Effects of various compounds on histidine decarboxylase activity: Active site mapping

The effect of about one hundred compounds on the activity of histidine decarboxylase partially purified from whole bodies of fetal rats was determined. Most of them at their 10 mM concentration had little effect on the enzyme activity; but 12 compounds inhibited the enzyme to a greater extent than 30%. Among these, except for -methylhistidine that has been known to be a strong and specific inhibitor, DOPA, homocysteine, cysteine, methionine and urocanic acid were the best inhibitors; -phenyllactic acid, phenylpyruvic acid and carnosine were less strong inhibitors; valine, oxaloacetic acid andN -methylimidazole acetic acid were weak inhibitors. Histamine had no inhibitory action. Thus, the substrate binding site of histidine decarboxylase is very rigid and specific forl-histidine.     

Trichinella spiralis-specific monoclonal antibodies and affinity-purified antigen-based diagnosis

Hybridomas secreting monoclonal antibodies (MAbs) to Trichinella spiralis were produced. Myeloma cells were fused with splenocytes of a mouse immunized with excretory-secretory (E-S) antigen of infective larvae. A large percentage of growing hybrids secreted antibodies cross-reactive to many of 23 heterologous parasites tested. Only 6 monoclones (designated 3F2, 5D1, 10F6, 11E4, 13D6 and 14D11) secreted MAbs specific to the E-S antigen and/or a crude extract (CE) of T. spiralis infective larvae. The 6 monoclones secreted IgM, IgG3, IgM, IgG3, IgG3 and IgG3, respectively. Clone 5D1 was selected to mass produce MAbs which were then coupled to CNBr-activated Sepharose CL-4B to prepare an affinity-purified antigen. Dot-blot ELISA with either purified antigen or CE was evaluated. There were 17 patients with acute trichinellosis and 76 individuals convalescing from T. spiralis infection (group 1). Controls were 170 patients with parasitic infections other than trichinellosis (group 2) and 35 healthy parasite-free controls (group 3). CE-ELISA was positive in all group 1 patients. However, sera from many group 2 patients also were reactive (opisthorchiasis-44.2%, schistosomiasis-44%, gnathostomiasis-30%, paragonimiasis-28.6%, taeniasis-27.3%, strongyloidiasis-23.1% and hookworm infections-20%). Affinity-purified antigen was 100% specific, all sera from group 2 and group 3 individuals tested negative. Although 74 of 76 patients (97.4%) with convalescing trichinellosis tested positive, sera from only 3 of 17 patients (17.6%) with acute T. spiralis were reactive. Thus, CE antigen is appropriate when sensitivity is needed, while purified antigen should be used when specificity is required. Dot-blot ELISA is easier to perform, more rapid and less expensive than indirect ELISA. Many samples can be assayed simultaneously, special equipment is not required, and results can be preserved for retrospective analysis. Dot-blot ELISA is therefore the method of choice for the rapid diagnosis of trichinellosis, particularly when more complex laboratory tests are unavailable.     

Lymphocyte chemotaxis in inflammation. VII. Isolation and purification of chemotactic factors for T lymphocytes from PPD-induced delayed hypersensitivity skin reaction site in the guinea-pig

Four types of lymphocyte chemotactic factor (LCF-a, -b, -c and -d) could be isolated from extract of 24-hr-old delayed-type hypersensitivity (DTH) skin reaction sites induced with purified protein derivative (PPD) in guinea-pigs by gel filtration on Sephadex G-100 followed by chromatography with DEAE-Sephadex. Partially purified LCF-b was thought to be a heat-stable protein with a molecular weight (mol. wt.) of about 14,000. LCF-c separated from LCF-d by chromatography with DEAE-Sephadex was highly purified by chromatography with CM-Sephadex, immunoadsorbent chromatography coupled with anti-IgG antibody, and chromatofocusing in that order. It was considered to be a heat-labile protein with a mol. wt. of about 160,000 and with pI of 8.1 +/- 0.2. LCF-d first separated from LCF-c was also highly purified by chromatography with CM-Sephadex followed by preparative isotachophoresis. The factor was considered to be a heat-labile protein with a mol. wt. of approximately 300,000 and with pI of 6.2 +/- 0.2. These factors were similarly active for non-adherent cells (mostly T cells) but not for cells (mostly B cells) adherent to anti-IgG antibody-coated petri-dishes. Since LCF-a was active for B cells as described earlier, it is thus suggested that LCF-b, LCF-c and LCF-d may be important for T cell migration in the DTH site to PPD.     

Polycondensation-addition. V. Polyurethan-ureas with asymmetric carbon atoms in the main chain from L- and DL-2-alkyl-2-isocyanatoethyl chloroformates and diamines1

L - and DL-2-Alkyl-2-isocyanatoethyl chloroformates were synthesized by the phosgenation of the corresponding amino alcohols. These optically active or racemic difunctional compounds were submitted to polycondensation-addition with various diamines to form high molecular weight polyurethan-ureas having asymmetric carbon atoms along the main chain. The optically active polyurethan-ureas obtained had slightly higher melting points than the corresponding racemic polymers.     

Parosteal fasciitis of the clavicle

A rare case of parosteal fasciitis arising from the periosteum of the left clavicle in a 27-year-old woman is reported. Magnetic resonance imaging demonstrated the lesion surrounding the periosteum of the clavicle. The lesion was iso-intense with muscle on T(1)-weighted images and hyperintense on T(2)-weighted images. At surgery, the lesion was discovered to be densely adherent with the periosteum, and excised along with the periosteum. Histopathological examination revealed the proliferation of myofibroblasts in a vague storiform or short fascicular pattern. A large amount of extravasated erythrocytes, and a few lymphocytes were present in the matrix. There were some foci of abundant myxoid materials. Immunohistochemical study showed the cells to be positive for vimentin, alpha-smooth muscle actin and HHF35, but negative for desmin. There was no local recurrence at a 6 months postoperative follow up.     

Malignant meningioma with cartilage and giant cells.

An autopsy case of recurrent and malignant meningioma is reported. This case was originally typical benign transitional meningioma of the falx, however, the histology of the tumor changed to show malignant features during successive recurrences. At autopsy, the tumor revealed findings consistent with malignant meningioma. One of the most interesting features was the presence of cartilage and giant cells in some parts. Immunohistochemistry showed positive immunoreactivity for S-100 protein in some cartilage and giant cells and for cytokeratin in some giant cells. Multidifferential potential of the meningioma cells was suggested in this case.     

Disseminated Atypical Mycobacteriosis

Two cases of disseminated infection caused by Mycobacterium intracellulare were reported and discussed. In the first case, the patient was a fifty-seven-year-old male who complained of general fatigue, weight loss, and fever. Biopsy of the right inguinal lymph nodes and the liver revealed infiltration by histiocytes engulfing many acid-fast bacilli. At autopsy an egg-sized abscess was found is the region of the right Iliac lymph nodes. Histological examination showed histiocytic infiltration in the abscess wall, neighboring lymph nodes, liver, and spleen. In the second case, the patient was a four-year-old boy, who had persistent fever and splenomegaly. Splenectomy was performed and histological examination of the spleen revealed multiple nodular infiltration by swollen histiocytes with many acid-fast bacilli in their cytoplasm. The bone marrow aspirates and liver tissue obtained in the necropsy also showed many histiocytes containing many acid-fast bacilli. The authors emphasized the importance of paying special attention to atypical mycobacteriosis in feverish patients having lesions with a proliferation of histiocytes.     

HLA antigens in Behçet''s disease with refractory ocular attacks

HLA class I, II, and III antigens were studied in Japanese patients with Beh?et's disease with refractory ocular attacks. In addition to the increased frequency of B51, DQw3, especially TA10-negative DQw3, was increased and DQw1 was decreased significantly in this subgroup of Beh?et's disease. As for complement markers, C4A Q0 was increased. A rare variant of BF S07 was first observed in Japanese. Although the mechanism for the DQw3 association is obscure, a possible hypothesis is that an immune-response or immune-suppression gene linked to the DQ antigens modulates the disease severity and the efficacy of treatments.     

Lactic dehydrogenase virus infection reduces the expulsion of the nematode <Emphasis Type="Italic">Nippostrongylus brasiliensis</Emphasis>

The interleukin (IL)-13-mediated goblet cell response is the major host effector system involved in the expulsion of Nippostrongylus brasiliensis. Lactic dehydrogenase virus (LDV) induced higher levels of N. brasiliensis egg production compared with controls, but the effect of LDV infection on worm expulsion of, and goblet cell and IL-13 responses to, N. brasiliensis have not been studied. In this study, the effects of LDV infection on these host responses against N. brasiliensis were examined. Mice with chronic LDV infection showed significantly lower worm expulsion rates than non-LDV-infected mice after N. brasiliensis infection, and there were no significant differences in the ratio of female versus male adult worms between control and LDV-infected mice. The number of goblet cells in LDV-infected mice was significantly lower than that in controls. In addition, the levels of IL-13 gene expression in lymph nodes were significantly lower in LDV-infected mice compared with controls. These results suggest that LDV infection reduces the protective immune responses against N. brasiliensis infection by the suppression of IL-13 production.