Study of Urinary and Fecal Excretion of Radioactive Chromium Cr51 in Man. Its Use in the Measurement of Intestinal Blood Loss Associated with Hookworm Infection1

Abstract

Since the work of Cruz (1) and Rhoads, Castle, Payne, and Lawson (2) iron deficiency has been attributed a pre-eminent role in the causation of the anemia associated with hookworm infection. At one time or another, however, this anemia has been blamed on the effect of hemolytic "toxins" from the hookworm, poor iron absorption, poor protein intake, and blood loss, or a combination of all or several of these factors. An exact evaluation of the role of each of these possible causes is not feasible until quantitative studies are carried out in the human being infected with the human hookworm.In the present study, quantitative evaluation of one of these factors, namely blood loss due to the parasite, is attempted.The radioactive isotope of chromium Cr5' has been used for marking red blood cells (3, 4), estimating their life span and measuring blood volume (4, 5). As a preliminary to our investigation on intestinal blood loss produced by hookworm, we wished to know: 1) How much Cr5' is absorbed from the intestinal tract when it is introduced into the stomach or duodenum of normal or hookworm infected patients, 2) whether Crl' which is absorbed from the intestinal tract enters the circulating erythrocytes in significant quantities, 3) what proportion of Cr5l within the circulating red blood cells appears daily in the feces and urine of non-infected subjects.In quantities. Furthermore, it appears from this study that blood loss, although less than the loss due to A. caninum in the dog (6, 7), is probably an important factor in the genesis of the anemia associated with human hookworm infections2 METHODS All subjects were hospitalized in the Medical or Surgical wards of the Hospital Vargas. Except for patients L.M. and J.F. (Table II), the non-infected subjects were patients who had been hospitalized for surgery, or for local skin conditions. In all subjects in this category, feces were free from hookworm ova in at least three examinations. Patient L.M. was a 30-year-old woman who had had an acute hemorrhage due to placenta previa, and was studied from day 13 to day 25 post partum. Patient J.F. had acute leukemia.Tagging of circulating erythrocytes. Approximately 20 ml. of blood was taken from the antecubital vein and introduced into a sterile bottle containing 3 ml. of A.C.D. solution and approximately 80 microcuries of Cr . The mixture was incubated at 37' C. and gently shaken every five minutes. The blood was then washed three times with 0.9 per cent saline solution in experiments in which intestinal absorption was studied, or reintroduced into the patient's circulation without further washing in the studies of Cr" excretion from circulating erythrocytes.Study of Cr" absorption from the gastrointestinal tract. The washed erythrocytes were resuspended in 5 per cent dextrose. A Levine tube was placed in the patient's duodenum, under fluoroscopic control, and exactly 10 ml. of the suspension was introduced through the tube by gravity with a volumetric pipette, followed by six successive washings with 10 ml. of the dilutin...

Gastro-Intestinal Blood Loss Measured by Radioactive Chromium

“…The recovery of 97.4% of relatively small orally administered doses of 51Cr-labelled red cells suggests that apparently hardly any of the 51Cr is absorbed from the gut, and thus agrees with the results of Owen et al (1954), Roche et al (1957), andEbaugh et al (1958). Hughes Jones (1958) gave oral doses of 21,uC of 51Cr and 8 tC to two patients, and was only able to recover 66% and 87% of the administered dose.…”

“…of whole blood was found. A similar figure was obtained by Hughes Jones (1958), and Levin, Hart, and Bothwell (1959) but is rather less than the quantity found by Roche et al (1957) and Ebaugh et al (1958), namely 1.2 ml. It has been suggested that this difference may be due to the fact that these authors did not remove the unattached 51Cr by washing their cells after labelling (Hughes Jones, 1958).…”

“…He concluded that it seemed reasonably certain that the discrepancy was due to reabsorption of some of the 51Cr by the gut. This assumption seems unlikely because both Roche et al (1957) and Ebaugh (1958) could recover less than 0 5% of the 51Cr from the urine, and found less than 0 2 % of the ingested 51Cr to be present in the circulating blood.…”

“…Owen, Bollman, and Grindlay (1954) showed that it could be used to measure the quantity of blood passed in the faeces of dogs. Their methods have been applied to man by Roche, Perez-Gimenez, Layrisse, and Di Prisco (1957), Ebaugh, Clemens, Rodnan, and Peterson (1958), and Bannerman (1957. All these workers calculate the amount of blood in the faeces by measuring the radioactivity in a weighed aliquot representing 3-4% of a fluid homogenate of the stool.…”

Fecal occult blood testing on Trichuris-infected primary school children in northeastern peninsular Malaysia.

“…The upper limit of normal intestinal blood loss as determined by radioisotope studies have been reported to range from 1 to 3 ml/day. 5,11,12 The stool samples were moistened with drops of distilled water immediately prior to occult blood testing since rehydration has been shown to improve the sensitivity of the guaiac test. 13 The observer developing and reading the Coloscreen slide was blinded to the parasitologic result.…”