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Biomedical subjects

R D Baynes

Publications and source records attributed to R D Baynes.

79 records · Page 5Linked to original sources

Haematological and iron-related measurements in active pulmonary tuberculosis.

59 patients with active pulmonary tuberculosis were evaluated in terms of haematological indices, iron-related measurements and markers of inflammation. The variables evaluated included the Hb, mean cell volume (MCV), serum iron, total iron-binding capacity, percentage saturation, serum ferritin, erythrocyte sedimentation rate (ESR) and C-reactive protein. In addition, marrow iron stores were assessed both histologically and chemically. Among the changes noted was a raised S-Ferritin, which appeared in part to be a component of the acute phase response, since it correlated with C-reactive protein concentration (r 0.59, p less than 0.0001). In addition, there was a good correlation between the S-Ferritin and the concentrations of non-haem iron in the marrow, as assessed chemically on trephine biopsies (r 0.78, p less than 0.0001) and histologically on aspirated and biopsy material (rS 0.78, p less than 0.0001 and rS 0.68, p less than 0.0001, respectively). Furthermore, the quantitative relationship between the S-Ferritin and the chemical concentrations of non-haem iron in the marrow was similar to that found previously in a heterogeneous group of subjects without infections. While the present findings confirm that iron is diverted into reticuloendothelial stores in active pulmonary tuberculosis, no evidence was found to suggest that the anaemia which was present in 45 of the 59 patients was secondary to iron-deficient erythropoiesis; the percentage saturations in the 2 groups were 30.3 and 31.1 respectively. In a final analysis, the present findings were compared with previous ones obtained in a group of patients with Hodgkin's disease. The degree of rise in the S-Ferritin for a given marrow non-haem iron concentration was significantly less in the patients with tuberculosis (p less than 0.0001).

Adult↗

Plasma lactoferrin content: differential effect of steroid administration and infective illnesses: lack of effect of ambient temperature at which specimens are collected.

The effect of parenteral hydrocortisone on plasma lactoferrin concentration, neutrophil count and lactoferrin:neutrophil ratio was assessed in 10 volunteer subjects. Administration of a single dose of corticosteroid was followed by a significant rise in the circulating neutrophil count, a significant but proportionately smaller rise in the plasma lactoferrin concentration and a significant fall in the lactoferrin:neutrophil ratio. Acute viral infections were found to be associated with a disproportionately low plasma lactoferrin concentration relative to the circulating neutrophil count. The relatively low lactoferrin concentrations in both these situations could be of significance in regard to the propensity to bacterial infection and superinfection which these 2 groups of subjects display. Compared to patients with viral infection, those suffering from Plasmodium falciparum malaria showed a significantly elevated lactoferrin:neutrophil ratio, although this ratio was not significantly different when malarial patients were compared to normal individuals. These findings suggest that the pathogenesis of relative neutropenia in viral and protozoal illnesses is fundamentally different. Finally, it was found that the temperature at which specimen collection takes place does not appear to be a significant variable determining the plasma lactoferrin concentration.

Acute Disease↗

Relationship of plasma lactoferrin content to neutrophil regeneration and bone marrow infusion.

Plasma concentrations of lactoferrin were measured in immediately separated EDTA samples from 5 subjects who had received HLA identical bone marrow transplants for leukaemia or aplastic anaemia and from 7 subjects who were leukopenic as a consequence of chemotherapy for a variety of malignant conditions. Plasma lactoferrin concentrations were found to closely parallel the leucocyte count and were not found to either predict or to antedate leucocyte regeneration. Serial measurements of plasma lactoferrin in a subject with no circulating neutrophils who received a bone marrow graft revealed that the clearance of lactoferrin followed an exponential pattern and had an initial half time of 2.2 h.

Agranulocytosis↗

Lack of correlation between iron stores and plasma lactoferrin concentration.

Plasma lactoferrin concentration and indices of iron nutrition including P-Ferritin, P-iron, total iron binding capacity and percentage saturation were measured in 75 otherwise normal females. This was done in order to evaluate previous reports that neutrophil lactoferrin content was altered by variations in iron storage status. Since P-Lactoferrin is derived from and hence reflects neutrophil lactoferrin content it would seem reasonable to assume that P-Lactoferrin would vary in accordance with iron stores. However, there was no statistically significant difference in P-Lactoferrin concentration between iron deficient subjects and those who were iron replete. Furthermore, there was no statistically significant correlation between any iron related parameter and P-Lactoferrin concentration.

Female↗

Enzyme linked immunosorbent assay for lactoferrin. Plasma and tissue measurements.

Highly purified lactoferrin was obtained from human breast milk by sequential use of affinity chromatography and isoelectric focusing. IgG antibody to purified lactoferrin was used to develop a sensitive and reproducible enzyme linked immunosorbent assay. Characteristics of the assay included linearity over a wide range of lactoferrin concentration (3.125-200 micrograms/l) and sensitivity (lower range less than 1 microgram/l). The assay can be adapted for use on tissue cytosol as well as plasma. Healthy subjects showed plasma lactoferrin levels ranging from 187.5-450.1 micrograms/l. Pulmonary tuberculosis and acute pneumonia are associated with a 2-3-fold increase in plasma lactoferrin content while neutropenic subjects have markedly depressed lactoferrin concentrations. The assay will be useful for further delineation of lactoferrin and neutrophil function and turnover.

Antibodies↗

Further local experience in the treatment of acute non-lymphoblastic leukaemia.

Ninety-two patients suffering from various forms of acute non-lymphoblastic leukaemia were seen at the Johannesburg General Hospital between January 1972 and December 1977. Seventy-four completed at least one course of therapy, and were therefore available for evaluation. Three basic regimens were used for inducing remissions. These included daunorubicin and cytosine arabinoside (regimen 1-19 patients); larger doses of daunorubicin together with cytosine arabinoside (regimen 2-29 patients); and a combination of cyclophosphamide, vincristine, cytosine arabinoside and prednisone (regimen 3-22 patients). Regimen 3 was normally used only in older patients. Supportive measures included the use of red cell, granulocyte and platelet transfusions. Complete remission rates with the 3 regimens were 36,8%, 55,1% and 40,9% respectively, with corresponding partial remission rates of 5,2%, 0% and 18,1% respectively. The mean duration of survival in those patients who achieved remission was 10 months, 18 months and 8 months respectively. In addition, a complete remission rate of 28,6% was obtained in 14 patients, 10 of whom had relapsed while being treated with other regimens and who were later treated with an 8-drug combination (TRAMPCOL).

Acute Disease↗