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Isoelectric focusing on thin layers of agarose was used to separate several human hemoglobin variants in narrow pH range (pH 6-9). Problems with gel flooding and distortions due to electroendosmotic flow were solved by altering the casting and processing of the gel, by modifying the focusing apparatus, and by utilizing commercial agarose that had been chemically modified to reduce electroendomosis. Hemoglobins C, O-ARAB, A2, and E were distinguished from one another, as were hemoglobins S, D-LOS ANGELES, G-PHILADELPHIA, F. A, I, and J. The technic is rapid, simple, and relatively inexpensive. The agarose is nontoxic, has excellent gelling properties, and possesses large pores, yet gives resolution equivalent or superior to that obtained on thin layers of polyacrylamide gel, making it preferable to polyacrylamide for thin-layer isoelectric focusing.

Summary The major utility of the glycosylated hemoglobin assay continues to be as a monitor for the effectiveness of diet/insulin or oral agent therapy in the normalization of serum glucose concentrations. During periods of poor glycemic control, as assessed by frequent positive urine glucose determinations, or by elevated fasting or postprandial blood glucose concentrations, or by episodes of ketoacidosis, the use of the glycosylated hemoglobin assay adds little information. Rather, it is most useful during periods of stable control, to assess the effectiveness of the combined therapy of diet, activity, and insulin or oral agents. As the glycosylated hemoglobin concentrations tend to reflect the metabolic control during the previous four to eight weeks, little is to be gained from more frequent use of this assay. An isolated elevated serum glucose concentration obtained in the office or hospital laboratory, associated with a near-normal serum glycosylated hemoglobin concentration need not demand drastic rearrangement of the patient's therapuetic regimen. The normal hemoglobin A 1c concentration reflects good blood glucose control over the past one to two months. The elevated blood glucose concentration may reflect a transient aberration secondary to stress, diet, or other factors. If, however, actual deterioration in the patient's metabolic control is occurring, this may not be reflected in the hemoglobin A 1c concentration for several weeks or months. Likewise, during a period of stable control, a normal office or lab glucose concentration associated with an elevated glycosylated hemoglobin concentration may indicate poor control, the normal glucose resulting from the peak effectiveness of either short- or intermediate-acting insulin. In this situation, more frequent glucose determinations would reveal elevation of blood glucose concentrations. Whereas the glycosylated hemoglobin assay may help the physician and patient to assess glycemic control, this alone cannot lead to improved control. In this regard the use of home glucose monitoring with or without insulin infusion pumps has led to near-normalization of blood glucose concentrations in Type I and in pregnant diabetic patients [105, 175, 176]. The frequent determination of blood glucose concentrations on a daily basis can allow for optimum use of dietary and insulin therapy. Moreover, the reported variability in glycosylated hemoglobin after periods of poor control may reflect the time relation between blood glucose and hemoglobin A 1c concentrations, or the stability of the glycosylated hemoglobin, and may diminish the clinical utility of the glycosylated hemoglobin concentration in the individual patient. The clinical utility of the glycosylated albumin or protein assay in diabetes management remains to be established [211]. At this time the combined use of multiple daily home blood glucose determinations, coupled with several well-spaced hemoglobin A 1 determinations may be the most sensitive indicators of the state of metabolic control. Thus, protein glycosylation provides an indication of glycemic regulation. Protein glycosylation may also contribute to the complications of diabetes mellitus, but such relationships, for the most part, remain to be established.

The authors evaluated the Kodak Ektachem Slides for total, "direct," conjugated, unconjugated, and albumin-bound ("delta") bilirubin. For various concentrations of control material, the precision (CV) within- and between-day ranged from 1.7 to 2.4% (2.8-6.6%) for total bilirubin, 0.8-4.2% (1.6-11.5%) for unconjugated bilirubin, and 1.6-9.5% (2.6-20.7%) for conjugated bilirubin. The Ektachem total and "direct" bilirubin assays demonstrated excellent correlation with the Jendrassik and Grof procedure; a 30% difference was observed, however, between absolute numbers with the two direct bilirubin methods. We found the measurement of true conjugated bilirubin by the Kodak Method to be superior to the measurement of "direct" bilirubin in following the response to treatment of various hepatic disorders manifested by extrahepatic and intrahepatic biliary obstruction.

The glutamate dehydrogenase activity found in the serum of patients with Reye's syndrome is shown to be inhibited about 1000-fold more potently by GTP than is the normal human enzyme. 1 mM ADP, which with the normal enzyme effectively reverse GTP inhibition, has no effect in the GTP inhibition of the Reye's syndrome serum activity.

Kidneys from an Rh-negative cadaver donor were transplanted to two Rh-positive patients. The donor's serum contained anti-Rho (D). In both patients, anti-Rho (D) was detected in their serum and on their red cells 3.5 weeks after transplantation. One patient had hemolysis. The antibodies persisted for nearly six months, despite graft rejection and nephrectomy in one case. These antibodies presumably arose from passenger B lymphocytes in the grafts from the Rh-immunized donor.

Recent evidence suggests that HLA-A,B antigens present on human platelets, are acquired from plasma. Using hypertonic acid chloroquine (200 mg/ml, pH 5.0, 1 hr, 4 degrees C), we demonstrate elution of most or all HLA-A2 and HLA-B7,40 immunoreactive material from platelets. Corresponding antigens on human lymphocytes were not affected by this treatment. These findings are consistent with the hypothesis that HLA- A,B antigens are adsorbed onto platelet surfaces.

Background Screening and determining the immune status of individuals for hepatitis B is usually done by detecting hepatitis B surface antigen (HBsAg) and hepatitis B surface antigen-specific antibodies (HBsAb). In some countries with the highest viral burden, performing these assays is currently impractical. This paper explores the use of filter paper as a blood specimen transport medium. Methods Samples, chosen from routine clinical laboratory pool, were applied and dried onto filter paper. Eluates, from the paper samples, were analyzed as routine clinical specimens on ADVIA Centaur 5634® immunoassay analyzers using the standard HBsAg and HBsAb kits. Dried blood samples were subjected to a range of environmental conditions in order to assess stability. Results After drying and elution the assays showed linearity and precision comparable to clinical assays performed on fresh serum. Elutions at various times during a 149 day incubation period showed very little variability in the Index numbers. All analytes were temperature stable except for a decrease in the HBsAg signal at 42°C. Conclusions Filter paper is an acceptable storage and transport medium for serum to be used in the detection of hepatitis B markers if atmospheric variability can be controlled. HBsAg, HBsAb and HBcAb are all stable for at least five months under storage conditions below room temperature. Drying specimens, particularly serum, on filter paper at remote locations, offers a reasonable solution to the problem of hepatitis surveillance in underdeveloped regions, although some attempt at temperature control might be desirable.