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W N Gibbs

Publications and source records attributed to W N Gibbs.

52 records · Page 3Linked to original sources

Spinal cord compression in thalassaemia.

Two cases of spinal cord compression resulting from extramedullary haemopoiesis in patients with thalassaemia of intermediate clinical severity are reported. The association between mild thalassaemia with long survival and the risk of spinal cord compression from extramedullary haemopoietic deposits is emphasised.

Adult↗

Hyperinfection syndrome with Strongyloides stercoralis in malignant lymphoma.

Hyperinfection with Strongyloides stercoralis occurred in three patients with malignant lymphoma. The probable cause in each case was alteration of the immune responses either as a result of the malignant lymphoma or by the treatment given. Though thiabendazole (Mintezol) has produced reasonable results in the treatment of the hyperinfection syndrome, preliminary data suggest that the new broad-spectrum anthelmintic levamisole (Ketrax) is more effective. All patients who live or have lived in an area where strongyloidiasis is endemic should be investigated to detect the presence of the nematode before and during treatment with drugs with immunosuppressive properties. In view of the high mortality with S. stercoralis hyperinfection, vigorous therapy should be instituted before the use of immunosuppressive drugs.

Adult↗

Erythrocyte Hb-S concentration. An important factor in the low oxygen affinity of blood in sickle cell anemia.

The blood in sickle cell anemia has a very low oxygen affinity and, although 2,3-diphosphoglycerate (2,3-DPG) is increased, there is doubt as to whether this is the only factor responsible. In this study of 15 patients with sickle cell anemia (Hb SS) no correlation was found between oxygen affinity (P(50) at pH 7.13) and 2,3-DPG in fresh venous blood. Whole populations of Hb SS erythrocytes were therefore separated, by an ultracentrifuge technique, into fractions of varying density. The packed red cell column was divided into three fractions; a bottom fraction rich in deformed cells or irreversibly sickled cells (ISC), with a very high mean corpuscular hemoglobin concentration (MCHC); a middle fraction containing cells with the highest content of fetal hemoglobin; and a top fraction containing reticulocytes and discoid cells but free of deformed cells. Oxygen affinity was shifted to the right in all layers (mean P(50) (pH 7.13)+/-1SD: top 46.3+/-2.9 mm Hg: middle 49.8+/-4.9 mm Hg; bottom 61.0+/-5.8 mm Hg) compared with normal blood (top 32.1+/-0.7 mm Hg: bottom 30.1+/-0.5 mm Hg). 2.3-DPG was increased in the top fraction, but was low or normal in the bottom fraction (top 21.8+/-3.4 mumol/g Hb: middle 17.7+/-2.2 mumol/g Hb; bottom 13.8+/-3.1 mumol/g Hb; normal whole blood 14.3+/-1.2 mumol/g Hb). The level of 2,3-DPG in top fractions could not account for the degree of right shift of P(50), and in the middle and bottom fractions the even greater right shifts were associated with lower levels of 2,3-DPG. Top fraction cells depleted of 2,3-DPG had a higher, but still abnormally low, oxygen affinity. A strong relationship was found between oxygen affinity and MCHC. The fractions with the greatest right shift in P(50) had the highest MCHC (top 32.4+/-2.0; middle 36.2+/-3.1; bottom 44.6+/-3.2 g/100 ml, respectively) and the plot of P(50) vs. MCHC showed a positive correlation (r = 0.90, P < 0.001). The red cell population in sickle cell anemia is not homogeneous but contains cells of widely varying Hb F content, 2,3-DPG, and hemoglobin concentration. Paradoxically, the cells with the lowest O(2) affinity have the lowest 2,3-DPG, but they also have the highest concentration of Hb S. The dense, deformed cell called the ISC is but the end stage in a process of membrane loss and consequent increase in hemoglobin concentration. The P(50) of Hb SS blood is, to a large extent, determined by the presence of these cells (r = 0.85, P < 0.001). Increased concentration of Hb S in the cell favors deoxygenation and crystallization even at relatively high P(o2). Lowered affinity for oxygen appears to be closely associated with Hb S concentration and not with 2,3-DPG content.

Adolescent↗

Clonal evolution in two patients with autoimmune disease and lymphoreticular neoplasia.

Two cases are described, one with proven lymphosarcoma and doubtful autoimmune disease, and the second with the reverse situation, in which circulating abnormal mononuclear cells showed PHA responsiveness and an abnormal chromosomal constitution (clonal evolution). These findings are discussed in the light of previous cytogenetic studies of lymphoreticular neoplasia and autoimmune disease and the relationship between these two conditions.

Adult↗

Parasitic infections in young Jamaicans in different ecological zones of the island.

Data are presented for the first country wide prospective study on gastrointestinal tract parasitic infections done in Jamaica. Samples from 2,947 young Jamaicans drawn from all ecological zones and from all parochial divisions of the island were analyzed. Pica was practised by 8.6%. Generally, prevalence of organisms was as follows: Trichuris trichiura (12.3%), Ascaris lumbricoides (9.5%), hookworm (2.2%), Strongyloides stercoralis (0.3%), Giardia lamblia (6.3%) and Entamoeba coli (7.7%). Several other spp. of protozoans were recorded. Prevalence of A. lumbricoides, T. trichiura and Necator americanus was significantly greater in upland than in lowland (both urban and rural), while the situation was reversed for G. lamblia-infections. Greatest variations were age-related. A. lumbricoides and T. trichiura reached peak prevalence of 15.3 and 20.5% respectively in 5-9-year-olds, while hookworm peaked later at 15-19 years of age. Suggestions are made for a national and even regional antihelminthic program for the mass treatment of pre- and primary school age children.

Adolescent↗