Immunohistochemistry of vacuoles occurring in rat hepatocytes after retinol administration

The vacuoles occurring in rat hepatocytes after intraportal injection of retinol (33 or 67 micrograms) were examined immunohistochemically using respective antibodies against rat albumin, human retinol-binding protein, human ceruloplasmin, human alpha 1-antitrypsin, human transferrin, and human prealbumin as representative plasma proteins. The occurrence of the vacuoles reached a numerical maximum 30 min after injection of 67 micrograms retinol, followed by a temporal decrease. Hepatocytes from control rats, which had been intraportally injected with either blood plasma diluted to 2/3 concentration or with retinol palmitate solvent (castor oil) dissolved in blood plasma, showed immunoreactive fine granules without the occurrence of vacuoles in the cytoplasm. Identical vacuoles in serial sections appeared immunohistochemically either immunoreactive or non-immunoreactive for all the antibodies used, with rare exceptions. The occurrence of several rare exceptions suggested that 2 kinds of vacuoles might be formed in different cytoplasmic compartments. A zonal distribution of vacuoles was apparent in the hepatic laminae (or acini) within the liver lobules. The vacuoles were predominantly distributed in zone 2, and to a lesser extent in zone 3 and zone 1 in that order.

Alpha-1-antitrypsin and lysozyme. Their limited significance in fibrohistiocytic tumors

A wide range of tumors were immunohistochemically analyzed for alpha-1-antitrypsin (AAT) and lysozyme in order to evaluate their specificity as histiocytic markers and their significance in the diagnostic and histogenetic evaluation of fibrohistiocytic tumors. Besides histiocytic lesions, AAT immunoreactivity was commonly found in different types of carcinomas and sarcomas, and strong immunoreactivity was found in carcinoid tumors, malignant melanomas, and schwannomas, which, however, had negative results for lysozyme. The AAT immunoreactivity could be abolished with the absorption of the antibody with purified AAT also in nonhistiocytic tumors. The neoplastic pleomorphic cells in malignant fibrous histiocytomas (MFHs) usually had strongly positive results for AAT, whereas only entrapped histocytes had positive results for lysozyme and for two monoclonal antibodies to histomonocytic cells. The results show that AAT has a relatively low specificity as a histiocytic marker, and one should be careful in concluding the histiocytic nature of tumors, such as MFHs, based on AAT immunostaining. It seems also questionable whether AAT can be used as a diagnostic marker for MFH. The reason for the widespread AAT immunoreactivity in various tumors may be that AAT is taken up from serum to various types of nonhistiocytic tumor cells.

Patterns of antigen expression in hepatoblastoma and hepatocellular carcinoma in childhood

Two hepatocellular carcinomas and six hepatoblastomas were examined for the presence of 13 antigens using immunoperoxidase, avidin-biotin, staining techniques. Primary antibodies were directed against alpha-fetoprotein (AFP), alpha-1-antitrypsin (AAT), lysozyme (LYS), carcinoembryonic antigen (CEA), human chorionic gonadotropin (HCG), glial fibrillary acidic protein (GFAP), neuron specific enolase (NSE), epithelial membrane antigen (EMA), hepatitis B surface antigen (HbSA), lactoferrin (LF), desmin (DES), vimentin (VIM), and keratin (KER). Except for HbSA, the antigen staining pattern was unable to differentiate between hepatoblastoma and hepatocellular carcinoma. Both neoplasms where positive for AFP, AAT, CEA, EMA, and KER; however, neither stained for GFAP, NSE, LYS, LF, HCG, or DES. Vimentin was weakly positive in those hepatoblastomas where mesenchymal tissue was present in the tumor. Only the tissue adjacent to hepatocellular carcinomas stained positively for HbSA and correlated with the elevated serum levels of HbSA.

Enhanced specificity in immunoscreening of expression cDNA clones using radiolabeled antigen overlay

A highly sensitive and specific method has been developed for immunoscreening clones from an expression cDNA library. The procedures utilize a radiolabeled antigen detection method described originally for the immunoblotting of plasma proteins (5). Screening of rat alpha 1-antitrypsin clones was used. Comparison between Western blots of alpha 1-antitrypsin using both labeled antigen and protein A detection methods showed that the former yielded lower background and greater sensitivity than the latter. Further, this technique was shown to have a lower detection limit of less than 20 ng through Western blot analysis of varying concentrations of alpha 1-antitrypsin. The procedures are based on the expression of the protein by cDNA clones containing the DNA inserts in the correct reading frame. Following the transfer of phage proteins to nitrocellulose membranes, the bivalent antibodies bind monovalently to both nitrocellulose-bound-antigen in the phage lysates and radiolabeled antigen. The radiolabeled antigen overlay method is superior to the protein A detection method in sensitivity, specificity and reproducibility. This improved method can be applied in general for screening expression cDNA libraries, provided that the specific antiserum and radiolabeled antigen are available.

Biologic characterization of human bone tumors IX. Occurrence of macrophages

Fifty bone tumors were investigated using immunohistological methods for an assessment of the amount and nature of macrophage infiltration. Polyclonal antibodies against lysozyme, alpha 1-antichymotrypsin, and alpha 1-antitrypsin were used as markers, besides certain monoclonal antibodies against blood monocytes and mature tissue macrophages. Particularly high macrophage infiltration was found in malignant fibrous histiocytomas, giant cell-containing osteosarcomas, giant cell tumors of bone, and aneurysmal bone cysts. Moderate infiltrates were seen in some highly malignant osteosarcomas, in fibrosarcoma, and in chondroblastoma. A low macrophage content was observed in some osteosarcomas, in Ewing's sarcomas, chordomas, fibrous dysplasias, aggressive fibromatoses, and cartilage tumors. Osteoclast-like giant cells showed distinctly positive reactions with the monoclonal antibody against mature tissue macrophages. In fibrohistiocytic tumors (MFH, giant cell tumor, non-ossifying fibroma) only macrophages gave positive reactions with those antibodies, whereas the reaction of spindle-shaped tumor cells was always negative. These results strongly indicate that the macrophages found in bone tumors (including those of fibrohistiocytic type) result from reactive infiltration. The autochthonous tumor cells are most probably derived from local mesenchymal cells, and are thus cytogenetically unrelated to the infiltrating macrophages.

Spindle-cell carcinoma of the aerodigestive tract. An immunohistochemical analysis of 21 cases

Immunohistochemical analysis of 21 prototypic mucosal spindle-cell carcinomas of the aerodigestive tract was performed at the Armed Forces Institute of Pathology (AFIP) to establish the usefulness of selected immunohistochemical markers in distinguishing spindle-cell carcinoma from other mucosal spindle-cell neoplasms. Immunoreactive keratin could be demonstrated in only 13/21 (62%) of cases. Coexpression of keratin and vimentin was demonstrated in 10/17 (59%) of the tumors evaluated for both of these intermediate filaments. All spindle-cell carcinomas lacked S100 protein, which is an immunoreactivity we would expect to find in spindle-cell malignant melanoma, one of the principal considerations in a differential diagnosis. Both alpha-1-antitrypsin (AAT) and alpha-1-antichymotrypsin (ACT) were demonstrated in the tumor cells in all cases. However, albumin had a similar distribution in the tumors, which suggested that passive uptake was a serious confusing factor. The results of this study indicate that AAT and ACT are unreliable markers for distinguishing spindle-cell carcinomas from malignant fibrous histiocytomas.

[Purification of human alpha-1-protease inhibitor and production of antisera for its immunochemical determination]

Human homogeneous alpha-I-inhibitor of proteases was isolated and purified by means of chromatography on DEAE cellulose, hydroxyapatite and concanavalin Sepharose 4B. After immunization of rabbits specific monovalent antiserum towards the inhibitor was produced. The antiserum was used in diagnosis of hereditary deficiency of alpha-I-inhibitor of proteases and for estimation of its content in newborns.

A comparative marker study of large cell lymphoma, Hodgkin's disease, and true histiocytic lymphoma in paraffin-embedded tissue

A comparative study of large cell lymphoma (LCL) (ten B and ten T), Hodgkin's disease (15 cases), and true histiocytic lymphoma (two cases) was undertaken, using formalin-fixed paraffin-embedded tissue sections, a panel of eight antibodies, and one lectin to determine if any particular antibody or immunologic profile could reliably distinguish between these entities. The antibodies used were against Leu-M1, alpha-1-anti-chymotrypsin (alpha-ACT), alpha-anti-trypsin (alpha-AT), lysozyme, kappa, lambda, leukocyte common antigen (LCA), and S-100 protein. The lectin used was peanut agglutinin (PNA). Although Leu-M1 staining was positive in 11 of 15 cases (73%) of Hodgkin's disease, it was also positive in 4 of 10 cases (40%) of T-cell lymphoma, 2 of 10 cases (20%) of B-cell lymphoma, and 1 of 2 cases (50%) of true histiocytic lymphoma. Peanut-agglutinin staining results were similar to Leu-M1. The only staining profile that emerged was the presence of Leu-M1, PNA-, alpha-ACT, and alpha-AT staining in Reed-Sternberg (RS) cells in 11 of 15 cases of Hodgkin's disease. Leu-M1 and its staining pattern is characteristic, but not entirely specific for RS cells, and it was not positive in at least 25% of the cases of Hodgkin's disease in formalin-fixed, paraffin-embedded tissues. The limitations of this antibody and others should be recognized.

Immunohistochemistry of primary gastrointestinal lymphomas: a study of 76 cases

A retrospective study of 76 primary gastrointestinal lymphomas utilizing an avidin: biotinylated horseradish peroxidase complex (ABC) technique demonstrated 22 B-cell lymphomas, including two associated with alpha-heavy chain disease. Seven cases were classified as true histiocytic lymphomas based on a positive reaction for one or more of three histiocytic enzyme markers utilized, predominantly alpha-1-antitrypsin and alpha-1-antichymotrypsin. However, in 20 cases, an intense admixture of reactive histiocytes was noted and these cells stained preferentially for the enzyme, lysozyme. Twenty cases, which stained for both kappa and lambda light chains and positively or negatively for albumin, could not be classified and 27 cases failed to stain with any of the antisera utilized.

Investigation of the heterogeneity of rhesus monkey alpha 1-antitrypsin

Rhesus monkey alpha 1-antitrypsin (n = 144) was examined for heterogeneity by acid starch gel electrophoresis, isoelectric focusing in agarose and agarose gel electrophoresis. In contrast to other studies, no heterogeneity of Rhesus monkey alpha 1-antitrypsin could be documented using specific antisera. Rhesus monkey alpha 1-antitrypsin contained a reactive thiol. The pIs of the major isoforms of Rhesus monkey alpha 1-antitrypsin were 4.63, 4.69, 4.84 and 4.86 at 4 degrees C. No deficiency state of Rhesus monkey alpha 1-antitrypsin was detected. The six protease inhibitors in Rhesus monkey sera cross-reacted with antisera to the six human protease inhibitors.

Immunophenotype analysis of malignant histiocytosis of the intestine

Five cases of malignant histiocytosis of the intestine and one case of true histiocytic lymphoma were studied using immunohistological techniques. In paraffin sections tumour cells in all cases were shown to contain alpha-1-antitrypsin and to express the leucocyte common antigen. Four of the five cases of malignant histiocytosis of the intestine and the case of histiocytic lymphoma expressed the epithelial membrane antigen. Cryostat sections in four cases of malignant histiocytosis of the intestine showed that most tumour cells reacted with anti-T cell monoclonal antibodies. Only a minority expressed a typical monocyte macrophage phenotype.

[A radioimmunological technic for the assay of human albumin at low concentrations]

In the present study a radioimmunoassay procedure for the measurement of human albumin is described which presents some modifications with respect to an earlier method used for the measurement of albumin in peritoneal dialyzate. The results of electrolytic labelling of albumin, the kinetic curve on the antigen-antibody reaction and the cross reactivity of the anti-albumin antiserum with alpha 1 antitrypsin are reported. The typical standard curve obtained with the proposed method allows the estimation of human albumin in biological fluids where the protein is present at very low quantities, not measurable by traditional complexometric and colorimetric techniques.

Sequential changes in the antimicrobial protein concentrations in human milk during lactation and its relevance to banked human milk

The concentrations of eight antimicrobial proteins, 11S IgA, IgG, IgM, alpha 1-antitrypsin, lactoferrin, lysozyme, C3, and C4 were measured in sequential samples of colostrum, transitional and mature milk from 47 women in Merseyside, England by single radial immunodiffusion. Concentrations were highest in colostrum and then declined until relatively stable concentrations were reached in mature milk. A wide variation in protein concentrations was noted in the milk from different individuals at any given postpartum time interval and this was particularly so during the first 4 days postpartum. The decline in individual antimicrobial protein concentrations seen in samples of transitional milk appeared to take a variable period of time to stabilize to mature milk concentrations of each protein. These variations may reflect different rates of transport or secretion of these proteins from the alveolar epithelial cells into the alveolar lumen. Because of the wide variations in antimicrobial proteins observed in milk samples from the individuals in this study at similar postpartum time intervals, it is suggested that banked milk should be monitored not only for bacterial contamination, but also for levels of antimicrobial proteins, if it is considered that a major advantage of unprocessed human milk is the immune protection which it confers.

The nature of cytoplasmic inclusions in cerebellar haemangioblastomas

Intracytoplasmic hyaline globules present in stromal cells in eight of a series of ten cerebellar haemangioblastomas have been shown to contain the glycoprotein alpha-1-antitrypsin.

Expression of human alpha 1-antitrypsin cDNA in the yeast Saccharomyces cerevisiae

Nucleotide sequences coding either for the precursor or the mature form of human alpha 1-antitrypsin have been placed under the control of the yeast ARG3 expression signals. Recombinant plasmids pRIT10782 and pRIT10787 express the precursor or the mature alpha 1-antitrypsin species, respectively, in two different yeast strains, with yields ranging between 0.3 and 1% of total soluble proteins. The alpha 1-antitrypsin synthesized in yeasts was specifically recognized by polyclonal and monoclonal antibodies raised against human alpha 1-antitrypsin. In addition, it was shown to be biologically active in its mature form only, with optimal activity in a peptidase-deficient yeast strain.

PI*LBEI and PI*JHOU: two new alpha-1-antitrypsin alleles

Two new variants of alpha-1-antitrypsin were found in a Chinese population by isoelectric focusing in polyacrylamide gel. They have been named Lbeijing (PI*LBEI) and Jhouyao (PI*JHOU) respectively. With the samples reduced and alkylated, both the variants were anodal to M1 and cathodal to L. Omitting the alkylation step, however, the relative mobilities of L and Jhouyao were altered. Under this condition, a characteristic of Jhouyao was revealed by isoelectric focusing in immobilized pH gradient 4.4-4.9, i.e., while its band 6 became anodal to L, band 4 was still cathodal to L.

[Plasmapheresis in extra-intestinal manifestations of Crohn's disease]

An assessment was undertaken of the value of plasmapheresis in patients with circulating immune complexes and/or extraintestinal manifestations of Crohn's disease (arthritis, iridocyclitis, erythema nodosum, pyoderma gangrenosum, stomatitis, fever). In 17 patients aged 20 to 50 years (median 34 years) 46 plasmaphereses were performed using a continuous flow-cell separator. Before and after plasmaphereses the concentrations of circulating immune complexes, of complement C4, of the immunoglobulins IgG and IgM and of the proteins alpha-1-antitrypsin, CRP, prealbumin and beta-lipoprotein were determined. 71% of patients given plasmaphereses showed clinical remission of the extraintestinal manifestations and 85% demonstrated a reduction of circulating immune complexes. Clinical follow-up of the patients was documented by the Crohn's Disease Activity Index (CDAI), which was reduced by plasmaphereses to a highly significant degree (p less than 0.005). For patients displaying an acute phase of Crohn's disease with extraintestinal manifestations and/or circulating immune complexes plasmapheresis represents an effective mode of therapy, which, moreover, lacks serious side effects.

The effect of purified alpha 1 antitrypsin on PWM driven IgG synthesis

As part of a study investigating the mechanisms for the association of alpha 1 antitrypsin (alpha 1 AT) deficiency with immune disorders, the effect of purified alpha 1 AT on PWM driven IgG synthesis of peripheral blood lymphocytes was investigated. This demonstrated that alpha 1 AT in physiological doses enhanced IgG synthesis in stimulated but not resting cells. This effect is probably due to the known inhibition by alpha 1 AT of macrophage function. Increasing number of macrophages are known to inhibit IgG synthesis in the PWM system suggesting that this apparently paradoxical enhancement by alpha 1 AT is probably due to inhibition of these cells.

Crossed immunoelectrophoresis of rat serum

A crossed immunoelectrophoresis (X-IEP) reference profile of normal (Sprague-Dawley) rat serum antigens was developed. Twenty-three antigens were detected; 13 were identified. These included inter-alpha-trypsin inhibitor, alpha 1-antichymotrypsin, and fibronectin, which had not previously been identified in rat serum. Many of the antigens were similar electrophoretically to their analogs in human and mouse serum, but some were substantially different. Inter-alpha-trypsin inhibitor, fibronectin, and C3 globulin were more anodic, while transferrin was more cathodic. Rat haptoglobin's mobility was between those of human and mouse haptoglobins. As in the mouse, but more so, alpha-macroglobulin in the rat had alpha 1 mobility rather than alpha 2 seen for this protein in human serum. Only rat alpha 1-antichymotrypsin exhibited a double peak. There were variations in haptoglobin and alpha 1-lipoprotein mobilities among different strains of rat. This establishment of a standard X-IEP map of rat serum will simultaneously permit multiple quantitative and qualitative analyses of rat serum antigens for various experimental and clinical purposes.