Case series of HbQ-India, a rare alpha globin variant in a referral laboratory setting in South India.

HbQ variants are rare alpha globin chain variants commonly found in Sindhi community. It results from a point mutation of α-1 globin gene at position 223 of the coding region of exon 64. It is inherited in an autosomal dominant fashion. HbQ-India is usually clinically silent in heterozygous state unless associated with other conditions like beta thalassemia, alpha thalassemia, HbE disease, or nutritional anemia. High performance liquid chromatography (HPLC) identifies HbQ-India with a prominent peak present just after the Sickle window. We present five cases of HbQ-India from a retrospective analysis of 6034 cases over a period of 3 years, a rarity in a referral setting of South India. Awareness of this entity is important for appropriate recognition to prevent clinically symptomatic hemoglobinopathies. This study also highlights the retention time (RT) and characteristic chromatographic HPLC pattern seen in HbQ-India.

A new Hg(2+) -selective fluorescent sensor based on a 1,3-alternate thiacalix[4]arene anchored with four 8-quinolinoloxy groups.

A new thiacalix [4]arene derivative in a 1,3-alternate conformation bearing four quinolinoloxy groups through propyl chains has been synthesized, and its metal ion-binding and fluorescence-sensing properties were investigated in both THF and 10% H2O-THF systems. The designed ligand exhibited pronounced Hg2+ -selective on-off type fluoroionophoric properties among the representative transition and heavy metal ions including Cu2+. The detection limit for Hg2+ was found to be 2.0 x 10(-6) M in the mixed H2O-THF system. Detailed spectral studies including 1H NMR and MALDI-TOF mass spectroscopy reveal the unusual formation of a tetramercury complex with the ligand, in which the four propyl arms containing the quinolinoloxy groups adopt a "tetrapodand" conformation enclosing one Hg2+ ion each in the four cavities thus formed.