Body weight, skeletal muscle morphology, and enzyme activities in relation to fasting serum insulin concentration and glucose tolerance in 48-year-old men.

Tissue samples were taken from the gastrocnemius muscle of 26 randomly selected, glucose-tolerant, 48-yr-old men. Hexokinase, phosphorylase, lactate dehydrogenase (LDH), succinate dehydrogenase, and lipoprotein lipase activity (LPLA), as well as the area per fiber type and capillary density, were determined. Mean fiber area correlated positively with relative body weight (r equals 0.53, P less than 0.01), but capillary density did not. The result is that, in cases of high body weight, each capillary supplies a larger muscle fiber area. Serum insulin concentration in the fasting state correlated positively with body weight (r equals 0.77, P less than 0.001) and with mean fiber area per capillary (r equals 0.87; P less than 0.001). Only during the latter part of an oral glucose tolerance test (OGTT) did blood glucose concentrations correlate with relative body weight and mean fiber area per capillary (r equals 0.42, r equals 0.51, P less than 0.05). A stepwise multiple regression analysis showed that the different muscle morphology measurements could account for 3/4 of the variation in the fasting serum insulin concentration, the fasting insulin/glucose ratio, and the blood glucose concentration at 120 min in the OGTT. Of the intracellular enzymes, only LDH (r equals -0.71, P less than 0.001) correlated with the mean fiber area per capillary. LPLA correlated with capillary density (r equals 0.66, P less than 0.001), and, long with the muscle morphology measurements, could account for 3/4 of the variation in serum triglyceride concentrations. The results show that a large mean muscle fiber area/capillary ratio indicates a morphologic imbalance, which is related to both glucose tolerance and various degrees of insulin sensitivity.

Para-aminosalicylic acid as a lipid-lowering agent.

The capacity of para-aminosalicylic acid (PAS) to lower initially high serum lipoprotein lipid concentrations was tested in a double-blind crossover study. Thirty patients who were on a lipid-lowering diet were treated with PAS (6 gm daily) for 4 wk. There was an average reduction of the serum triglyceride concentration of 28% (p less than 0.001) and of 12% of the serum cholesterol concentration (p less than 0.001) corresponding to a reduction of very low density lipoprotein (VLDL) triglycerides of 40% (p less than 0.001) and low density lipoprotein (LDL) cholesterol of 6% (p less than 0.05). In hypercholesterolemic patients, the LDL cholesterol reduction was 14% (p less than 0.001). In patients with hypertriglyceridemia type IV, the mean reduction of the VLDL triglyceride concentration was 47% (p less than 0.01), corresponding to a serum triglyceride reduction by 37% (p less than 0.01). In spite of the decrease of VLDL concentration, there was an unexpected reduction of the lipoprotein lipase activity in adipose tissue of 16% (p less than 0.02). The glucose tolerance and the serum insulin concentrations at fasting and after glucose injection were not changed.

Changes in glucose tolerance and plasma insulin during lipid-lowering treatment with diet, clofibrate and niceritrol.

In an effort to reduce serum lipids in patients with atherosclerotic manifestations, a combined treatment with a conventional lipid-lowering diet, clofibrate and niceritrol was used. The effect on glucose metabolism of such treatment was studied. Among the 106 patients 66 took the full dose of both drugs and of these 51 were weight-stable and non-diabetic. The effects of the diet and the drugs were evaluated in this subsample. Diet had no effect on fasting blood glucose concentration, the K value of an intravenous glucose tolerance test (IVGTT) and concentrations of serum insulin. Niceritrol treatment was associated with increased blood glucose, decreased K value, elevated fasting serum insulin and serum insulin at 60 min during IVGTT. Clofibrate had the opposite effects to niceritrol and when both drugs were combined, carbohydrate metabolism was unchanged compared with the pre-treatment state.

The effects of colestipol when combined with clofibrate in the treatment of severe hyperlipidemia. Short-term and long-term studies.

Twenty-two patients suffering from hyperlipidemia and receiving therapy consisting of a lipid-lowering diet and clofibrate (1 g X 2) were in addition given colestipol hydrochloride (5 g X 3) (Colestid, Upjohn) in a randomized, cross-over study for 2 periods of 6 weeks. Both the cholesterol and the triglyceride concentrations in very low density lipoproteins remained unchanged during the colestipol treatment. The cholesterol concentration in low density lipoproteins decreased by 23% (P < 0.001) and increased in high density lipoproteins by 4% (P < 0.01). In a second part of the project, the effects on the lipoprotein lipids of 15 g of colestipol divided into 1, 2 or 3 daily doses were studied when added to ongoing therapy with clofibrate (1 g X 2) and lipid-lowering diet. When the colespitol was divided into 2 or 3 daily doses, the effects were manifested equally but were less pronounced when 1 dose per day was given. In a third study, 14 patients who were treated with a combination of lipid-lowering diet, clofibrate (1 g X 2) and colestipol hydrochloride (15 g daily) were followed over a 2-year period, during which time the serum cholesterol and triglyceride concentrations were maintained at a reduced level. The fasting blood glucose and serum insulin concentrations were increased during colestipol treatment. Such treatment should therefore not be given to patients with impaired glucose tolerance.

Lipoprotein-lipase activity in human skeletal muscle and adipose tissue in the fasting and the fed states.

Sixteen healthy subjects, 7 females and 9 males, with a mean age of 25 years (range 22--29 years), were studied in the fasting state in the morning and 8 h later after partaking of breakfast, lunch and two small meals. The lipoprotein-lipase activity in the adipose tissue increased significantly from 80 +/- 32 to 117 +/- 61 nmol fatty acid released per gram and minute (nmol FA/g/min), whereas in skeletal-muscle tissue it decreased significantly from 25 +/- 11 to 17 +/- 9 nmol FA/g/min. The concentration of serum triglycerides increased significantly from 0.93 +/- 0.18 mmol/l (mean +/- SD) in the fasting state to 1.57 +/- 0.64 mmol/l in the fed state. In the fasting state the lipoprotein-lipase activity of skeletal muscle was inversely related to the ratio between the concentrations of insulin and glucagon.

Cystic fibrosis detection by means of a test-strip.

The effectiveness of meconium screening for albumin as an indication of cystic fibrosis is examined. BM-Test Meconium was applied to 69,000 investigations. In 60 positive tests, cystic fibrosis was confirmed later. No increased albumin content was observed in four cases of cystic fibrosis.

Fragments of chromogranin A are present in the urine of patients with carcinoid tumours: development of a specific radioimmunoassay for chromogranin A and its fragments.

Chromogranin A is a well-known protein constituent in granules of neuroendocrine cells. It is also known that plasma levels of chromogranin A increase considerably in patients with neuroendocrine tumours and thus chromogranin A is used as a marker for these tumours. In the present study, we have shown that fragments of chromogranin A are excreted into the urine in some patients with carcinoid tumours. The chromogranin A molecule appeared in the urine N-terminally cleaved at amino acid positions 116 and 210, which are previously reported cleavage sites of the molecule. The fragments identified were mainly of about 35 kDa in size. The unprocessed chromogranin A molecule was not excreted in the urine. Five out of 40 patients excreting the fragments had slight tubular dysfunction in the kidneys. We also showed that these renally excreted split products of chromogranin A were immunogenic and could be used for production of antibodies against chromogranin A. These antibodies were used both for immunocytochemistry and for the development of a specific and sensitive radioimmunoassay for chromogranin A and its fragments. Measurements of plasma chromogranin A by radioimmunoassay appeared to be a better marker for tumour growth than were measurements of chromogranin A in the urine.

Decrease of lipoprotein lipase activity in skeletal muscle in man during a short-term carbohydrate-rich dietary regime. With special reference to HDL-cholesterol, apolipoprotein and insulin concentrations.

Seven men took part in a study in which the diet was changed from an ordinary mixed one to a fat-rich diet [greater than 70% energy (E)] for 3 days followed by a carbohydrate-rich diet (greater than 70% E) for 3 days. Blood was drawn and muscle biopsies [for analysis of lipoprotein-lipase (LPL) activity] were taken before the study and at the end of each diet period. Insulin, apolipoprotein (apo) B, A-I and A-II, cholesterol and triglyceride concentrations were determined in serum and the lipids also in the high density lipoproteins (HDL). Serum insulin was higher (p less than 0.01) during the carbohydrate-rich diet than during the fat-rich diet (12.0 +/- 0.9 vs. 7.5 +/- 0.5 microunits/l, mean +/- SEM), as were serum-triglycerides (2.42 +/- 0.27 vs. 0.98 +/- 0.07 mmole/1, p less than 0.001). Muscle LPL activity, on the other hand, was lower (p less than 0.01), 27.3 +/- 6.1 vs. 75.1 +/- 13.2 microunits/g. HDL-cholesterol was 1.22 +/- 0.08 during the carbohydrate-rich diet which was lower (p less than 0.01) than during the fat-rich diet, 1.45 +/- 0.11. The concentration of apo A-I and A-II did not vary significantly. It is suggested that the increased insulin concentrations during a short-term, carbohydrate-rich diet may have a down-regulating effect on muscle LPL activity. Low muscle LPL activity may account for part of the elevation of serum triglycerides. An ineffective hydrolysis of VLDL-triglycerides may contribute to the variation in HDL-cholesterol concentration seen under these circumstances.

A hyaluronan-loading test applied to patients with liver and joint diseases.

The serum hyaluronan disappearance data, after an intravenous bolus injection of hyaluronan, were evaluated in terms of model-based parameters. The loading test was performed in 10 healthy persons (basal serum hyaluronan concentration, C0, 24.9 +/- 8.9 micrograms/l [mean +/- S.D.]), 6 patients with joint disease (62.3 +/- 41.1 micrograms/l) and 19 patients with liver disease (206 +/- 214 micrograms/l). The highest maximum Michaelis-Menten elimination rate (Vmax = 287 +/- 86 micrograms/min) was found in patients with joint disease, significantly higher than in healthy persons (Vmax = 179 +/- 16, P = 0.0015) and in patients with liver disease (Vmax = 149 +/- 59, P = 0.0002). C0 and Vmax were evaluated as discriminants for assessment of residual liver function. In patients with liver disease C0 correlated with liver function score (r = 0.875, P < 0.0001) and serum albumin concentration (r = -0.813, P < 0.0001). The Vmax parameter did not correlate with conventional liver function tests or with the liver score but a significantly negative correlation of Vmax with C0 was found in patients with liver disease. A combination of the C0 level and the Vmax parameter was found to discriminate between healthy persons, patients with joint disease and patients with liver disease and should be of benefit in separating patients, with or without elevated serum hyaluronan levels, into groups having increased influx or reduced elimination, respectively, of circulating hyaluronan.

Post-operative substrate utilisation and gas exchange using two different TPN-systems: glucose versus fat.

Twenty patients were studied over the first 4 post-operative days following abdominal aortic surgery. Ten patients had 93% of their non-protein energy as glucose and insulin was given to keep blood glucose below 10 mmol/l. The other 10 patients had 80% of non-protein energy as fat (Intralipid). Amino acids corresponding to 12 g of nitrogen were given in both groups. Gas exchange, nitrogen balance, phosphate balance, vanillylmandelic acid (VMA) excretion, 1- and 3-methylhistidine in urine, acute phase proteins, immunoglobulins and albumin were followed. Substrate utilisation was calculated from indirect calorimetry data and nitrogen excretion. Metabolism in the early post-operative phase was found to adapt to the nutrition regimen given even though the composition was extreme either in fat or carbohydrate content. The glucose-insulin regimen had a better nitrogen sparing effect and based on the difference in 3-methylhistidine excretion it is suggested that mainly protein muscle benefitted from this. Regardless of the TPN-regimen given, those patients whose RQ deviated the most from the average in their group had the highest nitrogen excretion. The two groups showed no differences in plasma proteins and catecholamine excretion.

Copper malabsorption in coeliac disease.

Copper uptake during three hours from an oral test dose of copper sulphate solution giving three mg Cu++, close to the recommended daily dietary intake, was significantly reduced in patients with proximal intestinal disease, compared with normal subjects. Three out of ten patients had abnormal and otherwise unexplained blood counts compatible with the known haematological effects of copper deficiency and were restored to normal levels on a gluten-free diet. Copper deficiency and proximal intestinal disease should be suspected in patients with otherwise unexplained anaemia, especially neutropenia.

Amino acid concentrations in cerebrospinal fluid in presenile and senile dementia of Alzheimer type and multi-infarct dementia.

Free amino acid levels were measured in cerebrospinal fluid (CSF) from demented patients (D, n = 30) suffering from presenile and senile dementia of Alzheimer type (PDAT, n = 7; SDAT, n = 9), multi-infarct dementia (MID, n = 14) and a reference sample group consisting of young neurotic patients (R, n = 16). Comparing the amino acid levels in the dementia subgroups, significantly higher alanine, methionine, phenylalanine and tyrosine levels were found both in MID and SDAT vs. PDAT. No difference was seen between SDAT and MID. Compared to the reference sample group, higher glycine levels were found in each dementia subgroup; higher alanine, methionine and ornithine levels in MID, and SDAT; and higher phenylalanine levels in MID. In PDAT the level of tyrosine was lower. Coefficients of correlation were calculated between amino acid levels and age, and the findings in the reference sample groups were divergent from those observed in dementia. The differences observed are discussed in terms of amino acid, carbohydrate and neurotransmitter metabolism.

Indices of alcohol intake. Comparison between serum concentrations of alkaline phosphatase and gamma glutamyltransferase in middle-aged men.

A comparison was performed on the validity of serum-gamma-glutamyltransferase (S-GT) and serum-alkaline phosphatase (S-ALP) concentrations for establishing the increased alcohol intake in a group of middle-aged men in Uppsala. These men were all born in 1915 and were participants of a special health investigation performed at their age of 60 years. Subjects who were registered at the Temperance Board, or had ethyl alcohol in urine or gave a positive reply to a question of alcohol intake were designated alcohol index cases. The mean S-GT values of these different alcohol index groups were significantly higher than that of a randomly selected subgroup devoid of alcohol findings in the same population. No such differences were found when comparing the corresponding mean S-ALP values. The authors thus point to the superiority of S-GT determinations to S-ALP determinations, especially in patients where the alcohol consumption certainly not is to be regarded as excessive.

Lipoprotein-lipase activity in subcutaneous, adipose tissue in healthy subjects: variation of activity in a population of 60-year-old men.

The lipoprotein-lipase activity (LPLA) in the abdominal, subcutaneous, adipose tissue was studied in a random sample (n = 69) of 60-year-old men. A new method for the quantification of LPLA was applied. The mean value was 67 mU/g when expressed per gram (wet weight) of adipose tissue. Several subjects within the lower part of the range of adipose-tissue LPLA values had low concentrations of serum-triglycerides (S-TG). There was no correlation between the LPLA and S-TG concentrations in the fasting state. Among the 69 subjects, four had newly detected diabetes mellitus and had significantly lower LPLA in the adipose tissue than the control group. The fat-cell size and the LPLA per gram of adipose tissue were not correlated. Thus, obesity without diabetes mellitus does not imply a low LPLA concentration in adipose tissue. The variation of the concentration of adipose-tissue LPLA in the fasting state in this population was explained only to a minor extent by the variation of S-insulin and blood-glucose parameters, when analysed statistically by a stepwise multiple-regression technique.

Changes in metabolism during a fasting period and a subsequent vegetarian diet with particular reference to glucose metabolism.

During an investigation on the effect of fasting and a vegetarian diet on the symptoms and signs in chronic cutaneous and arthritic diseases studies were made of glucose metabolism, liver function and the plasma concentration and urine excretion of some minerals. The study was performed on 27 patients who stayed as in-patients on a metabolic ward for five weeks. After the fasting period the blood glucose and serum insulin concentrations were lower (p less than 0.01) than before the fast. At the end of the period on the vegetarian (vegan) diet (three weeks) the insulin/glucose ratio was lower than at the start of the fast. Serum enzyme concentrations reflecting liver function increased during the fast, but normalized during the vegan diet. The intake of vitamin B12 and of selenium due to the vegan diets was very low, which may give reason for some concern during long-term use of this type of vegetarian diet.

A Nordic reference serum suitable for use as trueness control in the clinical routine laboratory.

The described reference serum is characterized by: liquid human serum at "normal" level stored in frozen state at -80 degrees C; minimum damage of proteins; aseptic preparation; cryoprecipitate and excess fibrin removed; serum cleared by ultracentrifugation; pH at 7.2-7.6; available in sealed glass ampoules with inert gas (one ml serum in each); specified components among most frequently analyzed analytes; homogeneity assured and stability monitored; produced under strict rules for good manufacturing practices (GMP). The assigned values are traceable to reference measurement procedures and reference materials of highest achievable metrological level; according to the present proposal the maximum allowable uncertainty of the assigned value is based on biological variation (shared common reference intervals); the uncertainty should ideally not exceed 1/5 of the maximum allowable bias of results obtained on patients samples (even 1/2 would theoretically be acceptable and, for a practical guide approximately < 1% may suffice). The present document provides some guidance of how the reference serum could be established in practice. The document also indicates the use of the material and further extension of the concept. The present work is done as a NORDKEM project.

[Results of multicenter evaluation of reagents for determination of sodium, potassium and chloride ions using enzyme activation]. / Ergebnisse der multizentrischen Evaluierung von Reagenzien zur Bestimmung von Natrium-, Kalium- und Chloridionen mittels Enzymaktivierung.

We present the results of a multicentre evaluation with Boehringer Mannheim/Hitachi instruments of new "enzymatic" methods for the determination of Na+, K+, and Cl- in serum or plasma. The between-day coefficient of variation was less than 1.4% (Na+), less than 2.6% (K+) and less than 1.7% (Cl-). The linear range of the assays were at least 80 to 200 mmol/l (Na+), 1.5 to 17 mmol/l (K+) and about 30 to at least 200 mmol/l (Cl-). The comparisons with routine flame atomic emission spectrometry and coulometry showed a satisfactory agreement of the test results. The "enzymatic" assays are insensitive to even grossly elevated levels of bilirubin and lipids (sodium, potassium, and chloride assays), NH4+ (potassium assay) and amylase (chloride assay). Interference by various drugs was not detected. Since the new methods can easily be adapted to photometric clinical chemistry instruments, they represent a valuable alternative to the use of ion-selective electrodes, flame atomic emission spectrometry and coulometry.

[Laboratory diagnosis of gastrinoma. Nordic collaboration can improve the quality]. / Laboratoriediagnostik av gastrinom. Nordiskt samarbete kan ge ökad säkerhet.

Measurement of gastrin in serum or plasma in patients with gastrinoma may be complicated by the presence of circulating biosynthetic intermediates which may not be detected by commonly available immunoassays. In contrast, the "processing-independent analysis" of gastrins developed by professor Jens Rehfeld et al in Copenhagen detects gastrin forms irrespective of their size. The authors review gastrinoma pathophysiology, the biochemistry of gastrin and other biomarkers of gastrinoma, the differential diagnosis of hypergastrinemia as well as other methods currently employed in the workup of gastrinoma patients, and illustrate with a clinical case.

[How reliable is the laboratory? Increased needs of patient-related quality assurance]. / Kan man lita på laboratoriet? Okat behov av patientrelaterad kvalitetssäkring. Expertgruppen för endokrinologi inom EQUALIS.

Recent developments in medical care and research involve the increased use of immunochemical assays for hormones, tumour markers, vitamins and drugs. External quality assurance programmes using pooled human sera usually fail to detect analytical interference due to substances (e.g. anti-immunoglobulin or anti-ligand antibodies) present in individual serum specimens. The article reports on experience gained during a three-year period when specimens from individual patients attending a thyroid unit were distributed to hospital laboratories in Sweden for analysis. Specimen selection criteria were based on contradictory findings at the initial clinical or laboratory evaluation. The programme has given rise to the formation of a network of the laboratories involved, under the co-ordination of EQUALIS (External quality assurance in laboratory medicine in Sweden).

Phosphate metabolism in renal stone formers. (I): Indices of phosphate handling in calcium stone patients and healthy subjects.

Healthy subjects (n = 112) and patients with recurrent idiopathic calcium nephrolithiasis (n = 44) were evaluated regarding various indices of phosphate handling: serum phosphate concentration, renal tubular reabsorption of phosphate, index of phosphate excretion and renal threshold concentration for phosphate (TmP/GFR). The 24 hour and fasting 2 hour urinary phosphate excretions were similar in the two groups and the index of phosphate excretion was higher in stone formers, but for all the other variables lower mean values were found in the group of stone formers than in the group of normal subjects. The renal tubular capacity for reabsorption of phosphate (as evaluated by the different indices) appeared to decrease with advancing age concomitant with a reduction of the serum phosphate concentration. When age- and sex-matched subjects from the two groups were compared with regard to the phosphate variables lower values were still found in the group of stone forming subjects. This study gives support to earlier observations that renal stone formers tend to waste phosphate by and altered renal handling.