[Sampling and sending of blood specimens].
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Blood Specimen Collection↗
Biomedical subjects
S Sandberg
Publications and source records attributed to S Sandberg.
[Porphyria variegata--the first case in Norway].
In Norway, the most common porphyrias are acute intermittent porphyria and porphyria cutanea tarda. We describe the first case of porphyria variegata in this country. The patient showed symptoms of the skin and had no abdominal discomfort. Her family was also evaluated and two other persons were found with suspected latent porphyria variegata. We discuss the main symptoms of this type of porphyria and the possibilities of treatment. We emphasize that examination of porphyrins in the feces of patients with porphyria variegata is essential for the diagnosis.
Humans↗
Automated differential leukocyte counts in newborn infants. Comparison of Coulter VCS and Technicon H1 with manual counts.
There was good agreement between results obtained with Coulter VCS/Technicon H1 and manual counting with respect to neutrophils and eosinophils. Coulter VCS overestimates the lymphocyte percentage compared to manual counting and to H1. If, however, the percentage of so called "naked" cells are added to the percentage of manually counted lymphocytes, the agreement between VCS and the manual method is improved. The alarms given by the two instruments are of little value in detecting left shift or nucleated red blood cells.
Automation↗
Improved automated differential counts of leukocytes from newborn infants using pre-dilution of blood samples.
A method for automated differential leukocyte counting using peroxidase staining and light scatter (H1) failed to present results in more than 25% of blood samples from newborn infants. These failures were mostly seen at or below 2 weeks of age, and with high concentrations of haemoglobin F (HbF). Dilution of the blood with equal amounts of isotonic saline made the problem disappear almost completely. The results of differential counts on such diluted blood samples also compared more favourably with traditional manual counts of blood smears than did the results obtained with undiluted blood. The present method with blood diluted 1/2 is therefore recommended for routine use in newborn infants.
Automation↗
Erythropoietic protoporphyria: photodynamic transfer of protoporphyrin from intact erythrocytes to other cells.
Erythrocytes in patients with erythropoietic protoporphyria (EPP) contain large amounts of protoporphyrin and are regarded as the main source of protoporphyrin in this disease. Cells in the skin of EPP patients accumulate protoporphyrin released from the erythrocytes and upon sun exposure endothelial cells are photodamaged. In the present study a light-induced transfer of protoporphyrin directly from EPP erythrocytes to cultured cells is demonstrated. Erythrocytes were layered upon cultured cells and irradiated. The nearness of erythrocyte and cultured cell membranes potentiated the transfer of protoporphyrin between these cells. This transfer was rapid and preceded the release of protoporphyrin to proteins in the medium. Further irradiation of the protoporphyrin-enriched cultured cells, after removal of the erythrocytes, caused severe photodamage to the cells and survival was dependent on both the amount of protoporphyrin transferred and on the light fluence. Clinical observations and the results of this study indicate that light energy may be involved in two steps in the pathophysiology of EPP: (A) light-induced release of protoporphyrin from erythrocytes to endothelial cells and (B) photodynamic damage to protoporphyrin-enriched endothelial cells.
Cell Line↗
Experiences with methods and equipment.
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Chemistry, Clinical↗
A comparison of the differential white blood cell count using the Technicon H1, the Technicon H6000 and the Coulter VCS.
One hundred blood samples were analysed on Technicon H1, Technicon H6000, and Coulter VCS hematology analysers, and the white cell differential counts were compared. All three instruments showed very good agreement for neutrophils and lymphocytes, good agreement for eosinophiles, and acceptable agreement for monocytes. For the material analysed there were no disparities of clinical significance between the results obtained from the three instruments.
Humans↗
[Glucose analysis in general practice. An examination of 4 instruments designed for general practice and self-monitoring].
Several examinations have shown that the analysis of glucose in primary health care is of poor quality. The reason could be the quality of the instruments and/or the way the instruments are operated. We have examined Glucometer II, Glucochek SC, Reflolux II and Hypocount GA. These instruments were studied both in general practice and at Haukeland Hospital. The test results were compared with the routine used in the hospital laboratory. There were no major analytical differences between the instruments. All the instruments were found to have an analytical quality lower than what is recommended by the Norwegian Quality Control. The requested analytical quality for the instrument depends on the clinical needs. We would recommend that these glucose instruments be used to diagnose acute hypo/hyperglucemia and to some extent in control of diabetes. For a certain diagnosis of diabetes, the use of a more precise instrument is to be preferred. The need for a Quality Control program for glucose measurement in primary health care is emphasized.
Blood Glucose↗
Mathematical formulation and studies of the risk parameters involved in HIV transmission.
The probability of becoming infected with HIV is formulated in terms of the total number of sexual contacts (N), the probability that a sexual act is infectious (r) and the prevalence (p). Using the appropriate equations we studied the effect of reducing each of the risk factors on lowering the probability of infection. We show that for many realistic situations the probability of becoming infected by multiple partners is equal to the probability of becoming infected by one partner in a monogamous relationship given that the prevalence is the same in both cases; however if the multiple partners are chosen over time from a pool of a growing prevalence, then one is better off in a monogamous relationship where that partner is chosen early in the epidemic.
Acquired Immunodeficiency Syndrome↗
Performance of dry-chemistry instruments in primary health care.
The results from an external quality control of dry-chemistry instruments are presented. The performance with regard to imprecision was good. With regard to accuracy, the performance was poor for aspartate aminotransferase, creatine kinase, lactate dehydrogenase, triglycerides and uric acid. The inaccuracy of alanine aminotransferase, bilirubin, cholesterol, creatinine, glucose and potassium was comparable to that obtained by hospital instruments using wet chemistry. There were no large differences with respect to quality between Seralyzer and Reflotron. However, Seralyzer users performed more analyses per week, analysed a higher number of constituents and had more experienced operators than the Reflotron users. Reflotron users more often analysed the sample in connection with the consultation. The importance of an established quality control programme for these instruments is underlined.
Blood Chemical Analysis↗
Influence of lipid and leukocytes on the haemoglobin determination by Coulter Counter S Plus III, Technicon H 6000, Technicon H 1, LK 540, Reflotron and Hemocap.
The influence of lipid and high concentrations of leukocytes on the haemoglobin determination by six different instruments was examined. The increase in the determination of haemoglobin concentration with elevated amounts of lipid in the samples was greatest with the Coulter Counter S plus III and the Technicon H 1 followed by the LK 540 and the Technicon H 6000. There was no effect of lipid on the haemoglobin determination using the Reflotron. High concentrations of leukocytes increased the haemoglobin determination most by Coulter Counter S plus III and Hemocap. There were no changes in the haemoglobin determinations by the LK 540 and the Technicon H 6000 when the samples contained increased amounts of leukocytes.
Hemoglobinometry↗
Quantification of pyuria by two methods correlation and interobserver agreement.
The aim of this study was to correlate the results of two methods of quantifying pyuria and to compare the diagnostic reliability of the two methods in terms of interobserver agreement. Three independent observers counted leucocytes in 56 urine samples by using high-power-field (HPF) microscopy on centrifuged urine sediment and by using a Bürker haemocytometer on uncentrifuged urine. The commonly accepted diagnostic level of ten leucocytes/mm3 in the haemocytometer was found to be equivalent to two leucocytes/HPF. This agrees with other reports but contrasts with the usual notion of a diagnostic level of five to ten leucocytes/HPF, and implies that urinary tract infection in the presence of symptoms should not be ruled out when less than five leucocytes/HPF are found. Kappa statistics were used to evaluate the interobserver agreement. The observers agreed on the diagnosis in 96% (K = 0.92) of the urines when the haemocytometer was used, and in 93-96% (K = 0.81-K = 0.91) when leucocytes were counted per HPF. The differences in Kappa values were not statistically significant. Our material indicates that the method of quantifying pyuria in centrifuged urine sediment by HPF microscopy may be used as the routine method in general practice.
Humans↗
Implications of probability analysis for interpreting results of leukocyte esterase and nitrite test strips.
We examined 288 urine samples, using test strips, sediment microscopy, and culture. The ability of the leukocyte esterase and nitrite test strips to detect or exclude urinary tract infection, as defined by a positive culture, was evaluated by probability analysis. We found that the diagnostic efficiency of the esterase-nitrite combination was similar to that of sediment microscopy. Moreover, once the strip test results had been obtained, little additional information was given by microscopy. The importance of estimating the prevalence, or pre-test probability, of infection before the test result is evaluated is emphasized. We conclude that, for detecting or excluding urinary-tract infection, microscopy can be replaced by the esterase and nitrite test strips. If the probability of infection predicted by the test strips is not high (or low) enough compared with medical decision limits, the samples should be cultured.
Esterases↗
[Quality control of laboratory analyses performed in general practice].
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Blood Chemical Analysis↗
Light-induced redistribution and photobleaching of protoporphyrin in erythrocytes from patients with erythropoietic protoporphyria: an explanation of the rapid fading of fluorocytes.
Erythrocytes from patients with erythropoietic protoporphyria (EPP) contain large amounts of protoporphyrin. By fluorescence microscopy it has been found that the erythrocytes show red fluorescence which fades very rapidly. During irradiation of erythrocytes from patients with EPP, a decrease in the fluorescence intensity and a red shift in the fluorescence emission maximum is observed. Since the human eye has a diminishing sensitivity in the red part of the spectrum, the red shift will augment the fluorescence decrease observed in the microscope. The decrease in fluorescence intensity is greater than what would be expected by photobleaching of protoporphyrin alone. We suggest that the rapid fading of fluorocytes observed in a fluorescence microscope can be explained both by photoinduced detachment of protoporphyrin from hemoglobin followed by a redistribution to the erythrocyte membrane and by protoporphyrin photobleaching.
Erythrocytes↗
Erythropoietic protoporphyria: a quantitative determination of erythrocyte protoporphyrin in individual cells by flow cytometry.
A fraction of the erythrocytes from patients with erythropoietic protoporphyria contains large amounts of protoporphyrin. By extraction methods, only a mean value of the protoporphyrin content in erythrocytes is obtained. In this study, flow cytometry was used to determine the protoporphyrin content in each individual erythrocyte. The mean erythrocyte protoporphyrin fluorescence, calculated from flow cytometric data, correlated linearly to the mean cellular protoporphyrin concentration measured by ethyl acetate/acetic acid extraction. This indicates that flow cytometry gives a reliable quantitative determination of protoporphyrin in individual cells. Erythrocytes from patients with erythropoietic protoporphyria had a markedly skewed distribution of protoporphyrin. In the most fluorescent erythrocytes (protoporphyrin concentration 3.3 mM), there was about one protoporphyrin molecule for every sixth haeme molecule. This might explain the slight anaemia in some of these patients.
Erythrocytes↗
Evaluation of serum separator tubes as a mail transport device in primary health care.
Serum separator tubes were evaluated as a serum separator system and a mail transport device. Using conventional tubes as controls, 26 serum constituents were examined. The samples were mailed from three different general practitioners to a central laboratory. Thirteen constituents had concentrations that were significantly different from the concentration in the conventional tubes. When medically important coefficients of variations were taken into account, however, the changes of only two constituents (potassium and cobalamin) were regarded as important.
Blood Chemical Analysis↗
[Dry chemistry in primary health service].
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Primary Health Care↗