Hereditary erythrocyte adenylate kinase deficiency: a defect of multiple phosphotransferases?

Abstract Adenylate kinase (AK) modulates the interconversion of adenine nucleotides (AMP + adenosine triphosphate----2 ADP). We evaluated the fifth kindred with hereditary erythrocyte (RBC) AK deficiency. The proband had chronic hemolytic anemia. Her RBC had undetectable AK activity when measured spectrophotometrically, whereas those of her parents had half-normal AK activity. AK electrophoresis showed only AK- 1 in the parents. The activities of pyruvate kinase and phosphoribosylpyrophosphate synthetase were decreased given the young age of the proband's RBC. Despite the absence of spectrophotometric AK activity, the proband's RBC were able to incorporate 14C-adenine into 14C-adenine nucleotides at 50% of the rate expected for her young RBC population, suggesting the possibility of an alternative pathway for the formation of ADP from AMP. Normal hemolysate had AMP:guanosine triphosphate (GTP) phosphotransferase activity, which produced ADP at 8% to 9% of the rate of AK (6.8 +/- 0.8 IU/mL RBC). AMP:GTP phosphotransferase activity was not detectable in the proband's or parent's hemolysates. These additional biochemical defects in the AK- deficient RBC further support the concept that AK deficiency per se may not cause hemolytic anemia. We propose that defects occur in multiple phosphotransferases in the AK-deficient RBC and that these other biochemical defects may produce deleterious lesions that promote the shortened RBC survival in AK deficiency.</jats:p

Hereditary erythrocyte adenylate kinase deficiency: a defect of multiple phosphotransferases?

Adenylate kinase (AK) modulates the interconversion of adenine nucleotides (AMP + adenosine triphosphate----2 ADP). We evaluated the fifth kindred with hereditary erythrocyte (RBC) AK deficiency. The proband had chronic hemolytic anemia. Her RBC had undetectable AK activity when measured spectrophotometrically, whereas those of her parents had half-normal AK activity. AK electrophoresis showed only AK- 1 in the parents. The activities of pyruvate kinase and phosphoribosylpyrophosphate synthetase were decreased given the young age of the proband's RBC. Despite the absence of spectrophotometric AK activity, the proband's RBC were able to incorporate 14C-adenine into 14C-adenine nucleotides at 50% of the rate expected for her young RBC population, suggesting the possibility of an alternative pathway for the formation of ADP from AMP. Normal hemolysate had AMP:guanosine triphosphate (GTP) phosphotransferase activity, which produced ADP at 8% to 9% of the rate of AK (6.8 +/- 0.8 IU/mL RBC). AMP:GTP phosphotransferase activity was not detectable in the proband's or parent's hemolysates. These additional biochemical defects in the AK- deficient RBC further support the concept that AK deficiency per se may not cause hemolytic anemia. We propose that defects occur in multiple phosphotransferases in the AK-deficient RBC and that these other biochemical defects may produce deleterious lesions that promote the shortened RBC survival in AK deficiency.</jats:p

Development of an environmental management system framework for Hong Kong higher education institutions

This research aims to develop an Environmental Management System Framework which is suitable for adoption by the higher education institutions (HEIs) in Hong Kong. There are eight publicly funded HEIs in Hong Kong. Through their pivotal and influential role, the HEIs are the key stakeholders in implementing environmental policies set by the government, educating the society on the environmental responsibility, and achieving sustainable future [1, 2]. All the above HEIs in Hong Kong are engaged with environmental sustainability in their management and operation and have conducted a series of initiatives to ensure their campuses are environmentally sustainable. Some HEIs have obtained significant public recognition for their endeavours. Examples include winning the Gold Sectorial Award by the Chinese University of Hong Kong in 2013 [3] and winning the Silver Sectorial Award by Hong Kong Baptist University in 2011 [4], respectively, at the Hong Kong Awards for Environmental Excellence under the category of Public Organizations and Utilities. The eight HEIs have formed a Hong Kong Consortium for Campus Sustainability (HKCCS) to promote environmental ¬ s ustainability on campus, and all these HEIs have signed a Hong Kong Declaration to that effect on 18 May 2010 which includes “a statement of principles regarding the importance of climate change and sustainable development for the universities…”. The document further commits the signatories’ institutions to reviewing their own campus operations; establishing targets for the reduction of energy consumption, greenhouse gas emissions, water use, and waste; incorporating relevant issues in the teaching curriculum; and reporting regularly on key environmental performance measures. Signing of the Hong Kong Declaration also formally establishes the HKCCS under the Heads of Universities Committee