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The role of the liver in diabetic keto-acidosis and idiopathic lactic acidosis: a review
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T HE A U S T R A L I A N A S S O C I A T I O N OF B I O C H E M I S T S
Pathology (1975), 7, July
THE ROLE OF THE LIVER IN DIABETIC KETO-ACIDOSIS AND IDIOPATHIC LACTIC ACIDOSIS: A REVIEW BERRY,M. N. School of Medicine, Flinders University, Bedford Park, South Australia
The primary site of ketone body production is the liver. Hence ketone body accumulation represents either hepatic over-production or peripheral under-utilization. On the other hand, the evidence suggests that net lactate production occurs in the periphery and the main site of lactate uptake is the liver. This implies that peripheral overproduction or hepatic under-utilization is the cause of lactic acidosis. The available experimental data suggest that alterations of metabolic rates within the liver are the usual primary cause of diabetic keto-acidosis and idiopathic lactic acidosis.
LACTIC ACIDOSIS: A REVIEW OF 57 CASES CHAPMAN, M. and THOMAS, D. W. Division of Clinical Chemistry, Instirute oJ Medical and Veterinary Science, Adelaide, South Australia During the past 2 yr 58 episodes of lactic acidosis were observed. These were divided into 3 groups. The first comprised 13 patients (23%) in whom the anion gap increase was wholly due to lactate ion. Circulatory collapse and anoxia were present in nearly half of these patients, while in the remainder reticulosis, diabetic hyperglycaemia, phenformin therapy, liver disease or ethanol intoxication were present. The second group consisted of 17 patients (29%) in whom at least half the anion gap increase was due to lactate ion. Most of these patients were receiving phenformin. The third group of patients numbered 28 (48%) and had increased anion gaps of which less than half was due to lactate ion. Diabetic hyperglycaemia with ketosis was observed in half of these patients, whilst the remainder were receiving phenformin or were in circulatory collapse. There was a high incidence of renal impairment and liver disease, in addition to diabetes mellitus, in these patients developing lactic acidosis.
THE CLINICAL VALUE OF VENOUS pH AND PCO2 MEASUREMENTS MEERKIN,M. and GAN,K. Division of Chemical Pathology, The Geelong Hospital, Geelong, Victoria
Simultaneous arterial and venous blood samples were obtained from hospital patients. Venous samples were taken into heparinized vacutainers, and a constant volume of sample was obtained in all patients. A close correlation between arterial and venous pH and PCO, was found. As venous sampling is easier than arterial sampling, measurement of venous pH and PCO, offers a simpler method for the routine assessment of acid-base status of patients.
COMPLEX LIPIDS: A REVIEW POULOS,A. Department of Chemical Pathology, Adelaide Children’s Hospital, North Adelaide, South Australia
Animal complex lipids contain both hydrophobic and hydrophilic moieties and may be broadly sub-divided into phospholipid and sphingolipid classes and together with protein are localized in membranes. Phospholipids are derivatives of diacylglycerophosphate: the acyl groups have 14-22 carbon atoms and 0-6 double bonds. The phosphate group is almost invariably linked to a hydrophilic residue, e.g. choline, serine. Sphingolipids are derivatives of ceramide-an acylated long chain P-aminoalcohol. Similar to the phospholipids, the acyl groups may have 14-26 carbon atoms but usually no more than one double bond. The alcohol grouping may be linked to phosphorylcholine to Form the ubiquitous sphingomyelin, or linked either toone orachain of carbohydrate moieties to form neutral glycosphingolipids. Further addition of one or more polar sialic acid residues form gangliosides. The sialo- and asialogly-cosphingolipids display haptenic properties and may be involved in cellular interactions.
ANALYSIS AND CLINICAL SIGNIFICANCE OF FREE CERAMIDES PARSONS, R. S. and POLYA,J. B. Department of Chemistry, University of Tasmania, Hobart , Tasmania Some of the problems associated with analysis of free ceramides relate to insufficient knowledge of the reactivity of free ceremides and the possible existence of hitherto little investigated cyclic structures.
T HE A U S T R A L I A N A S S O C I A T I O N OF B I O C H E M I S T S
Pathology (1975), 7, July
THE ROLE OF THE LIVER IN DIABETIC KETO-ACIDOSIS AND IDIOPATHIC LACTIC ACIDOSIS: A REVIEW BERRY,M. N. School of Medicine, Flinders University, Bedford Park, South Australia
The primary site of ketone body production is the liver. Hence ketone body accumulation represents either hepatic over-production or peripheral under-utilization. On the other hand, the evidence suggests that net lactate production occurs in the periphery and the main site of lactate uptake is the liver. This implies that peripheral overproduction or hepatic under-utilization is the cause of lactic acidosis. The available experimental data suggest that alterations of metabolic rates within the liver are the usual primary cause of diabetic keto-acidosis and idiopathic lactic acidosis.
LACTIC ACIDOSIS: A REVIEW OF 57 CASES CHAPMAN, M. and THOMAS, D. W. Division of Clinical Chemistry, Instirute oJ Medical and Veterinary Science, Adelaide, South Australia During the past 2 yr 58 episodes of lactic acidosis were observed. These were divided into 3 groups. The first comprised 13 patients (23%) in whom the anion gap increase was wholly due to lactate ion. Circulatory collapse and anoxia were present in nearly half of these patients, while in the remainder reticulosis, diabetic hyperglycaemia, phenformin therapy, liver disease or ethanol intoxication were present. The second group consisted of 17 patients (29%) in whom at least half the anion gap increase was due to lactate ion. Most of these patients were receiving phenformin. The third group of patients numbered 28 (48%) and had increased anion gaps of which less than half was due to lactate ion. Diabetic hyperglycaemia with ketosis was observed in half of these patients, whilst the remainder were receiving phenformin or were in circulatory collapse. There was a high incidence of renal impairment and liver disease, in addition to diabetes mellitus, in these patients developing lactic acidosis.
THE CLINICAL VALUE OF VENOUS pH AND PCO2 MEASUREMENTS MEERKIN,M. and GAN,K. Division of Chemical Pathology, The Geelong Hospital, Geelong, Victoria
Simultaneous arterial and venous blood samples were obtained from hospital patients. Venous samples were taken into heparinized vacutainers, and a constant volume of sample was obtained in all patients. A close correlation between arterial and venous pH and PCO, was found. As venous sampling is easier than arterial sampling, measurement of venous pH and PCO, offers a simpler method for the routine assessment of acid-base status of patients.
COMPLEX LIPIDS: A REVIEW POULOS,A. Department of Chemical Pathology, Adelaide Children’s Hospital, North Adelaide, South Australia
Animal complex lipids contain both hydrophobic and hydrophilic moieties and may be broadly sub-divided into phospholipid and sphingolipid classes and together with protein are localized in membranes. Phospholipids are derivatives of diacylglycerophosphate: the acyl groups have 14-22 carbon atoms and 0-6 double bonds. The phosphate group is almost invariably linked to a hydrophilic residue, e.g. choline, serine. Sphingolipids are derivatives of ceramide-an acylated long chain P-aminoalcohol. Similar to the phospholipids, the acyl groups may have 14-26 carbon atoms but usually no more than one double bond. The alcohol grouping may be linked to phosphorylcholine to Form the ubiquitous sphingomyelin, or linked either toone orachain of carbohydrate moieties to form neutral glycosphingolipids. Further addition of one or more polar sialic acid residues form gangliosides. The sialo- and asialogly-cosphingolipids display haptenic properties and may be involved in cellular interactions.
ANALYSIS AND CLINICAL SIGNIFICANCE OF FREE CERAMIDES PARSONS, R. S. and POLYA,J. B. Department of Chemistry, University of Tasmania, Hobart , Tasmania Some of the problems associated with analysis of free ceramides relate to insufficient knowledge of the reactivity of free ceremides and the possible existence of hitherto little investigated cyclic structures.