Visual evoked responses in megaloblastic anemia

Pattern shift visual evoked responses (PSVER) were studied in thirty patients suffering from severe megaloblastic anemia (mean Hb level was 4.25 +/- 1.22 g/dL) of nutritional origin. All patients lacked clinical stigmata of visual and neurologic impairment. Mean P100 latency in thirty age and sex matched controls was 96.35 +/- 6.75 ms (range 86-108 ms) and mean amplitude was 10.37 +/- 3.88 microV (range 4.8-20.8 microV). Mean P100 latency in megaloblastic anemia was 114.77 +/- 11.68 (range 91-142) ms, P < 001 vs. control) and mean amplitude was 8.85 +/- 2.8 microV (range 5.1-16.2 microV). Seventy percent cases had prolonged latency of P 100. After correction of anemia with therapeutic doses of vitamin B12 and folic acid in three months (mean Hb level was 12.08 +/- 1.86 g/dL), the mean P100 latency was 105.13 +/- 9.30 ms (range 92-121 ms P < 0.001 vs. controls) and mean amplitude was 10.72 +/- 4.13 microV (range 5.1-21.4 microV). There was significant improvement in P100 latency after correction of anemia (P < 0.01). There was a negative correlation between P100 latency and hemoglobin levels, though it was statistically not significant.

Folic acid to prevent neural tube defects: scientific advances and public health issues

Folic acid prevents some neural tube defects by correcting abnormal homocysteine metabolism. A defective gene coding for a homocysteine-related enzyme has been shown in people with neural tube defects. An extensive educational campaign will be required to alert women to the need to take 0.4 mg/day of folic acid during their childbearing years.

Iron utilization after iron dextran administration for iron deficiency in patients with dialysis-associated anemia: a prospective analysis and comparison of two agents

We sought to determine the rate and extent of iron utilization after administration of intravenous iron dextran and to compare the efficacy of iron dextran preparations of differing molecular weight. We randomized patients to receive either a 500-mg dose of iron dextran molecular weight (MW) 267,000 (group A) or iron dextran MW 96,000 (group B) administered in five sequential 100-mg doses, and examined indices of iron status before and at weekly intervals up to 4 weeks later. Although mean iron utilization was greater in the nine group A patients (46.7% +/- 21.3%) than in the 11 group B patients (31.7% +/- 26.6%), the difference was not statistically significant (P = 0.19). Iron utilization in both groups was substantially incomplete. Changes in serum ferritin and hemoglobin did not differ between the treatments (P = 0.49 and P = 0.34, respectively). We conclude that iron utilization after iron dextran administration is substantial within the first week after completing a course of therapy, associated with stable iron indices after the first 2 weeks, and incomplete for at least the first 4 weeks. Degree of iron utilization appears independent of molecular weight within the range we examined.

Intravenous iron sucrose complex in the treatment of iron deficiency anemia during pregnancy

OBJECTIVE

To evaluate the safety and efficacy of intravenous iron sucrose complex (ISC) as compared with oral ferrous sulfate in the treatment of iron deficiency anemia during pregnancy.

STUDY DESIGN

prospective, open, controlled study in which pregnant women with iron deficiency anemia were sequentially selected from the antenatal clinic and assigned either to ISC (study group) or to ferrous sulfate (control group).

METHODS

Each study patient was given the total calculated amount of ICS (Hb deficit (g/l) x body weight (kg) x 0.3) in divided doses (200 mg (elemental iron) in 100 ml normal saline intravenously over 1 h daily) followed by 10 mg/kg to replenish iron stores. Each patient of the control group was given ferrous sulfate 300 mg (60 mg elemental iron) orally three times a day. All patients were monitored for adverse effects, clinical and laboratory response.

RESULTS

There were 52 patients and 59 controls. ISC group achieved a significantly higher Hb level (128.5 +/- 6.6 g/l vs. 111.4 +/- 12.4 g/l in the control group P < or = 0.001) in a shorter period (6.9 +/- 1.8 weeks vs. 14.9 +/- 3.1 weeks in the control group, P < or = 0.001). ISC complex group showed no major side effects while 4 (6%) of the control group could not tolerate ferrous sulfate, 18 (30%) complained of disturbing gastrointestinal symptoms and 18 (30%) had poor compliance.

CONCLUSION

We conclude that ISC is safe and effective in the treatment of iron deficiency anemia during pregnancy.

[Hyperhomocysteinemia in coronary artery diseases. Apropos of a study on 102 patients]

Homocystein is at the crossroads of the metabolic pathways of sulphuric amino acids. Homocystinuria is a congenital autosomal recessive disease, usually related to cystathionine beta-synthetase deficiency. Children with homozygotic forms of the disease have early vascular complications which represent the main cause of death. Moderately elevated serum homocystein levels are related to two major genetic factors (heterozygotic cystathionine beta-synthetase deficiency and mutation of the 5-10 methylene tetrahydrofolate reductase) and several minor, genetic and non-genetic factors (folic acid, vitamins B6 and B12 and betain deficiencies). Previous studies have suggested that hyperhomocysteinaemia could be a cardiovascular risk factor. This study was based on 222 subjects including 102 consecutive patients with angiographically documented coronary artery disease and 120 control subjects without vascular disease. No relationship was observed between serum homocystein concentrations and the classical cardiovascular risk factors. Coronary patients had higher average homocystein concentrations than control subjects (11.27 +/- 0.52 vs 8.77 +/- 0.31 mumol/l); p < 0.0001): moreover, the prevalence of hyperhomocysteinaemia (> 15.67 mumol/l) was higher in the coronary group (15.7%) than in the controls (2.5%). A significant relationship was also observed between homocystein concentrations and the severity of the coronary disease (defined by a coronary score) and the number of diseased vascular territories. These results underline the relationship between homocystein and vascular risk, especially that of coronary artery disease. The treatment of hyperhomocysteinaemia by folic acid supplements is effective in correcting plasma levels, without side effects and at a relatively low cost.

Cobalamin deficiency with megaloblastic anaemia in one patient under long-term omeprazole therapy

The first case of cobalamin deficiency with megaloblastic anaemia in a patient under long-term omeprazole therapy is presented. This patient received omeprazole at a daily dose of 40-60 mg for 4 years as treatment for a gastro-oesophagal reflux complicated by peptic oesophagitis. Seric vitamin B12 was dramatically decreased at 80 pmol L-1. The Schilling test was normal (13%) with crystalline [57Co] cobalamin and it was at 0% with [57Co] cobalamin-labelled trout meat. All other assimilation tests were normal except an expiratory hydrogen breath test performed with lactulose. The haematological status was restored after intramuscular treatment with cobalamin. In conclusion, prolonged omeprazole therapy can be responsible for a cobalamin deficiency due to protein-bound cobalamin malabsorption.

Parenteral iron supplementation

Indications for the use of parenteral iron are limited to conditions in which the oral supplementation of iron is not possible or fails. An overview of iron balance and iron requirements is presented to describe situations in which iron supplementation may be required. When parenteral iron supplementation is required, careful attention to proper dosing and administration is necessary to optimize efficacy and safety. The purpose of this article is to review the literature regarding the clinical use of parenteral iron therapy and provide guidelines on dosing and administration. Methods of iron dextran administration, including the IV and intramuscular injection of undiluted drug and total dose infusion, are compared. Complications associated with the use of parenteral iron are also be reviewed. Finally, the use of iron supplementation in patients receiving parenteral nutrition care explored.

Baseline hemoglobin as a predictor of risk of transfusion and response to Epoetin alfa in orthopedic surgery patients

A multicenter, double-blind, placebo-controlled, parallel-group study was undertaken to determine whether Epoetin alfa can reduce perioperative transfusion requirements. Twenty-six medical centers enrolled 316 patients who were scheduled for major orthopedic surgery and were expected to require > or = 2 units of blood. Patients were stratified according to baseline hemoglobin levels and randomly assigned to receive either Epoetin alfa (300 IU/kg or 100 IU/kg) or placebo for 15 consecutive days starting 10 days prior to, on the day of, and for 4 days after surgery. Epoetin alfa (300 IU/kg) resulted in significantly less exposure to allogeneic blood transfusion compared with placebo (16%) versus 45%) in patients whose baseline hemoglobin level was > 10 to < or = 13 g/dL (P = 0.024). Mean number of units transfused per patient was also lower among those treated with Epoetin alfa (overall, P = 0.027). Epoetin alfa was safe and well tolerated in this population.

Hematologic and erythropoietin responses to iron dextran in the hemodialysis environment

OBJECTIVE

To investigate the hematologic and economic advantages of using iron dextran as the sole supplemental agent to safely increase and maintain hematocrit levels and iron availability while optimizing erythropoietin dosing in patients on chronic hemodialysis.

DESIGN

Iron dextran 100 mg (2 ml) was administered i.v. slow push, undiluted three times per week, sometime during the last 30 minutes of each hemodialysis treatment, until a total required ml (determined by using the package insert's formula) was attained. Maintenance doses of either 25 or 50 mg per week (dependent upon body weight) were administered ongoing to compensate for dialytic and gastrointestinal blood losses. The analysis duration was 12 months.

SAMPLE/SETTING

A prospective analysis was performed on 13 clinically stable hemodialysis outpatients in a rural community hospital-based dialysis facility (mean age 56.4 years ranging from 24-76; sample included 9 males, 4 females).

METHODS

The means and medians were calculated for each variable: hematocrit, ferritin, transferrin saturation, and erythropoietin dose. A one-tailed paired student t test was performed on doses of erythropoietin at -1 and 6 months, -1 and 9 months, and -1 and 12 months. Cost per patient of iron dextran loading dose and maintenance, as well as cost savings from actual erythropoietin dose reductions, were calculated at 3, 9, and 12 months. Cost savings reflected the cost of iron dextran.

RESULTS

After 6 months on the protocol, erythropoietin doses decreased an average of 3100 units per patient with an 8% increase in hematocrit and 66% and 78% increase in transferrin saturation and ferritin, respectively. Based on averages in actual reduced erythropoietin dosing, a savings of +5,070 per patient per year was realized.

CONCLUSIONS

This analysis found the use of iron dextran in the hemodialysis setting to be an effective and economic means to maintain hematocrit values and iron availability while optimizing erythropoietin dosing.

Dietary folate affects the response of rats to nickel deprivation

Because vitamin B12 and Ni are known to interact and because of the similar metabolic roles of vitamin B12 and folate, an experiment was performed to determine the effect of dietary folate on Ni deprivation in rats. A 2 x 2 factorially arranged experiment used groups of nine weanling Sprague-Dawley rats. Dietary variables were Ni, as NiCl(2) 6H(2)0, 0 or 1 mu g/g; and folic acid, 0 or 2 mg/kg. The basal diet, based on skim milk, contained less than 20 ng Ni/g. After 54 d, an interaction between dietary Ni and folate affected several variables including erythrocyte folate, plasma amino acids, and femur trace elements. For example, folate deprivation decreased erythrocyte folate; folate supplementation to the Ni-supplemented rats caused a larger increase in erythrocyte folate concentration than did folate supplementation to the Ni-deprived rats. Also, dietary Ni affected several plasma amino acids important in one-carbon metabolism (e.g., Ni deprivation increased the plasma concentrations of glycine and serine). This study shows that dietary Ni, folate, and their interaction can affect variables associated with one-carbon metabolism. This study does not show a specific site of action of Ni but it indicates that Ni may be important in processes related to the vitamin B12-dependent pathway in methionine metabolism, possibly one-carbon metabolism.

[Folic acid in the prevention of neural tube defects]

Neural tube defects (spina bifida) imply a severe limitation of quality of life. 70 to 100% of these defects are preventable by additional intake of folic acid during the periconceptional period. In accordance with the recommendations of Anglo-Saxon and other authorities prevention of this grave malformation should be attempted not only after a first-affected child, but primarily in a general manner in Switzerland, too. All women of childbearing age not under contraceptives should be advised to consume a diet rich in folic acid and to take an additional daily dose of 0.4 mg folic acid as a monosubstance or with a multivitamin preparation. A supplement of folic acid to cereal grain products, mainly bread flours, is recommended. A generally elevated folic acid intake may have further beneficial effects, such as risk reduction for the occurrence of carcinoma and atherosclerosis.

Anemia

OBJECTIVES

To provide an overview of the disorders that cause anemia and to review clinical and laboratory assessment and medical and nursing management of the anemic patient.

DATA SOURCES

Published articles and book chapters that pertain to red blood cell physiology and the major causes and types of anemia.

CONCLUSIONS

Advances in molecular and genetic aspects of anemia are leading to new developments in the diagnosis and management of all types of anemia. Symptomatic relief to maintain quality of life is essential for all anemic patients.

IMPLICATIONS FOR NURSING PRACTICE

Nurses can play a major role in the supportive care of patients with anemia through interventions related to pharmacological therapy, blood transfusions, nutritional counseling, and symptom management.

Kinetics of total plasma homocysteine in subjects with hyperhomocysteinemia due to folate or cobalamin deficiency

Hyperhomocysteinemia in cobalamin and folate deficiency reflects an imbalance between influx and elimination of homocysteine (Hcy) in plasma. We investigated the kinetics of total Hcy (tHcy) in plasma after peroral Hcy administration in 19 volunteers with hyperhomocysteinemia (mean +/- SD: 67.1 +/- 39.5 mumol/L; range: 23.5-142.8 mumol/L) before and after supplementation with cobalamin and/or folate. Vitamin therapy decreased plasma tHcy to 21.8 +/- 14.1 mumol/L (range: 9.6-57.9 mumol/L) but caused only a marginal decline in the area under the curve (AUC) by 8% and plasma half-life by 21%. Using the equations for steady-state kinetics, these data indicate that mean plasma tHcy clearance is normal and that massive export of Hcy from tissues into plasma is the major cause of hyperhomocysteinemia in cobalamin or folate deficiency. However, the spread in AUC and plasma half-life values was large in hyperhomocysteinemia subjects, suggesting marked individual variability in tHcy clearance. Plasma methionine after Hcy loading did not increase before (0.9 +/- 6.8 mumol/L) but increased normally (12.8 +/- 4.6 mumol/L) after vitamin therapy, and the methionine response discriminated between vitamin-deficient and vitamin-replete subjects. In cobalamin- or folate-deficient subjects, only 6.5 +/- 3.0% of the Hcy dose was excreted unchanged in the urine, demonstrating that urinary Hcy excretion does not explain normal tHcy plasma clearance in subjects with impaired Hcy remethylation. Our data suggest that hyperhomocysteinemia in folate and cobalamin deficiency is related to increased influx of Hcy to plasma, and that the methionine synthase function is not an important determinant of elimination of Hcy from plasma. The large interindividual difference in Hcy clearance may be explained by variable adaptation to impaired methionine synthase function through increased Hcy flux through alternate metabolic pathways.

Orthopedic aspects of myelodysplasia in children

A review of new developments in spina bifida shows that many cases are preventable by administration of periconceptual folic acid, reducing the relative risk by up to 86%. Currently, however, 50% of women of reproductive age have no folic acid in their usual diet. The Centers for Disease Control as recommended folic acid at 0.4 mg/d for all women anticipating pregnancy. The long-term outcomes of sacral level patients show a surprising decline in adult ambulatory status. Adult ambulatory status in spina bifida is significantly predictive (89% accurate) by two variables: motor level and sitting balance. Studies regarding hip dislocation, foot deformities in thoracic level children, the prevalence of spondylolisthesis, and surgical treatment of kyphosis are also reviewed.

Suboptimal compliance with periconceptual folic acid in an Irish hospital population

Awareness of and compliance with periconceptual folate was measured by questionnaire in our antenatal and infertility populations. Awareness was somewhat better in the private antenatal and infertility patients, but compliance was universally very poor. A substantial proportion of pregnancies were planned, and therefore there is potential for a much higher level of compliance.

Methotrexate update

Methotrexate (MTX) has become one of the most widely prescribed second-line agents world-wide for rheumatoid arthritis (RA). Studies have established efficacy in populations which have failed other second-line agents. Although MTX must be considered as a potential hepatotoxin, studies have shown that liver histologic changes can be predicted by monitoring of serum albumin and AST at four to eight week intervals. MTX pulmonary toxicity appears to be more common than liver disease. It most often presents with a subacute course with dry cough and dyspnea with or without fever. Clinicians must be aware of this presentation and withhold the drug when these symptoms appear. MTX may also cause mild renal impairment when used with NSAIDs. This effect has been observed with higher mean weekly doses in the 15 to 20 mg range, but not with a starting dose of 7.5 mg. Although MTX may exhibit a variety of effects in in vitro systems its mechanism of action in patients with RA has not yet been determined.

Bionursing: signs of iron deficiency

In the ninth article in our series on bionursing, the authors explain how an understanding of physiology can help nurses to identify the common signs and symptoms of iron deficiency and ensure patients receive prompt and appropriate treatment.

Folate supplementation and methotrexate

This review concentrates on the influence of folate supplementation on the toxicity and efficacy of methotrexate (MTX) in rheumatoid arthritis patients. The design, type of folate supplementation and timing of supplementation vary considerably between the six published controlled studies. Folate supplementation seems to have no effect on the efficacy of MTX but may influence toxicity in a favourable way. Further studies are needed to assess the type of supplementation (folic acid, folinic acid), the predisposing factors for toxicity and cost effectiveness.

Recombinant human erythropoietin and platinum-based chemotherapy in advanced ovarian cancer

PURPOSE

Patients with ovarian cancer often experience dose-limiting myelotoxicity, nephrotoxicity and anemia following treatment with platinum-based chemotherapy.

PATIENTS AND METHODS

To investigate the ability of recombinant human erythropoietin (epoetin alfa) to prevent the development of anemia, 30 patients with advanced ovarian carcinoma receiving cisplatin or carboplatin were randomly assigned to treatment with subcutaneous epoetin alfa 300 IU/kg three times a week in addition to conventional supportive treatment, or conventional supportive treatment alone, for up to six chemotherapy cycles. The dose of epoetin alfa was reduced if hemoglobin concentration exceeded 15 g/dL.

RESULTS

A highly significant difference in mean hemoglobin concentrations was observed between the two groups during the first cycle of chemotherapy due to a significant decrease in mean hemoglobin concentration in the control group. A maximal difference of 3.4 g/dL was achieved during cycle three. Fewer patients required blood or platelet transfusions in the epoetin alfa-treated group, although the difference was not significant compared to the control group. Epoetin alfa was well tolerated.

CONCLUSION

Epoetin alfa appears to be effective and well tolerated in preventing hemoglobin decline in patients undergoing aggressive cyclic platinum-based chemotherapy for advanced ovarian carcinoma.

Surgical management of patients with severe anaemia due to acute blood loss: a case for withholding perioperative blood transfusion

Twenty one consecutive patients who had an average packed cell volume (PCV) of 16.2% (range 13-25) due to acute blood loss were treated surgically without perioperative blood transfusion. All the surgical procedures were carried out under intravenous ketamine hydrochloride. The surgical wound in each patient healed by primary intention. The packed cell volume rose to 35% and above in an average of six weeks by use of oral haematinics. The only morbidity observed was dizziness which lasted for an average of six days in ten patients. There were no deaths and all the patients remained well at an average follow-up period of 42 weeks. The study shows that perioperative blood transfusion can be avoided in surgical care of most patients who have severe anaemia due to acute blood loss without mortality and without significant morbidity.

[Large cystic polyps of the stomach]

The Authors report the case of a 83 year old woman with large cystic polyps of the stomach. Gastric cystic polyps are polypoid lesions which may develop following functional disorders such as increased mucosal stimulation by gastrin, or excessive retention of gastric secretions. The incidence of these polyps is variable, depending on their being underestimated since they are not always macroscopically visible. The case here reported is very interesting not only for the number of lesions (over 50), but also for their size (5-25 mm in diameter).

Folic acid supplementation improves erythropoietin response

Therapy with recombinant human erythropoietin (rhEPO) has become most valuable for the treatment of renal anemia in patients with various chronic renal diseases. For the first time this study presents data showing that rhEPO affects the metabolism of folic acid. There were 13 patients enrolled; they suffered from different chronic renal diseases and showed an impaired responsiveness to rhEPO therapy. Before starting rhEPO therapy the mean corpuscular volume of erythrocytes (MCV) was measured; MCV was 90.4 fl. During rhEPO therapy the MCV increased significantly by 14.8 fl (p < 0.05). The developing macrocytic anemia was overcome when folic acid was administered additionally for a mean period of 3.14 +/- 3 months. Hematocrit (Hct) also responded accordingly. Whereas Hct did not increase adequately during the exclusive treatment with rhEPO, an increase in Hct from 23 +/- 3.3 to 30 +/- 4.2% (p < 0.01) was observed after the addition of folic acid. These results are rather remarkable as folic acid serum levels were clearly within the normal range during the whole study period. So it can be concluded that rhEPO therapy results in an increased demand for folic acid. Even if serum concentrations are within the normal range, the administration of folic acid will enhance the effectiveness of rhEPO therapy so that the rhEPO dosage can be reduced.

Bioavailability of iron from oral ferric polymaltose in humans

The bioavailability or iron from iron(III)hydroxide polymaltose complex (ferric polymaltose, Fe-PM) was studied in human volunteers with normal or depleted iron stores as well as in patients with iron deficiency anemia. From an oral iron dose of 100 mg neutron activated Fe-PM, starved subjects with depleted iron stores absorbed significantly less (p < 0.003) 59Fe (3.91 +/- 2.24%, mean +/- SD) as compared to the reference, aqueous 59Fe(II) ascorbate solution (13.8 +/- 6.19%). Using non-radiolabeled, commercial Fe-PM no postabsorptive serum iron increase was found after oral Fe-PM (100 mg Fe dosage) in a group of 7 patients with haemorrhagic or posthaemorrhagic iron deficiency anemia. In addition, almost no haemoglobin increase was observed in 9 patients during a 4-weeks treatment period when given Fe-PM (100-300 mg Fe/d) on empty stomach, whereas subsequent treatment with ferrous sulfate (100-200 mg Fe/d) was therapeutically effective (0.15-0.23 g/dl Hb-increase/d). When given 100 or 300 mg Fe/d Fe-PM together with meal, 3 out of 6 patients showed a higher iron utilization rate (3.4-11.9%/d) than given without meal (0.5-7.5%/d). In vitro incubation studies demonstrated that Fe-PM is very stable at neutral pH. A small release of iron from the high molecular weight complex was found only at low pH (< 2). However, high amounts of ionic iron were measured in the reaction tubes after incubating solutions of Fe-PM together with ascorbic acid. This finding could explain the somewhat higher bioavailability of Fe-PM when given with vitamin C containing meals.(ABSTRACT TRUNCATED AT 250 WORDS)

Anaemia and wound healing. A clinical observation in 38 patients

In a six year period, 38 patients who had an average packed cell volume of 17.9% (range 14-25%) were treated surgically and their anaemia was corrected with oral haematinics post-operatively. Twenty one of the patients had emergency while 17 had elective surgical procedures under spinal (N = 30), ketamine hydrochloride (N = 6) and local infiltrating (N = 2) anaesthesia. All the wounds healed by primary intention and no wound complication was observed after a mean follow-up period of three years. Headache following spinal anaesthesia occurred in 6 patients and was the only significant post-operative complication detected. We conclude that severe anaemia alone does not retard wound healing in man.

New drugs on the horizon

The agents covered in this article are useful in a wide range of illnesses, including infections, cancers, cardiovascular and gastrointestinal diseases, and others. One of the major forces driving the development of new drugs is the use of biotechnology. Biotechnology encompasses the techniques of recombinant DNA and monoclonal antibody technologies to produce protein drugs that have not been previously available in sufficiently pure form or in adequate quantities. As new drugs are developed, the authors hope that intensified efforts will be geared towards the development of unique drugs that offer important therapeutic gains.

A clinico-haematologic profile of paroxysmal nocturnal haemoglobinuria

Clinico-haematological parameters in sixteen patients of paroxysmal nocturnal haemoglobinuria (PNH) are presented. Their modes of presentation included recurrent episodes of cola-coloured urine (6/16), refractory anaemia (9/16) and predominant thrombotic manifestations (1/16). Laboratory investigations revealed the presence of anaemia (16/16), reticulocytosis (14/16), thrombocytopenia (11/16), leucopenia (5/16) and cellular bone marrow (14/16). Two patients had hypoplastic bone marrow initially but subsequently developed PNH. The patients were treated with haematinics, prednisolone (16/16) and oxymethalone (2). Prednisone was effective in suppressing haemolytic episodes. Oxymethalone given to the 2 patients with hypoplastic bone marrow resulted in amelioration of anaemia in one but no effect in the other patient.

Iron levels in pregnancy, physiology or pathology? Assessing the need for supplements

This paper re-examines the need for iron supplements among pregnant women by considering whether the changes they experience in iron levels are physiological or pathological. The literature reveals that changes in the blood leading to haemodilution are necessary adaptations to healthy pregnancy. These changes alter normal haematological values. Consequently, indices such as haemoglobin concentration lose their accuracy as measurements of iron status. Tests for iron stores such as serum ferritin are more likely to prove useful indicators of deficiency. Iron stores are greatly depleted early in pregnancy, whether or not supplements are taken, when absorption is low. They return to pre-pregnant levels quickly after delivery. Reasons for these phenomena are postulated. High levels of haemoglobin in pregnancy seem to be as undesirable as very low levels. As proved benefits from iron therapy are few, it is questionable whether the antenatal period is an appropriate time to supplement. However, the issue of physiology versus pathology remains unresolved. Pregnancy is assumed to be an abnormal variation of the non-pregnant state; its parameters being judged against those of the population at large. As most pregnancies form a normal part of a woman's life cycle, the physiological ranges for pregnancy itself need to be determined.

Iron metabolism: a 40-year overview

The study of iron metabolism during the past 40 years is summarized. The status of hematology in general, and of the Hematology Division at Washington University in particular, is retrospectively reviewed. From a baseline of accepted information in 1950, the major areas of iron metabolism in humans are examined and significant additions to the fund of knowledge are identified. Progress in most areas is characterized by slow accretion of knowledge rather than by true conceptual breakthroughs.

Clinical use of haematopoietic growth factors

Over the past decade experimental haematologists have identified and eventually characterised a number of polypeptide growth factors capable of stimulating the proliferation and differentiation of haemopoietic progenitor cells in vitro. The molecular cloning of these growth factors has now allowed their use in vivo, and some of them have shown promise in recent clinical trials. Most of the work has been done on erythropoietin and myeloid growth factors, which are discussed in this review. Erythropoietin has been used successfully as replacement therapy in the anaemia of end-stage renal failure, but may also prove clinically useful in other chronic anaemias and, in combination with other growth factors, as a stimulant of bone marrow regeneration following bone marrow transplant. Myeloid growth factors, and, in particular, granulocyte colony-stimulating factor, have been shown to accelerate neutrophil recover in cancer patients following chemotherapy, with a reduction in the number of severe infections and mucositis.

Response in serum ferritin and haemoglobin to iron therapy in blood donors

Seven hundred seventeen healthy male blood donors regularly donating four or more units a year were surveyed for haemoglobin and serum ferritin levels. One hundred fifty-one (21%) had a haemoglobin less than 13.5 g/dl and were therefore disqualified from further blood donation, having a mean serum ferritin of 28 micrograms/liter. Of the remaining 566 donors with haemoglobin levels equal to or greater than 13.5 g/dl, the mean serum ferritin was 33 micrograms/liter, although in 299 (53%) the value was less than 28 micrograms/liter. To document response to iron therapy 46 donors with haemoglobin levels equal to or greater than 13.5 g/dl were stratified into those with the lowest iron stores (group 1; n = 23), defined as a serum ferritin less than 20 micrograms/liter, and controls (group 2; n = 23), with serum ferritin between 50 and 150 micrograms/liter. Within each stratum donors randomly received ferric polymaltose at a dose of 100 mg elemental iron twice daily for 56 days (groups 1a and 2a) or an identical iron-free placebo tablet administered on the same schedule (groups 1b and 2b). Iron therapy in the iron-deficient group (group 1a:n = 11) resulted in a significant rise in haemoglobin (p = .03) and iron stores reflected in serum ferritin (p = .002) compared to those receiving placebo (group 1b). In the control group iron therapy or placebo was without significant effect. Thus, ferric polymaltose preparation is bioavailable and is notable for the virtual absence of gastrointestinal tract side effects.

A comparison of two combined iron-folic acid preparations in the prevention of anaemia in pregnancy

Forty patients were given one of two iron-folic acid tablets starting from the first ante-natal visit and continuing to parturition. Haemoglobin levels were measured at the commencement, at the end of the study and on at least one other occasion. A comparison was made of haemoglobin levels and side-effects.

Drug therapy in the elderly

Special considerations must be invoked when prescribing medications for the elderly. Although basic absorption is unchanged, many elderly patients are prone to chronic diarrhea or constipation, either of which may alter intestinal contact time and, thus, absorption. Concurrent use of such drugs as antacids or iron preparations may affect the availability of some compounds for absorption. The problem of drug interactions after absorption is also important, since studies have shown that elderly patients commonly receive several drugs concurrently.