Keiji Hagiwara

Jacalin, a jackfruit lectin, precipitates IgA1 but not IgA2 subclass on gel diffusion reaction

Precipitation reaction in agarose gel between jacalin, a lectin from jackfruit seeds, and purified immunoglobulins of various classes and their components was studied. Single precipitation arcs were observed with monomeric and dimeric IgA1 subclass as well as secretory IgA1, but not with IgA2 of both allotypes, IgG, IgM, IgD, IgE, free secretory component or with the J chain. Thus, jacalin can be used for differentiating IgA1 from IgA2 subclass by a simple agarose gel diffusion.

An epidemic of a pertussis-like illness caused by Chlamydia pneumoniae.

BACKGROUND Between June and July, 1994, we encountered an epidemic of a pertussis-like illness in adolescents in a junior high school located in a rural area of Japan. The purposes of this study were to record the clinical manifestations and to identify an etiology. PATIENTS AND METHODS We interviewed patients and parents and we performed physical examinations on patients with cough during the epidemic. The chest radiographs were also reviewed by us. To identify an etiology we performed culture and serologic studies for a variety of bacteria, Mycoplasma, chlamydiae and viruses. Polymerase chain reaction (PCR) for Chlamydia pneumoniae was carried out on throat swab specimens. RESULTS Of a total of 230 students 136 (59%) had severe cough illnesses. One developed pneumonia, 9 had bronchitis and the remaining 126 (93%) presented upper respiratory tract infections (URI). The mean duration of cough in cases with URI was 17.4 days and that in cases with bronchitis and pneumonia was 30.4 days. Serology and/or cultures for Bordetella pertussis, Bordetella parapertussis, Mycoplasma pneumoniae, Chlamydia trachomatis, Chlamydia psittaci or viruses were negative. Detection of C. pneumoniae infection was carried out in 46 patients with pneumonia, bronchitis or URI by serology and PCR. The patient with pneumonia, 7 of 7 patients with bronchitis and 32 (84%) of 38 patients with URI were documented to be infected by C. pneumoniae either by serology, PCR or both tests. CONCLUSION An epidemic of a pertussis-like illness in a junior high school population was caused by C. pneumoniae.

Isolation and characterization of immunoglobulin of hagfish, Eptatretus burgeri, a primitive vertebrate

The immunoglobulin of the hagfish, Eptatretus burgeri, one of the most primitive vertebrates extant, was isolated from the serum of non-immune normal adult hagfish in a pure form. Analysis of the immunoglobulin by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) under reducing condition indicated that the immunoglobulin was composed of heavy (H) and light (L) chains. The mol. wt of the H-chain was 68,000, slightly smaller than that of the human mu-chain. The L-chain of the immunoglobulin appeared as 2 bands on SDS-PAGE, with mol. wts of 25,000 and 22,000. These findings were confirmed by gel filtration of reduced-alkylated immunoglobulin in 5 M guanidine-HCl. The H:L molar ratio of the immunoglobulin was roughly 1:1. Gel filtration of the immunoglobulin in non-dissociating buffer indicated that the mol. wt of the intact immunoglobulin was 150,000-160,000. Thus, the subunit chain composition of the immunoglobulin was assumed to be H2L2, identical with the fundamental structure of immunoglobulins. The instability of the hagfish immunoglobulin was ascertained by the fact that it dissociated into heterogeneous mol. wt components ranging from approx. 90,000 to 160,000 upon SDS-PAGE under non-reducing conditions. However, almost no free or monomeric H- or L-chains were dissociated from the immunoglobulin by this procedure and also by gel filtration in 5 M guanidine-HCl. Theses results indicated that the hagfish immunoglobulin is unusually labile in its tertiary structure but has disulfide binding between at least more than 2 subunit chains.

Studies on immunoglobulin and immunoglobulin-forming cells in Heterodontusjaponicus, a cartilaginous fish

Immunoglobulin (Ig), lymphoid tissues and Ig-forming cells of the Japanese bullhead shark, Heterodontus japonicus were analyzed biochemically, histologically and immunocytochemically. The serum of Heterodontus contains two Igs with different molecular weights one with 900 K and the other with 180 K daltons. Heavy chains of the two Igs showed an identical molecular weight of 68 K and the same antigenicity, indicating that the two Igs belong to the same class with different molecular structure. Light chains of Heterodontus Igs showed two distinct bands using sodium dodecyl sulfate-polyacrylamide gel electrophoresis, one with the molecular weight of 25 K and the other with 22 K daltons. The latter finding indicates the possible existence of two light chain types in the Heterodontus Igs. White pulp of the spleen appeared as a well-developed lymphoid tissue accompanied large number of Ig-forming cells especially around blood vessels. Massive lymphocytic aggregations were found in the central area of the intestinal valves and certain lymphoid cells were demonstrated to be Ig-forming cells. Ig-forming cells were also observed in the epigonal organ, although the frequency was much less than in the former two tissues. Although the spleen is the major Ig-forming organ in Heterodontus japonicus, the valvular intestine and the epigonal organ also appear to share the function of Ig production.

Double Precipitin Arcs of Iga Myeloma Sera On Immunoelectrophoresis - Origin and Suggestion of Iga2m(2) Allotype

The serum from two patients with IgA myeloma displayed double precipitin arcs upon immunoelectrophoresis with class-specific (light chain absorbed) anti-IgA antisera obtained by immunization with monoclonal IgA1, but not IgA2 proteins. Both sera contained large amounts of monoclonal IgA2m(2) together with some polyclonal IgA1. No incomplete IgA molecules were found. The double precipitin arcs resulted from the reaction of large amounts of monoclonal IgA2m(2) with class-specific antibodies, and of small amounts of polyclonal IgA1 with subclass-specific anti-IgA1 antibodies of the same antiserum. Such double arcs, if not due to incomplete IgA molecules, could indicate the IgA2m(2) nature of the monoclonal IgA in these rare sera.

Serum proteins in vesicular fluid of hydatidiform moles: a lack of selectivity of molar trophoblast in the transfer of maternal serum proteins

Complete hydatidiform moles, an abnormal pregnancy of androgenetic origin consisting of swollen villi without an embryo, were studied to determine the protein constitution of vesicular fluids in the swollen villi and the ability of the molar tissue to synthesize protein. All 16 serum proteins tested were identified in the molar fluid. A reverse correlation was obtained when the logarithms of the molar fluid versus maternal serum concentration ratios of different proteins were plotted against the logarithms of their molecular weights. Logarithmic regression analysis showed a linear regression with a high coefficient (gamma = 0.9626). Phenotyping of haptoglobin in the molar fluid and in the parental sera indicated a definite contribution of maternal proteins to the molar fluid. The molar tissues synthesized no serum proteins but produced human chorionic gonadotrophin beta-subunit (hCG-beta) and pregnancy-specific beta 1-glycoprotein (SP1) when examined in tissue cultures metabolically labelled with [35S]methionine. These findings indicate that a variety of maternal serum protein components is transferred to the molar fluid without being selected by the molar trophoblastic cells.

Pfeiffer syndrome or Saethre-Chotzen syndrome?

SummaryA 4.5-year-old girl with clinical features of both the Pfeiffer and Saethre-Chotzen syndromes is described. She was severely mentally retarded, had brachycephaly, craniosynostosis, prominent forehead, proptosis, midface hypoplasia, low-set and small ears, a high arched palate, broad thumbs and great toes, short phalanges of the third toes, and soft tissue syndactyly between the second and third fingers and between the second and third toes. In addition, she showed several clinical features characteristic of the Saethre-Chotzen syndrome, including a low-set frontal hairline, mild ptosis, a deviated nasal septum, and a cleft soft palate. Thus, the disease in the patient may represent a transitional form between the Pfeiffer and Saethre-Chotzen syndromes. Her father and paternal grandmother each had a few clinical features of the disease, indicating that the disease was inherited in an autosomal dominant fashion.