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Alpha-thalassaemia early eluting peak for alpha-thalassaemia --SEA carrier screening: a multicentre diagnostic comparison with immunochromatographic strip test and haemoglobin H inclusion test.

While high-performance liquid chromatography (HPLC) is well-established for &#x3b2;-thalassaemia and haemoglobinopathies, phenotypic screening for &#x3b1;0-thalassaemia has been limited. To address this limitation, we aimed to translate the discovery of the &#x3b1;-thalassemia early eluting peak (&#x3b1;EEP) in HPLC into clinical practice by comparing its diagnostic performance with other existing methods (haemoglobin H inclusion test [HbHi] and immunochromatographic strip test [ICT]) in a multicentre setting, and elucidating the nature of the &#x3b1;EEP by liquid chromatography-tandem mass spectrometry (LC-MS/MS). With a cohort of 820 genotyped patients, the &#x3b1;EEP showed superior diagnostic performance in detecting --SEA (sensitivity 99.6%, specificity 100%) compared with HbHi (sensitivity 95.8%, P&#x2009;=&#x2009;0.006; specificity 97.3%, P&#x2009;<&#x2009;0.001) and ICT (sensitivity 95.8%, P&#x2009;=&#x2009;0.006; specificity 75.4%, P&#x2009;<&#x2009;0.001). Both HbHi and ICT showed reduced sensitivity in &#x3b2;-thalassaemia carriers versus non-carriers. ICT showed reduced specificity when Hb F&#x2009;&#x2265;&#x2009;1% compared with <&#x2009;1%. The &#x3b1;EEP remained robust across all subgroups. LC-MS/MS revealed a strong association between the &#x3b1;EEP and embryonic &#x3b6;-globin chains (P&#x2009;<&#x2009;0.001). The &#x3b1;EEP offered cost reductions of 98.6% over HbHi and 97.3% over ICT. Collectively, the &#x3b1;EEP is a highly reliable and cost-effective marker for detecting --SEA carriers, enabling a novel "all-in-one" HPLC screening strategy for --SEA, &#x3b2;-thalassaemia and haemoglobinopathies. Trial registration number: not applicable.

Humans↗

Comparison of the HbH inclusion test and a PCR test in routine screening for alpha thalassaemia in Hong Kong.

AIM: To compare the haemoglobin (Hb) H inclusion test with a polymerase chain reaction (PCR) test in routine screening for alpha thalassaemia. METHODS: Ninety nine peripheral blood samples from Chinese patients with mean corpuscular volume below 80 fl were screened for alpha thalassaemia using the HbH inclusion test and by PCR utilising primers bridging the common deletion breakpoint of the South East Asian (--SEA/) deletion. RESULTS: The HbH inclusion test was positive in 78 (79%) patients, 73 (93.7%) of whom carried the (--SEA/) deletion on analysis of their DNA by PCR, as did one patient with a negative HbH inclusion test. CONCLUSIONS: These results suggest that in areas with a high prevalence of the (--SEA/) deletion, such as Hong Kong, the HbH inclusion test can be replaced by PCR as the investigation of choice in screening for alpha thalassaemia.

Base Sequence↗

Comparison of haemoglobin H inclusion bodies with embryonic zeta globin in screening for alpha thalassaemia.

AIMS: To compare the haemoglobin (Hb) H inclusion test with immunocytochemical detection of embryonic zeta chains in screening for alpha thalassaemia. METHODS: Blood samples from 115 patients with relevant clinical history and hypochromic microcytic indexes were screened using the HbH inclusion test and the Variant Hemoglobin Testing System (BioRad, Hercules, CA, USA). RESULTS: The HbH inclusion test was positive in 61 of 115 cases, three of whom had HbH disease confirmed by electrophoresis. The remaining 58 had alpha thalassaemia 1. All three HbH cases and 56 of 58 cases of alpha thalassaemia 1 expressed embryonic zeta chains, giving a specificity of 96.7%. Fifty four of 115 cases had a negative HbH inclusion test, of whom 50 had beta thalassaemia trait and three had iron deficiency. No diagnosis was reached for the remaining patient. CONCLUSION: The immunocytochemical test is as sensitive as the HbH inclusion test in screening for alpha thalassaemia. The presence of zeta chains is highly specific for alpha thalassaemia 1 incorporating the (--/SEA) deletion. The specificity and simplicity of the immunocytochemical test make it the test of choice in screening for alpha thalassaemia.

Base Sequence↗

A double-blind study on the efficacy of oral dapsone in cutaneous leishmaniasis.

One hundred and twenty patients with localized cutaneous leishmaniasis were randomly allocated to receive tablets of dapsone (100 mg) or matching placebo tablets every 12 h for 6 weeks. No topical medication was used. Demonstration of Leishmania from skin lesions by the slit smear technique was mandatory for inclusion. Before, periodically during, and one month after completion of therapy an overall clinical assessment, haemoglobin determination, leucocyte count, and liver function tests were performed. 49 patients (82%) of those receiving dapsone were assessed as cured by clinical and parasitological criteria. Oral dapsone has certain advantages over other current forms of treatment: it is economical and widely available in countries where cutaneous leishmaniasis is common, and it is effective by mouth and well tolerated.

Administration, Oral↗

HbA1c predicts the likelihood of having impaired glucose tolerance in high-risk patients with normal fasting plasma glucose.

BACKGROUND: Although the oral glucose tolerance test (OGTT) is the 'gold standard' for diagnosing prediabetes/diabetes, it is inconvenient for the patient and time consuming. The only alternative simple screening test is fasting plasma glucose (FPG). FPG concentrations of > 6.0 mmol/L represent prediabetes/diabetes. FPG concentrations of < or = 6.0 mmol/L may be considered 'normal', although some such patients will demonstrate abnormal glucose tolerance when subjected to an OGTT. We have evaluated the use of glycated haemoglobin (HbA1c) as a screening test for diabetes or impaired glucose tolerance (IGT) in patients who have risk factors for diabetes but FPG < or = 6.0 mmol/L. METHODS AND RESULTS: A total of 580 patients with at least two risk factors for diabetes underwent an OGTT and HbA1c measurement. In all, 225 patients had a FPG < or = 6.0 mmol/L and met the inclusion criteria. Of these, 23.1% (n=52) had an abnormal OGTT result (45 had IGT and 7 had diabetes). Subjects with abnormal glucose tolerance had a higher percentage of HbA1c than subjects with normal glucose tolerance (P<0.001). An HbA1c of 5.6% gave an optimal sensitivity of 72% and specificity of 77% to predict a 2 h plasma glucose > or = 7.8 mmol/L. CONCLUSION: The use of FPG concentration followed by selective measurement of HbA1c in patients who are at high risk of developing diabetes may represent a reasonable approach to identifying patients requiring an OGTT.

Aged↗

Antiproliferative action of valorphin in cell cultures.

The antiproliferative effects of the haemoglobin beta-chain fragment (33-39) (valorphin or VV-haemorphin-5) were studied in a panel of tumour cell lines and normal cells of different origin, using various methods of activity determination (trypan blue inclusion test, sulphorhodamine B staining, MTT staining, flow cytometry and clonogenic test). Valorphin suppressed the proliferation of tumour cells by 25%-95%, depending on the cell line. The maximal valorphin activity was detected in transformed cells of fibroblastic (L929) and epithelial (MCF-7) origin, transformed haematopoietic cells (K562, HL-60) being less sensitive. In normal cells, valorphin activity was several fold lower (10%-15%). A study of the dynamics of cell proliferation in L929 cells using a visual cell count and flow cytometry showed that valorphin induced reversible and relatively short (24 h) S-phase arrest of cell proliferation, accompanied by a reversible increase of cell size. The proliferation delay was followed by a comparatively long period of reversible resistance of the cells to the peptide (96 h) when the cells are dividing at normal rate. The same dynamics were demonstrated for A549, MCF-7 and primary murine breast carcinoma cells. On the basis of the data obtained, a pattern of regulation of cell growth by valorphin is suggested.

Amino Acid Sequence↗

Efficacy of a modified improved technique for detecting red cell haemoglobin H inclusions.

Alpha-thalassaemia is a common disease in Taiwan. A feature useful in diagnosis is the excess of of beta-chains that result from impaired alpha-chain production. These excess chains assemble into beta 4 tetramers (i.e. Hb H) which can be detected by its rapid anodal migration on alkaline electrophoretic media as seen in Hb H disease. However, this technique cannot, and conventional Hb H inclusion staining rarely can visualize alpha-thalassaemic traits due to small quantities of Hb H formed in these patients. The staining for Hb H inclusion bodies uses brilliant cresyl blue (BCB) or methylene blue (MB) as an oxidant to denature Hb H as intracellular inclusions. We have improved the technique of Jones (who modified the original method in order to obtain enriched young red cells) by prolonging the incubation time from 30 min to 3 h. The sensitivity of this modified improved method was 91% for detecting obligatory alpha-thalassaemic traits as shown in table. No false positive results were seen in beta-thalassaemia or in others. We believe this can be used as a confirmatory test in heterozygous alpha 1-thalassaemia and homozygous alpha 2-thalassaemia.

Anemia, Hypochromic↗

Evaluation of a mutation screening strategy for sporadic cases of ATR-X syndrome.

We report on the evaluation of a strategy for screening for XNP/ATR-X mutations in males with mental retardation and associated dysmorphology. Because nearly half of the mutations in this gene reported to date fall into a short 300 bp region of the transcript, we decided to focus in this region and to extend the mutation analysis to cases with a negative family history. This study includes 21 mentally retarded male patients selected because they had severe mental retardation and a typical facial appearance. The presence of haemoglobin H or urogenital abnormalities was not considered critical for inclusion in this study. We have identified six mutations which represents a mutation detection rate of 28%. This figure is high enough for us to propose this strategy as a valid first level of screening in a selected subset of males with mental retardation. This approach is simple, does not require RNA preparation, does not involve time consuming mutation detection methods, and can thus be applied to a large number of patients at a low cost in any given laboratory.

Adolescent↗

Effects of propranolol and nitrates on exercise capacity, respiratory minute volume and capillary oxygen saturation during exercise in cirrhotic patients with portal hypertension.

A cross over study was performed in 16 cirrhotic patients with portal hypertension and oesophageal varices to assess the effects of propranolol and nitrates on the exercise capacity, respiratory minute volume and capillary oxygen saturation during exercise. All had normal peak expiratory flow rates, spirometry, chest X-ray, electrocardiography, ECHO cardiography, cardiac ejection fraction>55%, absent intra-pulmonary arterio-venous shunts (IPAVS) on contrast enhanced ECHO, and a haemoglobin>11 g/dl. Minute volume, capillary O(2) saturation and pulse rate, were measured during progressive exercise testing up to maximum exercise capacity. Testing was done on inclusion, after 1 month of treatment with propranolol (dose adequate for 25% reduction in resting pulse rate) and after another month of treatment with propranolol plus isosorbide dinitrate (ISDN). An age matched group of cirrhotics (n=9) (with no evidence of portal hypertension and had normal cardio respiratory functions as defined above) acted as controls. We observed a significant reduction in the minute volume at maximum exercise after both modes of treatment when compared to the pre-treatment values and the values of controls. There was a non-significant increase in capillary oxygen saturation. None of them had a reduction in exercise capacity after treatment. In conclusion, treatment with propranolol or a combination of propranolol and a nitrate dose not seem to impair exercise performance in patients who have hepatic cirrhosis with portal hypertension.

Journal Article↗

[Iron supplementation associated with malaria prevention among pregnant women in Abidjan].

BACKGROUND: Despite the demonstrated efficacy of iron supplements and malaria prevention, the effectiveness of antenatal care programs for prevention of anaemia (haemoglobin rate<11 g/dL) in pregnant women is low in West Africa. Apart from the issue of availability and despite low cost, the major reason evoked is the lack of motivation of pregnant women and health care professionals. In this study, iron supplements and malaria prophylactics were provided free of charge during pregnancy. The treatment was proposed at the first antenatal visit, with the objective of not interfering with routine practice of birth attendants and women in latter antenatal visits. METHODS: Haemoglobin rates were measured and Plasmodium falciparum tested for among pregnant women in four maternity units in Abidjan. The tests were carried out at inclusion during the first antenatal visit and during immediate post-partum in 631 pregnant women who delivered in one of the four wards. Considering the objective of the study, compliance was assessed for the month prior to delivery. RESULTS: Despite an habitual decrease in iron deficiency at the end of pregnancy, haemoglobin rates in the study population increased from 10.4 g/dL at inclusion to 10.9 g/dL during post-partum. Prevalence of anemia consequently decreased from 62.8% to 49.4% (p<0.01). A similar increase of 0.7 g/dL was observed among women stating a regular (57%) or irregular (36.9%) compliance with the protocol. A decrease of 0.4 g/dL (s.t.: 1.8 g/dL) was observed among women stating a lack of compliance with the protocol (5.6%). The prevalence of anaemia according to compliance was consequently 43.1%, 49.7% and 70.1% (p=0.02). Severe anaemia (<8 g/dL) at inclusion was an independent risk factor for post-partum anaemia although a 2.9 g/dL increase (s.t.: 2.0 g/dL) was observed in the latter (p<0.01). However, the 11 g/dL threshold was not reached. CONCLUSION: It is therefore important to reinforce the availability of treatments to prevent anaemia in pregnant women due to their demonstrated efficiency as a part of routine antenatal activities.

Adult↗

Prevalence of iron deficiency among schoolchildren of different socio-economic status in urban Turkey.

OBJECTIVE: To investigate the prevalence of iron deficiency among schoolchildren of different socio-economic status (SES), living in the three largest cities of Turkey. DESIGN: Cross-sectional study. SETTINGS: Primary schools of Istanbul, Ankara and Izmir. SUBJECTS: Schoolchildren aged 12 and 13 y (males: 504; females: 510) from nine primary schools. Inclusion of subjects in the study was on a voluntary basis. METHODS: Data were obtained on children SES, anthropometry, haematological and biochemical indices of iron status and consumption of food items related to dietary iron bioavailability. One-way analysis of variance was mainly applied, for the evaluation of the tested hypotheses, using Bonferroni correction in order to take into account the inflation of Type I error. RESULTS: Iron deficiency (serum ferritin <15 microg/l) prevalence was 17.5% among boys and 20.8% among girls. Furthermore, iron deficiency was significantly more prevalent among boys of lower SES, who were also found to have significantly lower levels of serum iron, serum ferritin, transferrin saturation, mean corpuscular haemoglobin and mean corpuscular haemoglobin concentration compared to those of higher SES. In terms of dietary factors affecting iron bioavailability, low SES boys exhibited significantly higher frequency of tea consumption and lower frequency of citrus fruit, red meat and fish consumption, compared to their higher SES counterparts. CONCLUSION: The prevalence of iron deficiency was relatively high, particularly among lower SES schoolboys. Higher tea and lower citrus fruits, red meat and fish consumption by boys of lower SES may provide an indication about the possible role of certain dietary patterns in the different manifestation of this medical condition among the socio-economic groups. However, further research is needed.

Adolescent↗

Complexities in ETS-domain transcription factor function and regulation: lessons from the TCF (ternary complex factor) subfamily. The Colworth Medal Lecture.

The ETS-domain transcription factor family can be divided into a series of subfamilies. Elk-1 represents the founding member of the ternary complex factor (TCF) subfamily. By focusing on the TCF subfamily, we can demonstrate the complexities that exist in the function and regulation of ETS-domain transcription factors. This article focuses on Elk-1 in detail and summarizes the functions of other TCFs. The key themes covered include the domain structure of the TCFs, the mechanisms of complex formation with serum response factor, regulation of TCFs by mitogen-activated protein kinase cascades, and transcriptional regulatory properties of the TCFs. Finally, the emerging role of the TCFs in vivo is discussed. A picture is developing indicating that, while these proteins exhibit significant sequence and functional conservation, key differences in their structure and regulation are being identified which may relate to unique functions of these proteins in vivo.

Amino Acid Sequence↗