exceeding 5 g/dL. Receiver operator characteristics curves for the prediction of anemia using different splenic circumference (MoM) values were constructed. Results Splenic circumference was an excellent predictor of severe anemia in cases with no prior transfusion: sensitivity 100% and specificity 94.7% (area under the curve = .97, P < .03). The measurement did not correlate significantly with severe anemia in the group with prior transfusion (area under the curve = .73, P = .19). Conclusion Splenomegaly is sensitive for the detection of severe anemia in nonhydropic Rh sensitized cases without prior transfusion. The splenic enlargement could be explained by extramedullary erythropoiesis. Fetal splenic enlargement predicts severe anemia in Rh-alloimmunized pregnancies.

Fetal splenic size in anemia due to rh-alloimmunization

Objective: To determine whether fetal splenic enlargement predicts anemia in Rh-alloimmunized nonhydropic singleton fetuses. Methods: Splenic circumference was measured before funipuncture in 21 singleton pregnancies on 47 occasions. The spleen was imaged in an axial section of the fetal abdomen close to the level used for measurement of the abdominal circumference. The splenic length and width were measured and the circumference calculated by the formula (length and width × 1.57). One measurement per patient was used for each analysis. Splenic circumference was measured and expressed as multiples of the normal median (MoM) for gestational age. One hundred twenty-one cases were used to provide cross-sectional normative data. The expected median splenic circumference values were derived from a normal group. Fetal anemia was defined as hemoglobin deficit, ie, mean hemoglobin concentration for gestation minus the measured value. Anemia was defined as hemoglobin deficit exceeding 2 g/dL, and severe anemia as hemoglobin deficit exceeding 5 g/dL. Receiver operator characteristics curves for the prediction of anemia using different splenic circumference (MoM) values were constructed. Results: Splenic circumference was an excellent predictor of severe anemia in cases with no prior transfusion: sensitivity 100% and specificity 94.7% (area under the curve = .97, P < .03). The measurement did not correlate significantly with severe anemia in the group with prior transfusion (area under the curve = .73, P = .19). Conclusion: Splenomegaly is sensitive for the detection of severe anemia in nonhydropic Rh sensitized cases without prior transfusion. The splenic enlargement could be explained by extramedullary erythropoiesis.

The Hemoglobin-Deficit Mouse: Analysis of Phenotype and Hematopoiesis in the Transplant Model

AbstractThe mouse mutant hemoglobin deficit (gene symbol hbd ) is characterized by a severe microcytic anemia that is inherited in an autosomal-recessive manner. To assess the mutation's effect on hematopoiesis, unfractionated bone marrow (BM) from either a mutant C57BL6/J-hbd/hbd, Gpi1b/Gpi1b (phenotype symbol HBD), or normal C57BL6/J -+hbd/+hbd, Gpi1b/Gpi1b mouse was injected intravenously into irradiated congenic C57BL6/J-+hbd/+hbd, Gpi1a/Gpi1a, Igha/Igha, Thy1a/Thy1a mice. The congenic recipients of mutant or normal marrow obtained complete red blood cell (RBC) and leukocyte reconstitution, with the exception of one recipient of HBD marrow. After 24 weeks posttransplantation, the normal recipients of HBD marrow obtained a microcytic anemia similar to the donor. These results suggest that the HBD phenotype is caused by a BM defect. We observed that the erythroid lineage derived from donor HBD marrow repopulated more slowly than the normal marrow at 4 weeks posttransplantation. To determine if this difference was a result of an erythropoietic defect, competitive repopulation was performed using either mutant or normal marrow competed against normal congenic marrow. For the erythroid lineage, no significant contribution from HBD marrow was observed. To assess if the RBC block was based on a deficiency of myeloid progenitors, both in vitro and in vivo assays were performed: absolute numbers of bone progenitors were increased, suggesting that the defect results in a late block to erythroid differentiation.

Ultrasonographic fetal spleen measurements in red blood cell-alloimmunized pregnancies

This study was performed to evaluate the possible relationship between fetal spleen size and fetal hemoglobin levels and to assess the predictive value of ultrasonographically measured fetal spleen size as an estimate of the severity of fetal hemolytic anemia. Before 85 consecutive fetal blood samples in 28 red blood cell-alloimmunized pregnancies ultrasonographic fetal spleen measurements were performed. Results were compared with our own longitudinally derived reference ranges and were correlated with fetal hemoglobin deficit. A significant positive correlation was found between spleen perimeter and fetal hemoglobin deficit. The ultrasonographic finding of splenomegaly correctly predicted severe fetal anemia (hemoglobin deficit > 5 SD from normal mean) in 44 of 47 cases, a positive predictive value of 94%. At first transfusion all fetuses showing splenomegaly were severely anemic. Fetal spleen measurements may be a useful adjunct to ultrasonographic evaluation in the management of severe red blood cell-alloimmunized pregnancies.

Fetal plasma erythropoietin concentration in red blood cell-isoimmunized pregnancies

OBJECTIVE: The aim of this study was to investigate the relationship between fetal anemia, plasma erythropoietin concentration, and erythroblastosis in red blood cell—isoimmunized pregnancies. STUDY DESIGN: Fetal plasma erythropoietin concentration in umbilical venous blood samples from 68 red blood cell—isoimmunized pregnancies at 18 to 35 weeks' gestation was measured. Measurements were compared with the appropriate reference range with gestation, and associations with blood pH, erythroblast count, and hemoglobin concentration were examined. RESULTS: The mean fetal plasma erythropoietin concentration and erythroblast count in red blood cell—isoimmunized pregnancies were significantly increased only in severe fetal anemia (hemoglobin deficit >7 gm/dl). Furthermore, some severely anemic fetuses were hydropic and acidemic. The degree of increase in plasma erythropoietin was significantly associated with both fetal acidemia and, more strongly, fetal erythroblastosis. CONCLUSION: These findings suggest that in fetuses from red blood cell—isoimmunized pregnancies the ability to prevent tissue hypoxia is present until anemia becomes severe, presumably by an increase in cardiac output and tissue perfusion. In severe anemia tissue hypoxia occurs, and the data indicate that fetuses respond by increasing erythropoietin production from at least 20 weeks' gestation. Furthermore, more accurate assessment of tissue oxygenation may be obtained by measuring the erythroblast count rather than the blood pH.

Surgical staples in cesarean section: A randomized controlled trial

This randomized controlled trial compares the use of the Auto Suture Poly CS 57 disposable surgical stapler (n = 98) with standard hysterotomy (n = 102) in low transverse cesarean sections. Subjective assessment of blood loss by the surgeon resulted in lower mean (±SEM) total blood loss estimates in the stapled group (492 ± 24 ml) than in the nonstapled group (579 ± 38 ml) (p = 0.05). However, surgeon's estimation of blood loss as a result of the hysterotomy and blood loss estimated by the hemoglobin deficit measured on the second postoperative day did not significantly differ between the two groups. The use of the stapling device tended to lengthen the total operating time, which averaged 42.5 minutes in the group with the staples and 39.2 minutes in the group with the standard hysterotomy (p = 0.05). The risk of febrile morbidity, the frequency of endometritis, and the length of hospitalization were similar in the two groups. Our results do not support the routine use of the Auto Suture Poly CS 57 disposable surgical stapler in low transverse cesarean sections. (Am J Obstet Gynecol 1990;163:1641-6.)

Prediction of fetal anemia by measurement of the mean blood velocity in the fetal aorta

In 68 red blood cell isoimmunized pregnancies the mean velocity of blood in the fetal aorta was measured by pulsed Doppler ultrasonography, and the fetal hemoglobin concentration was determined in blood samples obtained by cordocentesis. The values were compared to reference ranges of mean aortic velocity and hemoglobin for gestation, which were determined from 218 218 pregnancies that were not complicated by fetal hemolysis. In the red blood cell isoimmunized pregnancies there was a significant positive correlation between the aortic mean velocity and the hemoglobin deficit for the nonhydropic fetuses and a significant negative correlation between these two parameters for the hydropic fetuses.

Evaluation of surgical staples in cesarean section

Experience with Lactomer absorbable surgical staples (Auto Suture Poly CS 57 disposable surgical stapler) in 62 cesarean sections was compared with an equal number of operations performed with standard techniques. The technique of appliciation of the stapler evolved with experience. Countertraction to staplers with Allis' clamps prevented uterine V incisions. Operative time was longer for the stapled suture group for primary cesarean sections, but was unchanged for repeat procedures. Excellent hemostasis of the uterine incision was achieved even when varicose sinusoidal veins were present. Significant reductions of hemoglobin deficits from 2.16 to 1.31 gm/dl, postoperative anemia from 29% to 6.4%, and endometritis from 22.5% to 6.4% occurred respectively in nonstapled and stapled groups. A reduced hospital stay, shortened by 2.1 days, saved each patient $2950. Blood loss estimates by surgeons or anesthetists were often at variance. Surgeons' acceptance of the procedure grew with experience. On the basis of these results, use of absorbable staples offers certain advantages in reducing blood loss, infection, and hospital stay in cesarean deliveries.

FETAL HAEMOGLOBIN MEASUREMENT IN THE ASSESSMENT OF RED CELL ISOIMMUNISATION

A reference range of fetal haemoglobin concentration (g/dl) was established from umbilical cord blood samples obtained by cordocentesis (n=200) or at delivery (n=10). In normal pregnancy the mean fetal haemoglobin increases linearly from 11 g/dl at 17 weeks' gestation to 15 g/dl at 40 weeks' gestation and one standard deviation is approximately 1 g/dl. The haemoglobin was also measured in fetal blood from 154 red cell isoimmunised pregnancies from 17 to 36 weeks' gestation. In 48 fetuses with ultrasound features of hydrops the haemoglobin was 7-10 g/dl below the normal mean for gestation. It is proposed that in pregnancies complicated by red cell isoimmunisation the severity of the disease should be assessed and treated on the basis of the deviation of the fetal haemoglobin from the normal mean for gestation into mild (haemoglobin deficit < 2 g/dl), moderate (deficit 2-7 g/dl), and severe (deficit > 7 g/dl).

Hemoglobin deficit: an inherited hypochromic anemia in the mouse.

The character and pathogenesis of hemoglobin deficit (gene symbol, hbd), an autosomal recessive trait in the mouse, were studied. The main hematological features of hemoglobin deficit are anemia, red cell hypochromia and microcytosis, and reticulocytosis. The absence of raised fecal urobilinogen excretion and frank hyperbilirubinemia and bilirubinuria suggests that excess hemolysis is not the primary cause of the anemia. The raised plasma iron concentration and the failure of the anemia to respond to parenteral iron treatment indicate that the anemia is not due to iron deficiency. The absence of siderocytes and sideroblasts suggests that anemia is probably not due to ferrochelatase deficiency. Thalassemia is excluded by the finding of balanced reticulocyte globin chain synthesis. The markedly elevated levels of free red cell protoporphyrin taken together with the other findings already noted suggest that the anemia of hemoglobin deficit is due to a defect in the erythroid cell iron procurement mechanisms leading in turn to diminished heme and hemoglobin synthesis.

Oxygen Binding to Haemoglobin in Subjects with Hypoproliferative Anaemia, with and without Chronic Renal Disease: Role of pH

Summary. The relationships of haenioglobin concentration and blood pH to red cell 2,3‐dipliosphoglycerate and oxygen binding by haenioglobin have been studicd in healthy subjects and subjects with hypoproliferative anaemia with or without severe chronic renal disease. Red cell 2,3‐DPG was inversely correlated with haemoglobin deficit and directly and equally strongly associated with blood pH in anaemic subjects without chronic renal disease. In subjects with chronic renal disease receiving regular haemodialysis, predialysis pH was not increased despite severe anaemia, and red cell 2,3‐DPG was not significantly elevated, except in subjects who had a sustained alkalosis due to the use of sodium bicarbonate.In hypoproliferative anaemia, the incrcmcnt in pH was associated with the decrease in haenioglobin concentration such that 80% of the increase in p50 measured at standard conditions which occurred with anaemia was explicable by the relationship of (a) pH with haemoglobin concentration, (b) red cell 2,3‐DPG with pH, and (c) pso std with red cell 2,3‐DPG. However, p50 at the pH and base excess present in vivo was similar in all anaemic subjects whether an increase in red cell 2,3‐DPG occurred or not. Blood alkalosis and the accumulation of 2,3‐DPG cancelled each other's effect on oxygen binding by haemoglobin. Hence, increased red cell 2,3‐DPG and p50 compensated for the alkalosis of hypoproliferative anaemia, not for the deficit in haemoglobin concentration.

Hemoglobin Affinity for Oxygen in Chronic Renal Disease: The Effect of Hemodialysis

Abstract The affinity of hemoglobin for oxygen may increase significantly in subjects who are hypophosphatemic and alkalotic. We studied the organic phosphate content and oxygen binding by hemoglobin of red cells in subjects undergoing hemodialysis, during which time a decrease in plasma inorganic phosphate and an increase in blood pH may occur. Red cell 2,3-DPG was not correlated with plasma inorganic phosphorus, whereas red cell ATP was highly correlated with plasma inorganic phosphorus when analyses were made on predialysis samples. Predialysis red cell inorganic phosphorus was highly correlated with plasma inorganic phosphorus, supporting the concept that intraerythrocytic inorganic phosphorus is maintained by a gradient from plasma to cell. Plasma inorganic phosphorus decreased by 45% during the period of hemodialysis, whereas red cell inorganic phosphorus did not change. Red cell 2,3-DPG, ATP, and oxygen binding by hemoglobin at standard conditions of temperature, pH, and pCO2 were not altered after 6 hr of hemodialysis. Plasma pH and base excess increased during dialysis. The increase in base excess, an estimate of the non-pH-dependent effect of CO2 on oxygen binding by hemoglobin, counterbalanced a portion of the effect of elevated pH on hemoglobin— oxygen affinity under in vivo conditions. Hence, only a slight increase in oxygen binding by hemoglobin occurred. Moreover, late dialysis symptoms were not associated with the degree of alkalosis or with the extent of change in hemoglobin’s affinity for oxygen. Red cell 2,3-DPG content was lower and hemoglobin’s affinity for oxygen was higher in subjects with chronic renal disease than in nonazotemic subjects with similar hemoglobin deficits. Moreover, increased red cell ATP in chronic renal disease patients did not influence oxygen binding by hemoglobin.

Uterine closure with unlocked suture in cesarean section: Safety and Quality.

Objective: Comparing locked and unlocked uterine closure techniques in terms of bleeding control and uterine incision healing. Methods: The patients undergoing cesarean section in Sifa University Hospital between May - October 2012 were accepted to this prospective controlled study. Primarily, safety was evaluated. The hemoglobin count (HC) and serum creatine kinase (CK) levels of the patients in the locked (n = 47) and unlocked (n = 35) groups were measured just before and 24 hours after operation. Hemoglobin deficit, increase in CK and the additional hemostatic sutures were compared. Secondly, uterine scar healing was evaluated three months later. Scar thickness, niche and percentage of thinning of the scar region of the locked (n = 27) and unlocked (n = 32) groups were calculated and compared. Results: The hemoglobin deficit was similar in two groups. CK rise was less in the unlocked group but it was not significant (P = 0.082). Unlocked group needed more additional sutures (P = 0.016). The thickness of the niche and the percentage of thinning of the scar region were significantly less in the unlocked group (P= 0.002, P=0.000). Conclusions: Unlocked uterine closure technique is safe and has less damage to the myometrium.

Diverticulosis intestini and pernicious anaemia.

1) In very rare cases of multiple intestinal diverticulosis, pernicious anaemia with intact HC1 secretion into the stomach may he found. 2) A case is described in whom full correction of the hemoglobin deficit was obtained by iron treatment notwithstanding a blood picture typical of pernicious anaemia. A relapse 1 year later did not respond to iron treatment, whereas treatment by folic acid was successful. 3) In non coincidental multiple intestinal diverticulosis and pernicious anaemia, either a defective elimination of antipernicious substance or more probably a defective absorption of this substance may be pathogenetically important.

Urinary Coproporphyrins in Lead Poisoning

Many aspects of haemopoiesis in lead poisoning remain obscure. When industrial plumbism was common the haemolytic action of lead was fre quently described (Aub, Fairhall, Minot, and Reznikoff, 1925), although there were atypical features. The erythrocytes were somewhat deficient in haemoglobin, and faecal urobilinogen was not increased. Lead poisoning also differs from true haemolytic anaemia in the occurrence of copro porphyrin III in the urine (Grotepass, 1932 ; Fischer and Duesberg, 1932 ; Watson, 1936). It is coproporphyrin I which is excreted in haemolytic conditions characterized by hyperplasia of the bone marrow (Watson, 1937 ; Dobriner and Rhoads, 1938 ; Grinstein, Kamen, Wikoff, and Moore, 1950). Rimington (1936) advanced the view that in enzymic synthesis of the porphyrins, in addition to type III porphyrin used in haemoglobin formation, a small amount of type I series is always produced, which, being of no value, is excreted. Urinary coproporphyrin I excretion therefore provided an index of the rate of haemopoiesis. Rimington (1938) further postulated that the coproporphyrin III excretion in lead poisoning is due to a partial blockage by lead of the entrance of iron into protoporphyrin 9, thus interfering with haemoglobin formation (Fig. 1). He discounted the haemolytic action of lead, since faecal urobilinogen was normal, but recent isotopic studies by London, Shemin, and Rittenberg (1948) on the conversion in vivo of glycine N15 to stercobilinogen have shown that the latter is a very unreliable index of the rate of degradation of circulating haemoglobin. Kench, Gillam, and Lane (1942) found that excretion of coproporphyrin III was not sufficient by itself to account for the degree of haemoglobin deficit in this disease, and suggested that lead interfered all along the line of enzymatic syntheses, causing restricted formation of porphyrin and other inter mediates. RlMINGTONl'S EMZVMIC HYP0fH?5<S.