Sex difference in delayed footpad reaction to syngeneic testicular cells in C3H/He mice.

Delayed footpad reaction against syngeneic testicular cells was compared between males and virgin females of C3H/He mice. Mice were immunized subcutaneously with 1 x 10(7) of syngeneic testicular cells and the reaction was elicited with 1 x 10(6) of syngeneic testicular cells 6 days after the immunization. When mice were pretreated with 0, 25 or 50 mg/kg of cyclophosphamide (CY), the delayed footpad reaction was detected in female mice, but not in male mice under the same conditions. This sex difference in the reaction to testicular cells was not attributed to the recognition of H-Y antigen by female mice. A sex difference in the reaction to sheep red blood cells (SRBC) was not observed. The sex difference in the reaction to testicular cells was attributed to testicular cells other than sperm because a sex difference was not detected against sperm. The implications of these findings are discussed in relation to the tolerance phenomena of autologous testicular cells.     

A histological evaluation for guided bone regeneration induced by a collagenous membrane

This study was designed to evaluate the histological changes during ossification and cellular events including osteogenic differentiation responding to collagenous bioresorbable membranes utilized for GBR. Standardized artificial bony defects were prepared at rat maxillae, and covered with a collagenous bioresorbable membrane. These animals were sacrificed at 1, 2, 3 and 4 weeks after the GBR-operation. The paraffin sections were subject to tartrate resistant acid phosphatase (TRAP) enzyme histochemistry and immunohistochemistry for alkaline phosphatase (ALP), osteopontin (OP) and osteocalcin (OC). In the first week of the experimental group, woven bone with ALP-positive osteoblasts occupied the lower half of the cavity. The collagenous membrane included numerous ALP-negative cells and OP-immunoreactive extracellular matrices. At 2 weeks, the ALP-, OP- and OC-immunoreactivity came to be recognizable in the region of collagenous membrane. Since ALP-negative soft tissue separated the collagenous membrane and the new bone originating from the cavity bottom, the collagenous membrane appeared to induce osteogenesis in situ. At 3 weeks, numerous collagen fibers of the membrane were embedded in the adjacent bone matrix. At 4 weeks, the membrane-associated and the cavity-derived bones had completely integrated, showing the same height of the periosteal ridge as the surrounding alveolar bones. The collagen fibers of a GBR-membrane appear to participate in osteogenic differentiation.     

Anionic copolymerization of β-lactones in correlation with the mode of fission. studies on the syntheses of aliphatic polyesters. XI

The copolymerization behavior of β-propiolactone (PL) and α.α-bischloromethyl β-propiolactone (α-BCPL) is correlated with the mode of fission. With sodium acetate as catalyst, the formation of β-acetoxy propionic acid at the initiation reaction was observed and α-BCPL was more than five times as reactive as PL in copolymerization. Thus propagation by carboxylate anion through alkyl-oxygen fission was presumed in the case of pyridine and the acetate of Na, Li, and Mg as catalyst. On the other hand, the formation of ethyl β-hydroxy propionate and the decreased reactivity of α-BCPL in copolymerization was observed with magnesium and aluminum ethoxide as catalyst. In the case of the ethoxide of Na, Li, and Al, and Et₂Mg or Et₃Al as catalyst, propagation by alkoxide anions through acyl-oxygen fission of the coordinated lactones was presumed.     

Polymerization of methylmethacrylate initiated by hydrogenation catalysts

RANEY metals (Ni, Fe, Co), URUSHIBARA metals (Ni, Co) and ULIMANN cu initiate the polymerization of methylmethacrylate. Diamines, diols or organic halides enhance their reactivity. In the presence of CCl₄, the polymerization rate (R_p) is proportional to the square root of the amount of both metals and CCl₄, and to the first power of the monomer concentration, but R_p becomes constant and independent of the concentration of CCl₄ when there is a great excess of CCl₄. We concluded that this polymerization follows the free radical mechanism and the participation of a zero-valent metal atom in the initiation reaction including complex formation between metal and CCL₄ is suggested.     

Peritoneal macrophages which phagocytose autologous polymorphonuclear leucocytes in guinea-pigs. I: induction by irritants and microorgansisms and inhibition by colchicine.

In order to examine macrophages phagocytosing polymorphonuclear leucocytes (PMNs) in detail, we established a new method, whereby a large number of PMN-phagocytosing macrophages (PPMs) were easily induced. PPMs were harvested from the peritoneal cavity after thioglycollate medium, oyster glycogen, phytohaemagglutinin (PHA), L. monocytogenes or S. aureus had been injected i.p. into guinea-pigs. When thioglycollate medium or oyster glycogen was injected i.p., the number of the PPM reached a peak 48 h later and PPM formed 20% or more of total macrophages. When L. monocytogenes or S. aureus was injected i.p., the ratio of PPM to total macrophages reached a peak 24 h later. Morphologically, some of the phagocytosed PMNs were not degenerated and the others were at various stages of degeneration. The ability of macrophages to phagocytose PMNs was suppressed when 10(-6) mol/kg of colchicine was administered i.p. 1 day after the injection of the irritants.     

Interleukin-3-dependent potentiation of IgE responsiveness in mouse basophils

Basophils produce interleukins (IL)-4 in response to various stimuli and may contribute to type 2 immune responses to various infections and allergens. We found that resting basophils freshly isolated from mice produce IL-4 in response to IL-3 but not to high-affinity Fc receptor (FcεRI) cross-linking (CL), yet both required the immunoreceptor tyrosine-based activation motif (ITAM) containing adaptor Fc receptor γ-chain (FcRγ), while basophils activated in vitro by IL-3 become responsive to FcεRI CL. Acquisition of responsiveness to FcεRI CL occurred upon infection with Trichinella spiralis or administration of superantigen. Because cultured basophils return to a quiescent state upon starvation with IL-3 with surface FcεRI levels unchanged, this acquisition is reversible and probably reflects intracellular events requiring protein synthesis. Interestingly, similar activation-associated acquisition was observed for responsiveness to other stimuli, including CD200R3 CL, which is known to signal via DAP-12, and the allergen protease papain. This acquisition of responsiveness to FcεRI CL was inhibited by Jak inhibitor. Thus, the IL-3 signal bifurcates downstream of Jak, into two distinct pathway, one leading to IL-4 production and the other to render basophils competent to respond to stimuli dependent on ITAM-containing adaptors DAP12 and FcRγ for IL-4 production.     

A new mutation in the POU3F4 gene in a japanese family with x-linked mixed deafness (DFN3)

Objective: The molecular defect in patients with X-linked mixed deafness showing a perilymphatic gusher at stapedectomy (DFN3) has been attributed to mutations in the POU3F4 gene. This study aimed to clarify an allelic variant of this gene. Study Design: This was a genetic study of a single Japanese family with DFN3. Methods: Products of a polymerase chain reaction (PCR) were subjected to single-strand conformation polymorphism (SSCP) analysis. Direct sequencing of PCR products from patients and carriers showing SSCP variants was performed using the fluorescent dideoxy termination method and a sequencer. Results: Sequencing of the PCR product revealed a 6-base deletion (TTCAAA) at nucleotides 601 to 606, resulting in a two-amino-acid deletion in the POU3F4 protein, (phenylalanine and lysine at amino acid residues 201 and 202). The deletion was adjacent to the site of a nonsense mutation previously described. Conclusion: Microdeletions at a previously undescribed location account for some clinically important POU3F4 mutations. Laryngoscope, 108:1544–1547, 1998     

Extracellular PKCδ signals to epidermal growth factor receptor for tumor proliferation in liver cancer cells

Protein kinase C delta (PKCδ) is a multifunctional PKC family member and has been implicated in many types of cancers, including liver cancer. Recently, we have reported that PKCδ is secreted from liver cancer cells, and involved in cell proliferation and tumor growth. However, it remains unclear whether the extracellular PKCδ directly regulates cell surface growth factor receptors. Here, we identify epidermal growth factor receptor (EGFR) as a novel interacting protein of the cell surface PKCδ in liver cancer cells. Imaging studies showed that secreted PKCδ interacted with EGFR‐expressing cells in both autocrine and paracrine manners. Biochemical analysis revealed that PKCδ bound to the extracellular domain of EGFR. We further found that a part of the amino acid sequence on the C‐terminal region of PKCδ was similar to the putative EGFR binding site of EGF. In this regard, the point mutant of PKCδ in the binding site lacked the ability to bind to the extracellular domain of EGFR. Upon an extracellular PKCδ‐EGFR association, ERK1/2 activation, downstream of EGFR signaling, was apparently induced in liver cancer cells. This study indicates that extracellular PKCδ behaves as a growth factor and provides a molecular basis for extracellular PKCδ‐targeting therapy for liver cancer.