Small bowel morphology in British Indian and Afro Caribbean subjects: evidence of tropical enteropathy

Distal duodenal biopsy specimens taken from 30 white, 35 Indian, and 20 Afro-Caribbean residents of West Birmingham during routine endoscopy for dyspepsia, were assessed by disecting microscopy and morphometry. Finger-shaped villi were significantly less frequent in the Indian and Afro-Caribbean subjects than in the white subjects when assessed by disecting microscopy (p<0.005), and both immigrant groups had decreased mucosal thickness (p<0.01), villous height (p<0.001), villous:crypt ratios (p<0.01) and enterocyte height (p<0.05) compared with the white group. In the Indian subjects villous height and villous:crypt ratios correlated significantly with the time since the last visit to the Indian subcontinent (p<0.005). Serum alkaline phosphatase values were significantly higher in the Indian subjects compared with the white (p<0.02), and serum globulins were increased in both the Afro-Caribbean and Indian subjects (p<0.01). There were no correlations between morphometric indices and body habitus or biochemical or haematological indices and the long term effect of the morphological changes is not clear. (AU)

Sickle cell retinopathy in Jamaican children: further observations from a cohort study

Serial retinal examinations were performed in children aged 5 years and older and fluorescein angiography/angioscopy in children 6 years and older participating in a cohort study of sickle cell disease. There were 1229 patient years of observation among 389 children aged 5 - 13 years. Peripheral retinal vessel closure was present in approximately 50 percent of children with SS and SC genotypes at age 6 years and increased to affect 90 percent of children by age 12 years. A matched pair analysis, comparing groups with minimal and complete closure, indicated that complete closure was associated with significantly lower total haemoglobin and fetal haemoglobin levels and significantly lower weight in SS disease, whereas in SC disease the risk factors appeared to be high mean cell volume and low platelet count. Proliferative retinopathy was rare, occurring only once in an 8-year-old boy with SC disease, despite 592 patient years of observation in children over this age. (AU)

Haematological change in sickle cell-haemoglobin C disease and in sickle cell-beta thalassaemia: a cohort study from birth

The haematological changes in early years following neonatal diagnosis have been observed in representative groups of children with sickle cell-haemoglobin C (SC) disease, sickle cell-á+ thalassaemia, and in sickle cell-á Thalassaemia. Most haematological indices in SC disease were intermediate between previously published values in SS disease and in AA controls, generally being closer to values in normal children, Eceptions were microcytosis which may be genetically determined and a striking elevation of mean cell haemoglobin cocentration from age 2 months to 4 years. The combination of a raised MCHC and a lowered MCV is unusual and may be characteristic of SC disease. Features in sickle cell-á thalassaemaia generally differed accordingly to the type of á thalassaemia gene. Sickle cell-B degree thalassaemia had lower levels of haemoglobin, MCHC, red cell count, MCV, and higher reticulocytes, most differences being significant before 1 year. No differences between SB degree thalassaemia and Sá+ thalassaemia were apparent in HbF levels (which resembled those in SS disease) or in HbA2 levels (which exceeded those in SS disease by 1 year of age).(AU)

Alpha-Thalassemia changes erythrocyte heterogeniety in sickle cell disease

Homozygous alpha thalassemia has the beneficial effect in sickle cell anaemia of reducing the hemolytic severity while changing several other hematological parameters. We examined in detail some of these hematological alterations. We find that the broad distribution in erythrocyte density and the large proportion of dense cells associated with sickle cell anaemia are both reduced with co-existing alpha-thalassemia. Measurements of glycosylated hemoglobin levels as a function of cell density indicate that the accelerated increase in cell density, beyond normal cell ageing, in sickle cell anaemia is also reduced with alpha thalassemia. The patients with homozygous alpha-thalassemia and sickle cell disease have slightly lower levels of hemoglobin F than non-thalassemic patients. Examination of hemoglobin F production revealed that the proportion of hemoglobin F containing reticulocytes remained unchanged, as did the proportion of hemoglobin F in cells containing hemoglobin F (F cells). Preferential survival of F cells occurs in sickle cell anaemia, with or without alpha-thalassemia, and the slight difference in hemoglobin F levels appear to reflect differences in numbers of circulating F cells. Thus in sickle cell disease with co-existing alpha-thalassemia, the change in the erythrocyte density profile, possibly due to inhibition of polymerisation-related increases in cell density, explains the hematological improvement.(Summary)

Effect of alpha thalassaemia on the rheology of homozygous sickle cell disease

A study of rheological determinants (plasma viscosity, whole-blood viscosity, and erythrocyte deformability) was made in 24 matched pairs of patients with homozygous sickle cell disease, with and without homozygous x-thalassaemia. Patients with coexisting x-thalassaemia showed a significant increase in erythrocyte deformability measured as filtration of washed erythrocytes through 5 um diameter pores and also as viscosity of whole blood at high shear rate (230s-1) and standard haematocrit (0.45). This rheological advantage may explain the beneficial effect of x-thalassaemia 2 on haematological parameters and clinical events in homozygous sickle cell disease (AU)

The interaction of alpha-thalassemia and homozygous sickle-cell disease

Patients with homozygous sickle-cell disease may be homozygous for alpha-thalassemia 2 (O-/O-), may be heterozygous for alpha-thalessemia 2 (O-/OO), or may have a normal alpha-globin-gene complement (OO/OO). We compared the clinical and hematologic features of 44 patients who had sickle-cell disease and homozygous alpha-thalassemia 2 with those of controls with the two hematologic conditions. The patients with homozygous alpha-thalassemia 2 had significantly higher red-cell counts and levels of hemoglobin and hemoglobin Aý, as well as significantly lower hemoglobin F, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, mean corpuscular volume, reticulocyte counts, irreversibly-sickled-cell counts, and serum total billirubin levels, than those with a normal alpha-globin-gene complement. Heterozygotes (O-/OO) had intermediate values. In the group with homozygous alpha-thalassemia 2, fewer patients had episodes of acute chest syndrome and chronic leg ulceration and more patients had splenomegaly, as compared with patients in the other two subgroups. These data confirmed previous suggestions that alpha-thalassemia inhibits in vivo sickling in homozygous sickle-cell disease and may be an important genetic determinant of its hematologic severity.

Red cell size and the clinical and haematological features of homozygous sickle cell disease

The contribution of red cell (mean cell volume) to the clinical and haematological manifestations of homozygous sickle cell (SS) disease has been investigated by comparing the-/* features of two groups of patients with low (<80 fl) and high (>95 fl) MCV values after matching for age, sex, and fetal haemoglobin level. The microcytic group manifested significantly higher Hb, PCV, RBC and HbAý levels and significantly lower reticulocyte and irreversibly sickled-cell counts. Clinical features were not less severe in the microcytic group, splenomegaly persisting for longer and painful crises were more common although the latter difference did not reach significance. The milder haematological picture associated with decreased intravascular sickling was not reflected in a more mild clinical course. It is postulated that the higher vicosity accompanying the higher haemoglobin levels in microcytic patients may offset the rheological advantages of decreased intravascular sickling (Summary)

Haematological indices in normal negro children: a Jamaican cohort from birth to five years

Haematological indices, including total haemoglobin, mean cell haemoglobin concentration, red cell count, mean cell volume, mean cell haemoglobin, reticulocytes, and serum iron values, in a cohort of 243 randomly selected Negro children with normal haemoglobin genotype, followed from birth to 5 years, are reported. Total haemoglobin fell rapidly from high levels at birth to a plateau at 2-6 months, a secondary fall occurred after 6 months and a gradual increase after 18 months. The red cell count also fell rapidly, but increased after 2 months to a plateau and then slowly declined from age 1-5. Mean cell volume and mean cell haemoglobin fell continously from birth to the lowest values at 15 months and then progressively increased to the age of 5 years. Serum iron levels were low at one year of age (mean 9.7 mumol/1) increasing slowly by age 4 and sharply by age 5. Mean cell haemoglobin concentration fell gradually to 1-1 1/2 years and then increased progressively to age 5. Values for Hb, MCHC, MCV, and MCH were consistently and often significantly lower in males before the age of 2 years, compatible with greater depletion of iron stores. Serum iron values were generally lower in males but there was no sex difference at one year when highly significant differences in Hb, MCHC, MCV, and MCH occurred. The cause of sex differences in early haematological development is currently unclear (AU)

Determinants of haemoglobin level in sickle cell-haemoglobin C disease

The determinants of steady state haemoglobin levels in sickle cell-haemoglobin C (SC) disease were investigated by measuring routine haematological and biochemical indices, red cell survival, oxygen affinity, pitted erythrocytes, and red cell and plasma volumes in 31 adult patients (15 male; 16 female). Red cell survival was shortened in all subjects, and was positively correlated with haemoglobin level. However, many haemoglobin values were within the normal range, especially in male subjects. Palpable splenomegaly, which occurred in 53 percent of patients, did not appear to effect haemoglobin levels, red cell survival, plasma volume, but was associated with lower platelet counts and decreased pitted red cells. Sex related differences were found in total haemoglobin, packed cell volume, conductivity cell volume, red cell count, and in the blood volume measurements. Red cell, plasma and total blood volumes in patients varied with weight and cube of height in manner observed in normal subjects, although red cell volumes were lower and plasma volumes were greater than in normal subjects of given height and weight. Anaemia in SC disease is related to the haemolytic rate but the major determinant appears to be an inappropriate increase in plasma volume (Summary)

Nutritional assessment of Virgin Islands school children

A group of 427 students on St. Thomas, Virgin Islands was studied to obtain baseline data on some anthropemetric measures, biochemical values, food habits, and educational parameter. Body weight was similar for four-to-seven-year-old students. Nine per cent of the sample appeared to be excessively stout. The mean hemoglobin and hematocrit levels exceeded "acceptable" ranges of the Ten-State Nutrition Survey. Differences were noted in the food habits of students in public vs. parochial schools and by birth place. The reasons for the differences were not determined. When comparisons were made with a previous survey of V.I. adolecents, mean intakes of the vegetable-fruit and meat groups were higher. A trend existed between poor academic achievement and low food score. The extent of the contribution of the various factors of the assessed status needs to be appraised.(AU)

Comparison of haematological features of the ᧠and á+ thalassaemia traits in Jamaican negroes

Haematological characteristics have been compared in 29 subjects with heterozygous ᧠thalassaemia and in 33 subjects with heterozygous á+ thalassaemia, identified by the type of sickle-cell-á thalassaemia among close relatives, in a Jamaican Negro population. Total haemoglobin, MCV and MCH were significantly lower in the ᧠type but the level of Hb A2 was not significantly different. Individual values for MCV, MCH and Hb A2 in the 225+ type occasionally overlapped those in the normal population casting doubt on the adequacy of these criteria in identifying all cases of heterozygous á+ thalassaemia. The haematological differences are those which would be expected on theoretical grounds. The inability to confidently differentiate the two types of heterozygous á thalassaemia has implications for genetic counselling. The inability to distinguish heterozygous á+ thalassaemia from normals on any single haematological index suggests that surveys depending on estimations of Hb A2 or on MCV alone may have underestimated the prevalence of the á+ thalassaemia gene. (AU)

The clinical features of haemoglobin SC disease in Jamaica

The clinical and haematological features of 90 Jamaican patients with haemoglobin SC disease are reviewed. Mean haemoglobin levels indicated mild anaemia although individual haemoglobin levels were often within the normal range. The clinical features were qualitatively similar to those of homozygous sickle cell disease(SS disease) although they were generlly less frequent and of lesser severity. Ocular pathology was an exception, occuring more frequently in SS disease even in age-sex-matched groups. There is some evidence that the higher haemoglobin level in SC disease may be aetiologically related to retinal vascular disease. (AU)

Immunologic diagnosis of schistosomiasis. III. The effects of nutritional status and infection intensity on intradermal test results in St. Lucian children

The question of the insensitivity of immediate and delayed skin testing in children was studied with respect to both nutritional status and intensity of infection. Ninety-seven children on the island of St. Lucia, 5 to 11 years of age, with almost equal male:female distribution, all excreting eggs of Schistosoma mansoni were tested as follows: qualitatively and quantitative stool examinations; anthropometric measurements (height, weight, mid-arm circumference and triceps skinfold thickness); hematocrit; fluorescent antibody test; and skin tests with control material, S. mansoni adult worm antigen (both Puerto Rican and St. Lucian strains), and intermediate strenght PPD tuberculin. The anthropometric measurements revealed marginal malnutrition among the children. The overall positive intradermal response rate for each of the two antigens was similar, being 56 percent for the immediate and 37 percent for the delayed test. There was no relationship discernible between relative over- and under-nutrition and the skin test responses. A striking and highly significant positive association was revealed, however, between the intensity of infection, as shown by quantitative egg counts, and the sensitivity and extent of both the immediate and delayed skin test reactions.(AU)

Absorption of iron from maize (zea mays L.) and soya beans (Glycine hispida Max.) in Jamaican infants

The absorption of iron from 59Fe-labelled maize and soya-bean preparation was measured by whole-body counting in forty-two apparently healthy Jamaican infants and compared with the absorption of ferrous ascorbate. The mean absorption of Fe from maize was 4.3 percent and from soya bean baked at 300§, 9.4 percent, compared with 28.5 percent for ferrous ascorbate. In a group of children given boiled soya beans the mean absorption of Fe was 2.8 percent, and of ferrous ascorbate 16.7 percent. There was much variability between replicate tests made on the same child at intervals of 1-2 weeks. The absorption of food Fe was not increased in children who were considered to be anaemic (haemoglobin less than 100 g/l) or Fe-deficient (serum Fe less than 500 æg/l and saturation of total Fe-binding capacity less than 15 percent). The poor availability of Fe in maize meal, which is a staple food of children in Jamaica, is probably an important cause of the high prevalence of Fe-deficiency anaemia (AU)

A comparison of erythrocyte characteristics in sickle cell syndromes in Jamaica

Red-cell characteristics were studied in the steady state in 3 sickle-cell syndromes, homozygous sickle-cell disease (SS), sickle-cell/heamoglobin-C disease (SC), and sickle-cell/á-thalassaemia (S/thal). Hb-SC disease had the highest haemoglobin levels, red cells counts, and mean corpuscular haemoglobin concentrations, all of which may contribute to the high thrombotic tendency noted in this disease. The two types of S/thal (with and without Hb A) generally had different haematological features. The non-Hb-A type of S/thal, which may resemble SS disease on electrophoretic techniques and present a diagnostic problem, was distinguishable on many red cell characteristics reported here (Summary)

Plasma and blood volumes in severely malnourished Jamaican children

Twenty-six determinations of plasma and blood volumes were done in 7 malnourished Jamaican children, on admission to hospital and as they recovered. There was a fall in plasma volume expressed per unit of body weight but no change in blood volume. There were significant correlations between the plasma volume changes, the weight deficit, and the venous haematocrit. (AU)