Simultaneous continuous 13C, 12C analysis of expired gas in the 13C breath test

The ¹³C breath test is a method of clarifying the metabolism of loaded substances by administering ¹³C-labelled materials and calculating the ¹³CO₂ and ¹²CO₂ ratio (¹³C/¹²C isotope ratio) in the expired gas. The materials are metabolized and expelled in the expired gas. Because simultaneous continuous measurement of ¹³CO₂ and ¹²CO₂ in expired gas has been difficult up to the present, respective expired gases, including dead space before and after administration, have been sampled to separate sampling bags and ¹³C/¹²C has been measured in the bags and changed fraction of ¹³C/¹²C after administration (δ) has been used to judge the metabolic process. This method is affected by the contamination of the dead space gas. In the present study, in order to exclude the dead space effect, simultaneous continuous analysis of ¹²CO₂ and ¹³CO₂ of expired gas identifying alveolar gas was applied to the ¹³C-urea breath test in addition to the conventional sampling bag method. Both isotope detectors were attached to a mass spectrometer. Fifty-six cases receiving stomach health check-ups for Helicobacter pylori were examined. δ was calculated in the bag or in phase III of continuous gas measurement. Because the bag contains dead space, δ was reduced and sensitivity and specificity with reference to gastric fluoroscopy or Helicobacter pylori IgG antibody were reduced. Decreasing the dead space contamination is important in reducing the measurement error in the ¹³C breath test and simultaneous continuous measurement is a good tool for this purpose.     

Dynamic Uptake of Radioactive Substance in Rat Salivary Gland Following 3H-Melatonin Administration

Dynamics of radioactive accumulation in rat greater salivary gland following systemic administration of 3H-melatonin was studied to determine a possible action of the hormone in the gland. Progressive decline of 3H-melatonin concentrations was found in the serum, lung, skeletal muscle, liver, kidney, and salivary gland during 60 min following the administration. On the contrary, there was a progressive accumulation of radioactive substance other than 3H-melatonin in the salivary gland but not in other tissues mentioned. The radioactivity was also progressively and preferentially localized in the nuclear fraction of the gland cells. These results suggest a possible direct action of melatonin derivative in rat salivary gland.     

Experimental Iron Deficiency in the Rat THE USE OF 51Cr, DF32P AND 59Fe TO DETECT HAEMOLYSIS OF IRON-DEFICIENT CELLS

S ummary Dietary iron deficiency in the rat results in marked normoblastic hyperplasia of the bone marrow, peripheral blood reticulocytosis, the presence of nuclear remnants in red cells and a haeinolytic process. Haemolysis of the red cells was not detected using the ⁵¹Cr label. DF³²P did detect moderate shortening of red cells but to a lesser degree than would be expected by the degree of reticulocytosis. Cohort labelling of red cells using ⁵⁹Fe indicated an early rapid destruction of newly formed cells. These findings are at variance, in part, with the observations in human iron deficiency where reticulocytosis is minimal.     

125I-Transferrin Turnover in Rabbits with Haemolytic Anaemia

The metabolism of purified ¹²⁵I-labelled homologous transferrin in rabbits with haemolytic anaemia was compared to that in control rabbits and no significant differences were found. During 3 weeks of haemolysis plasma transferrin concentrations did not change appreciably. The fractional turnover rate was 43% of the intravascular pool per day. The intravascular pool was 45% of the total exchangeable transferrin.     

The kinetics of 111Indium distribution following injection of 111Indium labelled autologous granulocytes in man

The kinetics of human autologous granulocytes, separated and labelled with 111In without isolation from plasma, have been studied in subjects with and without sepsis with the aim of identifying the fate and sites of destruction of granulocytes in man. In subjects without inflammatory disease, 111In granulocyte recovery in faeces, urine and saliva over 4 d was less than 1% of the dose, so that the activity visualized by the gamma camera represented almost 100% of the dose. On images taken at 24 and 48 h, this activity was distributed between spleen, bone marrow and liver, with foci of additional abnormal activity in subjects with inflammatory disease. Splenic activity fell between 40 min and 24 h, consistent with the presence of a splenic granulocyte pool, but remained constant after 24 h. Since granulocyte clearance from the blood was predominantly completed by 24 h, the residual splenic activity at that time reflected splenic granulocyte destruction. In patients with sepsis, the fall in splenic activity was greater than in those without, implying diversion of granulocytes from splenic destruction to tissue utilization when inflammation is present. Bone marrow activity increased between 40 min and 24 h and then remained stable. Granulocytes that were extensively manipulated in saline prior to labelling failed to localize in marrow, suggesting that visualization of the latter reflected destruction of intact, normal granulocytes. Although the changes in splenic and marrow activities terminated at 24 h, at which time granulocyte clearance from blood was at least 80% completed, plasma 111In remained essentially unchanged between 40 min and 48 h at less than 5% of the dose, discounting it as the source of splenic and marrow activities.     

Iron Absorption, Iron Loss and Iron Retention in Man: Studies after Oral Administration of a Tracer Dose of 59FeSO4 and 131BaSO4

The absorption of iron administered as ferrosulphate was studied in normal subjects, in patients with iron deficiency and in patients with idiopathic and secondary haemosiderosis. By using a test dose combining radioactive iron (⁵⁹Fe) with radioactive barium sulphate (¹³¹Ba) as inert indicator, it was possible to determine how much iron was initially absorbed and whether a proportion of this was later excreted in the faeces.
The (initial) iron absorption, the iron loss as a percentage of the iron absorbed, and the (ultimate) iron retention 2 weeks after administration of the test dose were calculated.
In normal subjects and patients with secondary haemosiderosis, a large proportion of the initially absorbed iron later returned to the intestinal lumen. In patients with iron deficiency and those with idiopathic haemosiderosis, however, nearly all the initially absorbed iron was retained in the organism. In differential diagnosis between idiopathic and secondary haemosiderosis, therefore, determination of the iron absorption and iron retention percentages from a test dose may be important.
In patients with secondary haemosiderosis there seemed to be a negative correlation between the degree of haemosiderosis and the amount of iron from the test dose ultimately retained in the organism.     

Scintigraphic evaluation of the haemopoietic bone marrow using a 99mTc-anti-granulocyte antibody: a validation study with 52Fe

To specify the validity of bone marrow scanning using a monoclonal anti-granulocyte antibody labelled with ^99mTc (BW 250/183) for the functional assessment of haemopoiesis, we compared this method with ⁵²Fe scan in 16 patients with haematological disorders. The examinations were performed using a rectilinear whole-body scanner and the distribution of the two tracers was assessed visually and quantitatively in anatomical bone marrow segments, the spleen and liver. Qualitative comparison showed concordance in the bone marrow distribution of the two tracers in 83% of the segments. Discrepancies were found in six patients with hypoplastic or aplastic marrow. The spleen was visualized in all cases with the ^99mTc-Moab, including nine patients without splenic haemopoiesis (i.e. without spleen uptake of ⁵²Fe). The uptake of the two tracers, quantified in bone marrow segments and the spleen, correlated well (PO-0001), but not in the liver (NS). The correlation between the uptake values for each patient was excellent, except in cases of aplastic bone marrow. In conclusion, bone marrow scanning using a ^99mTc labelled anti-granulocyte monoclonal antibody enables functional evaluation of the distribution of haemopoiesis. Limitations include the evaluation of bone marrow aplasia and identification of splenic haemopoiesis, for which ⁵²Fe remains the tracer of choice.     

Evaluation of 51Cr as a Leucocyte Label

S ummary . A double label technique has been developed to compare the behaviour of ⁵¹Cr labelled leucocytes with DF³²P labelled leucocytes. Whole blood is divided into two aliquots and the leucocytes in each are labelled with a different isotope. After infusion of labelled cells, the radioactivity of each isotope can be determined simultaneously on the same blood sample using liquid scintillation counting. In studies of seven patients with solid tumours and one with leukaemia, the intravascular disappearance of autologous leucocytes labelled with ⁵¹Cr and DF³²P appeared similar in five of the eight patients during the initial 6 hr following infusion. Thereafter in all but one instance, ⁵¹Cr labelled leucocytes had slightly higher specific activities. ⁵¹Cr labelled lymphocytes and DF³²P labelled lymphocytes also behaved in the same manner. It is concluded that⁵¹Cr is a suitable leucocyte label and may be substituted for DF³²P under certain circumstances.     

67Gallium Uptake in Psittacosis Infection

Summary: 67Gallium uptake in psittacosis infection. J. T. Andrews and J. R. E. Fraser, Aust. N.Z. J. Med., 1979, 9, p. 437–439.
⁶⁷Gallium citrate isotope scanning was performed in a febrile patient with pneumonitis and hepatitis who was later shown to have psittacosis. Focal isotope uptake was detected in both lungs in the absence of radiological changes. There was no enhanced concentration in the liver where inflammatory cell infiltration was slight.     

Localization of neuroendocrine tumours and insulinomas using radiolabeled somatostatin analogues, 123 I-Try3-octreotide and 111in-pentatreitide

OBJECTIVE A number of neoplasms are known to express somatostatin receptors; the use of somatostatin receptor imaging in their localization has recently been described, but the resolution and discrimination of the isotopes used remains sub-optimal. We have looked at the use of a new” In-labelled analogue of somatostatin, pentatreotide, in the visualization and functional characterization of a number of neoplastic conditions. PATIENTS Thirteen patients with proven neoplasms were scanned using this agent. Planar and single-photon-emission computerized tomographic (SPECT) images of the relevant part of the body were obtained using a gamma-camera at 10 minutes and 4 and 21 hours after injection of the radiopharmaceutical. In six patients (three carcinoid, three insulinomas) scanning was also performed using ¹²³l-Tyr-3-octreotide. RESULTS Primary tumours or metastases were visualized in six of the seven patients with neuroendocrine tumours, and three of six patients with insulinoma. One patient with an insulinoma who had a positive scan showed absent uptake when rescanned after tumour removal. A rise In blood glucose (more than twice basal) in response to octreotide was seen only in those insulinoma patients with positive scans. In cases where both ¹¹¹ln-pentatreotide and ¹²³l-Tyr-3-octreotide scans were performed, both radiopharmaceuticals identified the same 4/ 6 tumours; however, tumour definition (reflecting high tumour to background ratio) was better with pentatreotide on the 21-hour images with minimum biliary and gut activity, allowing better resolution of the tumour image. CONCLUSION It appears that ¹¹¹ln-pentatreotide scintigraphy is a rapid and safe procedure for the visualization of neuroendocrine tumours possessing somatostatin binding sites. A positive scan may be predictive of neuroendocrine responsiveness to octreotide therapy. In addition, it also appears that¹” In-pentatreotide has superior kinetics compared to ¹²³I-Tyr-3-octreotide, typically achieving more satisfactory tumour to background ratios, and may thus be more useful in the localization of endocrine tumours.     

Decreased Incorporation of 14C-Glucosamine Relative to 3H-N-Acetyl Glucosamine in the Intestinal Mucosa of Patients with Inflammatory Bowel Disease

The synthesis of glycoproteins was investigated in intestinal mucosa from patients with inflammatory bowel disease (IBD) and from those with various other conditions. The incorporation into acid-insoluble macromolecules of the amino sugar glucosamine, the first and committed metabolite in the biosynthetic sequence, and its immediate derivative, N-acetyl glucosamine was determined. Tissue was incubated with 1-2 nmol ¹⁴C-glucosamine and ³ H-N-acetyl glucosamine and the simultaneous incorporation of both isotopes was measured. Bowel tissue from areas microscopically uninvolved in active disease process was examined. Values for the incorporation of both substrates into acid-soluble constituents were similar for both IBD and non-IBD groups, as was also the incorporation of ³H into acid-insoluble constituents. The incorporation of ¹⁴C, however, when expressed relative to that of H in each individual patient, ie., ¹⁴C/³H, was distinctly different in IBD cases. In 26 non-IBD samples this ratio ranged from 0.04-0.26 with a mean of 0.097 ± 0.009. In nine cases of Crohn's disease values ranged from 0.013-0.06 with a mean of 0.039 ± 0.011 ( p < 0.01); in nine cases of ulcerative colitis values were 0.007-0.06 with a mean of 0.031 ± 0.006 ( p < 0.01). It is concluded that the step involving the N-acetylation of the amino sugar is relatively deficient in patients with IBD and this could reduce the synthesis of the glycoprotein cover which protects the mucosa from damage by bowel contents.     

Measurement of Red Cell Folate Levels by 3H-Pteroylglutamic Acid (3H-PteGlu) Radioassay

S ummary . A siniple, rapid radioassay is described for the determination of red cell folate activity utilizing commercially available beta lactoglobulin as thc folate binding protein. The standard curve is prepared with a pteroylpolyglutamate and ³H-pteroylglutamic acid. The test is performed with a maximum of 20 nicrolitres of whole blood and multiple samples can be processed within 1 hr. Values of red cell folate in normal subjects range from 200 to 875 ng/ml packed cells giving good correlation with established microbiological procedures. Red cell folate levels were lowest in patients whose folate deficiency was accompanied by anaemia. This assay may be useful for measurement of pteroylpolyglutamates in other tissues since an equimolar amount of N-5-methyl tetrahydrofolate is barely measurable under the conditions of this assay.     

Concurrent label method with 111In and 51Cr allows accurate evaluation of platelet viability of stored platelet concentrates

Summary. The precision and reproducibility of ¹¹¹In and ⁵¹Cr platelet radiolabel agents for in vivo kinetic studies of stored platelet concentrates (PC) were investigated. The objective was to develop a precise method with concurrent labelling of two platelet populations using different isotopes, which would allow identification of small differences in in vivo platelet quality. Identical labelling procedures were used to investigate the effects of PC storage age, different methods of red cell (RBC) and white cell (WBC) contamination correction, and label elution correction on the results of ¹¹¹In and ⁵¹Cr kinetic studies. ¹¹¹In and ⁵¹Cr platelet survival curves from the same PC, even when uncorrected for elution and RBC contamination, exhibited excellent correlation, irrespective of the age of the concentrate and its viability. However, slightly higher, but statistically significant, post-infusion per cent recoveries with ⁵¹Cr labelled platelets were found. Two factors were identified as the cause for this difference. There was a higher affinity of contaminating RBC/WBC in PC for ⁵¹Cr than for ¹¹¹In. With determination of RBC/WBC activity by centrifugation/density separation, RBC/WBC fractions from the injectate were found to contain 12.6 ± 3·8%v 7·1 ± 3·6% of total ⁵¹Cr and ¹¹¹In activity, respectively, in 20 studies. In addition, there was a significantly higher ¹¹¹In activity in plasma immediately post-infusion than with ⁵¹Cr, 5·2 ± 1·3%v 2·8 ± 1·6%, respectively, suggesting more label elution or carryover. After correction for the activity of RBC/WBC and for elution or carryover, essentially identical ⁵¹Cr/¹¹¹In platelet survival curves were found. In 31 stored PC studies, the absolute average difference between ⁵¹Cr and ¹¹¹In per cent recoveries was only 4 ± 3% in a group of donors whose platelet recoveries ranged from 10% to 80%. Similarly, the average difference between ⁵¹Cr and ¹¹¹In survival was only 8±4 h within a range of survivals from 40 to 220 h. In conclusion, after correction for elution and contaminating RBC/WBC binding, these studies show that ⁵¹Cr and ¹¹¹In may be used interchangeably for labelling of stored PC, and that small differences between test and control platelets could be reliably detected using concurrent labelling with simultaneous infusion.     

Preparation of 131I-Asialo-α1-Acid Glycoprotein

Abstract. α₁-Acid glycoprotein (orosomucoid) was prepared from a byproduct of the ethanol plasma fractionation by means of ion-exchange procedures. Immunoelectrophoresis suggested a high degree of purity; the purified protein contained 13.5% sialic acid and 17.8% hexose. The α₁-acid glycoprotein was modified by removal of sialic acid with neuraminidase (EC 3.2.1.18) followed by iodination with ¹³¹I. The purpose of the preparation, its potential use as a pharmacon for liver function studies in nuclear medicine is the subject of further study.     

The in vivo kinetics of 111In- and 51Cr-labelled platelets: a comparative study using both stored and fresh platelets

The in vivo kinetics of simultaneously injected 51Cr- and 111In-labelled platelets was investigated in 20 healthy male volunteers. The studies were carried out using both fresh platelets and platelets stored for 5 d at 22 degrees C; the disappearance of platelet-bound radioactivity was measured on whole blood samples as well as platelet pellets. Compared to 111In, the labelling efficiency was notably lower for 51Cr, and a higher amount of 51Cr was bound to contaminating red cells. As regards the fresh platelets, only small dissimilarities were observed in the in vivo kinetics obtained with the two labels. 51Cr yielded a slightly higher platelet recovery and longer T1/2 than 111In, when whole blood samples were used for calculations; no differences were seen when using platelet pellets. When stored platelets were studied, 51Cr gave significantly longer T1/2 and mean life-span (MLS) than did 111In. This difference was present for all mathematical models used for the calculation of MLS, and when whole blood samples as well as platelet pellets were employed. It was demonstrated that the estimation of MLS was also highly dependent upon techniques of blood sampling and curve fitting. Calculation, in which the initial data points were excluded, gave consistently longer MLS (P less than 0.0001), as compared to when all data points were included. Furthermore, when all survival studies were grouped together, calculations using platelet pellets gave a significantly (P less than 0.001) shorter platelet MLS than calculations using whole blood samples. It is concluded that both 51Cr and 111In are acceptable as radiolabels for both fresh and stored platelets. However, it appears that the viability of stored platelets may be influenced by the choice of label, and caution must be taken when these isotopes are used together in dual tracer experiments. Also, our results show that a meticulously standardized processing of blood samples and experimental data is required to enable interlaboratory comparisons of the results.     

Eosinophilia associated with proliferation of CD3+4−8−αβ+ T cells with chromosome 16 anomalies

We describe a patient with eosinophilia and an abnormal CD3⁺4⁻8⁻αβ⁺ T-cell population. Chromosomal analysis of sorted CD3⁺4⁻8⁻ cells revealed abnormal karyotypes on chromosome 16. In the presence of IL-2 the production of IL-5 from CD3⁺4⁻8⁻ cells was higher than that from CD3⁺4⁺/8⁺ cells. Eosinophil survival-enhancing activity in the patient serum was inhibited by a combination of anti-IL-5 and anti-GM-CSF monoclonal antibodies. These data suggest that increased production of IL-5 and GM-CSF from the abnormal CD3⁺4⁻8⁻ cells might cause eosinophilia.     

Evaluation of Double 51CR Technique

Summary. The post-transfusion survival of multiple units of concentrated red cells was measured by ⁵¹chromium automated differential agglutination and double ⁵¹chromium technics. Since the mean 24 h survivals were similar with both assay methods, these methods are considered acceptable in evaluating red cell preservation. Analysis of the paired data, however, revealed a significant difference in the results, indicating that an average of 3% of ⁵¹chromium eluted from red cells during the first 24 h.     

Measurement of Erythropoiesis using 52Fe

S ummary A method for determining erythropoiesis quantitatively with ⁵²Fe has been applied to 25 patients with anaemia. The data were derived from quantitative scanning of the erythropoietic areas and the measurement of the plasma iron turnover. We have assessed this ⁵²Fe measurement of erythropoiesis by comparing it with total marrow iron turnover studies. Both methods give similar estimates of erythropoiesis except in patients with severe ineffective erythropoiesis and in a patient with significant peripheral haemolysis, when erythropoiesis as measured with the ⁵²Fe technique gave higher results. In these conditions, the estimate of total erythropoiesis might be more reliable using the ⁵²Fe quantitative scanning technique. However, the measurement of erythropoiesis with ⁵²Fe does not distinguish effective from ineffective erythropoiesis and cannot be applied to patients with extramedullary erythropoiesis.