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B Berg

Publications and source records attributed to B Berg.

At least 37 records · Page 2Linked to original sources

Guidelines for evaluation of reagent strips. Exemplified by analysis of urine albumin and glucose concentration using visually read reagent strips. International Federation of Clinical Chemistry, Scientific Division.

Reagent strips are frequently used in the practice of laboratory medicine as well as outside the professional laboratories. In the present report, a scheme is presented which allows a reproducible description of the performance of reagent strips. This is exemplified using strips intended for estimation of urinary albumin and glucose. Experimental conditions that are particularly important for these components are given. Suitable and necessary items which should be included in the protocol presenting results of an evaluation are listed. The guidelines might have general applicability in evaluation and description of tests with a limited number of possible results.

Albuminuria

Lipid lowering in severe familial hypercholesterolaemia: efficacy and safety of a new regenerating system for selective apheresis of apolipoprotein B-containing lipoproteins.

Preliminary experience of the efficacy and safety of a new regenerating system for selective extracorporeal removal of apolipoprotein B-containing lipoproteins is described. Four patients with familial hyperlipoproteinaemia were studied on 10 occasions. A system of two, parallel, dextran sulphate cellulose columns was used, and plasma was processed continuously by passage through one of the columns while the other was being regenerated. With this procedure, reductions of very low density and low density lipoprotein cholesterol levels by 73 and 43%, respectively, could be achieved after treatment for 2.5-3 h (1000-3200 ml of plasma volume). No clinically relevant changes in the concentrations of other plasma proteins, including high density lipoproteins, were observed, and the treatment was well tolerated. We conclude that continuous selective apolipoprotein B apheresis is a safe and efficient lipid-lowering procedure which may be used both for metabolic investigations and for studies on possible regression of atherosclerosis.

Apolipoproteins B

Quality of life after bilateral adrenalectomy in MEN 2.

Pheochromocytoma is a major cause of morbidity and mortality in the multiple endocrine neoplasia type 2 (MEN 2) syndrome. For the physician, surgical treatment seems well justified even though bilateral adrenalectomy will induce iatrogenically complete loss of adrenocortical function. For the patient this treatment may be a cause of medical problems as well as worry. We have evaluated quality of life after bilateral adrenalectomy in 27 MEN 2 patients through a combined oral and written approach. Mortality was low (one of 27), as was serious morbidity. Most patients had adapted well to the postadrenalectomy state. However, fatigue, worry, and noncompliance with daily medication often caused problems.

Adaptation, Psychological

DDAVP test for renal concentration capacity. Age-related reference intervals.

The effect of different levels of fluid intake on the renal concentration test was evaluated. Maximal urinary osmolality did not significantly differ whether strict fluid restriction was kept or not. One side effect, namely headache, seemed more frequent after fluid deprivation than after a more liberal fluid intake. We suggest a practical approach to the performance of the urinary concentration test with DDAVP. The maximal urinary concentration after a single subcutaneous injection of 4 micrograms DDAVP was determined in 212 healthy adults aged 20 to 80 years. A significant decline with age was found in maximum urinary concentration, mean values ranging from 982 mOsm/kg at 20 years to 823 mOsm/kg at 80 years. References are given for different ages which render the test useful in adult patients.

Adolescent

Importance of correct handling of samples for the results of blood gas analysis.

The importance of correct handling of samples for blood gas analysis was studied in 100 patients. Sixty minutes storage in iced water lowered pH by 0.02 pH-units. Storage at room temperature caused considerable changes in PCO2 and PO2 (+0.45 kPa and -1.05 kPa). Air bubbles in the syringes increased PO2 if not expelled within 30 s. Thirty minutes storage with air trapped inside the syringe caused an increase in PO2 of 1.8 kPa and a decrease in PCO2 of 0.16 kPa. The use of plastic syringes induced significant changes in PCO2 and PO2, of which the latter (+1.0 kPa) may be clinically significant. The findings indicate that sample collection and storage must be guarded by strict rules in order to avoid false results.

Blood Gas Analysis

Subcutaneous and intranasal administration of 1-deamino-8-d-arginine vasopressin in the assessment of renal concentration capacity.

Maximum urine concentration capacity was studied in healthy adults using different routes and doses of administration of 1-deamino-8-d-arginine vasopressin (DDAVP)-desmopressin. Plasma levels of DDAVP showed a dose-dependent increase after the subcutaneous but not after the intranasal administration. The effect on urine osmolality was similar but more prolonged after the subcutaneous as compared to the intranasal route. We conclude that subcutaneous injection is a simple and reliable way of administering DDAVP. A dose of 4 micrograms in adults is optimum diagnostically and it corresponds to 20-40 micrograms administered intranasally.

Administration, Intranasal

Catecholamine release after physical exercise. A new provocative test for early diagnosis of pheochromocytoma in multiple endocrine neoplasia type 2.

A simple and practical provocative test is needed for early asymptomatic pheochromocytoma, which is a major risk for patients with multiple endocrine neoplasia type 2 (MEN-2). We measured plasma catecholamines before and after submaximal exercise in 26 MEN-2 gene carriers, eight of whom with asymptomatic pheochromocytoma, nine with medullary thyroid carcinoma and 10 after uni- or bilateral adrenalectomy. Seventeen clinically healthy individuals and 11 patients with neurovegetative lability and symptoms mimicking pheochromocytoma served as controls. Plasma adrenaline, noradrenaline and dopamine increased after exercise except for adrenaline after bilateral adrenalectomy. The post-exercise levels of adrenaline and the adrenaline/dopamine ratio were significantly higher in the pheochromocytoma patients compared to the healthy controls and the patients with neurovegetative lability, while the patients with medullary thyroid carcinoma represented an intermediate group with a high probability of developing adrenal tumors. The present method is a physiological test with a high sensitivity and specificity. It is practical and well suited for repeated examinations and seems to be of value for the detection of early pheochromocytoma in MEN-2 patients. Furthermore, the test could be used in the differential diagnosis between pheochromocytoma and neurovegetative lability.

Adrenal Gland Neoplasms

Ascorbate interference in the estimation of urinary glucose by test strips.

Currently used test strip methods for the detection of glucose in urine are influenced by ascorbate and may thus give false negative results, e.g. in screening for diabetes. Six different test strips for urine glucose were evaluated for interference by ascorbate in vitro. Interference by ascorbate varied markedly, being highest at low glucose concentrations. Interference coefficients for the individual tests were calculated to serve as an approximate index of interference by ascorbate. A new test (BM 33.071, Boehringer Mannheim GmbH, currently used in Combur-9-Test/Chemstrip-9 and other multiple test strips of Boehringer Mannheim) was clearly much less influenced as no urine containing 5.5 mmol/l glucose was read as negative even at very high ascorbate concentration. Readability of test strips differed due to patchy colour reactions. Precision was good within-test strip and within-urine but markedly less between urines.

Ascorbic Acid

Cholestasis of pregnancy. Clinical and laboratory studies.

A prospective study was made of clinical symptoms, liver function and pregnancy prognosis in women with cholestasis of pregnancy (CP). We used several positive and negative criteria to allow a clinical definition of CP as itching limited to time of pregnancy with or without laboratory evidence of liver dysfunction. The incidence during 1971-74 was 1.5% (100/6798 women) and lower during 1980-82 (52/5441 = 1.0%). One hundred consecutive pregnant women without itching were used as clinical controls. The incidence of CP showed a distinct seasonal variation, culminating in November. Women with CP had often had itching during previous pregnancies and during use of contraceptive pills and described anamnestically itching in mother and sisters. Laboratory data in CP were compared with reference intervals for healthy pregnant women. Serum enzyme levels were significantly increased for serum alkaline phosphatase, 5-nucleotidase, aspartate aminotransferase and alanine aminotransferase in the second and especially in the third trimester. The enzyme distribution was often markedly skewed to the right, i.e. some patients reacted more than others. Most patients with cholestasis only had itching without pronounced abnormalities in laboratory data. This mild form of CP was associated with a good prognosis for both mother and child.

Adult

The effects of hydraulic resistance strength training in pre-pubertal males.

In order to examine the effectiveness and safety of hydraulic resistance strength training in young males, 26 pre-pubertal males (mean age = 8.2 +/- 1.3 yr) completed a 14-wk strength training study. Subjects were evaluated before and after the 14-wk experimental period for pubertal state (Tanner's sexual maturity rating, serum testosterone, and serum dihydroepiandrosterone sulfate). Effectiveness of the strength training program was determined by measuring pre-post differences in: isokinetic strength for flexion and extension at the knee and elbow joints at two speeds (30 degrees and 90 degrees X s-1) (KIN COM, Chattecx, Inc., Chattanooga, TN), flexibility, standing long jump, vertical jump, body composition parameters, maximal oxygen consumption, and creatinine phosphokinase. Safety of strength training was assessed by biphasic musculoskeletal scintigraphy before and after the program and by physician evaluation of complaints by subjects. Strength training subjects (N = 16) participated in a 45 min/session, 3 session/wk, 14-wk supervised strength training program with an attendance rate of 91.5%. Participants performed concentric work using hydraulic resistance equipment (Hydra-Fitness Industries, Belton, TX). Eccentric work was not performed. Control subjects (N = 10) did not strength train but did participate in sport activities and activities of daily living. Results indicated that strength training subjects increased isokinetic strength as a result of strength training (average concentric work/repetition increases by 18.5 to 36.6% for the eight motions tested; torque scores over the first 90% of the range of motion increases by 13.1 to 45.1% for the eight motions tested). These changes were significantly greater than changes seen in the control group (P less than 0.05). Strength training subjects also demonstrated significant improvements (as compared to control subjects) in vertical jump (+10.4%), flexibility (+8.4%), and maximal oxygen consumption [+19.4% (l X min-1), +13.8% (ml X kg X min-1)] after the experimental period. Musculoskeletal scintigraphy revealed no evidence of damage to epiphyses, bone, or muscle as a result of strength training. Only one strength training-related injury was reported (left shoulder pain, 3 strength training sessions missed). In contrast, six strength training subjects sustained injuries during activities of daily living, resulting in 47 missed strength training sessions. It was concluded that, in the short term, supervised concentric strength training using hydraulic resistance equipment is safe and effective in pre-pubertal boys.

Anthropometry