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A centrifugal analyser technique for measuring isoenzymes of acid phosphatase in column-chromatography fractions
330
AUSTRALIAN ASSOCIATION OF CLINICAL BIOCHEMISTS
Pathology (1979), 11, April
and animal albumin (bovine, equine, porcine) is grossly under-estimated. With these limitations, BCP-binding appears to be the method of choice for the rapid, precise, accurate and economical measurement of human albumin suitable for automated equipment. ELEVATED MATERNAL cxFP DUE TO FOETO-MATERNAL HAEMORRHAGE
D. L.
HAY
& I. HORACEK
Biochemistry Department, Royal Women's Hospital, Melbourne
Elevated maternal serum levels of ()(-foetoprotcin have been used as a screening procedure in the prenatal diagnosis of foetal neural tube defects where levels about the 98th percentile are indications for further testing. False positives due to multiple pregnancies, threatened abortions and incorrect gestations are well documented, however many false positives remain unexplained. In a survey of 150 women who gave birth to normal infants, 11/69 (l6:y',) of women with anterior placentas revealed elevated maternal ()(FP levels associated with increased numbers of foetal cells. This suggests that foeto-maternal haemorrhage in an otherwise normal pregnancy can account for a percentage of raised aFP levels. The use of Kleihauer technique would eliminate elevated aFP levels due to foetomaternal haemorrhage that appears to be prevalent in women with anterior placentas. THE ELECTROLYTE CONTENT OF SOME AUSTRALIAN FOODS AND BEVERAGES
N. E. DALE & J. F. ROGERS Alfred Hospital, Sydney
Department o{Biochemistry and Department of Dietetics, Royal Prince
Dietitians often need to know the electrolyte composition of foods and beverages in order to plan therapeutic diets. This study was undertaken because there are no recent analytical figures for many Australian foods. Solid foods were homogenized with distilled water and weighed aliquots analysed. For sodium and potassium estimations, the aliquots were pre-treated with hydrochloric acid, made up to volume and filtered. Estimations were performed on the filtrate using an IL flame photometer. For calcium, magnesium and phosphorus detcrminations, the aliquots were dried in an oven, ashed in a muffle furnace, and the ash dissolved in hydrochloric acid. Calcium and magnesium were measured by atomic absorption, and phosphorus by the Technicon autoanalyser. Canned drinks were analysed directly without prior treatment. Tea and coffee were treated with boiling water and the extract analysed. Examples: 100 g of canned baked beans contain 17.6 mmoles sodium, 9.3 mmoles potassium, 1.1 mmoles calcium, 1.4 mmoles magnesium and 3.2 mmoles phosphorus. 100 ml Coca Cola contains 0.2 mmoles sodium, no potassium or calcium, and has a pH of 2.6. Two g instant coffee contains 2.6 mmoles potassium, but no sodium or calcium. A CENTRIFUGAL ANALYSER TECHNIQUE FOR MEASURING ISOENZYMES OF ACID PHOSPHATASE IN COLUMN-CHROMATOGRAPHY FRACTIONS A.
V.
NICHOI.LS, A. MUIR
& W. J.
HENSI.EY
Royal Prince Alfred Hospital, Sydney
A column-chromatographic technique for separation of acid phosphatase (ACP) isoenzymes has been combined with a rapid and sensitive automated method for detecting ACP using a Centrifichem 300. The substrate used is pnitrophenyl phosphate (PNPP), in a citrate buffer of pH 6.5. At this pH the ACP activity is not significantly less than optimal, while the extinction coefficient of PNPP is high enough to detect changes in OD using a direct computer analysis of the Centrifichem OD readings. Three main peaks of isoenzyme activity are found; the second peak, containing isoenzyme 2, is the major fraction found in prostatic tissue and serum from patients with prostatic cancer. Serum from patients with normal values for total ACP was used to determine a normal range for isoenzyme 2. The value of this test is the sensitivity with which small amounts of isoenzyme 2 can be detected, increasing the possibility of detecting small elevations in prostatic ACP long before high total ACP indicates that prostatic cancer has metastasized. COMPARISON OF LIS RATIO, PALMITIC ACID CONCENTRATION AND PIS RATIO IN DIABETIC PREGNANCIES A.
G. ANDREWS & I. HORACEK
Biochemistry Department, Royal Women's Hospital. Melbourne
The lecithin-sphingomyelin ratio (LIS ratio), palmitic acid concentration and palmitic to stearic acid ratio (PIS ratio) were estimated on samples of amniotic fluid obtained from 51 patients with diabetes. These were compared to the LIS ratio, palmitic acid concentration and PIS ratio obtained from 177 non-diabetic patients. Significant
AUSTRALIAN ASSOCIATION OF CLINICAL BIOCHEMISTS
Pathology (1979), 11, April
and animal albumin (bovine, equine, porcine) is grossly under-estimated. With these limitations, BCP-binding appears to be the method of choice for the rapid, precise, accurate and economical measurement of human albumin suitable for automated equipment. ELEVATED MATERNAL cxFP DUE TO FOETO-MATERNAL HAEMORRHAGE
D. L.
HAY
& I. HORACEK
Biochemistry Department, Royal Women's Hospital, Melbourne
Elevated maternal serum levels of ()(-foetoprotcin have been used as a screening procedure in the prenatal diagnosis of foetal neural tube defects where levels about the 98th percentile are indications for further testing. False positives due to multiple pregnancies, threatened abortions and incorrect gestations are well documented, however many false positives remain unexplained. In a survey of 150 women who gave birth to normal infants, 11/69 (l6:y',) of women with anterior placentas revealed elevated maternal ()(FP levels associated with increased numbers of foetal cells. This suggests that foeto-maternal haemorrhage in an otherwise normal pregnancy can account for a percentage of raised aFP levels. The use of Kleihauer technique would eliminate elevated aFP levels due to foetomaternal haemorrhage that appears to be prevalent in women with anterior placentas. THE ELECTROLYTE CONTENT OF SOME AUSTRALIAN FOODS AND BEVERAGES
N. E. DALE & J. F. ROGERS Alfred Hospital, Sydney
Department o{Biochemistry and Department of Dietetics, Royal Prince
Dietitians often need to know the electrolyte composition of foods and beverages in order to plan therapeutic diets. This study was undertaken because there are no recent analytical figures for many Australian foods. Solid foods were homogenized with distilled water and weighed aliquots analysed. For sodium and potassium estimations, the aliquots were pre-treated with hydrochloric acid, made up to volume and filtered. Estimations were performed on the filtrate using an IL flame photometer. For calcium, magnesium and phosphorus detcrminations, the aliquots were dried in an oven, ashed in a muffle furnace, and the ash dissolved in hydrochloric acid. Calcium and magnesium were measured by atomic absorption, and phosphorus by the Technicon autoanalyser. Canned drinks were analysed directly without prior treatment. Tea and coffee were treated with boiling water and the extract analysed. Examples: 100 g of canned baked beans contain 17.6 mmoles sodium, 9.3 mmoles potassium, 1.1 mmoles calcium, 1.4 mmoles magnesium and 3.2 mmoles phosphorus. 100 ml Coca Cola contains 0.2 mmoles sodium, no potassium or calcium, and has a pH of 2.6. Two g instant coffee contains 2.6 mmoles potassium, but no sodium or calcium. A CENTRIFUGAL ANALYSER TECHNIQUE FOR MEASURING ISOENZYMES OF ACID PHOSPHATASE IN COLUMN-CHROMATOGRAPHY FRACTIONS A.
V.
NICHOI.LS, A. MUIR
& W. J.
HENSI.EY
Royal Prince Alfred Hospital, Sydney
A column-chromatographic technique for separation of acid phosphatase (ACP) isoenzymes has been combined with a rapid and sensitive automated method for detecting ACP using a Centrifichem 300. The substrate used is pnitrophenyl phosphate (PNPP), in a citrate buffer of pH 6.5. At this pH the ACP activity is not significantly less than optimal, while the extinction coefficient of PNPP is high enough to detect changes in OD using a direct computer analysis of the Centrifichem OD readings. Three main peaks of isoenzyme activity are found; the second peak, containing isoenzyme 2, is the major fraction found in prostatic tissue and serum from patients with prostatic cancer. Serum from patients with normal values for total ACP was used to determine a normal range for isoenzyme 2. The value of this test is the sensitivity with which small amounts of isoenzyme 2 can be detected, increasing the possibility of detecting small elevations in prostatic ACP long before high total ACP indicates that prostatic cancer has metastasized. COMPARISON OF LIS RATIO, PALMITIC ACID CONCENTRATION AND PIS RATIO IN DIABETIC PREGNANCIES A.
G. ANDREWS & I. HORACEK
Biochemistry Department, Royal Women's Hospital. Melbourne
The lecithin-sphingomyelin ratio (LIS ratio), palmitic acid concentration and palmitic to stearic acid ratio (PIS ratio) were estimated on samples of amniotic fluid obtained from 51 patients with diabetes. These were compared to the LIS ratio, palmitic acid concentration and PIS ratio obtained from 177 non-diabetic patients. Significant