Multi-centre phase II clinical trial of yttrium-90 resin microspheres alone in unresectable, chemotherapy refractory colorectal liver metastases.

BACKGROUND: This multi-centre phase II clinical trial is the first prospective evaluation of radioembolisation of patients with colorectal liver metastases (mCRC) who failed previous oxaliplatin- and irinotecan-based systemic chemotherapy regimens. METHODS: Eligible patients had adequate hepatic, haemopoietic and renal function, and an absence of major hepatic vascular anomalies and hepato-pulmonary shunting. Gastroduodenal and right gastric arteries were embolised before hepatic arterial administration of yttrium-90 resin microspheres (median activity, 1.7 GBq; range, 0.9-2.2). RESULTS: Of 50 eligible patients, 38 (76%) had received > or =4 lines of chemotherapy. Most presented with synchronous disease (72%), >4 hepatic metastases (58%), 25-50% replacement of total liver volume (60%) and bilateral spread (70%). Early and intermediate (>48 h) WHO G1-2 adverse events (mostly fever and pain) were observed in 16 and 22% of patients respectively. Two died due to renal failure at 40 days or liver failure at 60 days respectively. By intention-to-treat analysis using Response Evaluation Criteria in Solid Tumours, 1 patient (2%) had a complete response, 11 (22%) partial response, 12 (24%) stable disease, 22 (44%) progressive disease; 4 (8%) were non-evaluable. Median overall survival was 12.6 months (95% CI, 7.0-18.3); 2-year survival was 19.6%. CONCLUSION: Radioembolisation produced meaningful response and disease stabilisation in patients with advanced, unresectable and chemorefractory mCRC.

Duplication of the terminal band of the long arm of chromosome 7: a new case.

We report on a new case of de novo duplication of the terminal band of chromosome 7, 46, XX dup(7) (q36 > qter), defined by fluorescence in situ hybridization (FISH), which cause a recognizable phenotype consisting of macrocephaly, prominent frontal bossing, slight developmental delay.

Evidence from Sardinian basalt geochemistry for recycling of plume heads into the Earth's mantle.

Up to 10 per cent of the ocean floor consists of plateaux--regions of unusually thick oceanic crust thought to be formed by the heads of mantle plumes. Given the ubiquitous presence of recycled oceanic crust in the mantle source of hotspot basalts, it follows that plateau material should also be an important mantle constituent. Here we show that the geochemistry of the Pleistocene basalts from Logudoro, Sardinia, is compatible with the remelting of ancient ocean plateau material that has been recycled into the mantle. The Sr, Nd and Hf isotope compositions of these basalts do not show the signature of pelagic sediments. The basalts' low CaO/Al2O3 and Ce/Pb ratios, their unradiogenic 206Pb and 208Pb, and their Sr, Ba, Eu and Pb excesses indicate that their mantle source contains ancient gabbros formed initially by plagioclase accumulation, typical of plateau material. Also, the high Th/U ratios of the mantle source resemble those of plume magmas. Geochemically, the Logudoro basalts resemble those from Pitcairn Island, which contain the controversial EM-1 component that has been interpreted as arising from a mantle source sprinkled with remains of pelagic sediments. We argue, instead, that the EM-1 source from these two localities is essentially free of sedimentary material, the geochemical characteristics of these lavas being better explained by the presence of recycled oceanic plateaux. The storage of plume heads in the deep mantle through time offers a convenient explanation for the persistence of chemical and mineralogical layering in the mantle.

A promoter mutation, C-->T at position -92, leading to silent beta-thalassaemia.

This study describes the clinical phenotype of the C-->T mutation at position -92 of the beta-globin gene. Excluding two cases with HbA2 levels within the range of the beta-thalassemia carrier state, heterozygotes for this mutation showed normal or borderline red blood cells count, Hb levels, MCV, MCH and HbA2 values, and unbalanced globin chain synthesis. Compound heterozygotes for the -92 C-->T mutation and a beta zero-thalassaemia mutation (beta zero 39) (two cases) or severe beta+-thalassaemia (beta+ IVSII nt 745) (two cases) developed thalassaemia intermedia. According to these characteristics, the -92 promoter mutation should be added to the list of silent beta-thalassaemias.

Normal individuals with high Hb A2 levels.

Increased haemoglobin (Hb) A2 levels associated with reduced mean corpuscular volume (MCV) and Hb content per cell (MCH) are the most typical features of heterozygous beta thalassaemia. However, double heterozygotes for alpha and beta thalassaemia may have normal MCV and MCH but Hb A2 always in the carrier range. In this report we describe two Sardinian families who have increased Hb A2 levels, normal red blood cell indices and normal globin chain synthesis and in whom DNA sequence analysis of beta and delta globin genes did not reveal any abnormality. Our findings demonstrate the existence of a genetic trait not resulting from a defect of the beta globin gene cluster, transmitted in a dominant manner and manifested as isolated increase of Hb A2.

Heterozygous beta-thalassemia: relationship between the hematological phenotype and the type of beta-thalassemia mutation.

In this study we have correlated the severity of the hematological features to the type of the beta-thalassemia mutation [codon 39 (C----T), IVS-I nt 110 (G----A), IVS-I nt 1 (G----A), IVS-I nt 6 (T----C), IVS-II nt 745 (C----G), -87 (C----G) and beta 6 (-1 bp)], in a group of beta-thalassemia heterozygotes of Italian descent in whom we excluded the presence of iron deficiency or deletion alpha-thalassemia. The beta-thalassemia mutation was defined by dot blot analysis on amplified DNA with allelic specific oligonucleotide probes. We found that a) heterozygotes for beta+ IVS-I nt 6 and beta+ -87 mutations produce larger and better hemoglobinized red blood cells, and b) heterozygotes for beta+ IVS-I nt 6 and beta+ IVS-I nt 110 mutations have a less marked increase of Hb A2 levels as compared to heterozygotes for the other mutations investigated. These findings indicate that milder beta-thalassemia mutations such as the beta+ IVS-I nt 6 and beta+ -87, express also in the heterozygous state a milder phenotype as compared to beta o-thalassemia or severe beta+ thalassemia (beta+ IVS-I, nt 110). The Hb A2 levels, on the other hand, were not related to the severity of the mutation because of less marked increase was found in a mild (beta+ IVS-I nt 6) as well in a severe (beta+ IVS-I nt 110) mutation. From the practical point of view these findings should be adequately considered in carrier screening and genetic counselling.

Hemoglobin Sabine [beta 91 (F7) Leu-->Pro]: occurrence in a Sardinian individual with hemolytic anemia and inclusion bodies.

BACKGROUND: Hemoglobin (Hb) Sabine (beta 91 Leu-->Pro) is an unstable variant detected for the first time in a 16-year-old Scottish-English-German girl affected by moderately severe hemolytic anemia. A second case was described in a patient of Yugoslavian descent. We report another case of this Hb variant arising as a de novo mutation in a Sardinian patient. METHODS: Definition of the mutation was obtained by DNA direct sequencing on amplified beta-globin gene, as well as by structural analysis of the hemoglobin variant. RESULTS AND CONCLUSION: The patient presented a moderately severe hemolytic anemia with red blood cell inclusion bodies. Hemoglobin electrophoresis showed that quantitatively the abnormal fraction represented 9% of the total Hb amount. beta globin gene analysis revealed a single nucleotide substitution, T-->C, at codon 91, which gives rise to a leucine-->proline substitution. Structural analysis of the variant confirmed the amino acid substitution (Leu-->Pro) predicted by DNA sequencing.

Fetal hydrops in Sardinia: implications for genetic counselling.

This paper describes the first case of Hb Bart's hydrops fetalis syndrome in the Sardinian population. Despite the high frequency of a-thalassemia, fetal hydrops is extraordinarily rare in the Sardinian population because a-thalassemia is more usually the result of the single a-thalassemia globin gene deletion and is very rarely produced by the deletion of two a-globin genes. The fetus, the product of a consanguineous marriage at risk for beta-thalassemia, was monitored by chorionic villi DNA analysis which detected the heterozygous state for the codon 39 nonsense mutation. Follow-up ultrasound examination showed fetal hydrops, which led us to carry out further investigation. Hemoglobin and a-globin gene analysis on cord blood obtained by cordocentesis revealed the homozygous state for the most common deletion ao-thalassemia in Mediterranean populations. Retrospective evaluation of the father's hematological features showed very low MCH-MCV for a beta-thalassemia carrier which may indicate co-inherited a-thalassemia. These findings indicate that careful evaluation of red cell indices of parents at risk for beta-thalassemia and adequate consideration of the consanguinity may point to co-inherited a-thalassemia and lead to the appropriate analysis.

Heterozygous beta-thalassemia with thalassemia intermedia phenotype.

In this study we investigated the molecular bases of the beta-thalassemia intermedia phenotype in six patients belonging to two unrelated families of Sardinian descent. Sequence analysis of the beta globin gene from these patients detected, as the sole abnormality, the heterozygosity for the codon 39 nonsense mutation. The A gamma and Ggamma promoters as well as the HS2 and HS3 core sequences of the beta globin LCR from these patients, did not show any non-polymorphic nucleotide variation from the consensus sequence. One of the parents was heterozygous for codon 39 nonsense mutation but showed the beta-thalassemia carrier phenotype; the other was hematologically normal and had an entirely normal beta globin gene sequence. In both families, other members showed the typical hematological phenotype, clinically silent, of heterozygous beta thalassemia. To explain the thalassemia intermedia phenotype, we postulated the presence of an unknown molecular defect interacting with the beta globin gene mutation. Haplotype analysis excluded that this postulated defect lies in the beta globin gene cluster.

Evaluation of an automatic HPLC analyser for thalassemia and haemoglobin variants screening.

In this paper the authors report the evolution of a new automatic HPLC analyser for screening haemoglobinopathies. HbA(2) and F determinations are accurate and reproducible. The analysis time is short (6.5 min) and there is a good separation between the HbA(2) values of beta-thalassemia carriers from normals and alpha-thalassemia carriers, with no overlap between these groups. In addition, the system is also able to detect and quantitate most of the haemoglobin variants, particularly those (HbS, HbC, HbE and Hb Lepore) able to interact with beta-thalassemia and could make haemoglobin electrophoresis unnecessary in all samples. The ease of operation and the limited technical work make this system especially suitable for laboratories with a high workload and allow the cost of screening to be reduced.

Genotype of subjects with borderline hemoglobin A2 levels: implication for beta-thalassemia carrier screening.

In this study, we have defined by molecular analysis, the alpha, beta, and delta globin genotype in a group of individuals with normal or thal-like red cell indices but borderline hemoglobin (Hb)A2 levels, who were identified in a program for beta-thal carrier screening. In 37 of 125 individuals with borderline HbA2 levels, we detected a molecular defect in the beta, in both the delta and the beta, or in the alpha globin gene. Specifically seven of these subjects were carriers of the -101 C T mutation, ten of the IVSI nt6 T C mutation, 16 were double heterozygotes for delta and beta thal, and two had the triple alpha globin gene and two the single alpha globin gene deletion. From these results, we may conclude that subjects with borderline HbA2, particularly when they marry a typical beta-thal carrier, should be extensively investigated in order not to miss heterozygous beta-thalassemia.