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P Masters

Publications and source records attributed to P Masters.

At least 19 recordsLinked to original sources
PubMed1998

Bacterial expression and characterization of the mitochondrial outer membrane channel. Effects of n-terminal modifications.

Several forms of the voltage-dependent anion-selective channel (VDAC) have been expressed at high yield in Escherichia coli. Full-length constructs of the proteins of Neurospora crassa and Saccharomyces cerevisiae (ncVDAC and scVDAC) have been made with 20-residue-long, thrombin-cleavable, His6-containing N-terminal extensions. ncVDAC purified from bacteria or mitochondria displays a far-UV CD spectrum (in 1% lauryl dimethylamine oxide at pH 6-8) similar to that of bacterial porins, indicating extensive beta-sheet structure. Under the same conditions, the CD spectrum of bacterially expressed scVDAC indicates lower beta-sheet content, albeit higher than that of mitochondrial scVDAC under the same conditions. In phospholipid bilayers, the bacterially expressed proteins (with or without N-terminal extensions) form typical VDAC-like channels with stable, large conductance open states (4-4.5 nanosiemens in 1 M KCl) and voltage-dependent transitions to a predominant substate (about 2 nanosiemens). A variant of scVDAC missing the first eight residues and having no N-terminal extension also has been expressed in E. coli. The truncated protein has a CD spectrum similar to that of mitochondrial scVDAC, but its channel activity is abnormal, exhibiting an unstable open state and rapid transitions between multiple subconductance levels.

Amino Acid Sequence↗
PubMed1989

Angiodysplasia in patients with renal insufficiency.

Sixty-five patients with angiodysplasia were studied: 42 (64.6%) had normal renal function and 23 (35.4%) had renal insufficiency, defined as serum creatinine consistently greater than 1.5 mg/dl. Comparison of results in the two groups showed that there were no significant differences in the mode of presentation or anatomic distribution of angiodysplasia. Systemic hypertension, congestive cardiac failure, coronary artery disease, and diabetes mellitus were significantly more common in patients with renal failure. Recurrent bleeding from upper alimentary angiodysplasias occurred significantly more often in patients with renal failure than in those with normal renal function. However, a second source, as a cause of bleeding, was found significantly more often in patients with normal renal function.

Aged↗
PubMed1988

Determination of plasma bicarbonate of neonates in intensive care.

Most modern blood-gas analyzers are programmed to use the Henderson-Hasselbalch equation to calculate a value for plasma bicarbonate. It has been suggested, however, that among acutely ill patients, including newborns, these calculated values may be at variance with measured total CO2. To assess the clinical significance of such errors, we compared calculated bicarbonate with measured total CO2 in 79 blood samples from 40 babies in intensive care. The calculated bicarbonate values consistently exceeded the measured values by about 1.5 mmol/L. Of the errors, 94% were within the range -10% to +20%. When the systematic bias was removed, calculated and measured bicarbonate values agreed within +/- 3.30 mmol/L in 95% of cases. Because calculated values can be obtained much more quickly and frequently than laboratory measurements, we believe that these limits are clinically acceptable.

Bicarbonates↗
PubMed1983

Genetic screening of newborn in Australia. Results for 1981.

Since screening of newborn infants for phenylketonuria (PKU) by the Guthrie bacterial inhibition assay was established in the 1960s, 3 017 703 infants have been tested in Australia. Two hundred and fifty-one cases of PKU (0.83/10 000) and six cases of the variant forms of malignant hyperphenylalaninaemia (MHPA) (0.02/10 000) have been detected. In 1981, 11 infants with PKU were detected. Screening for congenital hypothyroidism was carried out in seven States, and 66 new cases were detected in 1981 (2.13/10 000). In Adelaide, 154 310 infants have been tested for galactosaemia and a total of seven cases have now been detected (0.45/10 000). In New South Wales, 35 955 infants have been tested for cystic fibrosis of the pancreas, and 17 cases were found (4.73/10 000).

Australia↗
PubMed1982

Primary amoebic meningoencephalitis in Western Australia.

This paper describes the findings in three fatal cases of primary amoebic meningoencephalitis. Two children developed the infection in January, 1980, in widely separated wheat-belt towns. The third child's infection, diagnosed by retrospective examination of necropsy material, developed in February, 1963, in the town where the second child lived. Infection with Naegleria fowleri was demonstrated by histological examination supplemented by specific immunofluorescence in all three cases, and by culture in the second case. For early diagnosis it is important to search for amoebae both on wet preparations and on stained films of cerebrospinal fluid when primary amoebic meningoencephalitis is suspected on epidemiological grounds of from cerebrospinal fluid findings.

Amebiasis↗
PubMed1982

Genetic screening of newborn in Australia: results for 1980.

Since screening of newborn infants for phenylketonuria (PKU) by Guthrie bacterial inhibition assay was established in the 1960s, 2779 790 infants have been tested in Australia. Two hundred and forty cases of PKU (rate: 1/11 582) and six cases of the variant forms of malignant hyperphenylalaninaemia (MHPA) (rate: 1/463 298) have been detected. In 1980, 18 infants with PKU were detected. Screening for congenital hypothyroidism was carried out in six centres, and 40 new cases were detected in 1980.

Australia↗
PubMed1981

Genetic screening of newborn in Australia: results for 1979.

Since screening of newborn infants for phenylketonuria (PKU) by Guthrie bacterial inhibition assay was established in the 1960s, 2 556 498 infants have been tested in Australia. Two hundred and twenty-two cases of PKU, and five cases of the variant forms of malignant hyperphenylalaninaemia (MHPA) have been found over this period, an incidence of 1/11 516 for PKU, and 1/511 300 for MHPA. In 1979, 18 infants with PKU and one with MHPA were detected. Screening for congenital hypothyroidism was carried out in four centres, and 28 new cases were detected in 1979 (an incidence of 1/5746).

Australia↗
PubMed1979

Genetic screening of the newborn in Australia. Results for 1978.

Since screening of newborn infants for phenylketonuria (PKU) by Guthrie bacterial inhibition assay was established in the 1960s. 2 334 679 infants have been tested in Australia, and 208 cases of PKU detected (an incidence of 1/11 224). In 1978, 21 infants with PKU were detected. Screening for hypothyroidism was carried out in three States, and 29 cases of congenital hypothyroidism were detected in 1978 (an incidence of 1/5894).

Australia↗
PubMed1978

Galactosaemia: case for neonatal screening illustrated by recent Australian experience.

The varied presentation and clinical features of classical galactosaemia are illustrated by the case histories of seven babies born in Western Australia since January, 1962, and of two babies born in South Australia in whom diagnosis was made as a result of adding galactosaemia to the Guthrie screening programme in October, 1974. All were shown to have a severe deficiency of galactose-1-phosphate uridyl transferase in their red blood cells. We compare our findings with those in 10 galactosaemic babies born in Victoria over a similar period, and show that in both groups these were two main modes of onset: acute and insidious. Jaundice and Escherichia coli infection were prominent in the 13 babies with an acute onset of galactosaemia, while poor weight gain, intermittent vomiting and cataracts were features of the five babies with an insidious onset. An enlarged liver was usually found in both groups. We discuss the various approaches to neonatal screening of galactosaemia in the light of experience in Massachusetts and South Australia. The use of cord blood can be expected to lead to diagnosis before babies with acute onset become ill, while the use of blood collected at five days for the Guthrie test avoids the collection of another routine sample for a relatively rare disorder. The result of red cell transferase assays of parents and siblings of our patients are discussed in relation to their implication for genetic counselling. The relevance of antenatal diagnosis to the prevention of possible intrauterine damage to an affected fetus is pointed out.

Australia↗