HFPK 334: An unusual Supernova Remnant in the Small Magellanic Cloud

We present new Australia Telescope Compact Array (ATCA) radio-continuum and XMM-Newton/Chandra X-ray Observatory (CXO) observations of the unusual supernova remnant HFPK 334 in the Small Magellanic Cloud (SMC). The remnant follows a shell type morphology in the radio-continuum and has a size of $\sim$20~pc at the SMC distance. The X-ray morphology is similar, however, we detect a prominent point source close to the center of the SNR exhibiting a spectrum with a best fit powerlaw with a photon index of $\Gamma = 2.7 \pm 0.5$. This central point source is most likely a background object and cannot be directly associated with the remnant. The high temperature, nonequilibrium conditions in the diffuse region suggest that this gas has been recently shocked and point toward a younger SNR with an age of $\lesssim 1800$ years. With an average radio spectral index of $\alpha=-0.59\pm0.09$ we find that an equipartition magnetic field for the remnant is $\sim$90~$\mu$G, a value typical of younger SNRs in low-density environments. Also, we report detection of scattered radio polarisation across the remnant at 20~cm, with a peak fractional polarisation level of 25$\pm$5\%.Comment: 19 pages, 6-figures, submitted to A

Severe central nervous system thrombotic events in hemoglobin Sabine patient

Hemoglobin (Hb) Sabine is a rare, unstable Hb variant resulting from the point mutation in codon 91 (CTG -- gt CCG) of beta-globin gene. We report a case of Hb Sabine patient with mild hemolytic anemia, unusually high Hb F level and severe central nervous system thrombotic disturbances. We have tried to elucidate possible genetic background of this unusual Hb Sabine phenotype. Extremely high level of Hb F and rather mild anemia in our patient could be partially explained by the presence of Ggamma Xmn I polymorphism. This case of Hb Sabine, unlike all other reported to date, shows extremely severe thromboembolic complications. It is our opinion that the hypercoagulable state described in thalassemia is not the only factor responsible for this specific clinical state. The presence of MTHFR C677T mutation in heterozygous state found in our patient and unstable Hb Sabine molecules could contribute to development of thromboembolic phenomena. However, it remains unclear whether other factors participate in pathogenesis of the disease. In this paper we emphasize different genetic background of father and son both affected with Hb Sabine, but with markedly different severity of the disease

Homogeneity of the Hb Lepore gene in FR Yugoslavia

Screening analysis of Yugoslav patients with suspected thalassemia syndromes in last 4 years revealed six patients who were Hb Lepore carriers. Three were compound heterozygotes for Hb Lepore and β-thalassemia, and they were affected with a thalassemia major syndrome. Family studies revealed 12 heterozygous relatives. All heterozygous carriers of Hb Lepore had a clinical phenotype of thalassemia trait. The detection of Hb Lepore was carried out by electrophoresis on cellulose acetate and confirmed by gap-polymerase chain reaction analysis of patients' DNA. Sequence analysis of all the Hb Lepore genes showed the same DNA sequence, indicating that the mutation was of the Hb Lepore-Boston-Washington type. Moreover, a single base substitution within the second intervening sequence [IVS-II-74 (G→T)] was detected in all analyzed hybrid genes. The molecular characteristics of this homogeneity represent additional data for the probable Balkan origin of this mutation

Molecular basis of Thalassemia syndromes in Serbia and Montenegro

This study reports the molecular characterization of thalassemia syndromes in Serbian and Montenegrin populations. We identified eight beta-thalassemia mutations [codon 39 (C - gt T), IVS-I-110 (G - gt A), IVS-II-745 (C - gt G), codon 44 (-C), -87 (C - gt G), IVS-II-1 (G - gt A), IVS-I-6 (T - gt C), IVS I-1 (G - gt A)] in 70 members of 29 families using polymerase chain reaction, reverse dot blot, amplification refractory mutation system and direct sequencing analysis. Hemoglobin (Hb) Lepore was found to be the most common cause of the thalassemia phenotype. Hb Sabine and alpha-thalassemia were detected as well. We also studied beta-globin gene cluster haplotypes and their association with the most common mutations. A novel haplotype associated with the Hb Lepore gene was identified. The results presented herein allowed the implementation of a prenatal diagnosis program in Serbia and Montenegro