Biomedical subjects

J Frohlich

Publications and source records attributed to J Frohlich.

At least 127 records · Page 7Linked to original sources

PubMed1980

Study of erythrocytes in a hereditary hemolytic syndrome (HHS): comparison with erythrocytes in lecithin:cholesterol acyltransferase (LCAT) deficiency.

Erythrocyte membrane abnormalities in 3 members of a family with a hereditary haemolytic syndrome (HHS) were compared to those previously described in a family with lecithin:cholesterol acyltransferase (LCAT) deficiency. Despite similarities including an increase in membrane phosphatidylcholine, a decrease in phosphatidylethanolamine, stomatocytosis, and a marked decrease in erythrocyte osmotic fragility a number of differences were observed. These included membrane cholesterol content (increased in homozygotes with LCAT deficiency), changes in sodium and potassium content and Na+,k+-ATPase activity (the latter being increased in HHS), changes in acetylcholinesterase and sulfhydryl group latency (present in LCAT deficiency, but not in HHS) and 2,3 DPG content (decreased in HHS, normal in LCAT deficiency. Full compensation of the erythrocyte defect occurred in HHS but the homozygotes for LCAT deficiency were slightly anaemic. It is concluded that, although similar abnormalities in phospholipid composition, osmotic fragility, and erythrocyte morphology exist in these two disorders, the molecular nature of the erythrocyte membrane structural and functional changes in HHS and LCAT deficiency is clearly different.

4-Nitrophenylphosphatase↗

PubMed1980

Unusual calcium oxalate crystals in ethylene glycol poisoning.

A patient poisoned with ethylene glycol exhibited the symptoms of (1) hysteria, (2) metabolic acidosis with both a large anion gap and osmolal gap, and (3) crystalluria. However, the shape of the urinary crystals was prismatic and resembled hippurate rather than the expected dipyramidal calcium oxalate dihydrate. X-ray crystallography positively identified them as calcium oxalate monohydrate.

Adolescent↗

PubMed1979

Spurious hypocalcemia in hemodialysis patients after heparinization. In-vitro formation of calcium soaps.

Patients on long-term hemodialysis via arteriovenous fistula received heparin when the fistula needle was inserted, before a sample of blood was obtained for chemical analysis. The resultant release of lipoprotein lipase activity in vivo and continued lipolytic activity in vitro sometimes produced sufficient free fatty acid to precipitate calcium soaps. The consequent spurious hypocalcemia was most frequently observed when the patients had chylomicronemia. This cause of apparent hypocalcemia was eliminated either by immediate analyses of the blood samples or by obtaining samples before systemic heparinization.

Arteriovenous Shunt, Surgical↗

PubMed1979

Real-time ultrasound observation of fetal activity in labour.

Fetal activity was observed by realtime ultrasound for one hour in 25 patients in labour. Fetal respiratory movement, although reduced compared to the antenatal period, was observed in 13 patients. In three patients, hiccough-like movements were noted. Fetal body and/or extremity movements were observed in all patients (mean 41/hour) and frequently occurred in episodes. These bursts of movements were significantly correlated with contractions and fetal heart rate (FHR) accelerations. There was a significant association between absent or reduced number of fetal respiratory movements and/or hiccoughs (10 or less/hour) and an abnormal FHR. Absence of any type of fetal activity was also significantly associated with an abnormal FHR. The correlation between fetal activity and conventional methods of fetal assessment is discussed.

Female↗

PubMed1979

Gas-chromatographic analysis of patterns of fatty acids of cholesteryl esters and phosphatidylcholine.

We have developed a quick, reliable method for compositional analysis of the C14 to C20 fatty acids of cholesteryl esters, based on the use of a double extraction-solvent system and whisker-walled capillary columns with a new polar phase. Fatty acids of phosphatidylcholine, after separation by thin-layer chromatography, were determined on the same column. Our normal values are in good agreement with those published previously. We found marked changes in the fatty acid composition of both cholesteryl esters and phosphatidylcholine in cord blood serum, in various disease states, and in post-mortem specimens. The previously reported correlation between oleic (18:1) and linoleic (18:2) acids in serum cholesteryl esters was confirmed for normal adults, but no such correlation exists in cord blood specimens. We also found a significant correlation between the relative amounts of fatty acids in cholesteryl esters and phosphatidylcholine for all unsaturated fatty acids and for palmitate in all groups of subjects.

Adult↗

PubMed1978

Effect of fasting on free and esterified carnitine levels in human serum and urine: correlation with serum levels of free fatty acids and beta-hydroxybutyrate.

Serum levels of free L-carnitine, acylcarnitines, creatinine, beta-hydroxybutyrate, free fatty acids, cholesterol, triglycerides, and glucose were determined in healthy volunteers during a 24-36-hr fast. The effect of oral administration of free L-carnitine (1 g/person) on these parameters was studied. Urinary excretion of carnitine and creatinine was monitored throughout. Serum and urine levels of free carnitine and its renal clearance decreased during the fast. However, the serum concentration and urinary excretion of acylcarnitines increased during the same interval. Following the ingestion of free L-carnitine, both serum and urinary levels of free L-carnitine rose. Within 6 hr of ingestion, 10% of the administered dose could be accounted for by urinary excretion. No significant effect on the other serum constituents under study was seen following the oral L-carnitine dose. A significant negative correlation was found between serum levels of free L-carnitine and beta-hydroxybutyrate and free fatty acids (r equal -0.567, p less than 0.001 and r equal -0.607, p less than 0.001, respectively) during the fast.

Acetylcarnitine↗

PubMed1978

Study of the value of CPK and LDH isoenzyme determinations in the differential diagnosis of ischemic chest pain.

1. One hundred consecutive patients admitted with ischemic chest pain to the Emergency Department of Vancouver General Hospital were studied. The diagnosis was based on clinical assessment, EKG changes and the total CPK and LDH activities. However, unknown to the clinician. CPK and LDH isozyme determinations were also carried out and their possible impact on the diagnosis and management of the patients was evaluated retrospectively. In 37 patients with definitive myocardial infarction by all the above mentioned criteria the isozyme dterminations were of no further help. Similarly, the isozyme analysis was of no value in 22 patients with negative findings. In 26 patients with normal or unchanged EKG but elevations in either LPK or LDH, the isozymes were not absolutely necessary for the diagnosis but would have been highly reassuring to the clinician. 2. In the remaining 15 patients, the isozyme analysis would have enabled the clinician to make diagnosis of myocardial damage in 12 and rule out myocardial infarction in 3.

Clinical Enzyme Tests↗

PubMed1978

Immunological evaluation of LCAT deficiency.

Antibody towards a highly purified LCAT preparation was tested against LCAT-deficient sera by using the technic of immunodiffusion and immunoinhibition. Reaction of identity among normal serum, deficient sera, and purified LCAT was observed in immunodiffusion with two different antibodies obtained from two different goats. When the antibodies were mixed with deficient sera and tested for immunoinhibition of LCAT activity, suggesting that deficient sera contained an enzymatically inactive LCAT. The other antibody preparation showed inhibition of enzyme activity even in antigen excess. It appears that the precipitin lines observed in immunodiffusion do not represent LCAT in serum. In view of the higher titre of antibody in immunoinhibition experiments with this antibody, it remains to be determined whether at lower ratios of antibody to deficient serum, immunoinhibition by the antibody will be abolished in this case too.

Antibodies↗

PubMed1978

Erythrocyte membrane alterations in lecithin:cholesterol acyltransferase deficiency.

Structural, compositional, and functional abnormalities were found in the erythrocyte membranes of homozygotes for LCAT deficiency. Similar but less pronounced abnormalities were also present in the heterozygotes for this disorder. Some of the membrane alterations, which included decreased osmotic fragility, changes in phospholipid composition, and membrane sulfydryl group latency, as well as changes in the activity of membrane p-nitrophenylphosphatases and acetylcholinesterase, may be secondary to the changes in plasma lipids. However, since plasma lipids (and LCAT activity) were normal in the hereozygotes, the existence in both the homo- and the heterozygotes of erythrocyte membrane abnormalities unrelated to plasma LCAT activity seems likely.

4-Nitrophenylphosphatase↗

PubMed1978

Bisalbuminemia. A new molecular variant, albumin Vancouver.

Of 18 members of a Fiji Indian family investigated, eight of the 12 males and two of the six females had an electrophoretically slow-type bisalbuminemia (alloalbuminemia). The albumin was characterized by the hiterto unique ratio of the two bands (Al A 35%: variant 65%), and by dye-binding studies and electrophoretic mobility in different media. The data suggest that this is a new variant, which we propose to call albumin Vancouver (Al Va).

Adolescent↗

PubMed1978

Familial LCAT deficiency. Report of two patients from a Canadian family of Italian and Swedish descent.

A 16-year-old male (S.F.) and his 21-year-old sister (D.H.) from a large family of Italian and Swedish descent had virtually identical lipoprotein pattern and complete absence of LCAT activity. Both had typical corneal opacities and mild anemia with target cells. S.F., but not D.H., presented with proteinuria, which has increased over three years of follow-up. His kidney biopsy revealed lipid deposits in the glomerular basement membrane. Ten relatives in 4 generations had normal LCAT activity and/or lipoprotein pattern. The patients and their relatives had haptoglobin type 2. Factors that might influence the different clinical presentation in our patients (previous renal disease, diet, abnormal lipoproteins), prognosis, and treatment (diet, enzyme replacement, cholestyramine) are discussed.

Adolescent↗

PubMed1977

Control of blood cholesterol levels in suckling and weanling rats.

The high blood cholesterol and glucagon levels of suckling rats can be rapidly decreased within 24 hours by prematurely weaning rats to a high carbohydrate diet on day 18. The fall in the cholesterol level is much smaller if rats are starved for 24 hours. This decrease can partly be inhibited by injections of glucagon. The only factor so far found to decrease blood cholesterol levels in suckling rats was starvation. Insulin, which slightly but significantly, depressed the level in 40 day old rats, increased it in suckling ones, as does prednisolone. It is concluded that blood cholesterol levels are more easily manipulated in suckling rats than in older rats, and that this is probably related to a different hormonal balance.

Animals↗

PubMed1977

Carnitine content of blood and amniotic fluid.

Free carnitine levels were determined in amniotic fluids between the 10th and 40th week of gestation. They were found to decrease significantly with gestational age. Blood levels of carnitine were lower in pregnant than in nonpregnant women. Levels were found to be higher in cord blood than in maternal blood and usually were higher in the umbilical artery than vein. Intra-arterial injection of L-carnitine into a pregnant ewe did not cause a rise in the fetal blood level of carnitine, which, in contrast to human fetal blood, contained less than half the level of carnitine in maternal blood.

Age Factors↗

PubMed1976

Physicians' response to abnormal results of routine urinalysis.

To determine the clinical usefulness of routine urinalysis, the records of 400 patients were examined for results of the first urinalysis following admission to hospital, and the attending physician's response to abnormal findings was evaluated. Results were abnormal for 116 patients (29.0%); there were 22 (5.5% of total urinalyses) abnormalities of chemical constituents (protein, glucose or bilirubin was present) only, 56 (14.0%) of sediment only and 38 (9.5%) of both chemical constituents and sediment. The attending physician did not respond to abnormal results in 50.9% of the 116 instances.

Attitude of Health Personnel↗

PubMed1976

Decreased anion gap associated with monoclonal and pseudomonoclonal gammopathy.

Nine patients with monoclonal and one with pseudomonoclonal gammopathy were found to have a decreased anion gap. Eight of the patients had multiple myeloma, one has plasma cell leukemia and one had chronic active hepatitis. In all of the the decreased anion gap was associated with an increased concentration of IgG greater than 5 g/dl.

Adult↗

PubMed1976

Automated method for L-carnitine determination.

Because of renewed interest in a possible connection between carnitine, lipid disorders, and myopathy, an automated method of analysis is desirable. Deproteinization of serum by use of membrane filter cones and automated assay with a bichromatic analyzer (the ABA-100) substantially increases efficiency without sacrificing the specificity and accuracy of the original manual enzymatic method. The described procedure allows for analysis of 80 speciments a day and is thus suitable for screening of selected populations. Normal values found in blood sera of adults were in the range of 25.0-73.8 mu mol/liter and the method has sufficient sensitivity to accurately measure concentrations as small as 10 mu mol/liter.

Adult↗

PubMed1975

Lecithin:cholesterol acyltransferase initial fractional rates of esterification in human and rat serum during development.

The initial fractional rates of cholesterol esterification were measured in human cord serum, in a group of apparently healthy "young adults" (mean age +/- S.D. 32 +/- 5 years), in a group of "middle aged" adults (51 +/- 8 years) with normal coronary angiograms and in newborn, 10-, 20-, 45-, 180- and 365-day-old rats. The initial fractional rate of esterification was inversely related to serum cholesterol levels in humans and, with the exception of newborns, also in rats. A theory of lecithin:cholesterol acyltransferase participation in cholesterol metabolism is discussed.

Acyltransferases↗

PubMed1975

High glucose concentration and phosphoenolpyruvate carboxykinase activity in human and rat fetal liver cultures.

In cultures of human and rat fetal liver, phosphoenolpyruvate carboxykinase activity increases during the first 24 hr of culturing. This increase can be suppressed by adding cycloheximide to the culture medium or by adding a high glucose concentration. This, however, applies only to human fetal liver and to fetal liver from rats obtained just before term. In younger rat fetal liver, glucose, on the contrary, increases the activity of phosphoenolpyruvate carboxykinase. A high glucose concentration in the medium also leads to higher citrate cleavage enzyme activity and to lower alpha-glycerolphosphate dehydrogenase (cytoplasmic) activity in rat fetal liver cultures.

Animals↗