Inhibitory effect of estradiol-17 beta and progesterone on bactericidal activity in uteri of rabbits infected with Escherichia coli.

The influence of ovarian hormones at different estrous stages on the bactericidal activity of the uterus in rabbits was investigated. When Escherichia coli cells were inoculated in ligated uteri, the survival period of the bacteria in the uterus at the luteal phase was clearly longer than that at the follicular phase. At the luteal phase, high levels of plasma estradiol-17 beta and progesterone were detected. A luteolytic treatment with prostaglandin F2 alpha and human chorionic gonadotropin at the luteal phase lowered plasma progesterone levels and prompted bacterial clearance from the uterus. In ovariectomized rabbits, E. coli from the uterine exudates was not detected 6 days after the inoculation in both the nontreated and estradiol-17 beta-treated animals. In the progesterone-treated rabbits, the survival period of E. coli was longer than that in the nontreated and estradiol-17 beta-treated animals. When estradiol-17 beta and progesterone at the ratio of 1:100 were administered concurrently, E. coli survived for the longest period in the rabbits treated with various doses of different hormones. Formalin-killed E. coli cells were inoculated into the uterine lumen, and 4 h later the proportion of heterophils phagocytizing the bacteria dropped in the progesterone-treated rabbits and in the estradiol-17 beta- and progesterone-treated rabbits, but there was no significant difference in heterophil numbers among the rabbits treated with different hormones. The present results suggest that progesterone inhibits the bactericidal activity of the uterus and that estrogen concurrently secreted at the luteal phase promotes the inhibitory action of progesterone, although estrogen alone hardly affects the uterine defense. In addition, the lowering of the bactericidal activity of the uterus at the luteal phase may be attributable to lower activity of phagocytosis by heterophils infiltrated into the uterine lumen.     

Neural fibrolipoma of the superficial peroneal nerve in the ankle: a case report with immunohistochemical analysis

This report presents a case of neural fibrolipoma arising from the superficial peroneal nerve in the ankle. A 28-year-old woman was referred with a soft tissue mass in the anterior aspect of the right ankle, which had been gradually enlarging for the past 10 years. Magnetic resonance imaging showed a mass lesion, measuring approximately 8 x 3 x 2 cm, with high to partially low signal intensity on both T1- and T2-weighted images. A band of low signal intensity within the lesion, which is indicative of coexistence with the tumor and the superficial peroneal nerve, could be detected on both T1- and T2-weighted images. The patient underwent an excisional biopsy. The specimen microscopically consisted of nerve bundles and fibro-fatty proliferation with abundant collagen fibers. Immunoreactivity for CD34 antigen antibody was detected in fibrous spindle cells. This is the first report to present an immunohistochemical profile of neural fibrolipoma. Neural fibrolipoma should be considered as a differential diagnosis when a lipomatous lesion is encountered in the foot or ankle as well as in the upper extremities.     

Development of a particle agglutination assay system for detecting Japanese encephalitis virus-specific human IgM,using hydroxyapatite-coated nylon beads

Japanese encephalitis virus-specific IgM is a reliable indicator for serodiagnosis of Japanese encephalitis. A particle agglutination (PA) assay system was developed to detect anti-Japanese encephalitis virus IgM in human serum samples. The newly developed PA assay consisted of hydroxyapatite-coated nylon beads and V-bottom 96-well microplates. Hydroxyapatite-coated nylon beads were coated with Japanese encephalitis virus antigens. Japanese encephalitis virus antigen-coated, hydroxyapatite-coated nylon beads agglutinated in the IgM-captured wells when anti-Japanese encephalitis virus IgM-positive serum samples were used. A button pattern was formed at the bottom of the wells when anti-Japanese encephalitis virus IgM-negative serum samples were used. Thirty anti-Japanese encephalitis virus IgM-positive serum samples from Japanese encephalitis-confirmed cases were tested by the PA assay. All these serum samples were determined to be Japanese encephalitis virus IgM-positive. IgM titers determined by the PA assay corresponded to those determined by enzyme-linked immunosorbent assay. The titers were consistent in two independent PA assays. These results indicate that the newly developed PA assay is a reliable method for detecting anti-Japanese encephalitis virus IgM in human serum samples and that this assay will be a suitable diagnostic system especially in rural areas of Asia.     

Strain combination-dependent genesis of necrotizing arteritis in anti-ICAM-1 antibody-perfused renal allografts in the rat

Rat kidneys were perfused with anti-intercellular adhesion molecule-1 (anti-ICAM-1) monoclonal antibody prior to allo-transplantation. In the two strain combinations examined, LEJ-to-WKAH transplants resulted in accelerated graft loss, and no prolongation of graft survival. The accelerated graft logs was the resut of frequent occurrence of necrotizing arterttis wlthln the grafts. In contrast, TO-to-WKAH transplants resulted in no change In graft survival and no arteritis. Necratidng vasculitis in the LEJ-to-WKAH grafts was characterlzed by flbrinoid necrosis, collection of cellular infiltrates and serum macromolecular protein entrapment. The F(ab')² form of anti-ICAM-1 antlbody partially preserved the antibody's capacity to accelerate graft loss. Therefore, although endothelial injury by Fc-mediated cytotoxicity may be involved in vascular damage, other mechanisms also come into play. The amount and distribution pattern of ICAM-1 antigen were identical in both TO and LEJ strains. Intravenous anti-CAM-1 antibody administration combined with lipopolysaccharide, Poly(1)-Poly(C), warm ischemia to the kidney, or subcutaneous immunization with allogeneic spleen cells, but without renal transplantation, did not generate necrotizing vasculitis or proteinuria. These observations plus our previous data on the rat liver transplantation model clearly show that graft perfusion with anti-ICAM-1 monoclonal antibody invokes extensive vascular damage within allografts by Fc-mediated and Fc-independent mechanisms, depending on the donor-to-host combination.     

Suitable image parameters and analytical method for quantitatively measuring cerebral blood flow volume with phase-contrast magnetic resonance imaging

The aim of this study was to determine suitable image parameters and an analytical method for phase-contrast magnetic resonance imaging (PC-MRI) as a means of measuring cerebral blood flow volume. This was done by constructing an experimental model and applying the results to a clinical application. The experimental model was constructed from the aorta of a bull and circulating isotonic saline. The image parameters of PC-MRI (repetition time, flip angle, matrix, velocity rate encoding, and the use of square pixels) were studied with percent flow volume (the ratio of actual flow volume to measured flow volume). The most suitable image parameters for accurate blood flow measurement were as follows: repetition time, 50 msec; flip angle, 20 degrees; and a 512 x 256 matrix without square pixels. Furthermore, velocity rate encoding should be set ranging from the maximum flow velocity in the vessel to five times this value. The correction in measuring blood flow was done with the intensity of the region of interest established in the background. With these parameters for PC-MRI, percent flow volume was greater than 90%. Using the image parameters for PC-MRI and the analytical method described above, we evaluated cerebral blood flow volume in 12 patients with occlusive disease of the major cervical arteries. The results were compared with conventional xenon computed tomography. The values found with both methods showed good correlation. Thus, we concluded that PC-MRI was a noninvasive method for evaluating cerebral blood flow in patients with occlusive disease of the major cervical arteries.     

Characterization of Aeromonas sobria hemolysin by use of monoclonal antibodies against Aeromonas hydrophila hemolysins.

Aeromonas sobria produces hemolysin in a form activable with trypsin under defined cultural conditions. In immunoblotting analyses with the culture supernatant of A. sobria, the monoclonal antibody reacting specifically to Aeromonas hydrophila CA-11 hemolysin bound to the 53,000- and 49,000-dalton bands before and after trypsinization, respectively. The monoclonal antibody reacting to A. hydrophila AH-1 hemolysin did not bind either band. A. sobria hemolysin is, therefore, related antigenically to CA-11 hemolysin, while the molecular weights before and after activation differ from those of A. hydrophila hemolysins, being 54,000 and 51,000, respectively. The hemolytic and enterotoxigenic activities of A. sobria hemolysin were both neutralized by the monoclonal antibody against CA-11 hemolysin. It seems, therefore, that the same site on A. sobria hemolysin is responsible for both biological activities.     

Feasibility of a self‐assembling peptide hydrogel scaffold for meniscal defect: An in vivo study in a rabbit model

The inner avascular zone of the meniscus has limited healing capacity as the area is poorly vascularized. Although peptide hydrogels have been reported to regenerate bone and cartilage, their effect on meniscus regeneration remains unknown. We tested whether the self‐assembling peptide hydrogel scaffold KI24RGDS stays in the meniscal lesion and facilitates meniscal repair and regeneration in an induced rabbit meniscal defect model. Full‐thickness (2.0 mm diameter) cylindrical defects were introduced into the inner avascular zones of the anterior portions of the medial menisci of rabbit knees (n = 40). Right knee defects were left empty (control group) while the left knee defects were transplanted with peptide hydrogel (KI24RGDS group). Macroscopic meniscus scores were significantly higher in the KI24RGDS group than in the control group at 2, 4, and 8 weeks after surgery. Histological examinations including quantitative and qualitative scores indicated that compared with the control group, the reparative tissue in the meniscus was significantly enhanced in the KI24RGDS group at 2, 4, 8, and 12 weeks after surgery. Immunohistochemical staining showed that the reparative tissue induced by KI24RGDS at 12 weeks postimplantation was positive for Type I and II collagen. KI24RGDS is highly biocompatible and biodegradable, with strong stiffness, and a three dimensional structure mimicking native extracellular matrix and RGDS sequences that enhance cell adhesion and proliferation. This in vivo study demonstrated that KI24RGDS remained in the meniscal lesion and facilitated the repair and regeneration in a rabbit meniscal defect model.