Mitsuaki Kameko

Immunocytochemical demonstration of retinol-binding protein in the lysosomes of the proximal tubules of the human kidney

SummaryThe localization of plasma retinol-binding protein (RBP) in the human kidney was determined by two immunocytochemical techniques, the PAP method and the protein A-gold technique. By using the affinity purified antibody against RBP obtained from the urine of the patients with cadmium poisoning (Itai-Itai disease), the immunoreactive substances were located by light microscopy in the proximal tubules of the human kidney. By immuno-electron microscopy, the stained organelles were identified as lysosomes in both S1 and S2 segments of the tubules. These data suggested that the reabsorption of low molecular weight plasma proteins like RBP can occur in the two segments. We inferred a similarity between the S1 and S2 segments concerning the reabsorption of RBP.

Immunohistochemical localization of plasma retinolbinding protein and prealbumin in human pancreatic islets

SummaryThis study was undertaken, employing the immunoenzyme method, to confirm the presence of retinol-binding protein in human pancreatic islets, and to compare its distribution with that of prealbumin, insulin, glucagon, somatostatin and pancreatic polypeptide. It was found that most islet cells contained retinol-binding protein, although centrally located cells showed stronger reactivity than those in the peripheral region. The distribution of each of the five polypeptides differed from that of retinolbinding protein, indicating that these peptides did not cross-react with anti-retinol-binding protein antibody. Islet cells which contained prealbumin, on the other hand, were mostly classified as A cells. Further studies are necessary to confirm whether the islet cells produce retinol-binding protein or only store it.

Significance of IgM antibody to hepatitis B core antigen for the differential diagnosis of acute and chronic hepatitis B virus infection and for the evaluation of the inflammatory activity of type B chronic liver diseases

SummaryIgM antibody to hepatitis B core antigen (anti-HBc) was assayed using a commercial kit in acute and chronic hepatitis B virus (HBV) infection and evaluated for its diagnostic and clinical significance. IgM anti-HBc was positive in all of 21 cases with type B acute hepatitis in the acute phase, and was also detected in 5 of 20 cases with type B chronic persistent hepatitis, in 4 of 20 patients with type B chronic active hepatitis and in one of 10 with type B liver cirrhosis. The absence of this marker was noted in all of 20 asymptomatic hepatitis B surface antigen (HBsAg) carriers and in 50 with HBsAg-negative patients with liver disease and in 200 healthy blood donors. The cut-off index of IgM anti-HBc was greater than 2.0 in all serum samples obtained in the acute phase of type B acute hepatitis, but was below 2.0 in type B chronic liver disease. A close relationship was found between the presence of IgM anti-HBc and the degree of inflammatory activity in patients with HBsAg-positive chronic liver disease.These data show that examination of IgM anti-HBc is useful in distingushing type B acute hepatitis from type B chronic liver disease, and also in evaluating the severity of disease in type B chronic liver disease.

Immunologic and immunohistochemical study of familial amyloid polyneuropathy

Amyloid fibril protein was purified from postmortem organs of patients with familial amyloid polyneuropathy. In immunodiffusion tests, the protein reacted with antihuman prealbumin antibody but not with antihuman retinol-binding protein or antihuman immunoglobulin G (IgG). In immunoelectrophoresis, the amyloid fibril protein gave a single line with a slightly faster mobility than prealbumin. Immunohistochemical analysis, using fluorescent and peroxidase-antiperoxidase methods, showed that the amyloid deposits contained antigenic determinants of human retinol-binding protein and IgG but not prealbumin.

Distribution of retinol-binding protein in the human digestive tract

SummaryBy employing polyclonal antibodies for retinol-binding protein (RBP), its distribution in the human pancreas and digestive tract mucosa was compared with those of transthyretin (TTR) and various peptide hormones. The materials used included surgically removed pancreas, esophagus, stomach, small and large intestines. Paraffin sections were stained by the indirect immunoenzyme method. The results indicate that RBP-containing cells are found in the pancreas and the gastro-intestinal mucosa, but most frequently in the gastric antrum and duodenum. In the pancreas, RBP-containing cells are found in the islets and among acinar and ductal epithelial cells, and consistently stain for chromogranin A. RBP-containing cells in the gastrointestinal mucosa showed typical features of endocrine cells and also stained for chromogranin A. The distribution of TTR in these tissue sites resembled that of RBP, but the immunoreactive intensities of both peptides altered independently. Comparison of the distribution of RBP, TTR, and various gastrointestinal peptide hormones revealed that the distribution of RBP coincided with none of the other peptides, although some of the RBP-containing cells stained for most of the peptides examined and vice versa. These results suggest that RBP may be a consistent component of gastrointestinal endocrine cells.

Prealbumin and Immunoglobulin in Serum and Cerebrospinal Fluid in Familial Amyloid Polyneuropathy

Prealbumin, immunoglobulin G, A, and M concentrations in serum and cerebrospinal fluid from patients with familial amyloid polyneuropathy (Japanese type) were determined and compared with those of asymptomatic relatives or controls. Prealbumin concentrations were not significantly different between them. Using polyacrylamide disc-gel electrophoresis, no qualitative difference in the serum prealbumin was found between them. Among the serum immunoglobulins, only the immunoglobulin A concentration was significantly elevated in the patients as compared with asymptomatic relatives.

Serum auto‐antibodies in patients with hepatocellular carcinoma: The clinical significance of antinuclear antibody

Auto‐antibodies including antinuclear antibody (ANA), antismooth muscle antibody, antimitochondrial antibody, rheumatoid factor, lupus erythematosus factor, antimicrosomal antibody and antithyroglobulin antibody were assayed in sera from 84 patients with hepatocellular carcinoma, 70 with liver cirrhosis, 50 with chronic hepatitis, 30 with cancer of the alimentary tract and 100 normal subjects. A significantly higher incidence and higher titre of ANA was found in patients with hepatocellular carcinoma, and the patterns of nuclear fluorescence detected by the indirect immunofluorescent test using cultured baby hamster kidney cells were predominantly speckled and nucleolar. In 16 patients with this disease, serial assays of ANA were done in sera obtained before and after development of hepatoma and/or after resection of the hepatic tumour. Antinuclear antibodies evolved in six patients in conjunction with the progression from cirrhosis to hepatoma, and two of three ANA‐positive patients who had the hepatic tumour resected lost ANA from their sera after resection.

Triiodothyronine (T3) Autoantibodies in a Woman with Nonthyroidal Disorder

A 48-year-old non-goitrous woman, who had undergone cardiac surgery for mitral stenosis under the extracorporeal circulation, showed high levels of serum T3 and free T3 in a recent follow-up study, employing antibody coated-bead RIA for T3 and -Amerlex M particle RIA for free T3. However, other thyroid function tests (T4, free T4, TSH and TBG) were normal. We suspected that thyroid hormone autoantibodies (THAA) in her serum interfered with T3 and free T3 analyses. The presence of THAA was demonstrated by the use of various procedures as follows. Firstly, the patients serum was directly incubated with 125I-T3 or -T4 analog which did not bind to TBG, followed by B/F separation with polyethyleneglycol, counting the precipitates. Secondly, after the serum was treated with an acid-charcoal solution to remove circulating thyroid hormone, the measurement of THAA was made as stated above. Normal sera were used as controls. Both the non- and acid-charcoal-treated sera showed much higher percentages of 125I-T3 analog precipitation as compared with controls. In the case of 125I-T4 analog, there was no difference between them. In the third study, the presence of IgG antibodies that bound T3 but not T4 was investigated. The IgG fraction of the patients serum was separated employing a Protein A-Sepharose CL-4B column chromatography. Then, the prepared IgG fraction was purified by a technique of gel filtration chromatography (Sephacryl S 200). Non-purified and purified-IgG fractions both revealed higher binding percentages of 125I-T3 analog than the control IgG fraction and non-IgG fraction of the patient. Furthermore, a good dose response was observed between the binding percentage of 125I-T3 analog and each dose of the patients serum or IgG fraction. From these observations, it was clarified that this woman had anti-T3 IgG autoantibodies using a Protein A column chromatography with confirmation of gel filtration chromatography.